xref: /linux/lib/Kconfig (revision 9f7861c56b51b84d30114e7fea9d744a9d5ba9b7)
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	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
43config BITREVERSE
44	tristate
45
46config 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
53config ARCH_HAS_STRNCPY_FROM_USER
54	bool
55
56config ARCH_HAS_STRNLEN_USER
57	bool
58
59config GENERIC_STRNCPY_FROM_USER
60	def_bool !ARCH_HAS_STRNCPY_FROM_USER
61
62config GENERIC_STRNLEN_USER
63	def_bool !ARCH_HAS_STRNLEN_USER
64
65config GENERIC_NET_UTILS
66	bool
67
68source "lib/math/Kconfig"
69
70config NO_GENERIC_PCI_IOPORT_MAP
71	bool
72
73config GENERIC_PCI_IOMAP
74	bool
75
76config GENERIC_IOMAP
77	bool
78	select GENERIC_PCI_IOMAP
79
80config STMP_DEVICE
81	bool
82
83config ARCH_USE_CMPXCHG_LOCKREF
84	bool
85
86config ARCH_HAS_FAST_MULTIPLIER
87	bool
88
89config ARCH_USE_SYM_ANNOTATIONS
90	bool
91
92config INDIRECT_PIO
93	bool "Access I/O in non-MMIO mode"
94	depends on ARM64
95	depends on HAS_IOPORT
96	help
97	  On some platforms where no separate I/O space exists, there are I/O
98	  hosts which can not be accessed in MMIO mode. Using the logical PIO
99	  mechanism, the host-local I/O resource can be mapped into system
100	  logic PIO space shared with MMIO hosts, such as PCI/PCIe, then the
101	  system can access the I/O devices with the mapped-logic PIO through
102	  I/O accessors.
103
104	  This way has relatively little I/O performance cost. Please make
105	  sure your devices really need this configure item enabled.
106
107	  When in doubt, say N.
108
109config INDIRECT_IOMEM
110	bool
111	help
112	  This is selected by other options/architectures to provide the
113	  emulated iomem accessors.
114
115config INDIRECT_IOMEM_FALLBACK
116	bool
117	depends on INDIRECT_IOMEM
118	help
119	  If INDIRECT_IOMEM is selected, this enables falling back to plain
120	  mmio accesses when the IO memory address is not a registered
121	  emulated region.
122
123config TRACE_MMIO_ACCESS
124	bool "Register read/write tracing"
125	depends on TRACING && ARCH_HAVE_TRACE_MMIO_ACCESS
126	help
127	  Create tracepoints for MMIO read/write operations. These trace events
128	  can be used for logging all MMIO read/write operations.
129
130source "lib/crypto/Kconfig"
131
132config CRC_CCITT
133	tristate "CRC-CCITT functions"
134	help
135	  This option is provided for the case where no in-kernel-tree
136	  modules require CRC-CCITT functions, but a module built outside
137	  the kernel tree does. Such modules that use library CRC-CCITT
138	  functions require M here.
139
140config CRC16
141	tristate "CRC16 functions"
142	help
143	  This option is provided for the case where no in-kernel-tree
144	  modules require CRC16 functions, but a module built outside
145	  the kernel tree does. Such modules that use library CRC16
146	  functions require M here.
147
148config CRC_T10DIF
149	tristate "CRC calculation for the T10 Data Integrity Field"
150	select CRYPTO
151	select CRYPTO_CRCT10DIF
152	help
153	  This option is only needed if a module that's not in the
154	  kernel tree needs to calculate CRC checks for use with the
155	  SCSI data integrity subsystem.
156
157config CRC64_ROCKSOFT
158	tristate "CRC calculation for the Rocksoft model CRC64"
159	select CRC64
160	select CRYPTO
161	select CRYPTO_CRC64_ROCKSOFT
162	help
163	  This option provides a CRC64 API to a registered crypto driver.
164	  This is used with the block layer's data integrity subsystem.
165
166config CRC_ITU_T
167	tristate "CRC ITU-T V.41 functions"
168	help
169	  This option is provided for the case where no in-kernel-tree
170	  modules require CRC ITU-T V.41 functions, but a module built outside
171	  the kernel tree does. Such modules that use library CRC ITU-T V.41
172	  functions require M here.
