1 # SPDX-License-Identifier: GPL-2.0-only
2 #
3 # Library configuration
4 #
5
6 config BINARY_PRINTF
7 def_bool n
8
9 menu "Library routines"
10
11 config RAID6_PQ
12 tristate
13
14 config RAID6_PQ_BENCHMARK
15 bool "Automatically choose fastest RAID6 PQ functions"
16 depends on RAID6_PQ
17 default y
18 help
19 Benchmark all available RAID6 PQ functions on init and choose the
20 fastest one.
21
22 config LINEAR_RANGES
23 tristate
24
25 config PACKING
26 bool "Generic bitfield packing and unpacking"
27 select BITREVERSE
28 default n
29 help
30 This option provides the packing() helper function, which permits
31 converting bitfields between a CPU-usable representation and a
32 memory representation that can have any combination of these quirks:
33 - Is little endian (bytes are reversed within a 32-bit group)
34 - The least-significant 32-bit word comes first (within a 64-bit
35 group)
36 - The most significant bit of a byte is at its right (bit 0 of a
37 register description is numerically 2^7).
38 Drivers may use these helpers to match the bit indices as described
39 in the data sheets of the peripherals they are in control of.
40
41 When in doubt, say N.
42
43 config BITREVERSE
44 tristate
45
46 config HAVE_ARCH_BITREVERSE
47 bool
48 default n
49 help
50 This option enables the use of hardware bit-reversal instructions on
51 architectures which support such operations.
52
53 config ARCH_HAS_STRNCPY_FROM_USER
54 bool
55
56 config ARCH_HAS_STRNLEN_USER
57 bool
58
59 config GENERIC_STRNCPY_FROM_USER
60 def_bool !ARCH_HAS_STRNCPY_FROM_USER
61
62 config GENERIC_STRNLEN_USER
63 def_bool !ARCH_HAS_STRNLEN_USER
64
65 config GENERIC_NET_UTILS
66 bool
67
68 source "lib/math/Kconfig"
69
70 config NO_GENERIC_PCI_IOPORT_MAP
71 bool
72
73 config GENERIC_IOMAP
74 bool
75 select GENERIC_PCI_IOMAP
76
77 config STMP_DEVICE
78 bool
79
80 config ARCH_USE_CMPXCHG_LOCKREF
81 bool
82
83 config ARCH_HAS_FAST_MULTIPLIER
84 bool
85
86 config ARCH_USE_SYM_ANNOTATIONS
87 bool
88
89 config INDIRECT_PIO
90 bool "Access I/O in non-MMIO mode"
91 depends on ARM64
92 depends on HAS_IOPORT
93 help
94 On some platforms where no separate I/O space exists, there are I/O
95 hosts which can not be accessed in MMIO mode. Using the logical PIO
96 mechanism, the host-local I/O resource can be mapped into system
97 logic PIO space shared with MMIO hosts, such as PCI/PCIe, then the
98 system can access the I/O devices with the mapped-logic PIO through
99 I/O accessors.
100
101 This way has relatively little I/O performance cost. Please make
102 sure your devices really need this configure item enabled.
103
104 When in doubt, say N.
105
106 config INDIRECT_IOMEM
107 bool
108 help
109 This is selected by other options/architectures to provide the
110 emulated iomem accessors.
111
112 config INDIRECT_IOMEM_FALLBACK
113 bool
114 depends on INDIRECT_IOMEM
115 help
116 If INDIRECT_IOMEM is selected, this enables falling back to plain
117 mmio accesses when the IO memory address is not a registered
118 emulated region.
119
120 config TRACE_MMIO_ACCESS
121 bool "Register read/write tracing"
122 depends on TRACING && ARCH_HAVE_TRACE_MMIO_ACCESS
123 help
124 Create tracepoints for MMIO read/write operations. These trace events
125 can be used for logging all MMIO read/write operations.
126
127 source "lib/crypto/Kconfig"
128
129 config CRC_CCITT
130 tristate "CRC-CCITT functions"
131 help
132 This option is provided for the case where no in-kernel-tree
133 modules require CRC-CCITT functions, but a module built outside
134 the kernel tree does. Such modules that use library CRC-CCITT
135 functions require M here.
136
137 config CRC16
138 tristate "CRC16 functions"
139 help
140 This option is provided for the case where no in-kernel-tree
141 modules require CRC16 functions, but a module built outside
142 the kernel tree does. Such modules that use library CRC16
143 functions require M here.
