Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1# SPDX-License-Identifier: GPL-2.0-only
2#
3# Library configuration
4#
5
6config BINARY_PRINTF
7 def_bool n
8
9menu "Library routines"
10
11config RAID6_PQ
12 tristate
13
14config 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
22config LINEAR_RANGES
23 tristate
24
25config PACKING
26 bool "Generic bitfield packing and unpacking"
27 default n
28 help
29 This option provides the packing() helper function, which permits
30 converting bitfields between a CPU-usable representation and a
31 memory representation that can have any combination of these quirks:
32 - Is little endian (bytes are reversed within a 32-bit group)
33 - The least-significant 32-bit word comes first (within a 64-bit
34 group)
35 - The most significant bit of a byte is at its right (bit 0 of a
36 register description is numerically 2^7).
37 Drivers may use these helpers to match the bit indices as described
38 in the data sheets of the peripherals they are in control of.
39
40 When in doubt, say N.
41
42config BITREVERSE
43 tristate
44
45config HAVE_ARCH_BITREVERSE
46 bool
47 default n
48 help
49 This option enables the use of hardware bit-reversal instructions on
50 architectures which support such operations.
51
52config ARCH_HAS_STRNCPY_FROM_USER
53 bool
54
55config ARCH_HAS_STRNLEN_USER
56 bool
57
58config GENERIC_STRNCPY_FROM_USER
59 def_bool !ARCH_HAS_STRNCPY_FROM_USER
60
61config GENERIC_STRNLEN_USER
62 def_bool !ARCH_HAS_STRNLEN_USER
63
64config GENERIC_NET_UTILS
65 bool
66
67source "lib/math/Kconfig"
68
69config NO_GENERIC_PCI_IOPORT_MAP
70 bool
71
72config GENERIC_PCI_IOMAP
73 bool
74
75config GENERIC_IOMAP
76 bool
77 select GENERIC_PCI_IOMAP
78
79config STMP_DEVICE
80 bool
81
82config ARCH_USE_CMPXCHG_LOCKREF
83 bool
84
85config ARCH_HAS_FAST_MULTIPLIER
86 bool
87
88config ARCH_USE_SYM_ANNOTATIONS
89 bool
90
91config INDIRECT_PIO
92 bool "Access I/O in non-MMIO mode"
93 depends on ARM64
94 help
95 On some platforms where no separate I/O space exists, there are I/O
96 hosts which can not be accessed in MMIO mode. Using the logical PIO
97 mechanism, the host-local I/O resource can be mapped into system
98 logic PIO space shared with MMIO hosts, such as PCI/PCIe, then the
99 system can access the I/O devices with the mapped-logic PIO through
100 I/O accessors.
101
102 This way has relatively little I/O performance cost. Please make
103 sure your devices really need this configure item enabled.
104
105 When in doubt, say N.
106
107config INDIRECT_IOMEM
108 bool
109 help
110 This is selected by other options/architectures to provide the
111 emulated iomem accessors.
112
113config INDIRECT_IOMEM_FALLBACK
114 bool
115 depends on INDIRECT_IOMEM
116 help
117 If INDIRECT_IOMEM is selected, this enables falling back to plain
118 mmio accesses when the IO memory address is not a registered
119 emulated region.
120
121source "lib/crypto/Kconfig"
122
123config CRC_CCITT
124 tristate "CRC-CCITT functions"
125 help
126 This option is provided for the case where no in-kernel-tree
127 modules require CRC-CCITT functions, but a module built outside
128 the kernel tree does. Such modules that use library CRC-CCITT
129 functions require M here.
130
131config CRC16
132 tristate "CRC16 functions"
133 help
134 This option is provided for the case where no in-kernel-tree
135 modules require CRC16 functions, but a module built outside
136 the kernel tree does. Such modules that use library CRC16
137 functions require M here.
