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TOMOYO Linux Cross Reference
Linux/arch/arm64/Kconfig

Version: ~ [ linux-6.12-rc7 ] ~ [ linux-6.11.7 ] ~ [ linux-6.10.14 ] ~ [ linux-6.9.12 ] ~ [ linux-6.8.12 ] ~ [ linux-6.7.12 ] ~ [ linux-6.6.60 ] ~ [ linux-6.5.13 ] ~ [ linux-6.4.16 ] ~ [ linux-6.3.13 ] ~ [ linux-6.2.16 ] ~ [ linux-6.1.116 ] ~ [ linux-6.0.19 ] ~ [ linux-5.19.17 ] ~ [ linux-5.18.19 ] ~ [ linux-5.17.15 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.171 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.229 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.285 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.323 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.336 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.337 ] ~ [ linux-4.4.302 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.12 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

Diff markup

Differences between /arch/arm64/Kconfig (Version linux-6.12-rc7) and /arch/i386/Kconfig (Version linux-2.6.0)


  1 # SPDX-License-Identifier: GPL-2.0-only        !!   1 #
  2 config ARM64                                   !!   2 # For a description of the syntax of this configuration file,
  3         def_bool y                             !!   3 # see Documentation/kbuild/kconfig-language.txt.
  4         select ACPI_APMT if ACPI               !!   4 #
  5         select ACPI_CCA_REQUIRED if ACPI       << 
  6         select ACPI_GENERIC_GSI if ACPI        << 
  7         select ACPI_GTDT if ACPI               << 
  8         select ACPI_HOTPLUG_CPU if ACPI_PROCES << 
  9         select ACPI_IORT if ACPI               << 
 10         select ACPI_REDUCED_HARDWARE_ONLY if A << 
 11         select ACPI_MCFG if (ACPI && PCI)      << 
 12         select ACPI_SPCR_TABLE if ACPI         << 
 13         select ACPI_PPTT if ACPI               << 
 14         select ARCH_HAS_DEBUG_WX               << 
 15         select ARCH_BINFMT_ELF_EXTRA_PHDRS     << 
 16         select ARCH_BINFMT_ELF_STATE           << 
 17         select ARCH_CORRECT_STACKTRACE_ON_KRET << 
 18         select ARCH_ENABLE_HUGEPAGE_MIGRATION  << 
 19         select ARCH_ENABLE_MEMORY_HOTPLUG      << 
 20         select ARCH_ENABLE_MEMORY_HOTREMOVE    << 
 21         select ARCH_ENABLE_SPLIT_PMD_PTLOCK if << 
 22         select ARCH_ENABLE_THP_MIGRATION if TR << 
 23         select ARCH_HAS_CACHE_LINE_SIZE        << 
 24         select ARCH_HAS_CURRENT_STACK_POINTER  << 
 25         select ARCH_HAS_DEBUG_VIRTUAL          << 
 26         select ARCH_HAS_DEBUG_VM_PGTABLE       << 
 27         select ARCH_HAS_DMA_OPS if XEN         << 
 28         select ARCH_HAS_DMA_PREP_COHERENT      << 
 29         select ARCH_HAS_ACPI_TABLE_UPGRADE if  << 
 30         select ARCH_HAS_FAST_MULTIPLIER        << 
 31         select ARCH_HAS_FORTIFY_SOURCE         << 
 32         select ARCH_HAS_GCOV_PROFILE_ALL       << 
 33         select ARCH_HAS_GIGANTIC_PAGE          << 
 34         select ARCH_HAS_KCOV                   << 
 35         select ARCH_HAS_KERNEL_FPU_SUPPORT if  << 
 36         select ARCH_HAS_KEEPINITRD             << 
 37         select ARCH_HAS_MEMBARRIER_SYNC_CORE   << 
 38         select ARCH_HAS_MEM_ENCRYPT            << 
 39         select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS  << 
 40         select ARCH_HAS_NON_OVERLAPPING_ADDRES << 
 41         select ARCH_HAS_PTE_DEVMAP             << 
 42         select ARCH_HAS_PTE_SPECIAL            << 
 43         select ARCH_HAS_HW_PTE_YOUNG           << 
 44         select ARCH_HAS_SETUP_DMA_OPS          << 
 45         select ARCH_HAS_SET_DIRECT_MAP         << 
 46         select ARCH_HAS_SET_MEMORY             << 
 47         select ARCH_STACKWALK                  << 
 48         select ARCH_HAS_STRICT_KERNEL_RWX      << 
 49         select ARCH_HAS_STRICT_MODULE_RWX      << 
 50         select ARCH_HAS_SYNC_DMA_FOR_DEVICE    << 
 51         select ARCH_HAS_SYNC_DMA_FOR_CPU       << 
 52         select ARCH_HAS_SYSCALL_WRAPPER        << 
 53         select ARCH_HAS_TICK_BROADCAST if GENE << 
 54         select ARCH_HAS_ZONE_DMA_SET if EXPERT << 
 55         select ARCH_HAVE_ELF_PROT              << 
 56         select ARCH_HAVE_NMI_SAFE_CMPXCHG      << 
 57         select ARCH_HAVE_TRACE_MMIO_ACCESS     << 
 58         select ARCH_INLINE_READ_LOCK if !PREEM << 
 59         select ARCH_INLINE_READ_LOCK_BH if !PR << 
 60         select ARCH_INLINE_READ_LOCK_IRQ if !P << 
 61         select ARCH_INLINE_READ_LOCK_IRQSAVE i << 
 62         select ARCH_INLINE_READ_UNLOCK if !PRE << 
 63         select ARCH_INLINE_READ_UNLOCK_BH if ! << 
 64         select ARCH_INLINE_READ_UNLOCK_IRQ if  << 
 65         select ARCH_INLINE_READ_UNLOCK_IRQREST << 
 66         select ARCH_INLINE_WRITE_LOCK if !PREE << 
 67         select ARCH_INLINE_WRITE_LOCK_BH if !P << 
 68         select ARCH_INLINE_WRITE_LOCK_IRQ if ! << 
 69         select ARCH_INLINE_WRITE_LOCK_IRQSAVE  << 
 70         select ARCH_INLINE_WRITE_UNLOCK if !PR << 
 71         select ARCH_INLINE_WRITE_UNLOCK_BH if  << 
 72         select ARCH_INLINE_WRITE_UNLOCK_IRQ if << 
 73         select ARCH_INLINE_WRITE_UNLOCK_IRQRES << 
 74         select ARCH_INLINE_SPIN_TRYLOCK if !PR << 
 75         select ARCH_INLINE_SPIN_TRYLOCK_BH if  << 
 76         select ARCH_INLINE_SPIN_LOCK if !PREEM << 
 77         select ARCH_INLINE_SPIN_LOCK_BH if !PR << 
 78         select ARCH_INLINE_SPIN_LOCK_IRQ if !P << 
 79         select ARCH_INLINE_SPIN_LOCK_IRQSAVE i << 
 80         select ARCH_INLINE_SPIN_UNLOCK if !PRE << 
 81         select ARCH_INLINE_SPIN_UNLOCK_BH if ! << 
 82         select ARCH_INLINE_SPIN_UNLOCK_IRQ if  << 
 83         select ARCH_INLINE_SPIN_UNLOCK_IRQREST << 
 84         select ARCH_KEEP_MEMBLOCK              << 
 85         select ARCH_MHP_MEMMAP_ON_MEMORY_ENABL << 
 86         select ARCH_USE_CMPXCHG_LOCKREF        << 
 87         select ARCH_USE_GNU_PROPERTY           << 
 88         select ARCH_USE_MEMTEST                << 
 89         select ARCH_USE_QUEUED_RWLOCKS         << 
 90         select ARCH_USE_QUEUED_SPINLOCKS       << 
 91         select ARCH_USE_SYM_ANNOTATIONS        << 
 92         select ARCH_SUPPORTS_DEBUG_PAGEALLOC   << 
 93         select ARCH_SUPPORTS_HUGETLBFS         << 
 94         select ARCH_SUPPORTS_MEMORY_FAILURE    << 
 95         select ARCH_SUPPORTS_SHADOW_CALL_STACK << 
 96         select ARCH_SUPPORTS_LTO_CLANG if CPU_ << 
 97         select ARCH_SUPPORTS_LTO_CLANG_THIN    << 
 98         select ARCH_SUPPORTS_CFI_CLANG         << 
 99         select ARCH_SUPPORTS_ATOMIC_RMW        << 
100         select ARCH_SUPPORTS_INT128 if CC_HAS_ << 
101         select ARCH_SUPPORTS_NUMA_BALANCING    << 
102         select ARCH_SUPPORTS_PAGE_TABLE_CHECK  << 
103         select ARCH_SUPPORTS_PER_VMA_LOCK      << 
104         select ARCH_SUPPORTS_HUGE_PFNMAP if TR << 
105         select ARCH_SUPPORTS_RT                << 
106         select ARCH_WANT_BATCHED_UNMAP_TLB_FLU << 
107         select ARCH_WANT_COMPAT_IPC_PARSE_VERS << 
108         select ARCH_WANT_DEFAULT_BPF_JIT       << 
109         select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_ << 
110         select ARCH_WANT_FRAME_POINTERS        << 
111         select ARCH_WANT_HUGE_PMD_SHARE if ARM << 
112         select ARCH_WANT_LD_ORPHAN_WARN        << 
113         select ARCH_WANTS_EXECMEM_LATE if EXEC << 
114         select ARCH_WANTS_NO_INSTR             << 
115         select ARCH_WANTS_THP_SWAP if ARM64_4K << 
116         select ARCH_HAS_UBSAN                  << 
117         select ARM_AMBA                        << 
118         select ARM_ARCH_TIMER                  << 
119         select ARM_GIC                         << 
120         select AUDIT_ARCH_COMPAT_GENERIC       << 
121         select ARM_GIC_V2M if PCI              << 
122         select ARM_GIC_V3                      << 
123         select ARM_GIC_V3_ITS if PCI           << 
124         select ARM_PSCI_FW                     << 
125         select BUILDTIME_TABLE_SORT            << 
126         select CLONE_BACKWARDS                 << 
127         select COMMON_CLK                      << 
128         select CPU_PM if (SUSPEND || CPU_IDLE) << 
129         select CPUMASK_OFFSTACK if NR_CPUS > 2 << 
130         select CRC32                           << 
131         select DCACHE_WORD_ACCESS              << 
132         select DYNAMIC_FTRACE if FUNCTION_TRAC << 
133         select DMA_BOUNCE_UNALIGNED_KMALLOC    << 
134         select DMA_DIRECT_REMAP                << 
135         select EDAC_SUPPORT                    << 
136         select FRAME_POINTER                   << 
137         select FUNCTION_ALIGNMENT_4B           << 
138         select FUNCTION_ALIGNMENT_8B if DYNAMI << 
139         select GENERIC_ALLOCATOR               << 
140         select GENERIC_ARCH_TOPOLOGY           << 
141         select GENERIC_CLOCKEVENTS_BROADCAST   << 
142         select GENERIC_CPU_AUTOPROBE           << 
143         select GENERIC_CPU_DEVICES             << 
144         select GENERIC_CPU_VULNERABILITIES     << 
145         select GENERIC_EARLY_IOREMAP           << 
146         select GENERIC_IDLE_POLL_SETUP         << 
147         select GENERIC_IOREMAP                 << 
148         select GENERIC_IRQ_IPI                 << 
149         select GENERIC_IRQ_PROBE               << 
150         select GENERIC_IRQ_SHOW                << 
151         select GENERIC_IRQ_SHOW_LEVEL          << 
152         select GENERIC_LIB_DEVMEM_IS_ALLOWED   << 
153         select GENERIC_PCI_IOMAP               << 
154         select GENERIC_PTDUMP                  << 
155         select GENERIC_SCHED_CLOCK             << 
156         select GENERIC_SMP_IDLE_THREAD         << 
157         select GENERIC_TIME_VSYSCALL           << 
158         select GENERIC_GETTIMEOFDAY            << 
159         select GENERIC_VDSO_TIME_NS            << 
160         select HARDIRQS_SW_RESEND              << 
161         select HAS_IOPORT                      << 
162         select HAVE_MOVE_PMD                   << 
163         select HAVE_MOVE_PUD                   << 
164         select HAVE_PCI                        << 
165         select HAVE_ACPI_APEI if (ACPI && EFI) << 
166         select HAVE_ALIGNED_STRUCT_PAGE        << 
167         select HAVE_ARCH_AUDITSYSCALL          << 
168         select HAVE_ARCH_BITREVERSE            << 
169         select HAVE_ARCH_COMPILER_H            << 
170         select HAVE_ARCH_HUGE_VMALLOC          << 
171         select HAVE_ARCH_HUGE_VMAP             << 
172         select HAVE_ARCH_JUMP_LABEL            << 
173         select HAVE_ARCH_JUMP_LABEL_RELATIVE   << 
174         select HAVE_ARCH_KASAN                 << 
175         select HAVE_ARCH_KASAN_VMALLOC         << 
176         select HAVE_ARCH_KASAN_SW_TAGS         << 
177         select HAVE_ARCH_KASAN_HW_TAGS if ARM6 << 
178         # Some instrumentation may be unsound, << 
179         select HAVE_ARCH_KCSAN if EXPERT       << 
180         select HAVE_ARCH_KFENCE                << 
181         select HAVE_ARCH_KGDB                  << 
182         select HAVE_ARCH_MMAP_RND_BITS         << 
183         select HAVE_ARCH_MMAP_RND_COMPAT_BITS  << 
184         select HAVE_ARCH_PREL32_RELOCATIONS    << 
185         select HAVE_ARCH_RANDOMIZE_KSTACK_OFFS << 
186         select HAVE_ARCH_SECCOMP_FILTER        << 
187         select HAVE_ARCH_STACKLEAK             << 
188         select HAVE_ARCH_THREAD_STRUCT_WHITELI << 
189         select HAVE_ARCH_TRACEHOOK             << 
190         select HAVE_ARCH_TRANSPARENT_HUGEPAGE  << 
191         select HAVE_ARCH_VMAP_STACK            << 
192         select HAVE_ARM_SMCCC                  << 
193         select HAVE_ASM_MODVERSIONS            << 
194         select HAVE_EBPF_JIT                   << 
195         select HAVE_C_RECORDMCOUNT             << 
196         select HAVE_CMPXCHG_DOUBLE             << 
197         select HAVE_CMPXCHG_LOCAL              << 
198         select HAVE_CONTEXT_TRACKING_USER      << 
199         select HAVE_DEBUG_KMEMLEAK             << 
200         select HAVE_DMA_CONTIGUOUS             << 
201         select HAVE_DYNAMIC_FTRACE             << 
202         select HAVE_DYNAMIC_FTRACE_WITH_ARGS \ << 
203                 if (GCC_SUPPORTS_DYNAMIC_FTRAC << 
204                     CLANG_SUPPORTS_DYNAMIC_FTR << 
205         select HAVE_DYNAMIC_FTRACE_WITH_DIRECT << 
206                 if DYNAMIC_FTRACE_WITH_ARGS && << 
207         select HAVE_DYNAMIC_FTRACE_WITH_CALL_O << 
208                 if (DYNAMIC_FTRACE_WITH_ARGS & << 
209                     (CC_IS_CLANG || !CC_OPTIMI << 
210         select FTRACE_MCOUNT_USE_PATCHABLE_FUN << 
211                 if DYNAMIC_FTRACE_WITH_ARGS    << 
212         select HAVE_SAMPLE_FTRACE_DIRECT       << 
213         select HAVE_SAMPLE_FTRACE_DIRECT_MULTI << 
214         select HAVE_EFFICIENT_UNALIGNED_ACCESS << 
215         select HAVE_GUP_FAST                   << 
216         select HAVE_FTRACE_MCOUNT_RECORD       << 
217         select HAVE_FUNCTION_TRACER            << 
218         select HAVE_FUNCTION_ERROR_INJECTION   << 
219         select HAVE_FUNCTION_GRAPH_TRACER      << 
220         select HAVE_FUNCTION_GRAPH_RETVAL      << 
221         select HAVE_GCC_PLUGINS                << 
222         select HAVE_HARDLOCKUP_DETECTOR_PERF i << 
223                 HW_PERF_EVENTS && HAVE_PERF_EV << 
224         select HAVE_HW_BREAKPOINT if PERF_EVEN << 
225         select HAVE_IOREMAP_PROT               << 
226         select HAVE_IRQ_TIME_ACCOUNTING        << 
227         select HAVE_MOD_ARCH_SPECIFIC          << 
228         select HAVE_NMI                        << 
229         select HAVE_PERF_EVENTS                << 
230         select HAVE_PERF_EVENTS_NMI if ARM64_P << 
231         select HAVE_PERF_REGS                  << 
232         select HAVE_PERF_USER_STACK_DUMP       << 
233         select HAVE_PREEMPT_DYNAMIC_KEY        << 
234         select HAVE_REGS_AND_STACK_ACCESS_API  << 
235         select HAVE_POSIX_CPU_TIMERS_TASK_WORK << 
236         select HAVE_FUNCTION_ARG_ACCESS_API    << 
237         select MMU_GATHER_RCU_TABLE_FREE       << 
238         select HAVE_RSEQ                       << 
239         select HAVE_RUST if RUSTC_SUPPORTS_ARM << 
240         select HAVE_STACKPROTECTOR             << 
241         select HAVE_SYSCALL_TRACEPOINTS        << 
242         select HAVE_KPROBES                    << 
243         select HAVE_KRETPROBES                 << 
244         select HAVE_GENERIC_VDSO               << 
245         select HOTPLUG_CORE_SYNC_DEAD if HOTPL << 
246         select IRQ_DOMAIN                      << 
247         select IRQ_FORCED_THREADING            << 
248         select KASAN_VMALLOC if KASAN          << 
249         select LOCK_MM_AND_FIND_VMA            << 
250         select MODULES_USE_ELF_RELA            << 
251         select NEED_DMA_MAP_STATE              << 
252         select NEED_SG_DMA_LENGTH              << 
253         select OF                              << 
254         select OF_EARLY_FLATTREE               << 
255         select PCI_DOMAINS_GENERIC if PCI      << 
256         select PCI_ECAM if (ACPI && PCI)       << 
257         select PCI_SYSCALL if PCI              << 
258         select POWER_RESET                     << 
259         select POWER_SUPPLY                    << 
260         select SPARSE_IRQ                      << 
261         select SWIOTLB                         << 
262         select SYSCTL_EXCEPTION_TRACE          << 
263         select THREAD_INFO_IN_TASK             << 
264         select HAVE_ARCH_USERFAULTFD_MINOR if  << 
265         select HAVE_ARCH_USERFAULTFD_WP if USE << 
266         select TRACE_IRQFLAGS_SUPPORT          << 
267         select TRACE_IRQFLAGS_NMI_SUPPORT      << 
268         select HAVE_SOFTIRQ_ON_OWN_STACK       << 
269         select USER_STACKTRACE_SUPPORT         << 
270         select VDSO_GETRANDOM                  << 
271         help                                   << 
272           ARM 64-bit (AArch64) Linux support.  << 
273                                                << 
274 config RUSTC_SUPPORTS_ARM64                    << 
275         def_bool y                             << 
276         depends on CPU_LITTLE_ENDIAN           << 
277         # Shadow call stack is only supported  << 
278         #                                      << 
279         # When using the UNWIND_PATCH_PAC_INTO << 
280         # required due to use of the -Zfixed-x << 
281         #                                      << 
282         # Otherwise, rustc version 1.82+ is re << 
283         # -Zsanitizer=shadow-call-stack flag.  << 
284         depends on !SHADOW_CALL_STACK || RUSTC << 
285                                                << 
286 config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS << 
287         def_bool CC_IS_CLANG                   << 
288         # https://github.com/ClangBuiltLinux/l << 
289         depends on AS_IS_GNU || (AS_IS_LLVM && << 
290                                                << 
291 config GCC_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS   << 
292         def_bool CC_IS_GCC                     << 
293         depends on $(cc-option,-fpatchable-fun << 
294                                                << 
295 config 64BIT                                   << 
296         def_bool y                             << 
297                                                << 
298 config MMU                                     << 
299         def_bool y                             << 
300                                                << 
301 config ARM64_CONT_PTE_SHIFT                    << 
302         int                                    << 
303         default 5 if PAGE_SIZE_64KB            << 
304         default 7 if PAGE_SIZE_16KB            << 
305         default 4                              << 
306                                                << 
307 config ARM64_CONT_PMD_SHIFT                    << 
308         int                                    << 
309         default 5 if PAGE_SIZE_64KB            << 
310         default 5 if PAGE_SIZE_16KB            << 
311         default 4                              << 
312                                                << 
313 config ARCH_MMAP_RND_BITS_MIN                  << 
314         default 14 if PAGE_SIZE_64KB           << 
315         default 16 if PAGE_SIZE_16KB           << 
316         default 18                             << 
317                                                << 
318 # max bits determined by the following formula << 
319 #  VA_BITS - PAGE_SHIFT - 3                    << 
320 config ARCH_MMAP_RND_BITS_MAX                  << 
321         default 19 if ARM64_VA_BITS=36         << 
322         default 24 if ARM64_VA_BITS=39         << 
323         default 27 if ARM64_VA_BITS=42         << 
324         default 30 if ARM64_VA_BITS=47         << 
325         default 29 if ARM64_VA_BITS=48 && ARM6 << 
326         default 31 if ARM64_VA_BITS=48 && ARM6 << 
327         default 33 if ARM64_VA_BITS=48         << 
328         default 14 if ARM64_64K_PAGES          << 
329         default 16 if ARM64_16K_PAGES          << 
330         default 18                             << 
331                                                << 
332 config ARCH_MMAP_RND_COMPAT_BITS_MIN           << 
333         default 7 if ARM64_64K_PAGES           << 
334         default 9 if ARM64_16K_PAGES           << 
335         default 11                             << 
336                                                << 
337 config ARCH_MMAP_RND_COMPAT_BITS_MAX           << 
338         default 16                             << 
339                                                << 
340 config NO_IOPORT_MAP                           << 
341         def_bool y if !PCI                     << 
342                                                << 
343 config STACKTRACE_SUPPORT                      << 
344         def_bool y                             << 
345                                                << 
346 config ILLEGAL_POINTER_VALUE                   << 
347         hex                                    << 
348         default 0xdead000000000000             << 
349                                                << 
350 config LOCKDEP_SUPPORT                         << 
351         def_bool y                             << 
352                                                << 
353 config GENERIC_BUG                             << 
354         def_bool y                             << 
355         depends on BUG                         << 
356                                                << 
357 config GENERIC_BUG_RELATIVE_POINTERS           << 
358         def_bool y                             << 
359         depends on GENERIC_BUG                 << 
360                                                << 
361 config GENERIC_HWEIGHT                         << 
362         def_bool y                             << 
363                                                << 
364 config GENERIC_CSUM                            << 
365         def_bool y                             << 
366                                                << 
367 config GENERIC_CALIBRATE_DELAY                 << 
368         def_bool y                             << 
369                                                << 
370 config SMP                                     << 
371         def_bool y                             << 
372                                                << 
373 config KERNEL_MODE_NEON                        << 
374         def_bool y                             << 
375                                                << 
376 config FIX_EARLYCON_MEM                        << 
377         def_bool y                             << 