144
145 config CRC_T10DIF
146 tristate "CRC calculation for the T10 Data Integrity Field"
147 select CRYPTO
148 select CRYPTO_CRCT10DIF
149 help
150 This option is only needed if a module that's not in the
151 kernel tree needs to calculate CRC checks for use with the
152 SCSI data integrity subsystem.
153
154 config CRC64_ROCKSOFT
155 tristate "CRC calculation for the Rocksoft model CRC64"
156 select CRC64
157 select CRYPTO
158 select CRYPTO_CRC64_ROCKSOFT
159 help
160 This option provides a CRC64 API to a registered crypto driver.
161 This is used with the block layer's data integrity subsystem.
162
163 config CRC_ITU_T
164 tristate "CRC ITU-T V.41 functions"
165 help
166 This option is provided for the case where no in-kernel-tree
167 modules require CRC ITU-T V.41 functions, but a module built outside
168 the kernel tree does. Such modules that use library CRC ITU-T V.41
169 functions require M here.
170
171 config CRC32
172 tristate "CRC32/CRC32c functions"
173 default y
174 select BITREVERSE
175 help
176 This option is provided for the case where no in-kernel-tree
177 modules require CRC32/CRC32c functions, but a module built outside
178 the kernel tree does. Such modules that use library CRC32/CRC32c
179 functions require M here.
180
181 config CRC32_SELFTEST
182 tristate "CRC32 perform self test on init"
183 depends on CRC32
184 help
185 This option enables the CRC32 library functions to perform a
186 self test on initialization. The self test computes crc32_le
187 and crc32_be over byte strings with random alignment and length
188 and computes the total elapsed time and number of bytes processed.
189
190 choice
191 prompt "CRC32 implementation"
192 depends on CRC32
193 default CRC32_SLICEBY8
194 help
195 This option allows a kernel builder to override the default choice
196 of CRC32 algorithm. Choose the default ("slice by 8") unless you
197 know that you need one of the others.
198
199 config CRC32_SLICEBY8
200 bool "Slice by 8 bytes"
201 help
202 Calculate checksum 8 bytes at a time with a clever slicing algorithm.
203 This is the fastest algorithm, but comes with a 8KiB lookup table.
204 Most modern processors have enough cache to hold this table without
205 thrashing the cache.
206
207 This is the default implementation choice. Choose this one unless
208 you have a good reason not to.
209
210 config CRC32_SLICEBY4
211 bool "Slice by 4 bytes"
212 help
213 Calculate checksum 4 bytes at a time with a clever slicing algorithm.
214 This is a bit slower than slice by 8, but has a smaller 4KiB lookup
215 table.
216
217 Only choose this option if you know what you are doing.
218
219 config CRC32_SARWATE
220 bool "Sarwate's Algorithm (one byte at a time)"
221 help
222 Calculate checksum a byte at a time using Sarwate's algorithm. This
223 is not particularly fast, but has a small 256 byte lookup table.
224
225 Only choose this option if you know what you are doing.
226
227 config CRC32_BIT
228 bool "Classic Algorithm (one bit at a time)"
229 help
230 Calculate checksum one bit at a time. This is VERY slow, but has
231 no lookup table. This is provided as a debugging option.
232
233 Only choose this option if you are debugging crc32.
234
235 endchoice
236
237 config CRC64
238 tristate "CRC64 functions"
239 help
240 This option is provided for the case where no in-kernel-tree
241 modules require CRC64 functions, but a module built outside
242 the kernel tree does. Such modules that use library CRC64
243 functions require M here.
244
245 config CRC4
246 tristate "CRC4 functions"
247 help
248 This option is provided for the case where no in-kernel-tree
249 modules require CRC4 functions, but a module built outside
250 the kernel tree does. Such modules that use library CRC4
251 functions require M here.
252
253 config CRC7
254 tristate "CRC7 functions"
255 help
256 This option is provided for the case where no in-kernel-tree
257 modules require CRC7 functions, but a module built outside
258 the kernel tree does. Such modules that use library CRC7
259 functions require M here.
260
261 config LIBCRC32C
262 tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check"
263 select CRYPTO
264 select CRYPTO_CRC32C
265 help
266 This option is provided for the case where no in-kernel-tree
267 modules require CRC32c functions, but a module built outside the
268 kernel tree does. Such modules that use library CRC32c functions
269 require M here. See Castagnoli93.