173
174config CRC32
175	tristate "CRC32/CRC32c functions"
176	default y
177	select BITREVERSE
178	help
179	  This option is provided for the case where no in-kernel-tree
180	  modules require CRC32/CRC32c functions, but a module built outside
181	  the kernel tree does. Such modules that use library CRC32/CRC32c
182	  functions require M here.
183
184config CRC32_SELFTEST
185	tristate "CRC32 perform self test on init"
186	depends on CRC32
187	help
188	  This option enables the CRC32 library functions to perform a
189	  self test on initialization. The self test computes crc32_le
190	  and crc32_be over byte strings with random alignment and length
191	  and computes the total elapsed time and number of bytes processed.
192
193choice
194	prompt "CRC32 implementation"
195	depends on CRC32
196	default CRC32_SLICEBY8
197	help
198	  This option allows a kernel builder to override the default choice
199	  of CRC32 algorithm.  Choose the default ("slice by 8") unless you
200	  know that you need one of the others.
201
202config CRC32_SLICEBY8
203	bool "Slice by 8 bytes"
204	help
205	  Calculate checksum 8 bytes at a time with a clever slicing algorithm.
206	  This is the fastest algorithm, but comes with a 8KiB lookup table.
207	  Most modern processors have enough cache to hold this table without
208	  thrashing the cache.
209
210	  This is the default implementation choice.  Choose this one unless
211	  you have a good reason not to.
212
213config CRC32_SLICEBY4
214	bool "Slice by 4 bytes"
215	help
216	  Calculate checksum 4 bytes at a time with a clever slicing algorithm.
217	  This is a bit slower than slice by 8, but has a smaller 4KiB lookup
218	  table.
219
220	  Only choose this option if you know what you are doing.
221
222config CRC32_SARWATE
223	bool "Sarwate's Algorithm (one byte at a time)"
224	help
225	  Calculate checksum a byte at a time using Sarwate's algorithm.  This
226	  is not particularly fast, but has a small 256 byte lookup table.
227
228	  Only choose this option if you know what you are doing.
229
230config CRC32_BIT
231	bool "Classic Algorithm (one bit at a time)"
232	help
233	  Calculate checksum one bit at a time.  This is VERY slow, but has
234	  no lookup table.  This is provided as a debugging option.
235
236	  Only choose this option if you are debugging crc32.
237
238endchoice
239
240config CRC64
241	tristate "CRC64 functions"
242	help
243	  This option is provided for the case where no in-kernel-tree
244	  modules require CRC64 functions, but a module built outside
245	  the kernel tree does. Such modules that use library CRC64
246	  functions require M here.
247
248config CRC4
249	tristate "CRC4 functions"
250	help
251	  This option is provided for the case where no in-kernel-tree
252	  modules require CRC4 functions, but a module built outside
253	  the kernel tree does. Such modules that use library CRC4
254	  functions require M here.
255
256config CRC7
257	tristate "CRC7 functions"
258	help
259	  This option is provided for the case where no in-kernel-tree
260	  modules require CRC7 functions, but a module built outside
261	  the kernel tree does. Such modules that use library CRC7
262	  functions require M here.
263
264config LIBCRC32C
265	tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check"
266	select CRYPTO
267	select CRYPTO_CRC32C
268	help
269	  This option is provided for the case where no in-kernel-tree
270	  modules require CRC32c functions, but a module built outside the
271	  kernel tree does. Such modules that use library CRC32c functions
272	  require M here.  See Castagnoli93.
273	  Module will be libcrc32c.
274
275config CRC8
276	tristate "CRC8 function"
277	help
278	  This option provides CRC8 function. Drivers may select this
279	  when they need to do cyclic redundancy check according CRC8
280	  algorithm. Module will be called crc8.
