1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Based on arch/arm/include/asm/assembler.h, arch/arm/mm/proc-macros.S
4 *
5 * Copyright (C) 1996-2000 Russell King
6 * Copyright (C) 2012 ARM Ltd.
7 */
8 #ifndef __ASSEMBLY__
9 #error "Only include this from assembly code"
10 #endif
11
12 #ifndef __ASM_ASSEMBLER_H
13 #define __ASM_ASSEMBLER_H
14
15 #include <linux/export.h>
16
17 #include <asm/alternative.h>
18 #include <asm/asm-bug.h>
19 #include <asm/asm-extable.h>
20 #include <asm/asm-offsets.h>
21 #include <asm/cpufeature.h>
22 #include <asm/cputype.h>
23 #include <asm/debug-monitors.h>
24 #include <asm/page.h>
25 #include <asm/pgtable-hwdef.h>
26 #include <asm/ptrace.h>
27 #include <asm/thread_info.h>
28
29 /*
30 * Provide a wxN alias for each wN register so what we can paste a xN
31 * reference after a 'w' to obtain the 32-bit version.
32 */
33 .irp n,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30
34 wx\n .req w\n
35 .endr
36
37 .macro disable_daif
38 msr daifset, #0xf
39 .endm
40
41 /*
42 * Save/restore interrupts.
43 */
44 .macro save_and_disable_irq, flags
45 mrs \flags, daif
46 msr daifset, #3
47 .endm
48
49 .macro restore_irq, flags
50 msr daif, \flags
51 .endm
52
53 .macro disable_step_tsk, flgs, tmp
54 tbz \flgs, #TIF_SINGLESTEP, 9990f
55 mrs \tmp, mdscr_el1
56 bic \tmp, \tmp, #DBG_MDSCR_SS
57 msr mdscr_el1, \tmp
58 isb // Take effect before a subsequent clear of DAIF.D
59 9990:
60 .endm
61
62 /* call with daif masked */
63 .macro enable_step_tsk, flgs, tmp
64 tbz \flgs, #TIF_SINGLESTEP, 9990f
65 mrs \tmp, mdscr_el1
66 orr \tmp, \tmp, #DBG_MDSCR_SS
67 msr mdscr_el1, \tmp
68 9990:
69 .endm
70
71 /*
72 * RAS Error Synchronization barrier
73 */
74 .macro esb
75 #ifdef CONFIG_ARM64_RAS_EXTN
76 hint #16
77 #else
78 nop
79 #endif
80 .endm
81
82 /*
83 * Value prediction barrier
84 */
85 .macro csdb
86 hint #20
87 .endm
88
89 /*
90 * Clear Branch History instruction
91 */
92 .macro clearbhb
93 hint #22
94 .endm
95
96 /*
97 * Speculation barrier
98 */
99 .macro sb
100 alternative_if_not ARM64_HAS_SB
101 dsb nsh
102 isb
103 alternative_else
104 SB_BARRIER_INSN
105 nop
106 alternative_endif
107 .endm
108
109 /*
110 * NOP sequence
111 */
112 .macro nops, num
113 .rept \num
114 nop
115 .endr
116 .endm
117
118 /*
119 * Register aliases.
120 */
121 lr .req x30 // link register
122
123 /*
124 * Vector entry
125 */
126 .macro ventry label
127 .align 7
128 b \label
129 .endm
130
131 /*
132 * Select code when configured for BE.
133 */
134 #ifdef CONFIG_CPU_BIG_ENDIAN
135 #define CPU_BE(code...) code
136 #else
137 #define CPU_BE(code...)
138 #endif
139
140 /*
141 * Select code when configured for LE.
142 */
143 #ifdef CONFIG_CPU_BIG_ENDIAN
144 #define CPU_LE(code...)
145 #else
146 #define CPU_LE(code...) code
147 #endif
148
149 /*
150 * Define a macro that constructs a 64-bit value by concatenating two
151 * 32-bit registers. Note that on big endian systems the order of the
152 * registers is swapped.