270 Module will be libcrc32c.
271
272 config CRC8
273 tristate "CRC8 function"
274 help
275 This option provides CRC8 function. Drivers may select this
276 when they need to do cyclic redundancy check according CRC8
277 algorithm. Module will be called crc8.
278
279 config XXHASH
280 tristate
281
282 config AUDIT_GENERIC
283 bool
284 depends on AUDIT && !AUDIT_ARCH
285 default y
286
287 config AUDIT_ARCH_COMPAT_GENERIC
288 bool
289 default n
290
291 config AUDIT_COMPAT_GENERIC
292 bool
293 depends on AUDIT_GENERIC && AUDIT_ARCH_COMPAT_GENERIC && COMPAT
294 default y
295
296 config RANDOM32_SELFTEST
297 bool "PRNG perform self test on init"
298 help
299 This option enables the 32 bit PRNG library functions to perform a
300 self test on initialization.
301
302 #
303 # compression support is select'ed if needed
304 #
305 config 842_COMPRESS
306 select CRC32
307 tristate
308
309 config 842_DECOMPRESS
310 select CRC32
311 tristate
312
313 config ZLIB_INFLATE
314 tristate
315
316 config ZLIB_DEFLATE
317 tristate
318 select BITREVERSE
319
320 config ZLIB_DFLTCC
321 def_bool y
322 depends on S390
323 prompt "Enable s390x DEFLATE CONVERSION CALL support for kernel zlib"
324 help
325 Enable s390x hardware support for zlib in the kernel.
326
327 config LZO_COMPRESS
328 tristate
329
330 config LZO_DECOMPRESS
331 tristate
332
333 config LZ4_COMPRESS
334 tristate
335
336 config LZ4HC_COMPRESS
337 tristate
338
339 config LZ4_DECOMPRESS
340 tristate
341
342 config ZSTD_COMMON
343 select XXHASH
344 tristate
345
346 config ZSTD_COMPRESS
347 select ZSTD_COMMON
348 tristate
349
350 config ZSTD_DECOMPRESS
351 select ZSTD_COMMON
352 tristate
353
354 source "lib/xz/Kconfig"
355
356 #
357 # These all provide a common interface (hence the apparent duplication with
358 # ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.)
359 #
360 config DECOMPRESS_GZIP
361 select ZLIB_INFLATE
362 tristate
363
364 config DECOMPRESS_BZIP2
365 tristate
366
367 config DECOMPRESS_LZMA
368 tristate
369
370 config DECOMPRESS_XZ
371 select XZ_DEC
372 tristate
373
374 config DECOMPRESS_LZO
375 select LZO_DECOMPRESS
376 tristate
377
378 config DECOMPRESS_LZ4
379 select LZ4_DECOMPRESS
380 tristate
381
382 config DECOMPRESS_ZSTD
383 select ZSTD_DECOMPRESS
384 tristate
385
386 #
387 # Generic allocator support is selected if needed
388 #
389 config GENERIC_ALLOCATOR
390 bool
391
392 #
393 # reed solomon support is select'ed if needed
394 #
395 config REED_SOLOMON
396 tristate
397
398 config REED_SOLOMON_ENC8
399 bool
400
401 config REED_SOLOMON_DEC8
402 bool
403
404 config REED_SOLOMON_ENC16
405 bool
406
407 config REED_SOLOMON_DEC16
408 bool
409
410 #
411 # BCH support is selected if needed
412 #
413 config BCH
414 tristate
415 select BITREVERSE
416
417 config BCH_CONST_PARAMS
418 bool
419 help
420 Drivers may select this option to force specific constant
421 values for parameters 'm' (Galois field order) and 't'
422 (error correction capability). Those specific values must
423 be set by declaring default values for symbols BCH_CONST_M
424 and BCH_CONST_T.
425 Doing so will enable extra compiler optimizations,
426 improving encoding and decoding performance up to 2x for
427 usual (m,t) values (typically such that m*t < 200).
428 When this option is selected, the BCH library supports
429 only a single (m,t) configuration. This is mainly useful
430 for NAND flash board drivers requiring known, fixed BCH
431 parameters.
432
433 config BCH_CONST_M
434 int
435 range 5 15
436 help
437 Constant value for Galois field order 'm'. If 'k' is the
438 number of data bits to protect, 'm' should be chosen such
439 that (k + m*t) <= 2**m - 1.