138
139config CRC_T10DIF
140 tristate "CRC calculation for the T10 Data Integrity Field"
141 select CRYPTO
142 select CRYPTO_CRCT10DIF
143 help
144 This option is only needed if a module that's not in the
145 kernel tree needs to calculate CRC checks for use with the
146 SCSI data integrity subsystem.
147
148config CRC_ITU_T
149 tristate "CRC ITU-T V.41 functions"
150 help
151 This option is provided for the case where no in-kernel-tree
152 modules require CRC ITU-T V.41 functions, but a module built outside
153 the kernel tree does. Such modules that use library CRC ITU-T V.41
154 functions require M here.
155
156config CRC32
157 tristate "CRC32/CRC32c functions"
158 default y
159 select BITREVERSE
160 help
161 This option is provided for the case where no in-kernel-tree
162 modules require CRC32/CRC32c functions, but a module built outside
163 the kernel tree does. Such modules that use library CRC32/CRC32c
164 functions require M here.
165
166config CRC32_SELFTEST
167 tristate "CRC32 perform self test on init"
168 depends on CRC32
169 help
170 This option enables the CRC32 library functions to perform a
171 self test on initialization. The self test computes crc32_le
172 and crc32_be over byte strings with random alignment and length
173 and computes the total elapsed time and number of bytes processed.
174
175choice
176 prompt "CRC32 implementation"
177 depends on CRC32
178 default CRC32_SLICEBY8
179 help
180 This option allows a kernel builder to override the default choice
181 of CRC32 algorithm. Choose the default ("slice by 8") unless you
182 know that you need one of the others.
183
184config CRC32_SLICEBY8
185 bool "Slice by 8 bytes"
186 help
187 Calculate checksum 8 bytes at a time with a clever slicing algorithm.
188 This is the fastest algorithm, but comes with a 8KiB lookup table.
189 Most modern processors have enough cache to hold this table without
190 thrashing the cache.
191
192 This is the default implementation choice. Choose this one unless
193 you have a good reason not to.
194
195config CRC32_SLICEBY4
196 bool "Slice by 4 bytes"
197 help
198 Calculate checksum 4 bytes at a time with a clever slicing algorithm.
199 This is a bit slower than slice by 8, but has a smaller 4KiB lookup
200 table.
201
202 Only choose this option if you know what you are doing.
203
204config CRC32_SARWATE
205 bool "Sarwate's Algorithm (one byte at a time)"
206 help
207 Calculate checksum a byte at a time using Sarwate's algorithm. This
208 is not particularly fast, but has a small 256 byte lookup table.
209
210 Only choose this option if you know what you are doing.
211
212config CRC32_BIT
213 bool "Classic Algorithm (one bit at a time)"
214 help
215 Calculate checksum one bit at a time. This is VERY slow, but has
216 no lookup table. This is provided as a debugging option.
217
218 Only choose this option if you are debugging crc32.
219
220endchoice
221
222config CRC64
223 tristate "CRC64 functions"
224 help
225 This option is provided for the case where no in-kernel-tree
226 modules require CRC64 functions, but a module built outside
227 the kernel tree does. Such modules that use library CRC64
228 functions require M here.
229
230config CRC4
231 tristate "CRC4 functions"
232 help
233 This option is provided for the case where no in-kernel-tree
234 modules require CRC4 functions, but a module built outside
235 the kernel tree does. Such modules that use library CRC4
236 functions require M here.
237
238config CRC7
239 tristate "CRC7 functions"
240 help
241 This option is provided for the case where no in-kernel-tree
242 modules require CRC7 functions, but a module built outside
243 the kernel tree does. Such modules that use library CRC7
244 functions require M here.
245
246config LIBCRC32C
247 tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check"
248 select CRYPTO
249 select CRYPTO_CRC32C
250 help
251 This option is provided for the case where no in-kernel-tree
252 modules require CRC32c functions, but a module built outside the
253 kernel tree does. Such modules that use library CRC32c functions
254 require M here. See Castagnoli93.