153 */
154 #ifndef CONFIG_CPU_BIG_ENDIAN
155 .macro regs_to_64, rd, lbits, hbits
156 #else
157 .macro regs_to_64, rd, hbits, lbits
158 #endif
159 orr \rd, \lbits, \hbits, lsl #32
160 .endm
161
162 /*
163 * Pseudo-ops for PC-relative adr/ldr/str <reg>, <symbol> where
164 * <symbol> is within the range +/- 4 GB of the PC.
165 */
166 /*
167 * @dst: destination register (64 bit wide)
168 * @sym: name of the symbol
169 */
170 .macro adr_l, dst, sym
171 adrp \dst, \sym
172 add \dst, \dst, :lo12:\sym
173 .endm
174
175 /*
176 * @dst: destination register (32 or 64 bit wide)
177 * @sym: name of the symbol
178 * @tmp: optional 64-bit scratch register to be used if <dst> is a
179 * 32-bit wide register, in which case it cannot be used to hold
180 * the address
181 */
182 .macro ldr_l, dst, sym, tmp=
183 .ifb \tmp
184 adrp \dst, \sym
185 ldr \dst, [\dst, :lo12:\sym]
186 .else
187 adrp \tmp, \sym
188 ldr \dst, [\tmp, :lo12:\sym]
189 .endif
190 .endm
191
192 /*
193 * @src: source register (32 or 64 bit wide)
194 * @sym: name of the symbol
195 * @tmp: mandatory 64-bit scratch register to calculate the address
196 * while <src> needs to be preserved.
197 */
198 .macro str_l, src, sym, tmp
199 adrp \tmp, \sym
200 str \src, [\tmp, :lo12:\sym]
201 .endm
202
203 /*
204 * @dst: destination register
205 */
206 #if defined(__KVM_NVHE_HYPERVISOR__) || defined(__KVM_VHE_HYPERVISOR__)
207 .macro get_this_cpu_offset, dst
208 mrs \dst, tpidr_el2
209 .endm
210 #else
211 .macro get_this_cpu_offset, dst
212 alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
213 mrs \dst, tpidr_el1
214 alternative_else
215 mrs \dst, tpidr_el2
216 alternative_endif
217 .endm
218
219 .macro set_this_cpu_offset, src
220 alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
221 msr tpidr_el1, \src
222 alternative_else
223 msr tpidr_el2, \src
224 alternative_endif
225 .endm
226 #endif
227
228 /*
229 * @dst: Result of per_cpu(sym, smp_processor_id()) (can be SP)
230 * @sym: The name of the per-cpu variable
231 * @tmp: scratch register
232 */
233 .macro adr_this_cpu, dst, sym, tmp
234 adrp \tmp, \sym
235 add \dst, \tmp, #:lo12:\sym
236 get_this_cpu_offset \tmp
237 add \dst, \dst, \tmp
238 .endm
239
240 /*
241 * @dst: Result of READ_ONCE(per_cpu(sym, smp_processor_id()))
242 * @sym: The name of the per-cpu variable
243 * @tmp: scratch register
244 */
245 .macro ldr_this_cpu dst, sym, tmp
246 adr_l \dst, \sym
247 get_this_cpu_offset \tmp
248 ldr \dst, [\dst, \tmp]
249 .endm
250
251 /*
252 * vma_vm_mm - get mm pointer from vma pointer (vma->vm_mm)
253 */
254 .macro vma_vm_mm, rd, rn
255 ldr \rd, [\rn, #VMA_VM_MM]
256 .endm
257
258 /*
259 * read_ctr - read CTR_EL0. If the system has mismatched register fields,
260 * provide the system wide safe value from arm64_ftr_reg_ctrel0.sys_val
261 */
262 .macro read_ctr, reg
263 #ifndef __KVM_NVHE_HYPERVISOR__
264 alternative_if_not ARM64_MISMATCHED_CACHE_TYPE
265 mrs \reg, ctr_el0 // read CTR
266 nop
267 alternative_else
268 ldr_l \reg, arm64_ftr_reg_ctrel0 + ARM64_FTR_SYSVAL
269 alternative_endif
270 #else
271 alternative_if_not ARM64_KVM_PROTECTED_MODE
272 ASM_BUG()
273 alternative_else_nop_endif
274 alternative_cb ARM64_ALWAYS_SYSTEM, kvm_compute_final_ctr_el0
275 movz \reg, #0
276 movk \reg, #0, lsl #16
277 movk \reg, #0, lsl #32
278 movk \reg, #0, lsl #48
279 alternative_cb_end
280 #endif
281 .endm
282
283
284 /*
285 * raw_dcache_line_size - get the minimum D-cache line size on this CPU
286 * from the CTR register.