378                                                << 
379 config PGTABLE_LEVELS                          << 
380         int                                    << 
381         default 2 if ARM64_16K_PAGES && ARM64_ << 
382         default 2 if ARM64_64K_PAGES && ARM64_ << 
383         default 3 if ARM64_64K_PAGES && (ARM64 << 
384         default 3 if ARM64_4K_PAGES && ARM64_V << 
385         default 3 if ARM64_16K_PAGES && ARM64_ << 
386         default 4 if ARM64_16K_PAGES && (ARM64 << 
387         default 4 if !ARM64_64K_PAGES && ARM64 << 
388         default 5 if ARM64_4K_PAGES && ARM64_V << 
389                                                << 
390 config ARCH_SUPPORTS_UPROBES                   << 
391         def_bool y                             << 
392                                                << 
393 config ARCH_PROC_KCORE_TEXT                    << 
394         def_bool y                             << 
395                                                << 
396 config BROKEN_GAS_INST                         << 
397         def_bool !$(as-instr,1:\n.inst 0\n.rep << 
398                                                << 
399 config BUILTIN_RETURN_ADDRESS_STRIPS_PAC       << 
400         bool                                   << 
401         # Clang's __builtin_return_address() s << 
402         # https://github.com/llvm/llvm-project << 
403         default y if CC_IS_CLANG               << 
404         # GCC's __builtin_return_address() str << 
405         # and this was backported to 10.2.0, 9 << 
406         # https://gcc.gnu.org/bugzilla/show_bu << 
407         default y if CC_IS_GCC && (GCC_VERSION << 
408         default y if CC_IS_GCC && (GCC_VERSION << 
409         default y if CC_IS_GCC && (GCC_VERSION << 
410         default y if CC_IS_GCC && (GCC_VERSION << 
411         default n                              << 
412                                                     5 
413 config KASAN_SHADOW_OFFSET                     !!   6 mainmenu "Linux Kernel Configuration"
414         hex                                    << 
415         depends on KASAN_GENERIC || KASAN_SW_T << 
416         default 0xdfff800000000000 if (ARM64_V << 
417         default 0xdfffc00000000000 if (ARM64_V << 
418         default 0xdffffe0000000000 if ARM64_VA << 
419         default 0xdfffffc000000000 if ARM64_VA << 
420         default 0xdffffff800000000 if ARM64_VA << 
421         default 0xefff800000000000 if (ARM64_V << 
422         default 0xefffc00000000000 if (ARM64_V << 
423         default 0xeffffe0000000000 if ARM64_VA << 
424         default 0xefffffc000000000 if ARM64_VA << 
425         default 0xeffffff800000000 if ARM64_VA << 
426         default 0xffffffffffffffff             << 
427                                                     7 
428 config UNWIND_TABLES                           !!   8 config X86
429         bool                                        9         bool
430                                                << 
431 source "arch/arm64/Kconfig.platforms"          << 
432                                                << 
433 menu "Kernel Features"                         << 
434                                                << 
435 menu "ARM errata workarounds via the alternati << 
436                                                << 
437 config AMPERE_ERRATUM_AC03_CPU_38              << 
438         bool "AmpereOne: AC03_CPU_38: Certain  << 
439         default y                                  10         default y
440         help                                       11         help
441           This option adds an alternative code !!  12           This is Linux's home port.  Linux was originally native to the Intel
442           errata AC03_CPU_38 and AC04_CPU_10 o !!  13           386, and runs on all the later x86 processors including the Intel
443                                                !!  14           486, 586, Pentiums, and various instruction-set-compatible chips by
444           The affected design reports FEAT_HAF !!  15           AMD, Cyrix, and others.
445           ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ << 
446           as required by the architecture. The << 
447           implementation suffers from an addit << 
448           A/D updates can occur after a PTE ha << 
449                                                << 
450           The workaround forces KVM to explici << 
451           which avoids enabling unadvertised h << 
452           at stage-2.                          << 
453                                                << 
454           If unsure, say Y.                    << 
455                                                    16 
456 config ARM64_WORKAROUND_CLEAN_CACHE            !!  17 config MMU
457         bool                                       18         bool
458                                                << 
459 config ARM64_ERRATUM_826319                    << 
460         bool "Cortex-A53: 826319: System might << 
461         default y                              << 
462         select ARM64_WORKAROUND_CLEAN_CACHE    << 
463         help                                   << 
464           This option adds an alternative code << 
465           erratum 826319 on Cortex-A53 parts u << 
466           AXI master interface and an L2 cache << 
467                                                << 
468           If a Cortex-A53 uses an AMBA AXI4 AC << 
469           and is unable to accept a certain wr << 
470           not progress on read data presented  << 
471           system can deadlock.                 << 
472                                                << 
473           The workaround promotes data cache c << 
474           data cache clean-and-invalidate.     << 
475           Please note that this does not neces << 
476           as it depends on the alternative fra << 
477           the kernel if an affected CPU is det << 
478                                                << 
479           If unsure, say Y.                    << 
480                                                << 
481 config ARM64_ERRATUM_827319                    << 
482         bool "Cortex-A53: 827319: Data cache c << 
483         default y                                  19         default y
484         select ARM64_WORKAROUND_CLEAN_CACHE    << 
485         help                                   << 
486           This option adds an alternative code << 
487           erratum 827319 on Cortex-A53 parts u << 
488           master interface and an L2 cache.    << 
489                                                << 
490           Under certain conditions this erratu << 
491           to occur at the same time as another << 
492           on the AMBA 5 CHI interface, which c << 
493           interconnect reorders the two transa << 
494                                                << 
495           The workaround promotes data cache c << 
496           data cache clean-and-invalidate.     << 
497           Please note that this does not neces << 
498           as it depends on the alternative fra << 
499           the kernel if an affected CPU is det << 
500                                                << 
501           If unsure, say Y.                    << 
502                                                << 
503 config ARM64_ERRATUM_824069                    << 
504         bool "Cortex-A53: 824069: Cache line m << 
505         default y                              << 
506         select ARM64_WORKAROUND_CLEAN_CACHE    << 
507         help                                   << 
508           This option adds an alternative code << 
509           erratum 824069 on Cortex-A53 parts u << 
510           to a coherent interconnect.          << 
511                                                    20 
512           If a Cortex-A53 processor is executi !!  21 config SBUS
513           write instruction at the same time a !!  22         bool
514           cluster is executing a cache mainten << 
515           address, then this erratum might cau << 
516           incorrectly marked as dirty.         << 
517                                                << 
518           The workaround promotes data cache c << 
519           data cache clean-and-invalidate.     << 
520           Please note that this option does no << 
521           workaround, as it depends on the alt << 
522           only patch the kernel if an affected << 
523                                                << 
524           If unsure, say Y.                    << 
525                                                    23 
526 config ARM64_ERRATUM_819472                    !!  24 config UID16
527         bool "Cortex-A53: 819472: Store exclus !!  25         bool
528         default y                                  26         default y
529         select ARM64_WORKAROUND_CLEAN_CACHE    << 
530         help                                   << 
531           This option adds an alternative code << 
532           erratum 819472 on Cortex-A53 parts u << 
533           present when it is connected to a co << 
534                                                << 
535           If the processor is executing a load << 
536           the same time as a processor in anot << 
537           maintenance operation to the same ad << 
538           cause data corruption.               << 
539                                                << 
540           The workaround promotes data cache c << 
541           data cache clean-and-invalidate.     << 
542           Please note that this does not neces << 
543           as it depends on the alternative fra << 
544           the kernel if an affected CPU is det << 
545                                                    27 
546           If unsure, say Y.                    !!  28 config GENERIC_ISA_DMA
547                                                !!  29         bool
548 config ARM64_ERRATUM_832075                    << 
549         bool "Cortex-A57: 832075: possible dea << 
550         default y                                  30         default y
551         help                                   << 
552           This option adds an alternative code << 
553           erratum 832075 on Cortex-A57 parts u << 
554                                                << 
555           Affected Cortex-A57 parts might dead << 
556           instructions to Write-Back memory ar << 
557                                                    31 
558           The workaround is to promote device  !!  32 source "init/Kconfig"
559           semantics.                           << 
560           Please note that this does not neces << 
561           as it depends on the alternative fra << 
562           the kernel if an affected CPU is det << 
563                                                << 
564           If unsure, say Y.                    << 
565                                                << 
566 config ARM64_ERRATUM_834220                    << 
567         bool "Cortex-A57: 834220: Stage 2 tran << 
568         depends on KVM                         << 
569         help                                   << 
570           This option adds an alternative code << 
571           erratum 834220 on Cortex-A57 parts u << 
572                                                    33 
573           Affected Cortex-A57 parts might repo << 
574           fault as the result of a Stage 1 fau << 
575           page boundary when there is a permis << 
576           alignment fault at Stage 1 and a tra << 
577                                                    34 
578           The workaround is to verify that the !!  35 menu "Processor type and features"
579           doesn't generate a fault before hand << 
580           Please note that this does not neces << 
581           as it depends on the alternative fra << 
582           the kernel if an affected CPU is det << 
583                                                    36 
584           If unsure, say N.                    !!  37 choice
                                                   >>  38         prompt "Subarchitecture Type"
                                                   >>  39         default X86_PC
585                                                    40 
586 config ARM64_ERRATUM_1742098                   !!  41 config X86_PC
587         bool "Cortex-A57/A72: 1742098: ELR rec !!  42         bool "PC-compatible"
588         depends on COMPAT                      << 
589         default y                              << 
590         help                                       43         help
591           This option removes the AES hwcap fo !!  44           Choose this option if your computer is a standard PC or compatible.
592           workaround erratum 1742098 on Cortex << 
593                                                << 
594           Affected parts may corrupt the AES s << 
595           taken between a pair of AES instruct << 
596           are only present if the cryptography << 
597           All software should have a fallback  << 
598           that don't implement the cryptograph << 
599                                                << 
600           If unsure, say Y.                    << 
601                                                    45 
602 config ARM64_ERRATUM_845719                    !!  46 config X86_VOYAGER
603         bool "Cortex-A53: 845719: a load might !!  47         bool "Voyager (NCR)"
604         depends on COMPAT                      << 
605         default y                              << 
606         help                                       48         help
607           This option adds an alternative code !!  49           Voyager is a MCA based 32 way capable SMP architecture proprietary
608           erratum 845719 on Cortex-A53 parts u !!  50           to NCR Corp.  Machine classes 345x/35xx/4100/51xx are voyager based.
609                                                !!  51           
610           When running a compat (AArch32) user !!  52           *** WARNING ***
611           part, a load at EL0 from a virtual a !!  53         
612           bits of the virtual address used by  !!  54           If you do not specifically know you have a Voyager based machine,
613           might return incorrect data.         !!  55           say N here otherwise the kernel you build will not be bootable.
614                                                << 
615           The workaround is to write the conte << 
616           return to a 32-bit task.             << 
617           Please note that this does not neces << 
618           as it depends on the alternative fra << 
619           the kernel if an affected CPU is det << 
620                                                << 
621           If unsure, say Y.                    << 
622                                                    56 
623 config ARM64_ERRATUM_843419                    !!  57 config X86_NUMAQ
624         bool "Cortex-A53: 843419: A load or st !!  58         bool "NUMAQ (IBM/Sequent)"
625         default y                              << 
626         help                                       59         help
627           This option links the kernel with '- !!  60           This option is used for getting Linux to run on a (IBM/Sequent) NUMA 
628           enables PLT support to replace certa !!  61           multiquad box. This changes the way that processors are bootstrapped,
629           cause subsequent memory accesses to  !!  62           and uses Clustered Logical APIC addressing mode instead of Flat Logical.
630           Cortex-A53 parts up to r0p4.         !!  63           You will need a new lynxer.elf file to flash your firmware with - send
631                                                !!  64           email to Martin.Bligh@us.ibm.com
632           If unsure, say Y.                    << 
633                                                    65 
634 config ARM64_LD_HAS_FIX_ERRATUM_843419         !!  66 config X86_SUMMIT
635         def_bool $(ld-option,--fix-cortex-a53- !!  67         bool "Summit/EXA (IBM x440)"
636                                                !!  68         depends on SMP
637 config ARM64_ERRATUM_1024718                   << 
638         bool "Cortex-A55: 1024718: Update of D << 
639         default y                              << 
640         help                                       69         help
641           This option adds a workaround for AR !!  70           This option is needed for IBM systems that use the Summit/EXA chipset.
                                                   >>  71           In particular, it is needed for the x440.
642                                                    72 
643           Affected Cortex-A55 cores (all revis !!  73           If you don't have one of these computers, you should say N here.
644           update of the hardware dirty bit whe << 
645           without a break-before-make. The wor << 
646           of hardware DBM locally on the affec << 
647           this erratum will continue to use th << 
648                                                    74 
649           If unsure, say Y.                    !!  75 config X86_BIGSMP
650                                                !!  76         bool "Support for other sub-arch SMP systems with more than 8 CPUs"
651 config ARM64_ERRATUM_1418040                   !!  77         depends on SMP
652         bool "Cortex-A76/Neoverse-N1: MRC read << 
653         default y                              << 
654         depends on COMPAT                      << 
655         help                                       78         help
656           This option adds a workaround for AR !!  79           This option is needed for the systems that have more than 8 CPUs
657           errata 1188873 and 1418040.          !!  80           and if the system is not of any sub-arch type above.
658                                                << 
659           Affected Cortex-A76/Neoverse-N1 core << 
660           cause register corruption when acces << 
661           from AArch32 userspace.              << 
662                                                    81 
663           If unsure, say Y.                    !!  82           If you don't have such a system, you should say N here.
664                                                    83 
665 config ARM64_WORKAROUND_SPECULATIVE_AT         !!  84 config X86_VISWS
666         bool                                   !!  85         bool "SGI 320/540 (Visual Workstation)"
667                                                << 
668 config ARM64_ERRATUM_1165522                   << 
669         bool "Cortex-A76: 1165522: Speculative << 
670         default y                              << 
671         select ARM64_WORKAROUND_SPECULATIVE_AT << 
672         help                                       86         help
673           This option adds a workaround for AR !!  87           The SGI Visual Workstation series is an IA32-based workstation
674                                                !!  88           based on SGI systems chips with some legacy PC hardware attached.
675           Affected Cortex-A76 cores (r0p0, r1p << 
676           corrupted TLBs by speculating an AT  << 
677           context switch.                      << 
678                                                    89 
679           If unsure, say Y.                    !!  90           Say Y here to create a kernel to run on the SGI 320 or 540.
680                                                    91 
681 config ARM64_ERRATUM_1319367                   !!  92           A kernel compiled for the Visual Workstation will not run on PCs
682         bool "Cortex-A57/A72: 1319537: Specula !!  93           and vice versa. See <file:Documentation/sgi-visws.txt> for details.
683         default y                              << 
684         select ARM64_WORKAROUND_SPECULATIVE_AT << 
685         help                                   << 
686           This option adds work arounds for AR << 
687           and A72 erratum 1319367              << 
688                                                    94 
689           Cortex-A57 and A72 cores could end-u !!  95 config X86_GENERICARCH
690           speculating an AT instruction during !!  96        bool "Generic architecture (Summit, bigsmp, default)"
                                                   >>  97        depends on SMP
                                                   >>  98        help
                                                   >>  99           This option compiles in the Summit, bigsmp, default subarchitectures.
                                                   >> 100           It is intended for a generic binary kernel.
691                                                   101 
692           If unsure, say Y.                    !! 102 config X86_ES7000
693                                                !! 103         bool "Support for Unisys ES7000 IA32 series"
694 config ARM64_ERRATUM_1530923                   !! 104         depends on SMP
695         bool "Cortex-A55: 1530923: Speculative << 
696         default y                              << 
697         select ARM64_WORKAROUND_SPECULATIVE_AT << 
698         help                                      105         help
699           This option adds a workaround for AR !! 106           Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
                                                   >> 107           supposed to run on an IA32-based Unisys ES7000 system. 
                                                   >> 108           Only choose this option if you have such a system, otherwise you 
                                                   >> 109           should say N here.