440 Drivers should declare a default value for this symbol if
441 they select option BCH_CONST_PARAMS.
442
443 config BCH_CONST_T
444 int
445 help
446 Constant value for error correction capability in bits 't'.
447 Drivers should declare a default value for this symbol if
448 they select option BCH_CONST_PARAMS.
449
450 #
451 # Textsearch support is select'ed if needed
452 #
453 config TEXTSEARCH
454 bool
455
456 config TEXTSEARCH_KMP
457 tristate
458
459 config TEXTSEARCH_BM
460 tristate
461
462 config TEXTSEARCH_FSM
463 tristate
464
465 config BTREE
466 bool
467
468 config INTERVAL_TREE
469 bool
470 help
471 Simple, embeddable, interval-tree. Can find the start of an
472 overlapping range in log(n) time and then iterate over all
473 overlapping nodes. The algorithm is implemented as an
474 augmented rbtree.
475
476 See:
477
478 Documentation/core-api/rbtree.rst
479
480 for more information.
481
482 config INTERVAL_TREE_SPAN_ITER
483 bool
484 depends on INTERVAL_TREE
485
486 config XARRAY_MULTI
487 bool
488 help
489 Support entries which occupy multiple consecutive indices in the
490 XArray.
491
492 config ASSOCIATIVE_ARRAY
493 bool
494 help
495 Generic associative array. Can be searched and iterated over whilst
496 it is being modified. It is also reasonably quick to search and
497 modify. The algorithms are non-recursive, and the trees are highly
498 capacious.
499
500 See:
501
502 Documentation/core-api/assoc_array.rst
503
504 for more information.
505
506 config CLOSURES
507 bool
508
509 config HAS_IOMEM
510 bool
511 depends on !NO_IOMEM
512 default y
513
514 config HAS_IOPORT
515 bool
516
517 config HAS_IOPORT_MAP
518 bool
519 depends on HAS_IOMEM && !NO_IOPORT_MAP
520 default y
521
522 source "kernel/dma/Kconfig"
523
524 config SGL_ALLOC
525 bool
526 default n
527
528 config IOMMU_HELPER
529 bool
530
531 config CHECK_SIGNATURE
532 bool
533
534 config CPUMASK_OFFSTACK
535 bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
536 help
537 Use dynamic allocation for cpumask_var_t, instead of putting
538 them on the stack. This is a bit more expensive, but avoids
539 stack overflow.
540
541 config FORCE_NR_CPUS
542 def_bool !SMP
543
544 config CPU_RMAP
545 bool
546 depends on SMP
547
548 config DQL
549 bool
550
551 config GLOB
552 bool
553 # This actually supports modular compilation, but the module overhead
554 # is ridiculous for the amount of code involved. Until an out-of-tree
555 # driver asks for it, we'll just link it directly it into the kernel
556 # when required. Since we're ignoring out-of-tree users, there's also
557 # no need bother prompting for a manual decision:
558 # prompt "glob_match() function"
559 help
560 This option provides a glob_match function for performing
561 simple text pattern matching. It originated in the ATA code
562 to blacklist particular drive models, but other device drivers
563 may need similar functionality.
564
565 All drivers in the Linux kernel tree that require this function
566 should automatically select this option. Say N unless you
567 are compiling an out-of tree driver which tells you that it
568 depends on this.
569
570 config GLOB_SELFTEST
571 tristate "glob self-test on init"
572 depends on GLOB
573 help
574 This option enables a simple self-test of the glob_match
575 function on startup. It is primarily useful for people
576 working on the code to ensure they haven't introduced any
577 regressions.
578
579 It only adds a little bit of code and slows kernel boot (or
580 module load) by a small amount, so you're welcome to play with
581 it, but you probably don't need it.
582
583 #
584 # Netlink attribute parsing support is select'ed if needed
585 #
586 config NLATTR
587 bool
588
589 #
590 # Generic 64-bit atomic support is selected if needed
591 #
592 config GENERIC_ATOMIC64
593 bool
594
595 config LRU_CACHE
596 tristate
597
598 config CLZ_TAB
599 bool
600
601 config IRQ_POLL
602 bool "IRQ polling library"
603 help
604 Helper library to poll interrupt mitigation using polling.
605
606 config MPILIB
607 tristate
608 select CLZ_TAB
609 help
610 Multiprecision maths library from GnuPG.
611 It is used to implement RSA digital signature verification,
612 which is used by IMA/EVM digital signature extension.