287 */
288 .macro raw_dcache_line_size, reg, tmp
289 mrs \tmp, ctr_el0 // read CTR
290 ubfm \tmp, \tmp, #16, #19 // cache line size encoding
291 mov \reg, #4 // bytes per word
292 lsl \reg, \reg, \tmp // actual cache line size
293 .endm
294
295 /*
296 * dcache_line_size - get the safe D-cache line size across all CPUs
297 */
298 .macro dcache_line_size, reg, tmp
299 read_ctr \tmp
300 ubfm \tmp, \tmp, #16, #19 // cache line size encoding
301 mov \reg, #4 // bytes per word
302 lsl \reg, \reg, \tmp // actual cache line size
303 .endm
304
305 /*
306 * raw_icache_line_size - get the minimum I-cache line size on this CPU
307 * from the CTR register.
308 */
309 .macro raw_icache_line_size, reg, tmp
310 mrs \tmp, ctr_el0 // read CTR
311 and \tmp, \tmp, #0xf // cache line size encoding
312 mov \reg, #4 // bytes per word
313 lsl \reg, \reg, \tmp // actual cache line size
314 .endm
315
316 /*
317 * icache_line_size - get the safe I-cache line size across all CPUs
318 */
319 .macro icache_line_size, reg, tmp
320 read_ctr \tmp
321 and \tmp, \tmp, #0xf // cache line size encoding
322 mov \reg, #4 // bytes per word
323 lsl \reg, \reg, \tmp // actual cache line size
324 .endm
325
326 /*
327 * tcr_set_t0sz - update TCR.T0SZ so that we can load the ID map
328 */
329 .macro tcr_set_t0sz, valreg, t0sz
330 bfi \valreg, \t0sz, #TCR_T0SZ_OFFSET, #TCR_TxSZ_WIDTH
331 .endm
332
333 /*
334 * tcr_set_t1sz - update TCR.T1SZ
335 */
336 .macro tcr_set_t1sz, valreg, t1sz
337 bfi \valreg, \t1sz, #TCR_T1SZ_OFFSET, #TCR_TxSZ_WIDTH
338 .endm
339
340 /*
341 * tcr_compute_pa_size - set TCR.(I)PS to the highest supported
342 * ID_AA64MMFR0_EL1.PARange value
343 *
344 * tcr: register with the TCR_ELx value to be updated
345 * pos: IPS or PS bitfield position
346 * tmp{0,1}: temporary registers
347 */
348 .macro tcr_compute_pa_size, tcr, pos, tmp0, tmp1
349 mrs \tmp0, ID_AA64MMFR0_EL1
350 // Narrow PARange to fit the PS field in TCR_ELx
351 ubfx \tmp0, \tmp0, #ID_AA64MMFR0_EL1_PARANGE_SHIFT, #3
352 mov \tmp1, #ID_AA64MMFR0_EL1_PARANGE_MAX
353 cmp \tmp0, \tmp1
354 csel \tmp0, \tmp1, \tmp0, hi
355 bfi \tcr, \tmp0, \pos, #3
356 .endm
357
358 .macro __dcache_op_workaround_clean_cache, op, addr
359 alternative_if_not ARM64_WORKAROUND_CLEAN_CACHE
360 dc \op, \addr
361 alternative_else
362 dc civac, \addr
363 alternative_endif
364 .endm
365
366 /*
367 * Macro to perform a data cache maintenance for the interval
368 * [start, end) with dcache line size explicitly provided.