700                                                   110 
701           Affected Cortex-A55 cores (r0p0, r0p !! 111 endchoice
702           corrupted TLBs by speculating an AT  << 
703           context switch.                      << 
704                                                << 
705           If unsure, say Y.                    << 
706                                                   112 
707 config ARM64_WORKAROUND_REPEAT_TLBI            !! 113 config ACPI_SRAT
708         bool                                      114         bool
709                                                << 
710 config ARM64_ERRATUM_2441007                   << 
711         bool "Cortex-A55: Completion of affect << 
712         select ARM64_WORKAROUND_REPEAT_TLBI    << 
713         help                                   << 
714           This option adds a workaround for AR << 
715                                                << 
716           Under very rare circumstances, affec << 
717           may not handle a race between a brea << 
718           CPU, and another CPU accessing the s << 
719           store to a page that has been unmapp << 
720                                                << 
721           Work around this by adding the affec << 
722           TLB sequences to be done twice.      << 
723                                                << 
724           If unsure, say N.                    << 
725                                                << 
726 config ARM64_ERRATUM_1286807                   << 
727         bool "Cortex-A76: Modification of the  << 
728         select ARM64_WORKAROUND_REPEAT_TLBI    << 
729         help                                   << 
730           This option adds a workaround for AR << 
731                                                << 
732           On the affected Cortex-A76 cores (r0 << 
733           address for a cacheable mapping of a << 
734           accessed by a core while another cor << 
735           address to a new physical page using << 
736           break-before-make sequence, then und << 
737           TLBI+DSB completes before a read usi << 
738           invalidated has been observed by oth << 
739           workaround repeats the TLBI+DSB oper << 
740                                                << 
741           If unsure, say N.                    << 
742                                                << 
743 config ARM64_ERRATUM_1463225                   << 
744         bool "Cortex-A76: Software Step might  << 
745         default y                                 115         default y
746         help                                   !! 116         depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
747           This option adds a workaround for Ar << 
748                                                << 
749           On the affected Cortex-A76 cores (r0 << 
750           of a system call instruction (SVC) c << 
751           subsequent interrupts when software  << 
752           exception handler of the system call << 
753           is enabled or VHE is in use.         << 
754                                                << 
755           Work around the erratum by triggerin << 
756           when handling a system call from a t << 
757           in a VHE configuration of the kernel << 
758                                                   117 
759           If unsure, say Y.                    !! 118 config X86_CYCLONE_TIMER
                                                   >> 119        bool 
                                                   >> 120        default y
                                                   >> 121        depends on X86_SUMMIT || X86_GENERICARCH
760                                                   122 
761 config ARM64_ERRATUM_1542419                   !! 123 config ES7000_CLUSTERED_APIC
762         bool "Neoverse-N1: workaround mis-orde !! 124         bool
763         help                                   << 
764           This option adds a workaround for AR << 
765           1542419.                             << 
766                                                << 
767           Affected Neoverse-N1 cores could exe << 
768           modified by another CPU. The workaro << 
769           counterpart.                         << 
770                                                << 
771           Workaround the issue by hiding the D << 
772           forces user-space to perform cache m << 
773                                                << 
774           If unsure, say N.                    << 
775                                                << 
776 config ARM64_ERRATUM_1508412                   << 
777         bool "Cortex-A77: 1508412: workaround  << 
778         default y                                 125         default y
779         help                                   !! 126         depends on SMP && X86_ES7000 && MPENTIUMIII
780           This option adds a workaround for Ar << 
781                                                   127 
782           Affected Cortex-A77 cores (r0p0, r1p !! 128 choice
783           of a store-exclusive or read of PAR_ !! 129         prompt "Processor family"
784           non-cacheable memory attributes. The !! 130         default M686
785           counterpart.                         << 
786                                                   131 
787           KVM guests must also have the workar !! 132 config M386
788           deadlock the system.                 !! 133         bool "386"
                                                   >> 134         ---help---
                                                   >> 135           This is the processor type of your CPU. This information is used for
                                                   >> 136           optimizing purposes. In order to compile a kernel that can run on
                                                   >> 137           all x86 CPU types (albeit not optimally fast), you can specify
                                                   >> 138           "386" here.
                                                   >> 139 
                                                   >> 140           The kernel will not necessarily run on earlier architectures than
                                                   >> 141           the one you have chosen, e.g. a Pentium optimized kernel will run on
                                                   >> 142           a PPro, but not necessarily on a i486.
                                                   >> 143 
                                                   >> 144           Here are the settings recommended for greatest speed:
                                                   >> 145           - "386" for the AMD/Cyrix/Intel 386DX/DXL/SL/SLC/SX, Cyrix/TI
                                                   >> 146           486DLC/DLC2, UMC 486SX-S and NexGen Nx586.  Only "386" kernels
                                                   >> 147           will run on a 386 class machine.
                                                   >> 148           - "486" for the AMD/Cyrix/IBM/Intel 486DX/DX2/DX4 or
                                                   >> 149           SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5D or U5S.
                                                   >> 150           - "586" for generic Pentium CPUs lacking the TSC
                                                   >> 151           (time stamp counter) register.
                                                   >> 152           - "Pentium-Classic" for the Intel Pentium.
                                                   >> 153           - "Pentium-MMX" for the Intel Pentium MMX.
                                                   >> 154           - "Pentium-Pro" for the Intel Pentium Pro.
                                                   >> 155           - "Pentium-II" for the Intel Pentium II or pre-Coppermine Celeron.
                                                   >> 156           - "Pentium-III" for the Intel Pentium III or Coppermine Celeron.
                                                   >> 157           - "Pentium-4" for the Intel Pentium 4 or P4-based Celeron.
                                                   >> 158           - "K6" for the AMD K6, K6-II and K6-III (aka K6-3D).
                                                   >> 159           - "Athlon" for the AMD K7 family (Athlon/Duron/Thunderbird).
                                                   >> 160           - "Crusoe" for the Transmeta Crusoe series.
                                                   >> 161           - "Winchip-C6" for original IDT Winchip.
                                                   >> 162           - "Winchip-2" for IDT Winchip 2.
                                                   >> 163           - "Winchip-2A" for IDT Winchips with 3dNow! capabilities.
                                                   >> 164           - "CyrixIII/VIA C3" for VIA Cyrix III or VIA C3.
                                                   >> 165           - "VIA C3-2 for VIA C3-2 "Nehemiah" (model 9 and above).
                                                   >> 166 
                                                   >> 167           If you don't know what to do, choose "386".
                                                   >> 168 
                                                   >> 169 config M486
                                                   >> 170         bool "486"
                                                   >> 171         help
                                                   >> 172           Select this for a 486 series processor, either Intel or one of the
                                                   >> 173           compatible processors from AMD, Cyrix, IBM, or Intel.  Includes DX,
                                                   >> 174           DX2, and DX4 variants; also SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5D or
                                                   >> 175           U5S.
                                                   >> 176 
                                                   >> 177 config M586
                                                   >> 178         bool "586/K5/5x86/6x86/6x86MX"
                                                   >> 179         help
                                                   >> 180           Select this for an 586 or 686 series processor such as the AMD K5,
                                                   >> 181           the Intel 5x86 or 6x86, or the Intel 6x86MX.  This choice does not
                                                   >> 182           assume the RDTSC (Read Time Stamp Counter) instruction.
                                                   >> 183 
                                                   >> 184 config M586TSC
                                                   >> 185         bool "Pentium-Classic"
                                                   >> 186         help
                                                   >> 187           Select this for a Pentium Classic processor with the RDTSC (Read
                                                   >> 188           Time Stamp Counter) instruction for benchmarking.
                                                   >> 189 
                                                   >> 190 config M586MMX
                                                   >> 191         bool "Pentium-MMX"
                                                   >> 192         help
                                                   >> 193           Select this for a Pentium with the MMX graphics/multimedia
                                                   >> 194           extended instructions.
                                                   >> 195 
                                                   >> 196 config M686
                                                   >> 197         bool "Pentium-Pro"
                                                   >> 198         help
                                                   >> 199           Select this for Intel Pentium Pro chips.  This enables the use of
                                                   >> 200           Pentium Pro extended instructions, and disables the init-time guard
                                                   >> 201           against the f00f bug found in earlier Pentiums.
                                                   >> 202 
                                                   >> 203 config MPENTIUMII
                                                   >> 204         bool "Pentium-II/Celeron(pre-Coppermine)"
                                                   >> 205         help
                                                   >> 206           Select this for Intel chips based on the Pentium-II and
                                                   >> 207           pre-Coppermine Celeron core.  This option enables an unaligned
                                                   >> 208           copy optimization, compiles the kernel with optimization flags
                                                   >> 209           tailored for the chip, and applies any applicable Pentium Pro
                                                   >> 210           optimizations.
                                                   >> 211 
                                                   >> 212 config MPENTIUMIII
                                                   >> 213         bool "Pentium-III/Celeron(Coppermine)/Pentium-III Xeon"
                                                   >> 214         help
                                                   >> 215           Select this for Intel chips based on the Pentium-III and
                                                   >> 216           Celeron-Coppermine core.  This option enables use of some
                                                   >> 217           extended prefetch instructions in addition to the Pentium II
                                                   >> 218           extensions.
                                                   >> 219 
                                                   >> 220 config MPENTIUM4
                                                   >> 221         bool "Pentium-4/Celeron(P4-based)/Xeon"
                                                   >> 222         help
                                                   >> 223           Select this for Intel Pentium 4 chips.  This includes both
                                                   >> 224           the Pentium 4 and P4-based Celeron chips.  This option
                                                   >> 225           enables compile flags optimized for the chip, uses the
                                                   >> 226           correct cache shift, and applies any applicable Pentium III
                                                   >> 227           optimizations.
                                                   >> 228 
                                                   >> 229 config MK6
                                                   >> 230         bool "K6/K6-II/K6-III"
                                                   >> 231         help
                                                   >> 232           Select this for an AMD K6-family processor.  Enables use of
                                                   >> 233           some extended instructions, and passes appropriate optimization
                                                   >> 234           flags to GCC.
                                                   >> 235 
                                                   >> 236 config MK7
                                                   >> 237         bool "Athlon/Duron/K7"
                                                   >> 238         help
                                                   >> 239           Select this for an AMD Athlon K7-family processor.  Enables use of
                                                   >> 240           some extended instructions, and passes appropriate optimization
                                                   >> 241           flags to GCC.
                                                   >> 242 
                                                   >> 243 config MK8
                                                   >> 244         bool "Opteron/Athlon64/Hammer/K8"
                                                   >> 245         help
                                                   >> 246           Select this for an AMD Opteron or Athlon64 Hammer-family processor.  Enables
                                                   >> 247           use of some extended instructions, and passes appropriate optimization
                                                   >> 248           flags to GCC.
                                                   >> 249 
                                                   >> 250 config MELAN
                                                   >> 251         bool "Elan"
                                                   >> 252 
                                                   >> 253 config MCRUSOE
                                                   >> 254         bool "Crusoe"
                                                   >> 255         help
                                                   >> 256           Select this for a Transmeta Crusoe processor.  Treats the processor
                                                   >> 257           like a 586 with TSC, and sets some GCC optimization flags (like a
                                                   >> 258           Pentium Pro with no alignment requirements).
                                                   >> 259 
                                                   >> 260 config MWINCHIPC6
                                                   >> 261         bool "Winchip-C6"
                                                   >> 262         help
                                                   >> 263           Select this for an IDT Winchip C6 chip.  Linux and GCC
                                                   >> 264           treat this chip as a 586TSC with some extended instructions
                                                   >> 265           and alignment requirements.
                                                   >> 266 
                                                   >> 267 config MWINCHIP2
                                                   >> 268         bool "Winchip-2"
                                                   >> 269         help
                                                   >> 270           Select this for an IDT Winchip-2.  Linux and GCC
                                                   >> 271           treat this chip as a 586TSC with some extended instructions
                                                   >> 272           and alignment requirements.
                                                   >> 273 
                                                   >> 274 config MWINCHIP3D
                                                   >> 275         bool "Winchip-2A/Winchip-3"
                                                   >> 276         help
                                                   >> 277           Select this for an IDT Winchip-2A or 3.  Linux and GCC
                                                   >> 278           treat this chip as a 586TSC with some extended instructions
                                                   >> 279           and alignment reqirements.  Also enable out of order memory
                                                   >> 280           stores for this CPU, which can increase performance of some
                                                   >> 281           operations.
                                                   >> 282 
                                                   >> 283 config MCYRIXIII
                                                   >> 284         bool "CyrixIII/VIA-C3"
                                                   >> 285         help
                                                   >> 286           Select this for a Cyrix III or C3 chip.  Presently Linux and GCC
                                                   >> 287           treat this chip as a generic 586. Whilst the CPU is 686 class,
                                                   >> 288           it lacks the cmov extension which gcc assumes is present when
                                                   >> 289           generating 686 code.
                                                   >> 290           Note that Nehemiah (Model 9) and above will not boot with this
                                                   >> 291           kernel due to them lacking the 3DNow! instructions used in earlier
                                                   >> 292           incarnations of the CPU.
                                                   >> 293 
                                                   >> 294 config MVIAC3_2
                                                   >> 295         bool "VIA C3-2 (Nehemiah)"
                                                   >> 296         help
                                                   >> 297           Select this for a VIA C3 "Nehemiah". Selecting this enables usage
                                                   >> 298           of SSE and tells gcc to treat the CPU as a 686.
                                                   >> 299           Note, this kernel will not boot on older (pre model 9) C3s.
789                                                   300 
790           Work around the issue by inserting D !! 301 endchoice
791           register reads and warning KVM users << 
792           to prevent a speculative PAR_EL1 rea << 
793                                                   302 
794           If unsure, say Y.                    !! 303 config X86_GENERIC
                                                   >> 304        bool "Generic x86 support" 
                                                   >> 305        help
                                                   >> 306           Including some tuning for non selected x86 CPUs too.
                                                   >> 307           when it has moderate overhead. This is intended for generic 
                                                   >> 308           distributions kernels.
795                                                   309 
796 config ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MO !! 310 #
                                                   >> 311 # Define implied options from the CPU selection here
                                                   >> 312 #
                                                   >> 313 config X86_CMPXCHG
797         bool                                      314         bool
798                                                !! 315         depends on !M386
799 config ARM64_ERRATUM_2051678                   << 
800         bool "Cortex-A510: 2051678: disable Ha << 
801         default y                                 316         default y
802         help                                   << 
803           This options adds the workaround for << 
804           Affected Cortex-A510 might not respe << 
805           hardware update of the page table's  << 
806           is to not enable the feature on affe << 
807                                                << 
808           If unsure, say Y.                    << 
809                                                   317 
810 config ARM64_ERRATUM_2077057                   !! 318 config X86_XADD
811         bool "Cortex-A510: 2077057: workaround !! 319         bool
                                                   >> 320         depends on !M386
812         default y                                 321         default y
813         help                                   << 
814           This option adds the workaround for  << 
815           Affected Cortex-A510 may corrupt SPS << 
816           expected, but a Pointer Authenticati << 
817           erratum causes SPSR_EL1 to be copied << 
818           EL1 to cause a return to EL2 with a  << 
819                                                << 
820           This can only happen when EL2 is ste << 
821                                                << 
822           When these conditions occur, the SPS << 
823           previous guest entry, and can be res << 
824                                                   322 
825           If unsure, say Y.                    !! 323 config X86_L1_CACHE_SHIFT
                                                   >> 324         int
                                                   >> 325         default "7" if MPENTIUM4 || X86_GENERIC
                                                   >> 326         default "4" if MELAN || M486 || M386
                                                   >> 327         default "5" if MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCRUSOE || MCYRIXIII || MK6 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || M586 || MVIAC3_2
                                                   >> 328         default "6" if MK7 || MK8
826                                                   329 
827 config ARM64_ERRATUM_2658417                   !! 330 config RWSEM_GENERIC_SPINLOCK
828         bool "Cortex-A510: 2658417: remove BF1 !! 331         bool
                                                   >> 332         depends on M386
829         default y                                 333         default y
830         help                                   << 
831           This option adds the workaround for  << 
832           Affected Cortex-A510 (r0p0 to r1p1)  << 
833           BFMMLA or VMMLA instructions in rare << 
834           A510 CPUs are using shared neon hard << 
835           discoverable by the kernel, hide the << 
836           user-space should not be using these << 
837                                                   334 
838           If unsure, say Y.                    !! 335 config RWSEM_XCHGADD_ALGORITHM
839                                                !! 336         bool
840 config ARM64_ERRATUM_2119858                   !! 337         depends on !M386
841         bool "Cortex-A710/X2: 2119858: workaro << 
842         default y                                 338         default y
843         depends on CORESIGHT_TRBE              << 
844         select ARM64_WORKAROUND_TRBE_OVERWRITE << 
845         help                                   << 
846           This option adds the workaround for  << 
847                                                << 
848           Affected Cortex-A710/X2 cores could  << 
849           data at the base of the buffer (poin << 
850           the event of a WRAP event.           << 
851                                                   339 
852           Work around the issue by always maki !! 340 config X86_PPRO_FENCE
853           256 bytes before enabling the buffer !! 341         bool
854           the buffer with ETM ignore packets u !! 342         depends on M686 || M586MMX || M586TSC || M586 || M486 || M386
855                                                << 
856           If unsure, say Y.                    << 
857                                                << 
858 config ARM64_ERRATUM_2139208                   << 
859         bool "Neoverse-N2: 2139208: workaround << 
860         default y                                 343         default y
861         depends on CORESIGHT_TRBE              << 
862         select ARM64_WORKAROUND_TRBE_OVERWRITE << 
863         help                                   << 
864           This option adds the workaround for  << 
865                                                   344 
866           Affected Neoverse-N2 cores could ove !! 345 config X86_F00F_BUG
867           data at the base of the buffer (poin << 
868           the event of a WRAP event.           << 
869                                                << 
870           Work around the issue by always maki << 
871           256 bytes before enabling the buffer << 
872           the buffer with ETM ignore packets u << 
873                                                << 
874           If unsure, say Y.                    << 
875                                                << 
876 config ARM64_WORKAROUND_TSB_FLUSH_FAILURE      << 
877         bool                                      346         bool
878                                                !! 347         depends on M586MMX || M586TSC || M586 || M486 || M386
879 config ARM64_ERRATUM_2054223                   << 
880         bool "Cortex-A710: 2054223: workaround << 
881         default y                                 348         default y
882         select ARM64_WORKAROUND_TSB_FLUSH_FAIL << 
883         help                                   << 
884           Enable workaround for ARM Cortex-A71 << 
885                                                << 
886           Affected cores may fail to flush the << 
887           the PE is in trace prohibited state. << 
888           of the trace cached.                 << 
889                                                << 
890           Workaround is to issue two TSB conse << 
891                                                   349 
892           If unsure, say Y.                    !! 350 config X86_WP_WORKS_OK
893                                                !! 351         bool
894 config ARM64_ERRATUM_2067961                   !! 352         depends on !M386
895         bool "Neoverse-N2: 2067961: workaround << 
896         default y                                 353         default y
897         select ARM64_WORKAROUND_TSB_FLUSH_FAIL << 
898         help                                   << 
899           Enable workaround for ARM Neoverse-N << 
900                                                << 
901           Affected cores may fail to flush the << 
902           the PE is in trace prohibited state. << 
903           of the trace cached.                 << 
904                                                   354 
905           Workaround is to issue two TSB conse !! 355 config X86_INVLPG
906                                                << 
907           If unsure, say Y.                    << 
908                                                << 
909 config ARM64_WORKAROUND_TRBE_WRITE_OUT_OF_RANG << 
910         bool                                      356         bool
911                                                !! 357         depends on !M386
912 config ARM64_ERRATUM_2253138                   << 
913         bool "Neoverse-N2: 2253138: workaround << 
914         depends on CORESIGHT_TRBE              << 
915         default y                                 358         default y
916         select ARM64_WORKAROUND_TRBE_WRITE_OUT << 
917         help                                   << 
918           This option adds the workaround for  << 
919                                                   359 
920           Affected Neoverse-N2 cores might wri !! 360 config X86_BSWAP
921           for TRBE. Under some conditions, the !! 361         bool
922           virtually addressed page following t !! 362         depends on !M386
923           (i.e., the TRBLIMITR_EL1.LIMIT), ins << 
924                                                << 
925           Work around this in the driver by al << 
926           page beyond the TRBLIMITR_EL1.LIMIT, << 
927                                                << 
928           If unsure, say Y.                    << 
929                                                << 
930 config ARM64_ERRATUM_2224489                   << 
931         bool "Cortex-A710/X2: 2224489: workaro << 
932         depends on CORESIGHT_TRBE              << 
933         default y                                 363         default y
934         select ARM64_WORKAROUND_TRBE_WRITE_OUT << 