281
282config XXHASH
283	tristate
284
285config AUDIT_GENERIC
286	bool
287	depends on AUDIT && !AUDIT_ARCH
288	default y
289
290config AUDIT_ARCH_COMPAT_GENERIC
291	bool
292	default n
293
294config AUDIT_COMPAT_GENERIC
295	bool
296	depends on AUDIT_GENERIC && AUDIT_ARCH_COMPAT_GENERIC && COMPAT
297	default y
298
299config RANDOM32_SELFTEST
300	bool "PRNG perform self test on init"
301	help
302	  This option enables the 32 bit PRNG library functions to perform a
303	  self test on initialization.
304
305#
306# compression support is select'ed if needed
307#
308config 842_COMPRESS
309	select CRC32
310	tristate
311
312config 842_DECOMPRESS
313	select CRC32
314	tristate
315
316config ZLIB_INFLATE
317	tristate
318
319config ZLIB_DEFLATE
320	tristate
321	select BITREVERSE
322
323config ZLIB_DFLTCC
324	def_bool y
325	depends on S390
326	prompt "Enable s390x DEFLATE CONVERSION CALL support for kernel zlib"
327	help
328	 Enable s390x hardware support for zlib in the kernel.
329
330config LZO_COMPRESS
331	tristate
332
333config LZO_DECOMPRESS
334	tristate
335
336config LZ4_COMPRESS
337	tristate
338
339config LZ4HC_COMPRESS
340	tristate
341
342config LZ4_DECOMPRESS
343	tristate
344
345config ZSTD_COMMON
346	select XXHASH
347	tristate
348
349config ZSTD_COMPRESS
350	select ZSTD_COMMON
351	tristate
352
353config ZSTD_DECOMPRESS
354	select ZSTD_COMMON
355	tristate
356
357source "lib/xz/Kconfig"
358
359#
360# These all provide a common interface (hence the apparent duplication with
361# ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.)
362#
363config DECOMPRESS_GZIP
364	select ZLIB_INFLATE
365	tristate
366
367config DECOMPRESS_BZIP2
368	tristate
369
370config DECOMPRESS_LZMA
371	tristate
372
373config DECOMPRESS_XZ
374	select XZ_DEC
375	tristate
376
377config DECOMPRESS_LZO
378	select LZO_DECOMPRESS
379	tristate
380
381config DECOMPRESS_LZ4
382	select LZ4_DECOMPRESS
383	tristate
384
385config DECOMPRESS_ZSTD
386	select ZSTD_DECOMPRESS
387	tristate
388
389#
390# Generic allocator support is selected if needed
391#
392config GENERIC_ALLOCATOR
393	bool
394
395#
396# reed solomon support is select'ed if needed
397#
398config REED_SOLOMON
399	tristate
400
401config REED_SOLOMON_ENC8
402	bool
403
404config REED_SOLOMON_DEC8
405	bool
406
407config REED_SOLOMON_ENC16
408	bool
409
410config REED_SOLOMON_DEC16
411	bool
412
413#
414# BCH support is selected if needed
415#
416config BCH
417	tristate
418	select BITREVERSE
419
420config BCH_CONST_PARAMS
421	bool
422	help
423	  Drivers may select this option to force specific constant
424	  values for parameters 'm' (Galois field order) and 't'
425	  (error correction capability). Those specific values must
426	  be set by declaring default values for symbols BCH_CONST_M
427	  and BCH_CONST_T.
428	  Doing so will enable extra compiler optimizations,
429	  improving encoding and decoding performance up to 2x for
430	  usual (m,t) values (typically such that m*t < 200).
431	  When this option is selected, the BCH library supports
432	  only a single (m,t) configuration. This is mainly useful
433	  for NAND flash board drivers requiring known, fixed BCH
434	  parameters.
435
436config BCH_CONST_M
437	int
438	range 5 15
439	help
440	  Constant value for Galois field order 'm'. If 'k' is the
441	  number of data bits to protect, 'm' should be chosen such
442	  that (k + m*t) <= 2**m - 1.
443	  Drivers should declare a default value for this symbol if
444	  they select option BCH_CONST_PARAMS.
445
446config BCH_CONST_T
447	int
448	help
449	  Constant value for error correction capability in bits 't'.
450	  Drivers should declare a default value for this symbol if
451	  they select option BCH_CONST_PARAMS.