369 *
370 * op: operation passed to dc instruction
371 * domain: domain used in dsb instruciton
372 * start: starting virtual address of the region
373 * end: end virtual address of the region
374 * linesz: dcache line size
375 * fixup: optional label to branch to on user fault
376 * Corrupts: start, end, tmp
377 */
378 .macro dcache_by_myline_op op, domain, start, end, linesz, tmp, fixup
379 sub \tmp, \linesz, #1
380 bic \start, \start, \tmp
381 .Ldcache_op\@:
382 .ifc \op, cvau
383 __dcache_op_workaround_clean_cache \op, \start
384 .else
385 .ifc \op, cvac
386 __dcache_op_workaround_clean_cache \op, \start
387 .else
388 .ifc \op, cvap
389 sys 3, c7, c12, 1, \start // dc cvap
390 .else
391 .ifc \op, cvadp
392 sys 3, c7, c13, 1, \start // dc cvadp
393 .else
394 dc \op, \start
395 .endif
396 .endif
397 .endif
398 .endif
399 add \start, \start, \linesz
400 cmp \start, \end
401 b.lo .Ldcache_op\@
402 dsb \domain
403
404 _cond_uaccess_extable .Ldcache_op\@, \fixup
405 .endm
406
407 /*
408 * Macro to perform a data cache maintenance for the interval
409 * [start, end)
410 *
411 * op: operation passed to dc instruction
412 * domain: domain used in dsb instruciton
413 * start: starting virtual address of the region
414 * end: end virtual address of the region
415 * fixup: optional label to branch to on user fault
416 * Corrupts: start, end, tmp1, tmp2
417 */
418 .macro dcache_by_line_op op, domain, start, end, tmp1, tmp2, fixup
419 dcache_line_size \tmp1, \tmp2
420 dcache_by_myline_op \op, \domain, \start, \end, \tmp1, \tmp2, \fixup
421 .endm
422
423 /*
424 * Macro to perform an instruction cache maintenance for the interval
425 * [start, end)
426 *
427 * start, end: virtual addresses describing the region
428 * fixup: optional label to branch to on user fault
429 * Corrupts: tmp1, tmp2
430 */
431 .macro invalidate_icache_by_line start, end, tmp1, tmp2, fixup
432 icache_line_size \tmp1, \tmp2
433 sub \tmp2, \tmp1, #1
434 bic \tmp2, \start, \tmp2
435 .Licache_op\@:
436 ic ivau, \tmp2 // invalidate I line PoU
437 add \tmp2, \tmp2, \tmp1
438 cmp \tmp2, \end
439 b.lo .Licache_op\@
440 dsb ish
441 isb
442
443 _cond_uaccess_extable .Licache_op\@, \fixup
444 .endm
445
446 /*
447 * load_ttbr1 - install @pgtbl as a TTBR1 page table
448 * pgtbl preserved
449 * tmp1/tmp2 clobbered, either may overlap with pgtbl
450 */
451 .macro load_ttbr1, pgtbl, tmp1, tmp2
452 phys_to_ttbr \tmp1, \pgtbl
453 offset_ttbr1 \tmp1, \tmp2
454 msr ttbr1_el1, \tmp1
455 isb
456 .endm
457
458 /*
459 * To prevent the possibility of old and new partial table walks being visible
460 * in the tlb, switch the ttbr to a zero page when we invalidate the old
461 * records. D4.7.1 'General TLB maintenance requirements' in ARM DDI 0487A.i
462 * Even switching to our copied tables will cause a changed output address at
463 * each stage of the walk.