255 Module will be libcrc32c.
256
257config CRC8
258 tristate "CRC8 function"
259 help
260 This option provides CRC8 function. Drivers may select this
261 when they need to do cyclic redundancy check according CRC8
262 algorithm. Module will be called crc8.
263
264config XXHASH
265 tristate
266
267config AUDIT_GENERIC
268 bool
269 depends on AUDIT && !AUDIT_ARCH
270 default y
271
272config AUDIT_ARCH_COMPAT_GENERIC
273 bool
274 default n
275
276config AUDIT_COMPAT_GENERIC
277 bool
278 depends on AUDIT_GENERIC && AUDIT_ARCH_COMPAT_GENERIC && COMPAT
279 default y
280
281config RANDOM32_SELFTEST
282 bool "PRNG perform self test on init"
283 help
284 This option enables the 32 bit PRNG library functions to perform a
285 self test on initialization.
286
287#
288# compression support is select'ed if needed
289#
290config 842_COMPRESS
291 select CRC32
292 tristate
293
294config 842_DECOMPRESS
295 select CRC32
296 tristate
297
298config ZLIB_INFLATE
299 tristate
300
301config ZLIB_DEFLATE
302 tristate
303 select BITREVERSE
304
305config ZLIB_DFLTCC
306 def_bool y
307 depends on S390
308 prompt "Enable s390x DEFLATE CONVERSION CALL support for kernel zlib"
309 help
310 Enable s390x hardware support for zlib in the kernel.
311
312config LZO_COMPRESS
313 tristate
314
315config LZO_DECOMPRESS
316 tristate
317
318config LZ4_COMPRESS
319 tristate
320
321config LZ4HC_COMPRESS
322 tristate
323
324config LZ4_DECOMPRESS
325 tristate
326
327config ZSTD_COMPRESS
328 select XXHASH
329 tristate
330
331config ZSTD_DECOMPRESS
332 select XXHASH
333 tristate
334
335source "lib/xz/Kconfig"
336
337#
338# These all provide a common interface (hence the apparent duplication with
339# ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.)
340#
341config DECOMPRESS_GZIP
342 select ZLIB_INFLATE
343 tristate
344
345config DECOMPRESS_BZIP2
346 tristate
347
348config DECOMPRESS_LZMA
349 tristate
350
351config DECOMPRESS_XZ
352 select XZ_DEC
353 tristate
354
355config DECOMPRESS_LZO
356 select LZO_DECOMPRESS
357 tristate
358
359config DECOMPRESS_LZ4
360 select LZ4_DECOMPRESS
361 tristate
362
363config DECOMPRESS_ZSTD
364 select ZSTD_DECOMPRESS
365 tristate
366
367#
368# Generic allocator support is selected if needed
369#
370config GENERIC_ALLOCATOR
371 bool
372
373#
374# reed solomon support is select'ed if needed
375#
376config REED_SOLOMON
377 tristate
378
379config REED_SOLOMON_ENC8
380 bool
381
382config REED_SOLOMON_DEC8
383 bool
384
385config REED_SOLOMON_ENC16
386 bool
387
388config REED_SOLOMON_DEC16
389 bool
390
391#
392# BCH support is selected if needed
393#
394config BCH
395 tristate
396
397config BCH_CONST_PARAMS
398 bool
399 help
400 Drivers may select this option to force specific constant
401 values for parameters 'm' (Galois field order) and 't'
402 (error correction capability). Those specific values must
403 be set by declaring default values for symbols BCH_CONST_M
404 and BCH_CONST_T.
405 Doing so will enable extra compiler optimizations,
406 improving encoding and decoding performance up to 2x for
407 usual (m,t) values (typically such that m*t < 200).
408 When this option is selected, the BCH library supports
409 only a single (m,t) configuration. This is mainly useful
410 for NAND flash board drivers requiring known, fixed BCH
411 parameters.
412
413config BCH_CONST_M
414 int
415 range 5 15
416 help
417 Constant value for Galois field order 'm'. If 'k' is the
418 number of data bits to protect, 'm' should be chosen such
419 that (k + m*t) <= 2**m - 1.