935         help                                   << 
936           This option adds the workaround for  << 
937                                                << 
938           Affected Cortex-A710/X2 cores might  << 
939           for TRBE. Under some conditions, the << 
940           virtually addressed page following t << 
941           (i.e., the TRBLIMITR_EL1.LIMIT), ins << 
942                                                << 
943           Work around this in the driver by al << 
944           page beyond the TRBLIMITR_EL1.LIMIT, << 
945                                                   364 
946           If unsure, say Y.                    !! 365 config X86_POPAD_OK
947                                                !! 366         bool
948 config ARM64_ERRATUM_2441009                   !! 367         depends on !M386
949         bool "Cortex-A510: Completion of affec << 
950         select ARM64_WORKAROUND_REPEAT_TLBI    << 
951         help                                   << 
952           This option adds a workaround for AR << 
953                                                << 
954           Under very rare circumstances, affec << 
955           may not handle a race between a brea << 
956           CPU, and another CPU accessing the s << 
957           store to a page that has been unmapp << 
958                                                << 
959           Work around this by adding the affec << 
960           TLB sequences to be done twice.      << 
961                                                << 
962           If unsure, say N.                    << 
963                                                << 
964 config ARM64_ERRATUM_2064142                   << 
965         bool "Cortex-A510: 2064142: workaround << 
966         depends on CORESIGHT_TRBE              << 
967         default y                                 368         default y
968         help                                   << 
969           This option adds the workaround for  << 
970                                                   369 
971           Affected Cortex-A510 core might fail !! 370 config X86_ALIGNMENT_16
972           TRBE has been disabled. Under some c !! 371         bool
973           writes into TRBE registers TRBLIMITR !! 372         depends on MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCYRIXIII || MELAN || MK6 || M586MMX || M586TSC || M586 || M486 || MVIAC3_2
974           and TRBTRG_EL1 will be ignored and w << 
975                                                << 
976           Work around this in the driver by ex << 
977           is stopped and before performing a s << 
978           registers.                           << 
979                                                << 
980           If unsure, say Y.                    << 
981                                                << 
982 config ARM64_ERRATUM_2038923                   << 
983         bool "Cortex-A510: 2038923: workaround << 
984         depends on CORESIGHT_TRBE              << 
985         default y                                 373         default y
986         help                                   << 
987           This option adds the workaround for  << 
988                                                << 
989           Affected Cortex-A510 core might caus << 
990           prohibited within the CPU. As a resu << 
991           might be corrupted. This happens aft << 
992           TRBLIMITR_EL1.E, followed by just a  << 
993           execution changes from a context, in << 
994           isn't, or vice versa. In these menti << 
995           is prohibited is inconsistent betwee << 
996           the trace buffer state might be corr << 
997                                                << 
998           Work around this in the driver by pr << 
999           trace is prohibited or not based on  << 
1000           change to TRBLIMITR_EL1.E with at l << 
1001           two ISB instructions if no ERET is  << 
1002                                                  374 
1003           If unsure, say Y.                   !! 375 config X86_GOOD_APIC
1004                                               !! 376         bool
1005 config ARM64_ERRATUM_1902691                  !! 377         depends on MK7 || MPENTIUM4 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || MK8
1006         bool "Cortex-A510: 1902691: workaroun << 
1007         depends on CORESIGHT_TRBE             << 
1008         default y                                378         default y
1009         help                                  << 
1010           This option adds the workaround for << 
1011                                               << 
1012           Affected Cortex-A510 core might cau << 
1013           into the memory. Effectively TRBE i << 
1014           trace data.                         << 
1015                                                  379 
1016           Work around this problem in the dri !! 380 config X86_INTEL_USERCOPY
1017           affected cpus. The firmware must ha !! 381         bool
1018           on such implementations. This will  !! 382         depends on MPENTIUM4 || MPENTIUMIII || MPENTIUMII || M586MMX || X86_GENERIC || MK8 || MK7
1019           do this already.                    << 
1020                                               << 
1021           If unsure, say Y.                   << 
1022                                               << 
1023 config ARM64_ERRATUM_2457168                  << 
1024         bool "Cortex-A510: 2457168: workaroun << 
1025         depends on ARM64_AMU_EXTN             << 
1026         default y                                383         default y
1027         help                                  << 
1028           This option adds the workaround for << 
1029                                               << 
1030           The AMU counter AMEVCNTR01 (constan << 
1031           as the system counter. On affected  << 
1032           incorrectly giving a significantly  << 
1033                                               << 
1034           Work around this problem by returni << 
1035           key locations that results in disab << 
1036           is the same to firmware disabling a << 
1037                                               << 
1038           If unsure, say Y.                   << 
1039                                                  384 
1040 config ARM64_ERRATUM_2645198                  !! 385 config X86_USE_PPRO_CHECKSUM
1041         bool "Cortex-A715: 2645198: Workaroun !! 386         bool
                                                   >> 387         depends on MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMIII || MPENTIUMII || M686 || MK8 || MVIAC3_2
1042         default y                                388         default y
1043         help                                  << 
1044           This option adds the workaround for << 
1045                                               << 
1046           If a Cortex-A715 cpu sees a page ma << 
1047           to non-executable, it may corrupt t << 
1048           next instruction abort caused by pe << 
1049                                                  389 
1050           Only user-space does executable to  !! 390 config X86_USE_3DNOW
1051           mprotect() system call. Workaround  << 
1052           TLB invalidation, for all changes t << 
1053                                               << 
1054           If unsure, say Y.                   << 
1055                                               << 
1056 config ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LO << 
1057         bool                                     391         bool
1058                                               !! 392         depends on MCYRIXIII || MK7
1059 config ARM64_ERRATUM_2966298                  << 
1060         bool "Cortex-A520: 2966298: workaroun << 
1061         select ARM64_WORKAROUND_SPECULATIVE_U << 
1062         default y                                393         default y
1063         help                                  << 
1064           This option adds the workaround for << 
1065                                                  394 
1066           On an affected Cortex-A520 core, a  !! 395 config X86_OOSTORE
1067           load might leak data from a privile !! 396         bool
1068                                               !! 397         depends on MWINCHIP3D || MWINCHIP2 || MWINCHIPC6
1069           Work around this problem by executi << 
1070                                               << 
1071           If unsure, say Y.                   << 
1072                                               << 
1073 config ARM64_ERRATUM_3117295                  << 
1074         bool "Cortex-A510: 3117295: workaroun << 
1075         select ARM64_WORKAROUND_SPECULATIVE_U << 
1076         default y                                398         default y
1077         help                                  << 
1078           This option adds the workaround for << 
1079                                               << 
1080           On an affected Cortex-A510 core, a  << 
1081           load might leak data from a privile << 
1082                                               << 
1083           Work around this problem by executi << 
1084                                               << 
1085           If unsure, say Y.                   << 
1086                                                  399 
1087 config ARM64_ERRATUM_3194386                  !! 400 config HPET_TIMER
1088         bool "Cortex-*/Neoverse-*: workaround !! 401         bool "HPET Timer Support"
1089         default y                             << 
1090         help                                     402         help
1091           This option adds the workaround for !! 403           This enables the use of the HPET for the kernel's internal timer.
1092                                               !! 404           HPET is the next generation timer replacing legacy 8254s.
1093           * ARM Cortex-A76 erratum 3324349    !! 405           You can safely choose Y here.  However, HPET will only be
1094           * ARM Cortex-A77 erratum 3324348    !! 406           activated if the platform and the BIOS support this feature.
1095           * ARM Cortex-A78 erratum 3324344    !! 407           Otherwise the 8254 will be used for timing services.
1096           * ARM Cortex-A78C erratum 3324346   << 
1097           * ARM Cortex-A78C erratum 3324347   << 
1098           * ARM Cortex-A710 erratam 3324338   << 
1099           * ARM Cortex-A715 errartum 3456084  << 
1100           * ARM Cortex-A720 erratum 3456091   << 
1101           * ARM Cortex-A725 erratum 3456106   << 
1102           * ARM Cortex-X1 erratum 3324344     << 
1103           * ARM Cortex-X1C erratum 3324346    << 
1104           * ARM Cortex-X2 erratum 3324338     << 
1105           * ARM Cortex-X3 erratum 3324335     << 
1106           * ARM Cortex-X4 erratum 3194386     << 
1107           * ARM Cortex-X925 erratum 3324334   << 
1108           * ARM Neoverse-N1 erratum 3324349   << 
1109           * ARM Neoverse N2 erratum 3324339   << 
1110           * ARM Neoverse-N3 erratum 3456111   << 
1111           * ARM Neoverse-V1 erratum 3324341   << 
1112           * ARM Neoverse V2 erratum 3324336   << 
1113           * ARM Neoverse-V3 erratum 3312417   << 
1114                                               << 
1115           On affected cores "MSR SSBS, #0" in << 
1116           subsequent speculative instructions << 
1117           speculative store bypassing.        << 
1118                                                  408 
1119           Work around this problem by placing !! 409           Choose N to continue using the legacy 8254 timer.
1120           Instruction Synchronization Barrier << 
1121           SSBS. The presence of the SSBS spec << 
1122           from hwcaps and EL0 reads of ID_AA6 << 
1123           will use the PR_SPEC_STORE_BYPASS p << 
1124                                                  410 
1125           If unsure, say Y.                   !! 411 config HPET_EMULATE_RTC
                                                   >> 412         def_bool HPET_TIMER && RTC=y
1126                                                  413 
1127 config CAVIUM_ERRATUM_22375                   !! 414 config SMP
1128         bool "Cavium erratum 22375, 24313"    !! 415         bool "Symmetric multi-processing support"
1129         default y                             !! 416         ---help---
1130         help                                  !! 417           This enables support for systems with more than one CPU. If you have
1131           Enable workaround for errata 22375  !! 418           a system with only one CPU, like most personal computers, say N. If
1132                                               !! 419           you have a system with more than one CPU, say Y.
1133           This implements two gicv3-its errat !! 420 
1134           with a small impact affecting only  !! 421           If you say N here, the kernel will run on single and multiprocessor
                                                   >> 422           machines, but will use only one CPU of a multiprocessor machine. If
                                                   >> 423           you say Y here, the kernel will run on many, but not all,
                                                   >> 424           singleprocessor machines. On a singleprocessor machine, the kernel
                                                   >> 425           will run faster if you say N here.
                                                   >> 426 
                                                   >> 427           Note that if you say Y here and choose architecture "586" or
                                                   >> 428           "Pentium" under "Processor family", the kernel will not work on 486
                                                   >> 429           architectures. Similarly, multiprocessor kernels for the "PPro"
                                                   >> 430           architecture may not work on all Pentium based boards.
                                                   >> 431 
                                                   >> 432           People using multiprocessor machines who say Y here should also say
                                                   >> 433           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
                                                   >> 434           Management" code will be disabled if you say Y here.
                                                   >> 435 
                                                   >> 436           See also the <file:Documentation/smp.tex>,
                                                   >> 437           <file:Documentation/smp.txt>, <file:Documentation/i386/IO-APIC.txt>,
                                                   >> 438           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
                                                   >> 439           <http://www.tldp.org/docs.html#howto>.
1135                                                  440 
1136             erratum 22375: only alloc 8MB tab !! 441           If you don't know what to do here, say N.
1137             erratum 24313: ignore memory acce << 
1138                                                  442 
1139           The fixes are in ITS initialization !! 443 config NR_CPUS
1140           type and table size provided by the !! 444         int "Maximum number of CPUs (2-255)"
                                                   >> 445         depends on SMP
                                                   >> 446         default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
                                                   >> 447         default "8"
                                                   >> 448         help
                                                   >> 449           This allows you to specify the maximum number of CPUs which this
                                                   >> 450           kernel will support.  The maximum supported value is 255 and the
                                                   >> 451           minimum value which makes sense is 2.
                                                   >> 452 
                                                   >> 453           This is purely to save memory - each supported CPU adds
                                                   >> 454           approximately eight kilobytes to the kernel image.
                                                   >> 455 
                                                   >> 456 config PREEMPT
                                                   >> 457         bool "Preemptible Kernel"
                                                   >> 458         help
                                                   >> 459           This option reduces the latency of the kernel when reacting to
                                                   >> 460           real-time or interactive events by allowing a low priority process to
                                                   >> 461           be preempted even if it is in kernel mode executing a system call.
                                                   >> 462           This allows applications to run more reliably even when the system is
                                                   >> 463           under load.
                                                   >> 464 
                                                   >> 465           Say Y here if you are building a kernel for a desktop, embedded
                                                   >> 466           or real-time system.  Say N if you are unsure.
                                                   >> 467 
                                                   >> 468 config X86_UP_APIC
                                                   >> 469         bool "Local APIC support on uniprocessors" if !SMP
                                                   >> 470         depends on !(X86_VISWS || X86_VOYAGER)
                                                   >> 471         ---help---
                                                   >> 472           A local APIC (Advanced Programmable Interrupt Controller) is an
                                                   >> 473           integrated interrupt controller in the CPU. If you have a single-CPU
                                                   >> 474           system which has a processor with a local APIC, you can say Y here to
                                                   >> 475           enable and use it. If you say Y here even though your machine doesn't
                                                   >> 476           have a local APIC, then the kernel will still run with no slowdown at
                                                   >> 477           all. The local APIC supports CPU-generated self-interrupts (timer,
                                                   >> 478           performance counters), and the NMI watchdog which detects hard
                                                   >> 479           lockups.
                                                   >> 480 
                                                   >> 481           If you have a system with several CPUs, you do not need to say Y
                                                   >> 482           here: the local APIC will be used automatically.
                                                   >> 483 
                                                   >> 484 config X86_UP_IOAPIC
                                                   >> 485         bool "IO-APIC support on uniprocessors"
                                                   >> 486         depends on !SMP && X86_UP_APIC
                                                   >> 487         help
                                                   >> 488           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
                                                   >> 489           SMP-capable replacement for PC-style interrupt controllers. Most
                                                   >> 490           SMP systems and a small number of uniprocessor systems have one.
                                                   >> 491           If you have a single-CPU system with an IO-APIC, you can say Y here
                                                   >> 492           to use it. If you say Y here even though your machine doesn't have
                                                   >> 493           an IO-APIC, then the kernel will still run with no slowdown at all.
1141                                                  494 
1142           If unsure, say Y.                   !! 495           If you have a system with several CPUs, you do not need to say Y
                                                   >> 496           here: the IO-APIC will be used automatically.
1143                                                  497 
1144 config CAVIUM_ERRATUM_23144                   !! 498 config X86_LOCAL_APIC
1145         bool "Cavium erratum 23144: ITS SYNC  !! 499         bool
1146         depends on NUMA                       !! 500         depends on !SMP && X86_UP_APIC
1147         default y                                501         default y
1148         help                                  << 
1149           ITS SYNC command hang for cross nod << 
1150                                               << 
1151           If unsure, say Y.                   << 
1152                                                  502 
1153 config CAVIUM_ERRATUM_23154                   !! 503 config X86_IO_APIC
1154         bool "Cavium errata 23154 and 38545:  !! 504         bool
                                                   >> 505         depends on !SMP && X86_UP_IOAPIC
1155         default y                                506         default y
1156         help                                  << 
1157           The ThunderX GICv3 implementation r << 
1158           reading the IAR status to ensure da << 
1159           (access to icc_iar1_el1 is not sync << 
1160                                                  507 
1161           It also suffers from erratum 38545  !! 508 config X86_TSC
1162           OcteonTX and OcteonTX2), resulting  !! 509         bool
1163           spuriously presented to the CPU int !! 510         depends on (MWINCHIP3D || MWINCHIP2 || MCRUSOE || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || MK8 || MVIAC3_2) && !X86_NUMAQ
1164                                               << 
1165           If unsure, say Y.                   << 
1166                                               << 
1167 config CAVIUM_ERRATUM_27456                   << 
1168         bool "Cavium erratum 27456: Broadcast << 
1169         default y                                511         default y
1170         help                                  << 
1171           On ThunderX T88 pass 1.x through 2. << 
1172           instructions may cause the icache t << 
1173           contains data for a non-current ASI << 
1174           invalidate the icache when changing << 
1175                                                  512 
1176           If unsure, say Y.                   !! 513 config X86_MCE
                                                   >> 514         bool "Machine Check Exception"
                                                   >> 515         ---help---
                                                   >> 516           Machine Check Exception support allows the processor to notify the
                                                   >> 517           kernel if it detects a problem (e.g. overheating, component failure).
                                                   >> 518           The action the kernel takes depends on the severity of the problem,
                                                   >> 519           ranging from a warning message on the console, to halting the machine.
                                                   >> 520           Your processor must be a Pentium or newer to support this - check the
                                                   >> 521           flags in /proc/cpuinfo for mce.  Note that some older Pentium systems
                                                   >> 522           have a design flaw which leads to false MCE events - hence MCE is
                                                   >> 523           disabled on all P5 processors, unless explicitly enabled with "mce"
                                                   >> 524           as a boot argument.  Similarly, if MCE is built in and creates a
                                                   >> 525           problem on some new non-standard machine, you can boot with "nomce"
                                                   >> 526           to disable it.  MCE support simply ignores non-MCE processors like
                                                   >> 527           the 386 and 486, so nearly everyone can say Y here.
                                                   >> 528 
                                                   >> 529 config X86_MCE_NONFATAL
                                                   >> 530         bool "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
                                                   >> 531         depends on X86_MCE
                                                   >> 532         help
                                                   >> 533           Enabling this feature starts a timer that triggers every 5 seconds which
                                                   >> 534           will look at the machine check registers to see if anything happened.
                                                   >> 535           Non-fatal problems automatically get corrected (but still logged).
                                                   >> 536           Disable this if you don't want to see these messages.
                                                   >> 537           Seeing the messages this option prints out may be indicative of dying hardware,
                                                   >> 538           or out-of-spec (ie, overclocked) hardware.
                                                   >> 539           This option only does something on certain CPUs.
                                                   >> 540           (AMD Athlon/Duron and Intel Pentium 4)
                                                   >> 541 
                                                   >> 542 config X86_MCE_P4THERMAL
                                                   >> 543         bool "check for P4 thermal throttling interrupt."
                                                   >> 544         depends on X86_MCE && (X86_UP_APIC || SMP)
                                                   >> 545         help
                                                   >> 546           Enabling this feature will cause a message to be printed when the P4
                                                   >> 547           enters thermal throttling.
                                                   >> 548 
                                                   >> 549 config TOSHIBA
                                                   >> 550         tristate "Toshiba Laptop support"
                                                   >> 551         ---help---
                                                   >> 552           This adds a driver to safely access the System Management Mode of
                                                   >> 553           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
                                                   >> 554           not work on models with a Phoenix BIOS. The System Management Mode
                                                   >> 555           is used to set the BIOS and power saving options on Toshiba portables.
                                                   >> 556 
                                                   >> 557           For information on utilities to make use of this driver see the
                                                   >> 558           Toshiba Linux utilities web site at:
                                                   >> 559           <http://www.buzzard.org.uk/toshiba/>.
                                                   >> 560 
                                                   >> 561           Say Y if you intend to run this kernel on a Toshiba portable.
                                                   >> 562           Say N otherwise.
                                                   >> 563 
                                                   >> 564 config I8K
                                                   >> 565         tristate "Dell laptop support"
                                                   >> 566         ---help---
                                                   >> 567           This adds a driver to safely access the System Management Mode
                                                   >> 568           of the CPU on the Dell Inspiron 8000. The System Management Mode
                                                   >> 569           is used to read cpu temperature and cooling fan status and to
                                                   >> 570           control the fans on the I8K portables.
                                                   >> 571 
                                                   >> 572           This driver has been tested only on the Inspiron 8000 but it may
                                                   >> 573           also work with other Dell laptops. You can force loading on other
                                                   >> 574           models by passing the parameter `force=1' to the module. Use at
                                                   >> 575           your own risk.
                                                   >> 576 
                                                   >> 577           For information on utilities to make use of this driver see the
                                                   >> 578           I8K Linux utilities web site at:
                                                   >> 579           <http://www.debian.org/~dz/i8k/>
                                                   >> 580 
                                                   >> 581           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
                                                   >> 582           Say N otherwise.
                                                   >> 583 
                                                   >> 584 config MICROCODE
                                                   >> 585         tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
                                                   >> 586         ---help---
                                                   >> 587           If you say Y here and also to "/dev file system support" in the
                                                   >> 588           'File systems' section, you will be able to update the microcode on
                                                   >> 589           Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
                                                   >> 590           Pentium III, Pentium 4, Xeon etc.  You will obviously need the
                                                   >> 591           actual microcode binary data itself which is not shipped with the
                                                   >> 592           Linux kernel.
                                                   >> 593 
                                                   >> 594           For latest news and information on obtaining all the required
                                                   >> 595           ingredients for this driver, check:
                                                   >> 596           <http://www.urbanmyth.org/microcode/>.