452
453#
454# Textsearch support is select'ed if needed
455#
456config TEXTSEARCH
457	bool
458
459config TEXTSEARCH_KMP
460	tristate
461
462config TEXTSEARCH_BM
463	tristate
464
465config TEXTSEARCH_FSM
466	tristate
467
468config BTREE
469	bool
470
471config INTERVAL_TREE
472	bool
473	help
474	  Simple, embeddable, interval-tree. Can find the start of an
475	  overlapping range in log(n) time and then iterate over all
476	  overlapping nodes. The algorithm is implemented as an
477	  augmented rbtree.
478
479	  See:
480
481		Documentation/core-api/rbtree.rst
482
483	  for more information.
484
485config INTERVAL_TREE_SPAN_ITER
486	bool
487	depends on INTERVAL_TREE
488
489config XARRAY_MULTI
490	bool
491	help
492	  Support entries which occupy multiple consecutive indices in the
493	  XArray.
494
495config ASSOCIATIVE_ARRAY
496	bool
497	help
498	  Generic associative array.  Can be searched and iterated over whilst
499	  it is being modified.  It is also reasonably quick to search and
500	  modify.  The algorithms are non-recursive, and the trees are highly
501	  capacious.
502
503	  See:
504
505		Documentation/core-api/assoc_array.rst
506
507	  for more information.
508
509config CLOSURES
510	bool
511
512config HAS_IOMEM
513	bool
514	depends on !NO_IOMEM
515	default y
516
517config HAS_IOPORT
518	bool
519
520config HAS_IOPORT_MAP
521	bool
522	depends on HAS_IOMEM && !NO_IOPORT_MAP
523	default y
524
525source "kernel/dma/Kconfig"
526
527config SGL_ALLOC
528	bool
529	default n
530
531config IOMMU_HELPER
532	bool
533
534config CHECK_SIGNATURE
535	bool
536
537config CPUMASK_OFFSTACK
538	bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
539	help
540	  Use dynamic allocation for cpumask_var_t, instead of putting
541	  them on the stack.  This is a bit more expensive, but avoids
542	  stack overflow.
543
544config FORCE_NR_CPUS
545       bool "Set number of CPUs at compile time"
546       depends on SMP && EXPERT && !COMPILE_TEST
547       help
548         Say Yes if you have NR_CPUS set to an actual number of possible
549         CPUs in your system, not to a default value. This forces the core
550         code to rely on compile-time value and optimize kernel routines
551         better.
552
553config CPU_RMAP
554	bool
555	depends on SMP
556
557config DQL
558	bool
559
560config GLOB
561	bool
562#	This actually supports modular compilation, but the module overhead
563#	is ridiculous for the amount of code involved.	Until an out-of-tree
564#	driver asks for it, we'll just link it directly it into the kernel
565#	when required.  Since we're ignoring out-of-tree users,	there's also
566#	no need bother prompting for a manual decision:
567#	prompt "glob_match() function"
568	help
569	  This option provides a glob_match function for performing
570	  simple text pattern matching.  It originated in the ATA code
571	  to blacklist particular drive models, but other device drivers
572	  may need similar functionality.
573
574	  All drivers in the Linux kernel tree that require this function
575	  should automatically select this option.  Say N unless you
576	  are compiling an out-of tree driver which tells you that it
577	  depends on this.
578
579config GLOB_SELFTEST
580	tristate "glob self-test on init"
581	depends on GLOB
582	help
583	  This option enables a simple self-test of the glob_match
584	  function on startup.	It is primarily useful for people
585	  working on the code to ensure they haven't introduced any
586	  regressions.
587
588	  It only adds a little bit of code and slows kernel boot (or
589	  module load) by a small amount, so you're welcome to play with
590	  it, but you probably don't need it.