613
614 config SIGNATURE
615 tristate
616 depends on KEYS
617 select CRYPTO
618 select CRYPTO_SHA1
619 select MPILIB
620 help
621 Digital signature verification. Currently only RSA is supported.
622 Implementation is done using GnuPG MPI library
623
624 config DIMLIB
625 tristate
626 depends on NET
627 help
628 Dynamic Interrupt Moderation library.
629 Implements an algorithm for dynamically changing CQ moderation values
630 according to run time performance.
631
632 #
633 # libfdt files, only selected if needed.
634 #
635 config LIBFDT
636 bool
637
638 config OID_REGISTRY
639 tristate
640 help
641 Enable fast lookup object identifier registry.
642
643 config UCS2_STRING
644 tristate
645
646 #
647 # generic vdso
648 #
649 source "lib/vdso/Kconfig"
650
651 source "lib/fonts/Kconfig"
652
653 config SG_SPLIT
654 def_bool n
655 help
656 Provides a helper to split scatterlists into chunks, each chunk being
657 a scatterlist. This should be selected by a driver or an API which
658 whishes to split a scatterlist amongst multiple DMA channels.
659
660 config SG_POOL
661 def_bool n
662 help
663 Provides a helper to allocate chained scatterlists. This should be
664 selected by a driver or an API which whishes to allocate chained
665 scatterlist.
666
667 #
668 # sg chaining option
669 #
670
671 config ARCH_NO_SG_CHAIN
672 def_bool n
673
674 config ARCH_HAS_PMEM_API
675 bool
676
677 config MEMREGION
678 bool
679
680 config ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
681 bool
682
683 config ARCH_HAS_MEMREMAP_COMPAT_ALIGN
684 bool
685
686 # use memcpy to implement user copies for nommu architectures
687 config UACCESS_MEMCPY
688 bool
689
690 config ARCH_HAS_UACCESS_FLUSHCACHE
691 bool
692
693 # arch has a concept of a recoverable synchronous exception due to a
694 # memory-read error like x86 machine-check or ARM data-abort, and
695 # implements copy_mc_to_{user,kernel} to abort and report
696 # 'bytes-transferred' if that exception fires when accessing the source
697 # buffer.
698 config ARCH_HAS_COPY_MC
699 bool
700
701 # Temporary. Goes away when all archs are cleaned up
702 config ARCH_STACKWALK
703 bool
704
705 config STACKDEPOT
706 bool
707 select STACKTRACE
708 help
709 Stack depot: stack trace storage that avoids duplication
710
711 config STACKDEPOT_ALWAYS_INIT
712 bool
713 select STACKDEPOT
714 help
715 Always initialize stack depot during early boot
716
717 config STACKDEPOT_MAX_FRAMES
718 int "Maximum number of frames in trace saved in stack depot"
719 range 1 256
720 default 64
721 depends on STACKDEPOT
722
723 config REF_TRACKER
724 bool
725 depends on STACKTRACE_SUPPORT
726 select STACKDEPOT
727
728 config SBITMAP
729 bool
730
731 config PARMAN
732 tristate "parman" if COMPILE_TEST
733
734 config OBJAGG
735 tristate "objagg" if COMPILE_TEST
736
737 config LWQ_TEST
738 bool "Boot-time test for lwq queuing"
739 help
740 Run boot-time test of light-weight queuing.
741
742 endmenu
743
744 config GENERIC_IOREMAP
745 bool
746
747 config GENERIC_LIB_ASHLDI3
748 bool
749
750 config GENERIC_LIB_ASHRDI3
751 bool
752
753 config GENERIC_LIB_LSHRDI3
754 bool
755
756 config GENERIC_LIB_MULDI3
757 bool
758
759 config GENERIC_LIB_CMPDI2
760 bool
761
762 config GENERIC_LIB_UCMPDI2
763 bool
764
765 config GENERIC_LIB_DEVMEM_IS_ALLOWED
766 bool
767
768 config PLDMFW
769 bool
770 default n
771
772 config ASN1_ENCODER
773 tristate
774
775 config POLYNOMIAL
776 tristate
777
778 config FIRMWARE_TABLE
779 bool
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