                                                   >> 597 
                                                   >> 598           To compile this driver as a module, choose M here: the
                                                   >> 599           module will be called microcode.
                                                   >> 600           If you use modprobe or kmod you may also want to add the line
                                                   >> 601           'alias char-major-10-184 microcode' to your /etc/modules.conf file.
                                                   >> 602 
                                                   >> 603 config X86_MSR
                                                   >> 604         tristate "/dev/cpu/*/msr - Model-specific register support"
                                                   >> 605         help
                                                   >> 606           This device gives privileged processes access to the x86
                                                   >> 607           Model-Specific Registers (MSRs).  It is a character device with
                                                   >> 608           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
                                                   >> 609           MSR accesses are directed to a specific CPU on multi-processor
                                                   >> 610           systems.
                                                   >> 611 
                                                   >> 612 config X86_CPUID
                                                   >> 613         tristate "/dev/cpu/*/cpuid - CPU information support"
                                                   >> 614         help
                                                   >> 615           This device gives processes access to the x86 CPUID instruction to
                                                   >> 616           be executed on a specific processor.  It is a character device
                                                   >> 617           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
                                                   >> 618           /dev/cpu/31/cpuid.
                                                   >> 619 
                                                   >> 620 config EDD
                                                   >> 621         tristate "BIOS Enhanced Disk Drive calls determine boot disk (EXPERIMENTAL)"
                                                   >> 622         depends on EXPERIMENTAL
                                                   >> 623         help
                                                   >> 624           Say Y or M here if you want to enable BIOS Enhanced Disk Drive
                                                   >> 625           Services real mode BIOS calls to determine which disk
                                                   >> 626           BIOS tries boot from.  This information is then exported via driverfs.
1177                                                  627 
1178 config CAVIUM_ERRATUM_30115                   !! 628           This option is experimental, but believed to be safe,
1179         bool "Cavium erratum 30115: Guest may !! 629           and most disk controller BIOS vendors do not yet implement this feature.
1180         default y                             << 
1181         help                                  << 
1182           On ThunderX T88 pass 1.x through 2. << 
1183           1.2, and T83 Pass 1.0, KVM guest ex << 
1184           interrupts in host. Trapping both G << 
1185           accesses sidesteps the issue.       << 
1186                                                  630 
1187           If unsure, say Y.                   !! 631 choice
                                                   >> 632         prompt "High Memory Support"
                                                   >> 633         default NOHIGHMEM
1188                                                  634 
1189 config CAVIUM_TX2_ERRATUM_219                 !! 635 config NOHIGHMEM
1190         bool "Cavium ThunderX2 erratum 219: P !! 636         bool "off"
1191         default y                             !! 637         ---help---
                                                   >> 638           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
                                                   >> 639           However, the address space of 32-bit x86 processors is only 4
                                                   >> 640           Gigabytes large. That means that, if you have a large amount of
                                                   >> 641           physical memory, not all of it can be "permanently mapped" by the
                                                   >> 642           kernel. The physical memory that's not permanently mapped is called
                                                   >> 643           "high memory".
                                                   >> 644 
                                                   >> 645           If you are compiling a kernel which will never run on a machine with
                                                   >> 646           more than 1 Gigabyte total physical RAM, answer "off" here (default
                                                   >> 647           choice and suitable for most users). This will result in a "3GB/1GB"
                                                   >> 648           split: 3GB are mapped so that each process sees a 3GB virtual memory
                                                   >> 649           space and the remaining part of the 4GB virtual memory space is used
                                                   >> 650           by the kernel to permanently map as much physical memory as
                                                   >> 651           possible.
                                                   >> 652 
                                                   >> 653           If the machine has between 1 and 4 Gigabytes physical RAM, then
                                                   >> 654           answer "4GB" here.
                                                   >> 655 
                                                   >> 656           If more than 4 Gigabytes is used then answer "64GB" here. This
                                                   >> 657           selection turns Intel PAE (Physical Address Extension) mode on.
                                                   >> 658           PAE implements 3-level paging on IA32 processors. PAE is fully
                                                   >> 659           supported by Linux, PAE mode is implemented on all recent Intel
                                                   >> 660           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
                                                   >> 661           then the kernel will not boot on CPUs that don't support PAE!
                                                   >> 662 
                                                   >> 663           The actual amount of total physical memory will either be
                                                   >> 664           auto detected or can be forced by using a kernel command line option
                                                   >> 665           such as "mem=256M". (Try "man bootparam" or see the documentation of
                                                   >> 666           your boot loader (lilo or loadlin) about how to pass options to the
                                                   >> 667           kernel at boot time.)
                                                   >> 668 
                                                   >> 669           If unsure, say "off".
                                                   >> 670 
                                                   >> 671 config HIGHMEM4G
                                                   >> 672         bool "4GB"
1192         help                                     673         help
1193           On Cavium ThunderX2, a load, store  !! 674           Select this if you have a 32-bit processor and between 1 and 4
1194           TTBR update and the corresponding c !! 675           gigabytes of physical RAM.
1195           cause a spurious Data Abort to be d << 
1196           the CPU core.                       << 
1197                                               << 
1198           Work around the issue by avoiding t << 
1199           trapping KVM guest TTBRx_EL1 writes << 
1200           trap handler performs the correspon << 
1201           instruction and ensures context syn << 
1202           exception return.                   << 
1203                                                  676 
1204           If unsure, say Y.                   !! 677 config HIGHMEM64G
1205                                               !! 678         bool "64GB"
1206 config FUJITSU_ERRATUM_010001                 << 
1207         bool "Fujitsu-A64FX erratum E#010001: << 
1208         default y                             << 
1209         help                                     679         help
1210           This option adds a workaround for F !! 680           Select this if you have a 32-bit processor and more than 4
1211           On some variants of the Fujitsu-A64 !! 681           gigabytes of physical RAM.
1212           accesses may cause undefined fault  << 
1213           This fault occurs under a specific  << 
1214           load/store instruction performs an  << 
1215           case-1  TTBR0_EL1 with TCR_EL1.NFD0 << 
1216           case-2  TTBR0_EL2 with TCR_EL2.NFD0 << 
1217           case-3  TTBR1_EL1 with TCR_EL1.NFD1 << 
1218           case-4  TTBR1_EL2 with TCR_EL2.NFD1 << 
1219                                                  682 
1220           The workaround is to ensure these b !! 683 endchoice
1221           The workaround only affects the Fuj << 
1222                                               << 
1223           If unsure, say Y.                   << 
1224                                                  684 
1225 config HISILICON_ERRATUM_161600802            !! 685 config HIGHMEM
1226         bool "Hip07 161600802: Erroneous redi !! 686         bool
                                                   >> 687         depends on HIGHMEM64G || HIGHMEM4G
1227         default y                                688         default y
1228         help                                  << 
1229           The HiSilicon Hip07 SoC uses the wr << 
1230           when issued ITS commands such as VM << 
1231           a 128kB offset to be applied to the << 
1232                                                  689 
1233           If unsure, say Y.                   !! 690 config X86_PAE
1234                                               !! 691         bool
1235 config QCOM_FALKOR_ERRATUM_1003               !! 692         depends on HIGHMEM64G
1236         bool "Falkor E1003: Incorrect transla << 
1237         default y                                693         default y
1238         help                                  << 
1239           On Falkor v1, an incorrect ASID may << 
1240           and BADDR are changed together in T << 
1241           in TTBR1_EL1, this situation only o << 
1242           then only for entries in the walk c << 
1243           is unchanged. Work around the errat << 
1244           entries for the trampoline before e << 
1245                                                  694 
1246 config QCOM_FALKOR_ERRATUM_1009               !! 695 # Common NUMA Features
1247         bool "Falkor E1009: Prematurely compl !! 696 config NUMA
1248         default y                             !! 697         bool "Numa Memory Allocation Support"
1249         select ARM64_WORKAROUND_REPEAT_TLBI   !! 698         depends on SMP && HIGHMEM64G && (X86_PC || X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI && !ACPI_HT_ONLY))
1250         help                                  !! 699         default n if X86_PC
1251           On Falkor v1, the CPU may premature !! 700         default y if (X86_NUMAQ || X86_SUMMIT)
1252           TLBI xxIS invalidate maintenance op !! 701 
1253           one more time to fix the issue.     !! 702 # Need comments to help the hapless user trying to turn on NUMA support
                                                   >> 703 comment "NUMA (NUMA-Q) requires SMP, 64GB highmem support"
                                                   >> 704         depends on X86_NUMAQ && (!HIGHMEM64G || !SMP)
1254                                                  705 
1255           If unsure, say Y.                   !! 706 comment "NUMA (Summit) requires SMP, 64GB highmem support, full ACPI"
                                                   >> 707         depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI || ACPI_HT_ONLY)
1256                                                  708 
1257 config QCOM_QDF2400_ERRATUM_0065              !! 709 config DISCONTIGMEM
1258         bool "QDF2400 E0065: Incorrect GITS_T !! 710         bool
                                                   >> 711         depends on NUMA
1259         default y                                712         default y
1260         help                                  << 
1261           On Qualcomm Datacenter Technologies << 
1262           ITE size incorrectly. The GITS_TYPE << 
1263           been indicated as 16Bytes (0xf), no << 
1264                                                  713 
1265           If unsure, say Y.                   !! 714 config HAVE_ARCH_BOOTMEM_NODE
1266                                               !! 715         bool
1267 config QCOM_FALKOR_ERRATUM_E1041              !! 716         depends on NUMA
1268         bool "Falkor E1041: Speculative instr << 
1269         default y                                717         default y
1270         help                                  << 
1271           Falkor CPU may speculatively fetch  << 
1272           memory location when MMU translatio << 
1273           to SCTLR_ELn[M]=0. Prefix an ISB in << 
1274                                                  718 
1275           If unsure, say Y.                   !! 719 config HIGHPTE
                                                   >> 720         bool "Allocate 3rd-level pagetables from highmem"
                                                   >> 721         depends on HIGHMEM4G || HIGHMEM64G
                                                   >> 722         help
                                                   >> 723           The VM uses one page table entry for each page of physical memory.
                                                   >> 724           For systems with a lot of RAM, this can be wasteful of precious
                                                   >> 725           low memory.  Setting this option will put user-space page table
                                                   >> 726           entries in high memory.
                                                   >> 727 
                                                   >> 728 config MATH_EMULATION
                                                   >> 729         bool "Math emulation"
                                                   >> 730         ---help---
                                                   >> 731           Linux can emulate a math coprocessor (used for floating point
                                                   >> 732           operations) if you don't have one. 486DX and Pentium processors have
                                                   >> 733           a math coprocessor built in, 486SX and 386 do not, unless you added
                                                   >> 734           a 487DX or 387, respectively. (The messages during boot time can
                                                   >> 735           give you some hints here ["man dmesg"].) Everyone needs either a
                                                   >> 736           coprocessor or this emulation.
                                                   >> 737 
                                                   >> 738           If you don't have a math coprocessor, you need to say Y here; if you
                                                   >> 739           say Y here even though you have a coprocessor, the coprocessor will
                                                   >> 740           be used nevertheless. (This behavior can be changed with the kernel
                                                   >> 741           command line option "no387", which comes handy if your coprocessor
                                                   >> 742           is broken. Try "man bootparam" or see the documentation of your boot
                                                   >> 743           loader (lilo or loadlin) about how to pass options to the kernel at
                                                   >> 744           boot time.) This means that it is a good idea to say Y here if you
                                                   >> 745           intend to use this kernel on different machines.
                                                   >> 746 
                                                   >> 747           More information about the internals of the Linux math coprocessor
                                                   >> 748           emulation can be found in <file:arch/i386/math-emu/README>.
                                                   >> 749 
                                                   >> 750           If you are not sure, say Y; apart from resulting in a 66 KB bigger
                                                   >> 751           kernel, it won't hurt.
                                                   >> 752 
                                                   >> 753 config MTRR
                                                   >> 754         bool "MTRR (Memory Type Range Register) support"
                                                   >> 755         ---help---
                                                   >> 756           On Intel P6 family processors (Pentium Pro, Pentium II and later)
                                                   >> 757           the Memory Type Range Registers (MTRRs) may be used to control
                                                   >> 758           processor access to memory ranges. This is most useful if you have
                                                   >> 759           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
                                                   >> 760           allows bus write transfers to be combined into a larger transfer
                                                   >> 761           before bursting over the PCI/AGP bus. This can increase performance
                                                   >> 762           of image write operations 2.5 times or more. Saying Y here creates a
                                                   >> 763           /proc/mtrr file which may be used to manipulate your processor's
                                                   >> 764           MTRRs. Typically the X server should use this.
                                                   >> 765 
                                                   >> 766           This code has a reasonably generic interface so that similar
                                                   >> 767           control registers on other processors can be easily supported
                                                   >> 768           as well:
                                                   >> 769 
                                                   >> 770           The Cyrix 6x86, 6x86MX and M II processors have Address Range
                                                   >> 771           Registers (ARRs) which provide a similar functionality to MTRRs. For
                                                   >> 772           these, the ARRs are used to emulate the MTRRs.
                                                   >> 773           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
                                                   >> 774           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
                                                   >> 775           write-combining. All of these processors are supported by this code
                                                   >> 776           and it makes sense to say Y here if you have one of them.
                                                   >> 777 
                                                   >> 778           Saying Y here also fixes a problem with buggy SMP BIOSes which only
                                                   >> 779           set the MTRRs for the boot CPU and not for the secondary CPUs. This
                                                   >> 780           can lead to all sorts of problems, so it's good to say Y here.
1276                                                  781 
1277 config NVIDIA_CARMEL_CNP_ERRATUM              !! 782           You can safely say Y even if your machine doesn't have MTRRs, you'll
1278         bool "NVIDIA Carmel CNP: CNP on Carme !! 783           just add about 9 KB to your kernel.
1279         default y                             << 
1280         help                                  << 
1281           If CNP is enabled on Carmel cores,  << 
1282           invalidate shared TLB entries insta << 
1283           on standard ARM cores.              << 
1284                                                  784 
1285           If unsure, say Y.                   !! 785           See <file:Documentation/mtrr.txt> for more information.
1286                                                  786 
1287 config ROCKCHIP_ERRATUM_3588001               !! 787 config HAVE_DEC_LOCK
1288         bool "Rockchip 3588001: GIC600 can no !! 788         bool
                                                   >> 789         depends on (SMP || PREEMPT) && X86_CMPXCHG
1289         default y                                790         default y
1290         help                                  << 
1291           The Rockchip RK3588 GIC600 SoC inte << 
1292           This means, that its sharability fe << 
1293           is supported by the IP itself.      << 
1294                                               << 
1295           If unsure, say Y.                   << 
1296                                                  791 
1297 config SOCIONEXT_SYNQUACER_PREITS             !! 792 # turning this on wastes a bunch of space.