464 */
465 .macro break_before_make_ttbr_switch zero_page, page_table, tmp, tmp2
466 phys_to_ttbr \tmp, \zero_page
467 msr ttbr1_el1, \tmp
468 isb
469 tlbi vmalle1
470 dsb nsh
471 load_ttbr1 \page_table, \tmp, \tmp2
472 .endm
473
474 /*
475 * reset_pmuserenr_el0 - reset PMUSERENR_EL0 if PMUv3 present
476 */
477 .macro reset_pmuserenr_el0, tmpreg
478 mrs \tmpreg, id_aa64dfr0_el1
479 ubfx \tmpreg, \tmpreg, #ID_AA64DFR0_EL1_PMUVer_SHIFT, #4
480 cmp \tmpreg, #ID_AA64DFR0_EL1_PMUVer_NI
481 ccmp \tmpreg, #ID_AA64DFR0_EL1_PMUVer_IMP_DEF, #4, ne
482 b.eq 9000f // Skip if no PMU present or IMP_DEF
483 msr pmuserenr_el0, xzr // Disable PMU access from EL0
484 9000:
485 .endm
486
487 /*
488 * reset_amuserenr_el0 - reset AMUSERENR_EL0 if AMUv1 present
489 */
490 .macro reset_amuserenr_el0, tmpreg
491 mrs \tmpreg, id_aa64pfr0_el1 // Check ID_AA64PFR0_EL1
492 ubfx \tmpreg, \tmpreg, #ID_AA64PFR0_EL1_AMU_SHIFT, #4
493 cbz \tmpreg, .Lskip_\@ // Skip if no AMU present
494 msr_s SYS_AMUSERENR_EL0, xzr // Disable AMU access from EL0
495 .Lskip_\@:
496 .endm
497 /*
498 * copy_page - copy src to dest using temp registers t1-t8
499 */
500 .macro copy_page dest:req src:req t1:req t2:req t3:req t4:req t5:req t6:req t7:req t8:req
501 9998: ldp \t1, \t2, [\src]
502 ldp \t3, \t4, [\src, #16]
503 ldp \t5, \t6, [\src, #32]
504 ldp \t7, \t8, [\src, #48]
505 add \src, \src, #64
506 stnp \t1, \t2, [\dest]
507 stnp \t3, \t4, [\dest, #16]
508 stnp \t5, \t6, [\dest, #32]
509 stnp \t7, \t8, [\dest, #48]
510 add \dest, \dest, #64
511 tst \src, #(PAGE_SIZE - 1)
512 b.ne 9998b
513 .endm
514
515 /*
516 * Annotate a function as being unsuitable for kprobes.
517 */
518 #ifdef CONFIG_KPROBES
519 #define NOKPROBE(x) \
520 .pushsection "_kprobe_blacklist", "aw"; \
521 .quad x; \
522 .popsection;
523 #else
524 #define NOKPROBE(x)
525 #endif
526
527 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
528 #define EXPORT_SYMBOL_NOKASAN(name)
529 #else
530 #define EXPORT_SYMBOL_NOKASAN(name) EXPORT_SYMBOL(name)
531 #endif
532
533 /*
534 * Emit a 64-bit absolute little endian symbol reference in a way that
535 * ensures that it will be resolved at build time, even when building a
536 * PIE binary. This requires cooperation from the linker script, which
537 * must emit the lo32/hi32 halves individually.
538 */
539 .macro le64sym, sym
540 .long \sym\()_lo32
541 .long \sym\()_hi32
542 .endm
543
544 /*
545 * mov_q - move an immediate constant into a 64-bit register using
546 * between 2 and 4 movz/movk instructions (depending on the
547 * magnitude and sign of the operand)
548 */
549 .macro mov_q, reg, val
550 .if (((\val) >> 31) == 0 || ((\val) >> 31) == 0x1ffffffff)
551 movz \reg, :abs_g1_s:\val
552 .else
553 .if (((\val) >> 47) == 0 || ((\val) >> 47) == 0x1ffff)
554 movz \reg, :abs_g2_s:\val
555 .else
556 movz \reg, :abs_g3:\val
557 movk \reg, :abs_g2_nc:\val
558 .endif
559 movk \reg, :abs_g1_nc:\val
560 .endif
561 movk \reg, :abs_g0_nc:\val
562 .endm
563
564 /*
565 * Return the current task_struct.