591
592#
593# Netlink attribute parsing support is select'ed if needed
594#
595config NLATTR
596	bool
597
598#
599# Generic 64-bit atomic support is selected if needed
600#
601config GENERIC_ATOMIC64
602       bool
603
604config LRU_CACHE
605	tristate
606
607config CLZ_TAB
608	bool
609
610config IRQ_POLL
611	bool "IRQ polling library"
612	help
613	  Helper library to poll interrupt mitigation using polling.
614
615config MPILIB
616	tristate
617	select CLZ_TAB
618	help
619	  Multiprecision maths library from GnuPG.
620	  It is used to implement RSA digital signature verification,
621	  which is used by IMA/EVM digital signature extension.
622
623config SIGNATURE
624	tristate
625	depends on KEYS
626	select CRYPTO
627	select CRYPTO_SHA1
628	select MPILIB
629	help
630	  Digital signature verification. Currently only RSA is supported.
631	  Implementation is done using GnuPG MPI library
632
633config DIMLIB
634	bool
635	help
636	  Dynamic Interrupt Moderation library.
637	  Implements an algorithm for dynamically changing CQ moderation values
638	  according to run time performance.
639
640#
641# libfdt files, only selected if needed.
642#
643config LIBFDT
644	bool
645
646config OID_REGISTRY
647	tristate
648	help
649	  Enable fast lookup object identifier registry.
650
651config UCS2_STRING
652	tristate
653
654#
655# generic vdso
656#
657source "lib/vdso/Kconfig"
658
659source "lib/fonts/Kconfig"
660
661config SG_SPLIT
662	def_bool n
663	help
664	 Provides a helper to split scatterlists into chunks, each chunk being
665	 a scatterlist. This should be selected by a driver or an API which
666	 whishes to split a scatterlist amongst multiple DMA channels.
667
668config SG_POOL
669	def_bool n
670	help
671	 Provides a helper to allocate chained scatterlists. This should be
672	 selected by a driver or an API which whishes to allocate chained
673	 scatterlist.
674
675#
676# sg chaining option
677#
678
679config ARCH_NO_SG_CHAIN
680	def_bool n
681
682config ARCH_HAS_PMEM_API
683	bool
684
685config MEMREGION
686	bool
687
688config ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
689	bool
690
691config ARCH_HAS_MEMREMAP_COMPAT_ALIGN
692	bool
693
694# use memcpy to implement user copies for nommu architectures
695config UACCESS_MEMCPY
696	bool
697
698config ARCH_HAS_UACCESS_FLUSHCACHE
699	bool
700
701# arch has a concept of a recoverable synchronous exception due to a
702# memory-read error like x86 machine-check or ARM data-abort, and
703# implements copy_mc_to_{user,kernel} to abort and report
704# 'bytes-transferred' if that exception fires when accessing the source
705# buffer.
706config ARCH_HAS_COPY_MC
707	bool
708
709# Temporary. Goes away when all archs are cleaned up
710config ARCH_STACKWALK
711       bool
712
713config STACKDEPOT
714	bool
715	select STACKTRACE
716
717config STACKDEPOT_ALWAYS_INIT
718	bool
719	select STACKDEPOT
720
721config REF_TRACKER
722	bool
723	depends on STACKTRACE_SUPPORT
724	select STACKDEPOT
725
726config SBITMAP
727	bool
728
729config PARMAN
730	tristate "parman" if COMPILE_TEST
731
732config OBJAGG
733	tristate "objagg" if COMPILE_TEST
734
735config LWQ_TEST
736	bool "Boot-time test for lwq queuing"
737	help
738          Run boot-time test of light-weight queuing.
739
740endmenu
741
742config GENERIC_IOREMAP
743	bool
744
745config GENERIC_LIB_ASHLDI3
746	bool
747
748config GENERIC_LIB_ASHRDI3
749	bool
750
751config GENERIC_LIB_LSHRDI3
752	bool
753
754config GENERIC_LIB_MULDI3
755	bool
756
757config GENERIC_LIB_CMPDI2
758	bool
759
760config GENERIC_LIB_UCMPDI2
761	bool
762
763config GENERIC_LIB_DEVMEM_IS_ALLOWED
764	bool
765
766config PLDMFW
767	bool
768	default n
769
770config ASN1_ENCODER
771       tristate
772
773config POLYNOMIAL
774       tristate
775
776config FIRMWARE_TABLE
777	bool
778