1298         bool "Socionext Synquacer: Workaround !! 793 # Summit needs it only when NUMA is on
                                                   >> 794 config BOOT_IOREMAP
                                                   >> 795         bool
                                                   >> 796         depends on ((X86_SUMMIT || X86_GENERICARCH) && NUMA)
1299         default y                                797         default y
1300         help                                  << 
1301           Socionext Synquacer SoCs implement  << 
1302           MSI doorbell writes with non-zero v << 
1303                                               << 
1304           If unsure, say Y.                   << 
1305                                               << 
1306 endmenu # "ARM errata workarounds via the alt << 
1307                                               << 
1308 choice                                        << 
1309         prompt "Page size"                    << 
1310         default ARM64_4K_PAGES                << 
1311         help                                  << 
1312           Page size (translation granule) con << 
1313                                               << 
1314 config ARM64_4K_PAGES                         << 
1315         bool "4KB"                            << 
1316         select HAVE_PAGE_SIZE_4KB             << 
1317         help                                  << 
1318           This feature enables 4KB pages supp << 
1319                                               << 
1320 config ARM64_16K_PAGES                        << 
1321         bool "16KB"                           << 
1322         select HAVE_PAGE_SIZE_16KB            << 
1323         help                                  << 
1324           The system will use 16KB pages supp << 
1325           requires applications compiled with << 
1326           aligned segments.                   << 
1327                                               << 
1328 config ARM64_64K_PAGES                        << 
1329         bool "64KB"                           << 
1330         select HAVE_PAGE_SIZE_64KB            << 
1331         help                                  << 
1332           This feature enables 64KB pages sup << 
1333           allowing only two levels of page ta << 
1334           look-up. AArch32 emulation requires << 
1335           with 64K aligned segments.          << 
1336                                               << 
1337 endchoice                                     << 
1338                                               << 
1339 choice                                        << 
1340         prompt "Virtual address space size"   << 
1341         default ARM64_VA_BITS_52              << 
1342         help                                  << 
1343           Allows choosing one of multiple pos << 
1344           space sizes. The level of translati << 
1345           a combination of page size and virt << 
1346                                               << 
1347 config ARM64_VA_BITS_36                       << 
1348         bool "36-bit" if EXPERT               << 
1349         depends on PAGE_SIZE_16KB             << 
1350                                               << 
1351 config ARM64_VA_BITS_39                       << 
1352         bool "39-bit"                         << 
1353         depends on PAGE_SIZE_4KB              << 
1354                                               << 
1355 config ARM64_VA_BITS_42                       << 
1356         bool "42-bit"                         << 
1357         depends on PAGE_SIZE_64KB             << 
1358                                               << 
1359 config ARM64_VA_BITS_47                       << 
1360         bool "47-bit"                         << 
1361         depends on PAGE_SIZE_16KB             << 
1362                                               << 
1363 config ARM64_VA_BITS_48                       << 
1364         bool "48-bit"                         << 
1365                                               << 
1366 config ARM64_VA_BITS_52                       << 
1367         bool "52-bit"                         << 
1368         depends on ARM64_PAN || !ARM64_SW_TTB << 
1369         help                                  << 
1370           Enable 52-bit virtual addressing fo << 
1371           requested via a hint to mmap(). The << 
1372           virtual addresses for its own mappi << 
1373           this feature is available, otherwis << 
1374                                               << 
1375           NOTE: Enabling 52-bit virtual addre << 
1376           ARMv8.3 Pointer Authentication will << 
1377           reduced from 7 bits to 3 bits, whic << 
1378           impact on its susceptibility to bru << 
1379                                               << 
1380           If unsure, select 48-bit virtual ad << 
1381                                               << 
1382 endchoice                                     << 
1383                                               << 
1384 config ARM64_FORCE_52BIT                      << 
1385         bool "Force 52-bit virtual addresses  << 
1386         depends on ARM64_VA_BITS_52 && EXPERT << 
1387         help                                  << 
1388           For systems with 52-bit userspace V << 
1389           to maintain compatibility with olde << 
1390           unless a hint is supplied to mmap.  << 
1391                                               << 
1392           This configuration option disables  << 
1393           forces all userspace addresses to b << 
1394           should only enable this configurati << 
1395           memory management code. If unsure s << 
1396                                               << 
1397 config ARM64_VA_BITS                          << 
1398         int                                   << 
1399         default 36 if ARM64_VA_BITS_36        << 
1400         default 39 if ARM64_VA_BITS_39        << 
1401         default 42 if ARM64_VA_BITS_42        << 
1402         default 47 if ARM64_VA_BITS_47        << 
1403         default 48 if ARM64_VA_BITS_48        << 
1404         default 52 if ARM64_VA_BITS_52        << 
1405                                               << 
1406 choice                                        << 
1407         prompt "Physical address space size"  << 
1408         default ARM64_PA_BITS_48              << 
1409         help                                  << 
1410           Choose the maximum physical address << 
1411           support.                            << 
1412                                               << 
1413 config ARM64_PA_BITS_48                       << 
1414         bool "48-bit"                         << 
1415         depends on ARM64_64K_PAGES || !ARM64_ << 
1416                                               << 
1417 config ARM64_PA_BITS_52                       << 
1418         bool "52-bit"                         << 
1419         depends on ARM64_64K_PAGES || ARM64_V << 
1420         depends on ARM64_PAN || !ARM64_SW_TTB << 
1421         help                                  << 
1422           Enable support for a 52-bit physica << 
1423           part of the ARMv8.2-LPA extension.  << 
1424                                               << 
1425           With this enabled, the kernel will  << 
1426           do not support ARMv8.2-LPA, but wit << 
1427           minor performance overhead).        << 
1428                                               << 
1429 endchoice                                     << 
1430                                               << 
1431 config ARM64_PA_BITS                          << 
1432         int                                   << 
1433         default 48 if ARM64_PA_BITS_48        << 
1434         default 52 if ARM64_PA_BITS_52        << 
1435                                               << 
1436 config ARM64_LPA2                             << 
1437         def_bool y                            << 
1438         depends on ARM64_PA_BITS_52 && !ARM64 << 
1439                                               << 
1440 choice                                        << 
1441         prompt "Endianness"                   << 
1442         default CPU_LITTLE_ENDIAN             << 
1443         help                                  << 
1444           Select the endianness of data acces << 
1445           applications will need to be compil << 
1446           that is selected here.              << 
1447                                               << 
1448 config CPU_BIG_ENDIAN                         << 
1449         bool "Build big-endian kernel"        << 
1450         # https://github.com/llvm/llvm-projec << 
1451         depends on AS_IS_GNU || AS_VERSION >= << 
1452         help                                  << 
1453           Say Y if you plan on running a kern << 
1454                                               << 
1455 config CPU_LITTLE_ENDIAN                      << 
1456         bool "Build little-endian kernel"     << 
1457         help                                  << 
1458           Say Y if you plan on running a kern << 
1459           This is usually the case for distri << 
1460                                               << 
1461 endchoice                                     << 
1462                                               << 
1463 config SCHED_MC                               << 
1464         bool "Multi-core scheduler support"   << 
1465         help                                  << 
1466           Multi-core scheduler support improv << 
1467           making when dealing with multi-core << 
1468           increased overhead in some places.  << 
1469                                               << 
1470 config SCHED_CLUSTER                          << 
1471         bool "Cluster scheduler support"      << 
1472         help                                  << 
1473           Cluster scheduler support improves  << 
1474           making when dealing with machines t << 
1475           Cluster usually means a couple of C << 
1476           by sharing mid-level caches, last-l << 
1477           busses.                             << 
1478                                               << 
1479 config SCHED_SMT                              << 
1480         bool "SMT scheduler support"          << 
1481         help                                  << 
1482           Improves the CPU scheduler's decisi << 
1483           MultiThreading at a cost of slightl << 
1484           places. If unsure say N here.       << 
1485                                               << 
1486 config NR_CPUS                                << 
1487         int "Maximum number of CPUs (2-4096)" << 
1488         range 2 4096                          << 
1489         default "512"                         << 
1490                                               << 
1491 config HOTPLUG_CPU                            << 
1492         bool "Support for hot-pluggable CPUs" << 
1493         select GENERIC_IRQ_MIGRATION          << 
1494         help                                  << 
1495           Say Y here to experiment with turni << 
1496           can be controlled through /sys/devi << 
1497                                               << 
1498 # Common NUMA Features                        << 
1499 config NUMA                                   << 
1500         bool "NUMA Memory Allocation and Sche << 
1501         select GENERIC_ARCH_NUMA              << 
1502         select OF_NUMA                        << 
1503         select HAVE_SETUP_PER_CPU_AREA        << 
1504         select NEED_PER_CPU_EMBED_FIRST_CHUNK << 
1505         select NEED_PER_CPU_PAGE_FIRST_CHUNK  << 
1506         select USE_PERCPU_NUMA_NODE_ID        << 
1507         help                                  << 
1508           Enable NUMA (Non-Uniform Memory Acc << 
1509                                               << 
1510           The kernel will try to allocate mem << 
1511           local memory of the CPU and add som << 
1512           NUMA awareness to the kernel.       << 
1513                                               << 
1514 config NODES_SHIFT                            << 
1515         int "Maximum NUMA Nodes (as a power o << 
1516         range 1 10                            << 
1517         default "4"                           << 
1518         depends on NUMA                       << 
1519         help                                  << 
1520           Specify the maximum number of NUMA  << 
1521           system.  Increases memory reserved  << 
1522                                               << 
1523 source "kernel/Kconfig.hz"                    << 
1524                                               << 
1525 config ARCH_SPARSEMEM_ENABLE                  << 
1526         def_bool y                            << 
1527         select SPARSEMEM_VMEMMAP_ENABLE       << 
1528         select SPARSEMEM_VMEMMAP              << 
1529                                               << 
1530 config HW_PERF_EVENTS                         << 
1531         def_bool y                            << 
1532         depends on ARM_PMU                    << 
1533                                               << 
1534 # Supported by clang >= 7.0 or GCC >= 12.0.0  << 
1535 config CC_HAVE_SHADOW_CALL_STACK              << 
1536         def_bool $(cc-option, -fsanitize=shad << 
1537                                               << 
1538 config PARAVIRT                               << 
1539         bool "Enable paravirtualization code" << 
1540         help                                  << 
1541           This changes the kernel so it can m << 
1542           under a hypervisor, potentially imp << 
1543           over full virtualization.           << 
1544                                               << 
1545 config PARAVIRT_TIME_ACCOUNTING               << 
1546         bool "Paravirtual steal time accounti << 
1547         select PARAVIRT                       << 
1548         help                                  << 
1549           Select this option to enable fine g << 
1550           accounting. Time spent executing ot << 
1551           the current vCPU is discounted from << 
1552           that, there can be a small performa << 
1553                                               << 
1554           If in doubt, say N here.            << 
1555                                               << 
1556 config ARCH_SUPPORTS_KEXEC                    << 
1557         def_bool PM_SLEEP_SMP                 << 
1558                                               << 
1559 config ARCH_SUPPORTS_KEXEC_FILE               << 
1560         def_bool y                            << 
1561                                               << 
1562 config ARCH_SELECTS_KEXEC_FILE                << 
1563         def_bool y                            << 
1564         depends on KEXEC_FILE                 << 
1565         select HAVE_IMA_KEXEC if IMA          << 
1566                                               << 
1567 config ARCH_SUPPORTS_KEXEC_SIG                << 
1568         def_bool y                            << 
1569                                                  798 
1570 config ARCH_SUPPORTS_KEXEC_IMAGE_VERIFY_SIG   !! 799 endmenu
1571         def_bool y                            << 
1572                                                  800 
1573 config ARCH_DEFAULT_KEXEC_IMAGE_VERIFY_SIG    << 
1574         def_bool y                            << 
1575                                                  801 
1576 config ARCH_SUPPORTS_CRASH_DUMP               !! 802 menu "Power management options (ACPI, APM)"
1577         def_bool y                            !! 803         depends on !X86_VOYAGER
1578                                                  804 
1579 config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATI !! 805 source kernel/power/Kconfig
1580         def_bool CRASH_RESERVE                << 
1581                                                  806 
1582 config TRANS_TABLE                            !! 807 source "drivers/acpi/Kconfig"
1583         def_bool y                            << 
1584         depends on HIBERNATION || KEXEC_CORE  << 
1585                                               << 
1586 config XEN_DOM0                               << 
1587         def_bool y                            << 
1588         depends on XEN                        << 
1589                                               << 
1590 config XEN                                    << 
1591         bool "Xen guest support on ARM64"     << 
1592         depends on ARM64 && OF                << 
1593         select SWIOTLB_XEN                    << 
1594         select PARAVIRT                       << 
1595         help                                  << 
1596           Say Y if you want to run Linux in a << 
1597                                                  808 
1598 # include/linux/mmzone.h requires the followi !! 809 menu "APM (Advanced Power Management) BIOS Support"
1599 #                                             !! 810 depends on PM
1600 #   MAX_PAGE_ORDER + PAGE_SHIFT <= SECTION_SI << 
1601 #                                             << 
1602 # so the maximum value of MAX_PAGE_ORDER is S << 
1603 #                                             << 
1604 #     | SECTION_SIZE_BITS |  PAGE_SHIFT  |  m << 
1605 # ----+-------------------+--------------+--- << 
1606 # 4K  |       27          |      12      |    << 
1607 # 16K |       27          |      14      |    << 
1608 # 64K |       29          |      16      |    << 
1609 config ARCH_FORCE_MAX_ORDER                   << 
1610         int                                   << 
1611         default "13" if ARM64_64K_PAGES       << 
1612         default "11" if ARM64_16K_PAGES       << 
1613         default "10"                          << 
1614         help                                  << 
1615           The kernel page allocator limits th << 
1616           contiguous allocations. The limit i << 
1617           defines the maximal power of two of << 
1618           allocated as a single contiguous bl << 
1619           overriding the default setting when << 
1620           large blocks of physically contiguo << 
1621                                                  811 
1622           The maximal size of allocation cann !! 812 config APM
1623           section, so the value of MAX_PAGE_O !! 813         tristate "APM (Advanced Power Management) BIOS support"
                                                   >> 814         depends on PM
                                                   >> 815         ---help---
                                                   >> 816           APM is a BIOS specification for saving power using several different
                                                   >> 817           techniques. This is mostly useful for battery powered laptops with
                                                   >> 818           APM compliant BIOSes. If you say Y here, the system time will be
                                                   >> 819           reset after a RESUME operation, the /proc/apm device will provide
                                                   >> 820           battery status information, and user-space programs will receive
                                                   >> 821           notification of APM "events" (e.g. battery status change).
                                                   >> 822 
                                                   >> 823           If you select "Y" here, you can disable actual use of the APM
                                                   >> 824           BIOS by passing the "apm=off" option to the kernel at boot time.
                                                   >> 825 
                                                   >> 826           Note that the APM support is almost completely disabled for
                                                   >> 827           machines with more than one CPU.
                                                   >> 828 
                                                   >> 829           In order to use APM, you will need supporting software. For location
                                                   >> 830           and more information, read <file:Documentation/pm.txt> and the
                                                   >> 831           Battery Powered Linux mini-HOWTO, available from
                                                   >> 832           <http://www.tldp.org/docs.html#howto>.
                                                   >> 833 
                                                   >> 834           This driver does not spin down disk drives (see the hdparm(8)
                                                   >> 835           manpage ("man 8 hdparm") for that), and it doesn't turn off
                                                   >> 836           VESA-compliant "green" monitors.
                                                   >> 837 
                                                   >> 838           This driver does not support the TI 4000M TravelMate and the ACER
                                                   >> 839           486/DX4/75 because they don't have compliant BIOSes. Many "green"
                                                   >> 840           desktop machines also don't have compliant BIOSes, and this driver
                                                   >> 841           may cause those machines to panic during the boot phase.
                                                   >> 842 
                                                   >> 843           Generally, if you don't have a battery in your machine, there isn't
                                                   >> 844           much point in using this driver and you should say N. If you get
                                                   >> 845           random kernel OOPSes or reboots that don't seem to be related to
                                                   >> 846           anything, try disabling/enabling this option (or disabling/enabling
                                                   >> 847           APM in your BIOS).
                                                   >> 848 
                                                   >> 849           Some other things you should try when experiencing seemingly random,
                                                   >> 850           "weird" problems:
                                                   >> 851 
                                                   >> 852           1) make sure that you have enough swap space and that it is
                                                   >> 853           enabled.
                                                   >> 854           2) pass the "no-hlt" option to the kernel
                                                   >> 855           3) switch on floating point emulation in the kernel and pass
                                                   >> 856           the "no387" option to the kernel
                                                   >> 857           4) pass the "floppy=nodma" option to the kernel
                                                   >> 858           5) pass the "mem=4M" option to the kernel (thereby disabling
                                                   >> 859           all but the first 4 MB of RAM)
                                                   >> 860           6) make sure that the CPU is not over clocked.
                                                   >> 861           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
                                                   >> 862           8) disable the cache from your BIOS settings
                                                   >> 863           9) install a fan for the video card or exchange video RAM
                                                   >> 864           10) install a better fan for the CPU
                                                   >> 865           11) exchange RAM chips
                                                   >> 866           12) exchange the motherboard.
                                                   >> 867 
                                                   >> 868           To compile this driver as a module, choose M here: the
                                                   >> 869           module will be called apm.
                                                   >> 870 
                                                   >> 871 config APM_IGNORE_USER_SUSPEND
                                                   >> 872         bool "Ignore USER SUSPEND"
                                                   >> 873         depends on APM
                                                   >> 874         help
                                                   >> 875           This option will ignore USER SUSPEND requests. On machines with a
                                                   >> 876           compliant APM BIOS, you want to say N. However, on the NEC Versa M
                                                   >> 877           series notebooks, it is necessary to say Y because of a BIOS bug.
                                                   >> 878 
                                                   >> 879 config APM_DO_ENABLE
                                                   >> 880         bool "Enable PM at boot time"
                                                   >> 881         depends on APM
                                                   >> 882         ---help---
                                                   >> 883           Enable APM features at boot time. From page 36 of the APM BIOS
                                                   >> 884           specification: "When disabled, the APM BIOS does not automatically
                                                   >> 885           power manage devices, enter the Standby State, enter the Suspend
                                                   >> 886           State, or take power saving steps in response to CPU Idle calls."
                                                   >> 887           This driver will make CPU Idle calls when Linux is idle (unless this
                                                   >> 888           feature is turned off -- see "Do CPU IDLE calls", below). This
                                                   >> 889           should always save battery power, but more complicated APM features
                                                   >> 890           will be dependent on your BIOS implementation. You may need to turn
                                                   >> 891           this option off if your computer hangs at boot time when using APM
                                                   >> 892           support, or if it beeps continuously instead of suspending. Turn
                                                   >> 893           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
                                                   >> 894           T400CDT. This is off by default since most machines do fine without
                                                   >> 895           this feature.
1624                                                  896 
1625             MAX_PAGE_ORDER + PAGE_SHIFT <= SE !! 897 config APM_CPU_IDLE
                                                   >> 898         bool "Make CPU Idle calls when idle"
                                                   >> 899         depends on APM
                                                   >> 900         help
                                                   >> 901           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
                                                   >> 902           On some machines, this can activate improved power savings, such as
                                                   >> 903           a slowed CPU clock rate, when the machine is idle. These idle calls
                                                   >> 904           are made after the idle loop has run for some length of time (e.g.,
                                                   >> 905           333 mS). On some machines, this will cause a hang at boot time or
                                                   >> 906           whenever the CPU becomes idle. (On machines with more than one CPU,
                                                   >> 907           this option does nothing.)
                                                   >> 908 
                                                   >> 909 config APM_DISPLAY_BLANK
                                                   >> 910         bool "Enable console blanking using APM"
                                                   >> 911         depends on APM
                                                   >> 912         help
                                                   >> 913           Enable console blanking using the APM. Some laptops can use this to
                                                   >> 914           turn off the LCD backlight when the screen blanker of the Linux
                                                   >> 915           virtual console blanks the screen. Note that this is only used by
                                                   >> 916           the virtual console screen blanker, and won't turn off the backlight
                                                   >> 917           when using the X Window system. This also doesn't have anything to
                                                   >> 918           do with your VESA-compliant power-saving monitor. Further, this
                                                   >> 919           option doesn't work for all laptops -- it might not turn off your
                                                   >> 920           backlight at all, or it might print a lot of errors to the console,
                                                   >> 921           especially if you are using gpm.
                                                   >> 922 
                                                   >> 923 config APM_RTC_IS_GMT
                                                   >> 924         bool "RTC stores time in GMT"
                                                   >> 925         depends on APM
                                                   >> 926         help
                                                   >> 927           Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
                                                   >> 928           stores the time in GMT (Greenwich Mean Time). Say N if your RTC
                                                   >> 929           stores localtime.
                                                   >> 930 
                                                   >> 931           It is in fact recommended to store GMT in your RTC, because then you
                                                   >> 932           don't have to worry about daylight savings time changes. The only
                                                   >> 933           reason not to use GMT in your RTC is if you also run a broken OS
                                                   >> 934           that doesn't understand GMT.
                                                   >> 935 
                                                   >> 936 config APM_ALLOW_INTS
                                                   >> 937         bool "Allow interrupts during APM BIOS calls"
                                                   >> 938         depends on APM
                                                   >> 939         help
                                                   >> 940           Normally we disable external interrupts while we are making calls to
                                                   >> 941           the APM BIOS as a measure to lessen the effects of a badly behaving
                                                   >> 942           BIOS implementation.  The BIOS should reenable interrupts if it
                                                   >> 943           needs to.  Unfortunately, some BIOSes do not -- especially those in
                                                   >> 944           many of the newer IBM Thinkpads.  If you experience hangs when you
                                                   >> 945           suspend, try setting this to Y.  Otherwise, say N.
                                                   >> 946 
                                                   >> 947 config APM_REAL_MODE_POWER_OFF
                                                   >> 948         bool "Use real mode APM BIOS call to power off"
                                                   >> 949         depends on APM
                                                   >> 950         help
                                                   >> 951           Use real mode APM BIOS calls to switch off the computer. This is
                                                   >> 952           a work-around for a number of buggy BIOSes. Switch this option on if
                                                   >> 953           your computer crashes instead of powering off properly.
                                                   >> 954 
                                                   >> 955 endmenu
1626                                                  956 
1627           Don't change if unsure.             !! 957 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
1628                                                  958 
1629 config UNMAP_KERNEL_AT_EL0                    !! 959 endmenu
1630         bool "Unmap kernel when running in us << 
1631         default y                             << 
1632         help                                  << 
1633           Speculation attacks against some hi << 
1634           be used to bypass MMU permission ch << 
1635           userspace. This can be defended aga << 
1636           when running in userspace, mapping  << 
1637           via a trampoline page in the vector << 
1638                                                  960 
1639           If unsure, say Y.                   << 
1640                                                  961 
1641 config MITIGATE_SPECTRE_BRANCH_HISTORY        !! 962 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
1642         bool "Mitigate Spectre style attacks  << 
1643         default y                             << 
1644         help                                  << 
1645           Speculation attacks against some hi << 
1646           make use of branch history to influ << 
1647           When taking an exception from user- << 
1648           or a firmware call overwrites the b << 
1649                                                  963 
1650 config RODATA_FULL_DEFAULT_ENABLED            !! 964 config X86_VISWS_APIC
1651         bool "Apply r/o permissions of VM are !! 965         bool
                                                   >> 966         depends on X86_VISWS
1652         default y                                967         default y
1653         help                                  << 
1654           Apply read-only attributes of VM ar << 
1655           the backing pages as well. This pre << 
1656           from being modified (inadvertently  << 
1657           mapping of the same memory page. Th << 
1658           be turned off at runtime by passing << 
1659           with rodata=full if this option is  << 
1660                                               << 
1661           This requires the linear region to  << 
1662           which may adversely affect performa << 
1663                                               << 
1664 config ARM64_SW_TTBR0_PAN                     << 
1665         bool "Emulate Privileged Access Never << 
1666         depends on !KCSAN                     << 
1667         help                                  << 
1668           Enabling this option prevents the k << 
1669           user-space memory directly by point << 
1670           zeroed area and reserved ASID. The  << 
1671           restore the valid TTBR0_EL1 tempora << 
1672                                                  968 
1673 config ARM64_TAGGED_ADDR_ABI                  !! 969 config X86_LOCAL_APIC
1674         bool "Enable the tagged user addresse !! 970         bool
                                                   >> 971         depends on (X86_VISWS || SMP) && !X86_VOYAGER
1675         default y                                972         default y
1676         help                                  << 
1677           When this option is enabled, user a << 
1678           relaxed ABI via prctl() allowing ta << 
1679           to system calls as pointer argument << 
1680           Documentation/arch/arm64/tagged-add << 
1681                                                  973 
1682 menuconfig COMPAT                             !! 974 config X86_IO_APIC
1683         bool "Kernel support for 32-bit EL0"  !! 975         bool
1684         depends on ARM64_4K_PAGES || EXPERT   !! 976         depends on SMP && !(X86_VISWS || X86_VOYAGER)
1685         select HAVE_UID16                     << 
1686         select OLD_SIGSUSPEND3                << 
1687         select COMPAT_OLD_SIGACTION           << 
1688         help                                  << 
1689           This option enables support for a 3 << 
1690           kernel at EL1. AArch32-specific com << 
1691           the user helper functions, VFP supp << 
1692           handled appropriately by the kernel << 
1693                                               << 
1694           If you use a page size other than 4 << 
1695           that you will only be able to execu << 
1696           with page size aligned segments.    << 
1697                                               << 
1698           If you want to execute 32-bit users << 
1699                                               << 
1700 if COMPAT                                     << 
1701                                               << 
1702 config KUSER_HELPERS                          << 
1703         bool "Enable kuser helpers page for 3 << 
1704         default y                                977         default y
1705         help                                  << 
1706           Warning: disabling this option may  << 
1707                                                  978 
1708           Provide kuser helpers to compat tas !! 979 config PCI
1709           helper code to userspace in read on !! 980         bool "PCI support" if !X86_VISWS
1710           to allow userspace to be independen !! 981         depends on !X86_VOYAGER
1711           the system. This permits binaries t !! 982         default y if X86_VISWS
1712           to ARMv8 without modification.      !! 983         help
                                                   >> 984           Find out whether you have a PCI motherboard. PCI is the name of a
                                                   >> 985           bus system, i.e. the way the CPU talks to the other stuff inside
                                                   >> 986           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
                                                   >> 987           VESA. If you have PCI, say Y, otherwise N.