566 */
567 .macro get_current_task, rd
568 mrs \rd, sp_el0
569 .endm
570
571 /*
572 * If the kernel is built for 52-bit virtual addressing but the hardware only
573 * supports 48 bits, we cannot program the pgdir address into TTBR1 directly,
574 * but we have to add an offset so that the TTBR1 address corresponds with the
575 * pgdir entry that covers the lowest 48-bit addressable VA.
576 *
577 * Note that this trick is only used for LVA/64k pages - LPA2/4k pages uses an
578 * additional paging level, and on LPA2/16k pages, we would end up with a root
579 * level table with only 2 entries, which is suboptimal in terms of TLB
580 * utilization, so there we fall back to 47 bits of translation if LPA2 is not
581 * supported.
582 *
583 * orr is used as it can cover the immediate value (and is idempotent).
584 * ttbr: Value of ttbr to set, modified.
585 */
586 .macro offset_ttbr1, ttbr, tmp
587 #if defined(CONFIG_ARM64_VA_BITS_52) && !defined(CONFIG_ARM64_LPA2)
588 mrs \tmp, tcr_el1
589 and \tmp, \tmp, #TCR_T1SZ_MASK
590 cmp \tmp, #TCR_T1SZ(VA_BITS_MIN)
591 orr \tmp, \ttbr, #TTBR1_BADDR_4852_OFFSET
592 csel \ttbr, \tmp, \ttbr, eq
593 #endif
594 .endm
595
596 /*
597 * Arrange a physical address in a TTBR register, taking care of 52-bit
598 * addresses.
599 *
600 * phys: physical address, preserved
601 * ttbr: returns the TTBR value
602 */
603 .macro phys_to_ttbr, ttbr, phys
604 #ifdef CONFIG_ARM64_PA_BITS_52
605 orr \ttbr, \phys, \phys, lsr #46
606 and \ttbr, \ttbr, #TTBR_BADDR_MASK_52
607 #else
608 mov \ttbr, \phys
609 #endif
610 .endm
611
612 .macro phys_to_pte, pte, phys
613 #ifdef CONFIG_ARM64_PA_BITS_52
614 orr \pte, \phys, \phys, lsr #PTE_ADDR_HIGH_SHIFT
615 and \pte, \pte, #PHYS_TO_PTE_ADDR_MASK
616 #else
617 mov \pte, \phys
618 #endif
619 .endm
620
621 /*
622 * tcr_clear_errata_bits - Clear TCR bits that trigger an errata on this CPU.
623 */
624 .macro tcr_clear_errata_bits, tcr, tmp1, tmp2
625 #ifdef CONFIG_FUJITSU_ERRATUM_010001
626 mrs \tmp1, midr_el1
627
628 mov_q \tmp2, MIDR_FUJITSU_ERRATUM_010001_MASK
629 and \tmp1, \tmp1, \tmp2
630 mov_q \tmp2, MIDR_FUJITSU_ERRATUM_010001
631 cmp \tmp1, \tmp2
632 b.ne 10f
633
634 mov_q \tmp2, TCR_CLEAR_FUJITSU_ERRATUM_010001
635 bic \tcr, \tcr, \tmp2
636 10:
637 #endif /* CONFIG_FUJITSU_ERRATUM_010001 */
638 .endm
639
640 /**
641 * Errata workaround prior to disable MMU. Insert an ISB immediately prior
642 * to executing the MSR that will change SCTLR_ELn[M] from a value of 1 to 0.
643 */
644 .macro pre_disable_mmu_workaround
645 #ifdef CONFIG_QCOM_FALKOR_ERRATUM_E1041
646 isb
647 #endif
648 .endm
649
650 /*
651 * frame_push - Push @regcount callee saved registers to the stack,
652 * starting at x19, as well as x29/x30, and set x29 to
653 * the new value of sp. Add @extra bytes of stack space
654 * for locals.