420 Drivers should declare a default value for this symbol if
421 they select option BCH_CONST_PARAMS.
422
423config BCH_CONST_T
424 int
425 help
426 Constant value for error correction capability in bits 't'.
427 Drivers should declare a default value for this symbol if
428 they select option BCH_CONST_PARAMS.
429
430#
431# Textsearch support is select'ed if needed
432#
433config TEXTSEARCH
434 bool
435
436config TEXTSEARCH_KMP
437 tristate
438
439config TEXTSEARCH_BM
440 tristate
441
442config TEXTSEARCH_FSM
443 tristate
444
445config BTREE
446 bool
447
448config INTERVAL_TREE
449 bool
450 help
451 Simple, embeddable, interval-tree. Can find the start of an
452 overlapping range in log(n) time and then iterate over all
453 overlapping nodes. The algorithm is implemented as an
454 augmented rbtree.
455
456 See:
457
458 Documentation/core-api/rbtree.rst
459
460 for more information.
461
462config XARRAY_MULTI
463 bool
464 help
465 Support entries which occupy multiple consecutive indices in the
466 XArray.
467
468config ASSOCIATIVE_ARRAY
469 bool
470 help
471 Generic associative array. Can be searched and iterated over whilst
472 it is being modified. It is also reasonably quick to search and
473 modify. The algorithms are non-recursive, and the trees are highly
474 capacious.
475
476 See:
477
478 Documentation/core-api/assoc_array.rst
479
480 for more information.
481
482config HAS_IOMEM
483 bool
484 depends on !NO_IOMEM
485 default y
486
487config HAS_IOPORT_MAP
488 bool
489 depends on HAS_IOMEM && !NO_IOPORT_MAP
490 default y
491
492source "kernel/dma/Kconfig"
493
494config SGL_ALLOC
495 bool
496 default n
497
498config IOMMU_HELPER
499 bool
500
501config CHECK_SIGNATURE
502 bool
503
504config CPUMASK_OFFSTACK
505 bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
506 help
507 Use dynamic allocation for cpumask_var_t, instead of putting
508 them on the stack. This is a bit more expensive, but avoids
509 stack overflow.
510
511config CPU_RMAP
512 bool
513 depends on SMP
514
515config DQL
516 bool
517
518config GLOB
519 bool
520# This actually supports modular compilation, but the module overhead
521# is ridiculous for the amount of code involved. Until an out-of-tree
522# driver asks for it, we'll just link it directly it into the kernel
523# when required. Since we're ignoring out-of-tree users, there's also
524# no need bother prompting for a manual decision:
525# prompt "glob_match() function"
526 help
527 This option provides a glob_match function for performing
528 simple text pattern matching. It originated in the ATA code
529 to blacklist particular drive models, but other device drivers
530 may need similar functionality.
531
532 All drivers in the Linux kernel tree that require this function
533 should automatically select this option. Say N unless you
534 are compiling an out-of tree driver which tells you that it
535 depends on this.
536
537config GLOB_SELFTEST
538 tristate "glob self-test on init"
539 depends on GLOB
540 help
541 This option enables a simple self-test of the glob_match
542 function on startup. It is primarily useful for people
543 working on the code to ensure they haven't introduced any
544 regressions.
545
546 It only adds a little bit of code and slows kernel boot (or
547 module load) by a small amount, so you're welcome to play with
548 it, but you probably don't need it.
549
550#
551# Netlink attribute parsing support is select'ed if needed
552#
553config NLATTR
554 bool
555
556#
557# Generic 64-bit atomic support is selected if needed
558#
559config GENERIC_ATOMIC64
560 bool
561
562config LRU_CACHE
563 tristate
564
565config CLZ_TAB
566 bool
567
568config IRQ_POLL
569 bool "IRQ polling library"
570 help
571 Helper library to poll interrupt mitigation using polling.
572
573config MPILIB
574 tristate
575 select CLZ_TAB
576 help
577 Multiprecision maths library from GnuPG.
578 It is used to implement RSA digital signature verification,
579 which is used by IMA/EVM digital signature extension.