                                                   >> 988 
                                                   >> 989           The PCI-HOWTO, available from
                                                   >> 990           <http://www.tldp.org/docs.html#howto>, contains valuable
                                                   >> 991           information about which PCI hardware does work under Linux and which
                                                   >> 992           doesn't.
1713                                                  993 
1714           See Documentation/arch/arm/kernel_u !! 994 choice
                                                   >> 995         prompt "PCI access mode"
                                                   >> 996         depends on PCI && !X86_VISWS
                                                   >> 997         default PCI_GOANY
                                                   >> 998 
                                                   >> 999 config PCI_GOBIOS
                                                   >> 1000         bool "BIOS"
                                                   >> 1001         ---help---
                                                   >> 1002           On PCI systems, the BIOS can be used to detect the PCI devices and
                                                   >> 1003           determine their configuration. However, some old PCI motherboards
                                                   >> 1004           have BIOS bugs and may crash if this is done. Also, some embedded
                                                   >> 1005           PCI-based systems don't have any BIOS at all. Linux can also try to
                                                   >> 1006           detect the PCI hardware directly without using the BIOS.
                                                   >> 1007 
                                                   >> 1008           With this option, you can specify how Linux should detect the PCI
                                                   >> 1009           devices. If you choose "BIOS", the BIOS will be used, if you choose
                                                   >> 1010           "Direct", the BIOS won't be used, and if you choose "Any", the
                                                   >> 1011           kernel will try the direct access method and falls back to the BIOS
                                                   >> 1012           if that doesn't work. If unsure, go with the default, which is
                                                   >> 1013           "Any".
1715                                                  1014 
1716           However, the fixed address nature o !! 1015 config PCI_GODIRECT
1717           by ROP (return orientated programmi !! 1016         bool "Direct"
1718           exploits.                           << 
1719                                                  1017 
1720           If all of the binaries and librarie !! 1018 config PCI_GOANY
1721           are built specifically for your pla !! 1019         bool "Any"
1722           these helpers, then you can turn th << 
1723           such exploits. However, in that cas << 
1724           relying on those helpers is run, it << 
1725                                                  1020 
1726           Say N here only if you are absolute !! 1021 endchoice
1727           need these helpers; otherwise, the  << 
1728                                                  1022 
1729 config COMPAT_VDSO                            !! 1023 config PCI_BIOS
1730         bool "Enable vDSO for 32-bit applicat !! 1024         bool
1731         depends on !CPU_BIG_ENDIAN            !! 1025         depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1732         depends on (CC_IS_CLANG && LD_IS_LLD) << 
1733         select GENERIC_COMPAT_VDSO            << 
1734         default y                                1026         default y
1735         help                                  << 
1736           Place in the process address space  << 
1737           ELF shared object providing fast im << 
1738           and clock_gettime.                  << 
1739                                                  1027 
1740           You must have a 32-bit build of gli !! 1028 config PCI_DIRECT
1741           to seamlessly take advantage of thi !! 1029         bool
1742                                               !! 1030         depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1743 config THUMB2_COMPAT_VDSO                     << 
1744         bool "Compile the 32-bit vDSO for Thu << 
1745         depends on COMPAT_VDSO                << 
1746         default y                                1031         default y
1747         help                                  << 
1748           Compile the compat vDSO with '-mthu << 
1749           otherwise with '-marm'.             << 
1750                                                  1032 
1751 config COMPAT_ALIGNMENT_FIXUPS                !! 1033 source "drivers/pci/Kconfig"
1752         bool "Fix up misaligned multi-word lo << 
1753                                                  1034 
1754 menuconfig ARMV8_DEPRECATED                   !! 1035 config ISA
1755         bool "Emulate deprecated/obsolete ARM !! 1036         bool "ISA support"
1756         depends on SYSCTL                     !! 1037         depends on !(X86_VOYAGER || X86_VISWS)
1757         help                                     1038         help
1758           Legacy software support may require !! 1039           Find out whether you have ISA slots on your motherboard.  ISA is the
1759           that have been deprecated or obsole !! 1040           name of a bus system, i.e. the way the CPU talks to the other stuff
1760                                               !! 1041           inside your box.  Other bus systems are PCI, EISA, MicroChannel
1761           Enable this config to enable select !! 1042           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1762           features.                           !! 1043           newer boards don't support it.  If you have ISA, say Y, otherwise N.
1763                                                  1044 
1764           If unsure, say Y                    !! 1045 config EISA
                                                   >> 1046         bool "EISA support"
                                                   >> 1047         depends on ISA
                                                   >> 1048         ---help---
                                                   >> 1049           The Extended Industry Standard Architecture (EISA) bus was
                                                   >> 1050           developed as an open alternative to the IBM MicroChannel bus.
1765                                                  1051 
1766 if ARMV8_DEPRECATED                           !! 1052           The EISA bus provided some of the features of the IBM MicroChannel
                                                   >> 1053           bus while maintaining backward compatibility with cards made for
                                                   >> 1054           the older ISA bus.  The EISA bus saw limited use between 1988 and
                                                   >> 1055           1995 when it was made obsolete by the PCI bus.
1767                                                  1056 
1768 config SWP_EMULATION                          !! 1057           Say Y here if you are building a kernel for an EISA-based machine.
1769         bool "Emulate SWP/SWPB instructions"  << 
1770         help                                  << 
1771           ARMv8 obsoletes the use of A32 SWP/ << 
1772           they are always undefined. Say Y he << 
1773           emulation of these instructions for << 
1774           This feature can be controlled at r << 
1775           sysctl which is disabled by default << 
1776                                                  1058 
1777           In some older versions of glibc [<= !! 1059           Otherwise, say N.
1778           trylock() operations with the assum << 
1779           be preempted. This invalid assumpti << 
1780           with SWP emulation enabled, leading << 
1781           application.                        << 
1782                                                  1060 
1783           NOTE: when accessing uncached share !! 1061 source "drivers/eisa/Kconfig"
1784           on an external transaction monitori << 
1785           monitor to maintain update atomicit << 
1786           implement a global monitor, this op << 
1787           perform SWP operations to uncached  << 
1788                                                  1062 
1789           If unsure, say Y                    !! 1063 config MCA
1790                                               !! 1064         bool "MCA support"
1791 config CP15_BARRIER_EMULATION                 !! 1065         depends on !(X86_VISWS || X86_VOYAGER)
1792         bool "Emulate CP15 Barrier instructio << 
1793         help                                     1066         help
1794           The CP15 barrier instructions - CP1 !! 1067           MicroChannel Architecture is found in some IBM PS/2 machines and
1795           CP15DMB - are deprecated in ARMv8 ( !! 1068           laptops.  It is a bus system similar to PCI or ISA. See
1796           strongly recommended to use the ISB !! 1069           <file:Documentation/mca.txt> (and especially the web page given
1797           instructions instead.               !! 1070           there) before attempting to build an MCA bus kernel.
1798                                                  1071 
1799           Say Y here to enable software emula !! 1072 config MCA
1800           instructions for AArch32 userspace  !! 1073         depends on X86_VOYAGER
1801           enabled, CP15 barrier usage is trac !! 1074         default y if X86_VOYAGER
1802           identify software that needs updati << 
1803           controlled at runtime with the abi. << 
1804                                                  1075 
1805           If unsure, say Y                    !! 1076 source "drivers/mca/Kconfig"
1806                                                  1077 
1807 config SETEND_EMULATION                       !! 1078 config SCx200
1808         bool "Emulate SETEND instruction"     !! 1079         tristate "NatSemi SCx200 support"
                                                   >> 1080         depends on !X86_VOYAGER
1809         help                                     1081         help
1810           The SETEND instruction alters the d !! 1082           This provides basic support for the National Semiconductor SCx200 
1811           AArch32 EL0, and is deprecated in A !! 1083           processor.  Right now this is just a driver for the GPIO pins.
1812                                                  1084 
1813           Say Y here to enable software emula !! 1085           If you don't know what to do here, say N.
1814           for AArch32 userspace code. This fe << 
1815           at runtime with the abi.setend sysc << 
1816                                                  1086 
1817           Note: All the cpus on the system mu !! 1087           This support is also available as a module.  If compiled as a
1818           for this feature to be enabled. If  !! 1088           module, it will be called scx200.
1819           endian - is hotplugged in after thi << 
1820           be unexpected results in the applic << 
1821                                                  1089 
1822           If unsure, say Y                    !! 1090 config HOTPLUG
1823 endif # ARMV8_DEPRECATED                      !! 1091         bool "Support for hot-pluggable devices"
                                                   >> 1092         ---help---
                                                   >> 1093           Say Y here if you want to plug devices into your computer while
                                                   >> 1094           the system is running, and be able to use them quickly.  In many
                                                   >> 1095           cases, the devices can likewise be unplugged at any time too.
1824                                                  1096 
1825 endif # COMPAT                                !! 1097           One well known example of this is PCMCIA- or PC-cards, credit-card
                                                   >> 1098           size devices such as network cards, modems or hard drives which are
                                                   >> 1099           plugged into slots found on all modern laptop computers.  Another
                                                   >> 1100           example, used on modern desktops as well as laptops, is USB.
1826                                                  1101 
1827 menu "ARMv8.1 architectural features"         !! 1102           Enable HOTPLUG and KMOD, and build a modular kernel.  Get agent
                                                   >> 1103           software (at <http://linux-hotplug.sourceforge.net/>) and install it.
                                                   >> 1104           Then your kernel will automatically call out to a user mode "policy
                                                   >> 1105           agent" (/sbin/hotplug) to load modules and set up software needed
                                                   >> 1106           to use devices as you hotplug them.
1828                                                  1107 
1829 config ARM64_HW_AFDBM                         !! 1108 source "drivers/pcmcia/Kconfig"
1830         bool "Support for hardware updates of << 
1831         default y                             << 
1832         help                                  << 
1833           The ARMv8.1 architecture extensions << 
1834           hardware updates of the access and  << 
1835           table entries. When enabled in TCR_ << 
1836           capable processors, accesses to pag << 
1837           set this bit instead of raising an  << 
1838           Similarly, writes to read-only page << 
1839           clear the read-only bit (AP[2]) ins << 
1840           permission fault.                   << 
1841                                                  1109 
1842           Kernels built with this configurati !! 1110 source "drivers/pci/hotplug/Kconfig"
1843           to work on pre-ARMv8.1 hardware and << 
1844           minimal. If unsure, say Y.          << 
1845                                                  1111 
1846 config ARM64_PAN                              !! 1112 endmenu
1847         bool "Enable support for Privileged A << 
1848         default y                             << 
1849         help                                  << 
1850           Privileged Access Never (PAN; part  << 
1851           prevents the kernel or hypervisor f << 
1852           memory directly.                    << 
1853                                               << 
1854           Choosing this option will cause any << 
1855           copy_to_user et al) memory access t << 
1856                                                  1113 
1857           The feature is detected at runtime, << 
1858           instruction if the cpu does not imp << 
1859                                                  1114 
1860 config AS_HAS_LSE_ATOMICS                     !! 1115 menu "Executable file formats"
1861         def_bool $(as-instr,.arch_extension l << 
1862                                                  1116 
1863 config ARM64_LSE_ATOMICS                      !! 1117 source "fs/Kconfig.binfmt"
1864         bool                                  << 
1865         default ARM64_USE_LSE_ATOMICS         << 
1866         depends on AS_HAS_LSE_ATOMICS         << 
1867                                                  1118 
1868 config ARM64_USE_LSE_ATOMICS                  !! 1119 endmenu
1869         bool "Atomic instructions"            << 
1870         default y                             << 
1871         help                                  << 
1872           As part of the Large System Extensi << 
1873           atomic instructions that are design << 
1874           very large systems.                 << 
1875                                                  1120 
1876           Say Y here to make use of these ins !! 1121 source "drivers/Kconfig"
1877           atomic routines. This incurs a smal << 
1878           not support these instructions and  << 
1879           built with binutils >= 2.25 in orde << 
1880           to be used.                         << 
1881                                                  1122 
1882 endmenu # "ARMv8.1 architectural features"    !! 1123 source "fs/Kconfig"
1883                                                  1124 
1884 menu "ARMv8.2 architectural features"         !! 1125 source "arch/i386/oprofile/Kconfig"
1885                                                  1126 
1886 config AS_HAS_ARMV8_2                         << 
1887         def_bool $(cc-option,-Wa$(comma)-marc << 
1888                                                  1127 
1889 config AS_HAS_SHA3                            !! 1128 menu "Kernel hacking"
1890         def_bool $(as-instr,.arch armv8.2-a+s << 
1891                                                  1129 
1892 config ARM64_PMEM                             !! 1130 config DEBUG_KERNEL
1893         bool "Enable support for persistent m !! 1131         bool "Kernel debugging"
1894         select ARCH_HAS_PMEM_API              << 
1895         select ARCH_HAS_UACCESS_FLUSHCACHE    << 
1896         help                                     1132         help
1897           Say Y to enable support for the per !! 1133           Say Y here if you are developing drivers or trying to debug and
1898           ARMv8.2 DCPoP feature.              !! 1134           identify kernel problems.
1899                                                  1135 
1900           The feature is detected at runtime, !! 1136 config DEBUG_STACKOVERFLOW
1901           operations if DC CVAP is not suppor !! 1137         bool "Check for stack overflows"
1902           DC CVAP itself if the system does n !! 1138         depends on DEBUG_KERNEL
1903                                                  1139 
1904 config ARM64_RAS_EXTN                         !! 1140 config DEBUG_SLAB
1905         bool "Enable support for RAS CPU Exte !! 1141         bool "Debug memory allocations"
1906         default y                             !! 1142         depends on DEBUG_KERNEL
1907         help                                     1143         help
1908           CPUs that support the Reliability,  !! 1144           Say Y here to have the kernel do limited verification on memory
1909           (RAS) Extensions, part of ARMv8.2 a !! 1145           allocation as well as poisoning memory on free to catch use of freed
1910           errors, classify them and report th !! 1146           memory.
1911                                               << 
1912           On CPUs with these extensions syste << 
1913           barriers to determine if faults are << 
1914           classification from a new set of re << 
1915                                                  1147 
1916           Selecting this feature will allow t !! 1148 config DEBUG_IOVIRT
1917           and access the new registers if the !! 1149         bool "Memory mapped I/O debugging"
1918           Platform RAS features may additiona !! 1150         depends on DEBUG_KERNEL
1919                                               << 
1920 config ARM64_CNP                              << 
1921         bool "Enable support for Common Not P << 
1922         default y                             << 
1923         depends on ARM64_PAN || !ARM64_SW_TTB << 
1924         help                                     1151         help
1925           Common Not Private (CNP) allows tra !! 1152           Say Y here to get warned whenever an attempt is made to do I/O on
1926           be shared between different PEs in  !! 1153           obviously invalid addresses such as those generated when ioremap()
1927           domain, so the hardware can use thi !! 1154           calls are forgotten.  Memory mapped I/O will go through an extra
1928           caching of such entries in the TLB. !! 1155           check to catch access to unmapped ISA addresses, an access method
                                                   >> 1156           that can still be used by old drivers that are being ported from
                                                   >> 1157           2.0/2.2.
1929                                                  1158 
1930           Selecting this option allows the CN !! 1159 config MAGIC_SYSRQ
1931           at runtime, and does not affect PEs !! 1160         bool "Magic SysRq key"
1932           this feature.                       !! 1161         depends on DEBUG_KERNEL
1933                                               << 
1934 endmenu # "ARMv8.2 architectural features"    << 
1935                                               << 
1936 menu "ARMv8.3 architectural features"         << 
1937                                               << 
1938 config ARM64_PTR_AUTH                         << 
1939         bool "Enable support for pointer auth << 
1940         default y                             << 
1941         help                                     1162         help
1942           Pointer authentication (part of the !! 1163           If you say Y here, you will have some control over the system even
1943           instructions for signing and authen !! 1164           if the system crashes for example during kernel debugging (e.g., you
1944           keys, which can be used to mitigate !! 1165           will be able to flush the buffer cache to disk, reboot the system
1945           and other attacks.                  !! 1166           immediately or dump some status information). This is accomplished
                                                   >> 1167           by pressing various keys while holding SysRq (Alt+PrintScreen). It
                                                   >> 1168           also works on a serial console (on PC hardware at least), if you
                                                   >> 1169           send a BREAK and then within 5 seconds a command keypress. The
                                                   >> 1170           keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
                                                   >> 1171           unless you really know what this hack does.
1946                                                  1172 
1947           This option enables these instructi !! 1173 config DEBUG_SPINLOCK
1948           Choosing this option will cause the !! 1174         bool "Spinlock debugging"
1949           for each process at exec() time, wi !! 1175         depends on DEBUG_KERNEL
1950           context-switched along with the pro << 
1951                                               << 
1952           The feature is detected at runtime. << 
1953           hardware it will not be advertised  << 
1954           be enabled.                         << 
1955                                               << 
1956           If the feature is present on the bo << 
1957           the late CPU will be parked. Also,  << 
1958           address auth and the late CPU has t << 
1959           but with the feature disabled. On s << 
1960           not be selected.                    << 
1961                                               << 
1962 config ARM64_PTR_AUTH_KERNEL                  << 
1963         bool "Use pointer authentication for  << 
1964         default y                             << 
1965         depends on ARM64_PTR_AUTH             << 
1966         depends on (CC_HAS_SIGN_RETURN_ADDRES << 
1967         # Modern compilers insert a .note.gnu << 
1968         # which is only understood by binutil << 
1969         depends on LD_IS_LLD || LD_VERSION >= << 
1970         depends on !CC_IS_CLANG || AS_HAS_CFI << 
1971         depends on (!FUNCTION_GRAPH_TRACER || << 
1972         help                                     1176         help
1973           If the compiler supports the -mbran !! 1177           Say Y here and build SMP to catch missing spinlock initialization
1974           -msign-return-address flag (e.g. GC !! 1178           and certain other kinds of spinlock errors commonly made.  This is
1975           will cause the kernel itself to be  !! 1179           best used in conjunction with the NMI watchdog so that spinlock
1976           protection. In this case, and if th !! 1180           deadlocks are also debuggable.
1977           support pointer authentication, the << 
1978           disabled with minimal loss of prote << 
1979                                               << 
1980           This feature works with FUNCTION_GR << 
1981           DYNAMIC_FTRACE_WITH_ARGS is enabled << 
1982                                               << 
1983 config CC_HAS_BRANCH_PROT_PAC_RET             << 
1984         # GCC 9 or later, clang 8 or later    << 
1985         def_bool $(cc-option,-mbranch-protect << 
1986                                               << 
1987 config CC_HAS_SIGN_RETURN_ADDRESS             << 
1988         # GCC 7, 8                            << 
1989         def_bool $(cc-option,-msign-return-ad << 
1990                                               << 
1991 config AS_HAS_ARMV8_3                         << 
1992         def_bool $(cc-option,-Wa$(comma)-marc << 
1993                                               << 
1994 config AS_HAS_CFI_NEGATE_RA_STATE             << 
1995         def_bool $(as-instr,.cfi_startproc\n. << 
1996                                               << 
1997 config AS_HAS_LDAPR                           << 
1998         def_bool $(as-instr,.arch_extension r << 
1999                                               << 
2000 endmenu # "ARMv8.3 architectural features"    << 
2001                                                  1181 
2002 menu "ARMv8.4 architectural features"         !! 1182 config DEBUG_PAGEALLOC
2003                                               !! 1183         bool "Page alloc debugging"
2004 config ARM64_AMU_EXTN                         !! 1184         depends on DEBUG_KERNEL
2005         bool "Enable support for the Activity << 
2006         default y                             << 
2007         help                                     1185         help
2008           The activity monitors extension is  !! 1186           Unmap pages from the kernel linear mapping after free_pages().