655 */
656 .macro frame_push, regcount:req, extra
657 __frame st, \regcount, \extra
658 .endm
659
660 /*
661 * frame_pop - Pop the callee saved registers from the stack that were
662 * pushed in the most recent call to frame_push, as well
663 * as x29/x30 and any extra stack space that may have been
664 * allocated.
665 */
666 .macro frame_pop
667 __frame ld
668 .endm
669
670 .macro __frame_regs, reg1, reg2, op, num
671 .if .Lframe_regcount == \num
672 \op\()r \reg1, [sp, #(\num + 1) * 8]
673 .elseif .Lframe_regcount > \num
674 \op\()p \reg1, \reg2, [sp, #(\num + 1) * 8]
675 .endif
676 .endm
677
678 .macro __frame, op, regcount, extra=0
679 .ifc \op, st
680 .if (\regcount) < 0 || (\regcount) > 10
681 .error "regcount should be in the range [0 ... 10]"
682 .endif
683 .if ((\extra) % 16) != 0
684 .error "extra should be a multiple of 16 bytes"
685 .endif
686 .ifdef .Lframe_regcount
687 .if .Lframe_regcount != -1
688 .error "frame_push/frame_pop may not be nested"
689 .endif
690 .endif
691 .set .Lframe_regcount, \regcount
692 .set .Lframe_extra, \extra
693 .set .Lframe_local_offset, ((\regcount + 3) / 2) * 16
694 stp x29, x30, [sp, #-.Lframe_local_offset - .Lframe_extra]!
695 mov x29, sp
696 .endif
697
698 __frame_regs x19, x20, \op, 1
699 __frame_regs x21, x22, \op, 3
700 __frame_regs x23, x24, \op, 5
701 __frame_regs x25, x26, \op, 7
702 __frame_regs x27, x28, \op, 9
703
704 .ifc \op, ld
705 .if .Lframe_regcount == -1
706 .error "frame_push/frame_pop may not be nested"
707 .endif
708 ldp x29, x30, [sp], #.Lframe_local_offset + .Lframe_extra
709 .set .Lframe_regcount, -1
710 .endif
711 .endm
712
713 /*
714 * Set SCTLR_ELx to the @reg value, and invalidate the local icache
715 * in the process. This is called when setting the MMU on.
716 */
717 .macro set_sctlr, sreg, reg
718 msr \sreg, \reg
719 isb
720 /*
721 * Invalidate the local I-cache so that any instructions fetched
722 * speculatively from the PoC are discarded, since they may have
723 * been dynamically patched at the PoU.
724 */
725 ic iallu
726 dsb nsh
727 isb
728 .endm
729
730 .macro set_sctlr_el1, reg
731 set_sctlr sctlr_el1, \reg
732 .endm
733
734 .macro set_sctlr_el2, reg
735 set_sctlr sctlr_el2, \reg
736 .endm
737
738 /*
739 * Check whether asm code should yield as soon as it is able. This is
740 * the case if we are currently running in task context, and the
741 * TIF_NEED_RESCHED flag is set. (Note that the TIF_NEED_RESCHED flag
742 * is stored negated in the top word of the thread_info::preempt_count
743 * field)
744 */
745 .macro cond_yield, lbl:req, tmp:req, tmp2
746 #ifdef CONFIG_PREEMPT_VOLUNTARY
747 get_current_task \tmp
748 ldr \tmp, [\tmp, #TSK_TI_PREEMPT]
749 /*
750 * If we are serving a softirq, there is no point in yielding: the
751 * softirq will not be preempted no matter what we do, so we should
752 * run to completion as quickly as we can. The preempt_count field will
753 * have BIT(SOFTIRQ_SHIFT) set in this case, so the zero check will
754 * catch this case too.
755 */
756 cbz \tmp, \lbl
757 #endif
758 .endm
759
760 /*
761 * Branch Target Identifier (BTI)
762 */
763 .macro bti, targets
764 .equ .L__bti_targets_c, 34
765 .equ .L__bti_targets_j, 36
766 .equ .L__bti_targets_jc,38
767 hint #.L__bti_targets_\targets
768 .endm
769
770 /*
771 * This macro emits a program property note section identifying
772 * architecture features which require special handling, mainly for
773 * use in assembly files included in the VDSO.