580
581config SIGNATURE
582 tristate
583 depends on KEYS
584 select CRYPTO
585 select CRYPTO_SHA1
586 select MPILIB
587 help
588 Digital signature verification. Currently only RSA is supported.
589 Implementation is done using GnuPG MPI library
590
591config DIMLIB
592 bool
593 help
594 Dynamic Interrupt Moderation library.
595 Implements an algorithm for dynamically changing CQ moderation values
596 according to run time performance.
597
598#
599# libfdt files, only selected if needed.
600#
601config LIBFDT
602 bool
603
604config OID_REGISTRY
605 tristate
606 help
607 Enable fast lookup object identifier registry.
608
609config UCS2_STRING
610 tristate
611
612#
613# generic vdso
614#
615source "lib/vdso/Kconfig"
616
617source "lib/fonts/Kconfig"
618
619config SG_SPLIT
620 def_bool n
621 help
622 Provides a helper to split scatterlists into chunks, each chunk being
623 a scatterlist. This should be selected by a driver or an API which
624 whishes to split a scatterlist amongst multiple DMA channels.
625
626config SG_POOL
627 def_bool n
628 help
629 Provides a helper to allocate chained scatterlists. This should be
630 selected by a driver or an API which whishes to allocate chained
631 scatterlist.
632
633#
634# sg chaining option
635#
636
637config ARCH_NO_SG_CHAIN
638 def_bool n
639
640config ARCH_HAS_PMEM_API
641 bool
642
643config MEMREGION
644 bool
645
646config ARCH_HAS_MEMREMAP_COMPAT_ALIGN
647 bool
648
649# use memcpy to implement user copies for nommu architectures
650config UACCESS_MEMCPY
651 bool
652
653config ARCH_HAS_UACCESS_FLUSHCACHE
654 bool
655
656# arch has a concept of a recoverable synchronous exception due to a
657# memory-read error like x86 machine-check or ARM data-abort, and
658# implements copy_mc_to_{user,kernel} to abort and report
659# 'bytes-transferred' if that exception fires when accessing the source
660# buffer.
661config ARCH_HAS_COPY_MC
662 bool
663
664# Temporary. Goes away when all archs are cleaned up
665config ARCH_STACKWALK
666 bool
667
668config STACKDEPOT
669 bool
670 select STACKTRACE
671
672config STACKDEPOT_ALWAYS_INIT
673 bool
674 select STACKDEPOT
675
676config STACK_HASH_ORDER
677 int "stack depot hash size (12 => 4KB, 20 => 1024KB)"
678 range 12 20
679 default 20
680 depends on STACKDEPOT
681 help
682 Select the hash size as a power of 2 for the stackdepot hash table.
683 Choose a lower value to reduce the memory impact.
684
685config REF_TRACKER
686 bool
687 depends on STACKTRACE_SUPPORT
688 select STACKDEPOT
689
690config SBITMAP
691 bool
692
693config PARMAN
694 tristate "parman" if COMPILE_TEST
695
696config OBJAGG
697 tristate "objagg" if COMPILE_TEST
698
699endmenu
700
701config GENERIC_IOREMAP
702 bool
703
704config GENERIC_LIB_ASHLDI3
705 bool
706
707config GENERIC_LIB_ASHRDI3
708 bool
709
710config GENERIC_LIB_LSHRDI3
711 bool
712
713config GENERIC_LIB_MULDI3
714 bool
715
716config GENERIC_LIB_CMPDI2
717 bool
718
719config GENERIC_LIB_UCMPDI2
720 bool
721
722config GENERIC_LIB_DEVMEM_IS_ALLOWED
723 bool
724
725config PLDMFW
726 bool
727 default n
728
729config ASN1_ENCODER
730 tristate