2009           by the ARMv8.4 CPU architecture. Th !! 1187           This results in a large slowdown, but helps to find certain types
2010           of the activity monitors architectu !! 1188           of memory corruptions.
2011                                               << 
2012           To enable the use of this extension << 
2013                                               << 
2014           Note that for architectural reasons << 
2015           support when running on CPUs that p << 
2016           extension. The required support is  << 
2017             * Version 1.5 and later of the AR << 
2018                                                  1189 
2019           For kernels that have this configur !! 1190 config DEBUG_HIGHMEM
2020           firmware, you may need to say N her !! 1191         bool "Highmem debugging"
2021           Otherwise you may experience firmwa !! 1192         depends on DEBUG_KERNEL && HIGHMEM
2022           accessing the counter registers. Ev << 
2023           symptoms, the values returned by th << 
2024           correctly reflect reality. Most com << 
2025           indicating that the counter is not  << 
2026                                               << 
2027 config AS_HAS_ARMV8_4                         << 
2028         def_bool $(cc-option,-Wa$(comma)-marc << 
2029                                               << 
2030 config ARM64_TLB_RANGE                        << 
2031         bool "Enable support for tlbi range f << 
2032         default y                             << 
2033         depends on AS_HAS_ARMV8_4             << 
2034         help                                     1193         help
2035           ARMv8.4-TLBI provides TLBI invalida !! 1194           This options enables addition error checking for high memory systems.
2036           range of input addresses.           !! 1195           Disable for production systems.
2037                                               << 
2038           The feature introduces new assembly << 
2039           support when binutils >= 2.30.      << 
2040                                                  1196 
2041 endmenu # "ARMv8.4 architectural features"    !! 1197 config DEBUG_INFO
2042                                               !! 1198         bool "Compile the kernel with debug info"
2043 menu "ARMv8.5 architectural features"         !! 1199         depends on DEBUG_KERNEL
2044                                               << 
2045 config AS_HAS_ARMV8_5                         << 
2046         def_bool $(cc-option,-Wa$(comma)-marc << 
2047                                               << 
2048 config ARM64_BTI                              << 
2049         bool "Branch Target Identification su << 
2050         default y                             << 
2051         help                                     1200         help
2052           Branch Target Identification (part  !! 1201           If you say Y here the resulting kernel image will include
2053           provides a mechanism to limit the s !! 1202           debugging info resulting in a larger kernel image.
2054           branch instructions such as BR or B !! 1203           Say Y here only if you plan to use gdb to debug the kernel.
2055                                               !! 1204           If you don't debug the kernel, you can say N.
2056           To make use of BTI on CPUs that sup !! 1205           
2057                                               !! 1206 config DEBUG_SPINLOCK_SLEEP
2058           BTI is intended to provide compleme !! 1207         bool "Sleep-inside-spinlock checking"
2059           flow integrity protection mechanism << 
2060           authentication mechanism provided a << 
2061           For this reason, it does not make s << 
2062           also enabling support for pointer a << 
2063           enabling this option you should als << 
2064                                               << 
2065           Userspace binaries must also be spe << 
2066           this mechanism.  If you say N here  << 
2067           BTI, such binaries can still run, b << 
2068           enforcement of branch destinations. << 
2069                                               << 
2070 config ARM64_BTI_KERNEL                       << 
2071         bool "Use Branch Target Identificatio << 
2072         default y                             << 
2073         depends on ARM64_BTI                  << 
2074         depends on ARM64_PTR_AUTH_KERNEL      << 
2075         depends on CC_HAS_BRANCH_PROT_PAC_RET << 
2076         # https://gcc.gnu.org/bugzilla/show_b << 
2077         depends on !CC_IS_GCC || GCC_VERSION  << 
2078         # https://gcc.gnu.org/bugzilla/show_b << 
2079         depends on !CC_IS_GCC                 << 
2080         depends on (!FUNCTION_GRAPH_TRACER || << 
2081         help                                     1208         help
2082           Build the kernel with Branch Target !! 1209           If you say Y here, various routines which may sleep will become very
2083           and enable enforcement of this for  !! 1210           noisy if they are called with a spinlock held.        
2084           is enabled and the system supports  << 
2085           modular code must have BTI enabled. << 
2086                                                  1211 
2087 config CC_HAS_BRANCH_PROT_PAC_RET_BTI         !! 1212 config FRAME_POINTER
2088         # GCC 9 or later, clang 8 or later    !! 1213         bool "Compile the kernel with frame pointers"
2089         def_bool $(cc-option,-mbranch-protect << 
2090                                               << 
2091 config ARM64_E0PD                             << 
2092         bool "Enable support for E0PD"        << 
2093         default y                             << 
2094         help                                     1214         help
2095           E0PD (part of the ARMv8.5 extension !! 1215           If you say Y here the resulting kernel image will be slightly larger
2096           that EL0 accesses made via TTBR1 al !! 1216           and slower, but it will give very useful debugging information.
2097           providing similar benefits to KASLR !! 1217           If you don't debug the kernel, you can say N, but we may not be able
2098           with lower overhead and without dis !! 1218           to solve problems without frame pointers.
2099           kernel memory such as SPE.          << 
2100                                               << 
2101           This option enables E0PD for TTBR1  << 
2102                                               << 
2103 config ARM64_AS_HAS_MTE                       << 
2104         # Initial support for MTE went in bin << 
2105         # ".arch armv8.5-a+memtag" below. How << 
2106         # as a late addition to the final arc << 
2107         # is only supported in the newer 2.32 << 
2108         # versions, hence the extra "stgm" in << 
2109         def_bool $(as-instr,.arch armv8.5-a+m << 
2110                                               << 
2111 config ARM64_MTE                              << 
2112         bool "Memory Tagging Extension suppor << 
2113         default y                             << 
2114         depends on ARM64_AS_HAS_MTE && ARM64_ << 
2115         depends on AS_HAS_ARMV8_5             << 
2116         depends on AS_HAS_LSE_ATOMICS         << 
2117         # Required for tag checking in the ua << 
2118         depends on ARM64_PAN                  << 
2119         select ARCH_HAS_SUBPAGE_FAULTS        << 
2120         select ARCH_USES_HIGH_VMA_FLAGS       << 
2121         select ARCH_USES_PG_ARCH_2            << 
2122         select ARCH_USES_PG_ARCH_3            << 
2123         help                                  << 
2124           Memory Tagging (part of the ARMv8.5 << 
2125           architectural support for run-time, << 
2126           various classes of memory error to  << 
2127           to eliminate vulnerabilities arisin << 
2128           languages.                          << 
2129                                               << 
2130           This option enables the support for << 
2131           Extension at EL0 (i.e. for userspac << 
2132                                               << 
2133           Selecting this option allows the fe << 
2134           runtime. Any secondary CPU not impl << 
2135           not be allowed a late bring-up.     << 
2136                                               << 
2137           Userspace binaries that want to use << 
2138           explicitly opt in. The mechanism fo << 
2139           described in:                       << 
2140                                               << 
2141           Documentation/arch/arm64/memory-tag << 
2142                                               << 
2143 endmenu # "ARMv8.5 architectural features"    << 
2144                                               << 
2145 menu "ARMv8.7 architectural features"         << 
2146                                                  1219 
2147 config ARM64_EPAN                             !! 1220 config X86_EXTRA_IRQS
2148         bool "Enable support for Enhanced Pri !! 1221         bool
                                                   >> 1222         depends on X86_LOCAL_APIC || X86_VOYAGER
2149         default y                                1223         default y
2150         depends on ARM64_PAN                  << 
2151         help                                  << 
2152           Enhanced Privileged Access Never (E << 
2153           Access Never to be used with Execut << 
2154                                               << 
2155           The feature is detected at runtime, << 
2156           if the cpu does not implement the f << 
2157 endmenu # "ARMv8.7 architectural features"    << 
2158                                               << 
2159 menu "ARMv8.9 architectural features"         << 
2160                                               << 
2161 config ARM64_POE                              << 
2162         prompt "Permission Overlay Extension" << 
2163         def_bool y                            << 
2164         select ARCH_USES_HIGH_VMA_FLAGS       << 
2165         select ARCH_HAS_PKEYS                 << 
2166         help                                  << 
2167           The Permission Overlay Extension is << 
2168           Protection Keys. Memory Protection  << 
2169           enforcing page-based protections, b << 
2170           of the page tables when an applicat << 
2171                                               << 
2172           For details, see Documentation/core << 
2173                                                  1224 
2174           If unsure, say y.                   !! 1225 config X86_FIND_SMP_CONFIG
2175                                               !! 1226         bool
2176 config ARCH_PKEY_BITS                         !! 1227         depends on X86_LOCAL_APIC || X86_VOYAGER
2177         int                                   << 
2178         default 3                             << 
2179                                               << 
2180 endmenu # "ARMv8.9 architectural features"    << 
2181                                               << 
2182 config ARM64_SVE                              << 
2183         bool "ARM Scalable Vector Extension s << 
2184         default y                                1228         default y
2185         help                                  << 
2186           The Scalable Vector Extension (SVE) << 
2187           execution state which complements a << 
2188           of the base architecture to support << 
2189           additional vectorisation opportunit << 
2190                                               << 
2191           To enable use of this extension on  << 
2192                                                  1229 
2193           On CPUs that support the SVE2 exten !! 1230 config X86_MPPARSE
2194           those too.                          !! 1231         bool
2195                                               !! 1232         depends on X86_LOCAL_APIC && !X86_VISWS
2196           Note that for architectural reasons << 
2197           support when running on SVE capable << 
2198           is present in:                      << 
2199                                               << 
2200             * version 1.5 and later of the AR << 
2201             * the AArch64 boot wrapper since  << 
2202               ("bootwrapper: SVE: Enable SVE  << 
2203                                               << 
2204           For other firmware implementations, << 
2205           or vendor.                          << 
2206                                               << 
2207           If you need the kernel to boot on S << 
2208           firmware, you may need to say N her << 
2209           fixed.  Otherwise, you may experien << 
2210           booting the kernel.  If unsure and  << 
2211           symptoms, you should assume that it << 
2212                                               << 
2213 config ARM64_SME                              << 
2214         bool "ARM Scalable Matrix Extension s << 
2215         default y                                1233         default y
2216         depends on ARM64_SVE                  << 
2217         depends on BROKEN                     << 
2218         help                                  << 
2219           The Scalable Matrix Extension (SME) << 
2220           execution state which utilises a su << 
2221           instruction set, together with the  << 
2222           register state capable of holding t << 
2223           enable various matrix operations.   << 
2224                                                  1234 
2225 config ARM64_PSEUDO_NMI                       !! 1235 endmenu
2226         bool "Support for NMI-like interrupts << 
2227         select ARM_GIC_V3                     << 
2228         help                                  << 
2229           Adds support for mimicking Non-Mask << 
2230           GIC interrupt priority. This suppor << 
2231           ARM GIC.                            << 
2232                                                  1236 
2233           This high priority configuration fo !! 1237 source "security/Kconfig"
2234           explicitly enabled by setting the k << 
2235           "irqchip.gicv3_pseudo_nmi" to 1.    << 
2236                                                  1238 
2237           If unsure, say N                    !! 1239 source "crypto/Kconfig"
2238                                                  1240 
2239 if ARM64_PSEUDO_NMI                           !! 1241 source "lib/Kconfig"
2240 config ARM64_DEBUG_PRIORITY_MASKING           << 
2241         bool "Debug interrupt priority maskin << 
2242         help                                  << 
2243           This adds runtime checks to functio << 
2244           interrupts when using priority mask << 
2245           the validity of ICC_PMR_EL1 when ca << 
2246                                               << 
2247           If unsure, say N                    << 
2248 endif # ARM64_PSEUDO_NMI                      << 
2249                                                  1242 
2250 config RELOCATABLE                            !! 1243 config X86_SMP
2251         bool "Build a relocatable kernel imag !! 1244         bool
2252         select ARCH_HAS_RELR                  !! 1245         depends on SMP && !X86_VOYAGER
2253         default y                                1246         default y
2254         help                                  << 
2255           This builds the kernel as a Positio << 
2256           which retains all relocation metada << 
2257           kernel binary at runtime to a diffe << 
2258           address it was linked at.           << 
2259           Since AArch64 uses the RELA relocat << 
2260           relocation pass at runtime even if  << 
2261           same address it was linked at.      << 
2262                                               << 
2263 config RANDOMIZE_BASE                         << 
2264         bool "Randomize the address of the ke << 
2265         select RELOCATABLE                    << 
2266         help                                  << 
2267           Randomizes the virtual address at w << 
2268           loaded, as a security feature that  << 
2269           relying on knowledge of the locatio << 
2270                                               << 
2271           It is the bootloader's job to provi << 
2272           random u64 value in /chosen/kaslr-s << 
2273                                                  1247 
2274           When booting via the UEFI stub, it  !! 1248 config X86_HT
2275           EFI_RNG_PROTOCOL implementation (if !! 1249         bool
2276           to the kernel proper. In addition,  !! 1250         depends on SMP && !(X86_VISWS || X86_VOYAGER)
2277           location of the kernel Image as wel << 
2278                                               << 
2279           If unsure, say N.                   << 
2280                                               << 
2281 config RANDOMIZE_MODULE_REGION_FULL           << 
2282         bool "Randomize the module region ove << 
2283         depends on RANDOMIZE_BASE             << 
2284         default y                                1251         default y
2285         help                                  << 
2286           Randomizes the location of the modu << 
2287           covering the core kernel. This way, << 
2288           to leak information about the locat << 
2289           but it does imply that function cal << 
2290           kernel will need to be resolved via << 
2291                                               << 
2292           When this option is not set, the mo << 
2293           a limited range that contains the [ << 
2294           core kernel, so branch relocations  << 
2295           the region is exhausted. In this pa << 
2296           exhaustion, modules might be able t << 
2297                                               << 
2298 config CC_HAVE_STACKPROTECTOR_SYSREG          << 
2299         def_bool $(cc-option,-mstack-protecto << 
2300                                               << 
2301 config STACKPROTECTOR_PER_TASK                << 
2302         def_bool y                            << 
2303         depends on STACKPROTECTOR && CC_HAVE_ << 
2304                                                  1252 
2305 config UNWIND_PATCH_PAC_INTO_SCS              !! 1253 config X86_BIOS_REBOOT
2306         bool "Enable shadow call stack dynami !! 1254         bool
2307         # needs Clang with https://github.com !! 1255         depends on !(X86_VISWS || X86_VOYAGER)
2308         depends on CC_IS_CLANG && CLANG_VERSI << 
2309         depends on ARM64_PTR_AUTH_KERNEL && C << 
2310         depends on SHADOW_CALL_STACK          << 
2311         select UNWIND_TABLES                  << 
2312         select DYNAMIC_SCS                    << 
2313                                               << 
2314 config ARM64_CONTPTE                          << 
2315         bool "Contiguous PTE mappings for use << 
2316         depends on TRANSPARENT_HUGEPAGE       << 
2317         default y                                1256         default y
2318         help                                  << 
2319           When enabled, user mappings are con << 
2320           bit, for any mappings that meet the << 
2321           This reduces TLB pressure and impro << 
2322                                               << 
2323 endmenu # "Kernel Features"                   << 
2324                                               << 
2325 menu "Boot options"                           << 
2326                                               << 
2327 config ARM64_ACPI_PARKING_PROTOCOL            << 
2328         bool "Enable support for the ARM64 AC << 
2329         depends on ACPI                       << 
2330         help                                  << 
2331           Enable support for the ARM64 ACPI p << 
2332           the kernel will not allow booting t << 
2333           protocol even if the corresponding  << 
2334           MADT table.                         << 
2335                                                  1257 
2336 config CMDLINE                                !! 1258 config X86_TRAMPOLINE
2337         string "Default kernel command string << 
2338         default ""                            << 
2339         help                                  << 
2340           Provide a set of default command-li << 
2341           entering them here. As a minimum, y << 
2342           root device (e.g. root=/dev/nfs).   << 
2343                                               << 
2344 choice                                        << 
2345         prompt "Kernel command line type"     << 
2346         depends on CMDLINE != ""              << 
2347         default CMDLINE_FROM_BOOTLOADER       << 
2348         help                                  << 
2349           Choose how the kernel will handle t << 
2350           command line string.                << 
2351                                               << 
2352 config CMDLINE_FROM_BOOTLOADER                << 
2353         bool "Use bootloader kernel arguments << 
2354         help                                  << 
2355           Uses the command-line options passe << 
2356           the boot loader doesn't provide any << 
2357           string provided in CMDLINE will be  << 
2358                                               << 
2359 config CMDLINE_FORCE                          << 
2360         bool "Always use the default kernel c << 
2361         help                                  << 
2362           Always use the default kernel comma << 
2363           loader passes other arguments to th << 
2364           This is useful if you cannot or don << 
2365           command-line options your boot load << 
2366                                               << 
2367 endchoice                                     << 
2368                                               << 
2369 config EFI_STUB                               << 
2370         bool                                     1259         bool
2371                                               !! 1260         depends on SMP || X86_VISWS
2372 config EFI                                    << 
2373         bool "UEFI runtime support"           << 
2374         depends on OF && !CPU_BIG_ENDIAN      << 
2375         depends on KERNEL_MODE_NEON           << 
2376         select ARCH_SUPPORTS_ACPI             << 
2377         select LIBFDT                         << 
2378         select UCS2_STRING                    << 
2379         select EFI_PARAMS_FROM_FDT            << 
2380         select EFI_RUNTIME_WRAPPERS           << 
2381         select EFI_STUB                       << 
2382         select EFI_GENERIC_STUB               << 
2383         imply IMA_SECURE_AND_OR_TRUSTED_BOOT  << 
2384         default y                                1261         default y
2385         help                                  << 
2386           This option provides support for ru << 
2387           by UEFI firmware (such as non-volat << 
2388           clock, and platform reset). A UEFI  << 
2389           allow the kernel to be booted as an << 
2390           is only useful on systems that have << 
2391                                                  1262 
2392 config COMPRESSED_INSTALL                     !! 1263 config PC
2393         bool "Install compressed image by def !! 1264         bool
2394         help                                  !! 1265         depends on X86 && !EMBEDDED
2395           This makes the regular "make instal << 
2396           image we built, not the legacy unco << 
2397                                               << 
2398           You can check that a compressed ima << 
2399           "make zinstall" first, and verifyin << 
2400           in your environment before making " << 
2401           you.                                << 
2402                                               << 
2403 config DMI                                    << 
2404         bool "Enable support for SMBIOS (DMI) << 
2405         depends on EFI                        << 
2406         default y                                1266         default y
2407         help                                  << 
2408           This enables SMBIOS/DMI feature for << 
2409                                               << 
2410           This option is only useful on syste << 
2411           However, even with this option, the << 
2412           continue to boot on existing non-UE << 
2413                                               << 
2414 endmenu # "Boot options"                      << 
2415                                               << 
2416 menu "Power management options"               << 
2417                                               << 
2418 source "kernel/power/Kconfig"                 << 
2419                                               << 
2420 config ARCH_HIBERNATION_POSSIBLE              << 
2421         def_bool y                            << 
2422         depends on CPU_PM                     << 
2423                                               << 
2424 config ARCH_HIBERNATION_HEADER                << 
2425         def_bool y                            << 
2426         depends on HIBERNATION                << 
2427                                               << 
2428 config ARCH_SUSPEND_POSSIBLE                  << 
2429         def_bool y                            << 
2430                                               << 
2431 endmenu # "Power management options"          << 
2432                                               << 
2433 menu "CPU Power Management"                   << 
2434                                               << 
2435 source "drivers/cpuidle/Kconfig"              << 
2436                                               << 
2437 source "drivers/cpufreq/Kconfig"              << 
2438                                               << 
2439 endmenu # "CPU Power Management"              << 
2440                                               << 
2441 source "drivers/acpi/Kconfig"                 << 
2442                                               << 
2443 source "arch/arm64/kvm/Kconfig"               << 
2444                                               << 
                                                      

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