774 */
775
776 #define NT_GNU_PROPERTY_TYPE_0 5
777 #define GNU_PROPERTY_AARCH64_FEATURE_1_AND 0xc0000000
778
779 #define GNU_PROPERTY_AARCH64_FEATURE_1_BTI (1U << 0)
780 #define GNU_PROPERTY_AARCH64_FEATURE_1_PAC (1U << 1)
781
782 #ifdef CONFIG_ARM64_BTI_KERNEL
783 #define GNU_PROPERTY_AARCH64_FEATURE_1_DEFAULT \
784 ((GNU_PROPERTY_AARCH64_FEATURE_1_BTI | \
785 GNU_PROPERTY_AARCH64_FEATURE_1_PAC))
786 #endif
787
788 #ifdef GNU_PROPERTY_AARCH64_FEATURE_1_DEFAULT
789 .macro emit_aarch64_feature_1_and, feat=GNU_PROPERTY_AARCH64_FEATURE_1_DEFAULT
790 .pushsection .note.gnu.property, "a"
791 .align 3
792 .long 2f - 1f
793 .long 6f - 3f
794 .long NT_GNU_PROPERTY_TYPE_0
795 1: .string "GNU"
796 2:
797 .align 3
798 3: .long GNU_PROPERTY_AARCH64_FEATURE_1_AND
799 .long 5f - 4f
800 4:
801 /*
802 * This is described with an array of char in the Linux API
803 * spec but the text and all other usage (including binutils,
804 * clang and GCC) treat this as a 32 bit value so no swizzling
805 * is required for big endian.
806 */
807 .long \feat
808 5:
809 .align 3
810 6:
811 .popsection
812 .endm
813
814 #else
815 .macro emit_aarch64_feature_1_and, feat=0
816 .endm
817
818 #endif /* GNU_PROPERTY_AARCH64_FEATURE_1_DEFAULT */
819
820 .macro __mitigate_spectre_bhb_loop tmp
821 #ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY
822 alternative_cb ARM64_ALWAYS_SYSTEM, spectre_bhb_patch_loop_iter
823 mov \tmp, #32 // Patched to correct the immediate
824 alternative_cb_end
825 .Lspectre_bhb_loop\@:
826 b . + 4
827 subs \tmp, \tmp, #1
828 b.ne .Lspectre_bhb_loop\@
829 sb
830 #endif /* CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */
831 .endm
832
833 .macro mitigate_spectre_bhb_loop tmp
834 #ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY
835 alternative_cb ARM64_ALWAYS_SYSTEM, spectre_bhb_patch_loop_mitigation_enable
836 b .L_spectre_bhb_loop_done\@ // Patched to NOP
837 alternative_cb_end
838 __mitigate_spectre_bhb_loop \tmp
839 .L_spectre_bhb_loop_done\@:
840 #endif /* CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */
841 .endm
842
843 /* Save/restores x0-x3 to the stack */
844 .macro __mitigate_spectre_bhb_fw
845 #ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY
846 stp x0, x1, [sp, #-16]!
847 stp x2, x3, [sp, #-16]!
848 mov w0, #ARM_SMCCC_ARCH_WORKAROUND_3
849 alternative_cb ARM64_ALWAYS_SYSTEM, smccc_patch_fw_mitigation_conduit
850 nop // Patched to SMC/HVC #0
851 alternative_cb_end
852 ldp x2, x3, [sp], #16
853 ldp x0, x1, [sp], #16
854 #endif /* CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */
855 .endm
856
857 .macro mitigate_spectre_bhb_clear_insn
858 #ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY
859 alternative_cb ARM64_ALWAYS_SYSTEM, spectre_bhb_patch_clearbhb
860 /* Patched to NOP when not supported */
861 clearbhb
862 isb
863 alternative_cb_end
864 #endif /* CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */
865 .endm
866 #endif /* __ASM_ASSEMBLER_H */
867
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