xref: /openbmc/linux/lib/Kconfig (revision 6342a20e)
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
419config BCH_CONST_PARAMS
420	bool
421	help
422	  Drivers may select this option to force specific constant
423	  values for parameters 'm' (Galois field order) and 't'
424	  (error correction capability). Those specific values must
425	  be set by declaring default values for symbols BCH_CONST_M
426	  and BCH_CONST_T.
427	  Doing so will enable extra compiler optimizations,
428	  improving encoding and decoding performance up to 2x for
429	  usual (m,t) values (typically such that m*t < 200).
430	  When this option is selected, the BCH library supports
431	  only a single (m,t) configuration. This is mainly useful
432	  for NAND flash board drivers requiring known, fixed BCH
433	  parameters.
434
435config BCH_CONST_M
436	int
437	range 5 15
438	help
439	  Constant value for Galois field order 'm'. If 'k' is the
440	  number of data bits to protect, 'm' should be chosen such
441	  that (k + m*t) <= 2**m - 1.
442	  Drivers should declare a default value for this symbol if
443	  they select option BCH_CONST_PARAMS.
444
445config BCH_CONST_T
446	int
447	help
448	  Constant value for error correction capability in bits 't'.
449	  Drivers should declare a default value for this symbol if
450	  they select option BCH_CONST_PARAMS.
451
452#
453# Textsearch support is select'ed if needed
454#
455config TEXTSEARCH
456	bool
457
458config TEXTSEARCH_KMP
459	tristate
460
461config TEXTSEARCH_BM
462	tristate
463
464config TEXTSEARCH_FSM
465	tristate
466
467config BTREE
468	bool
469
470config INTERVAL_TREE
471	bool
472	help
473	  Simple, embeddable, interval-tree. Can find the start of an
474	  overlapping range in log(n) time and then iterate over all
475	  overlapping nodes. The algorithm is implemented as an
476	  augmented rbtree.
477
478	  See:
479
480		Documentation/core-api/rbtree.rst
481
482	  for more information.
483
484config INTERVAL_TREE_SPAN_ITER
485	bool
486	depends on INTERVAL_TREE
487
488config XARRAY_MULTI
489	bool
490	help
491	  Support entries which occupy multiple consecutive indices in the
492	  XArray.
493
494config ASSOCIATIVE_ARRAY
495	bool
496	help
497	  Generic associative array.  Can be searched and iterated over whilst
498	  it is being modified.  It is also reasonably quick to search and
499	  modify.  The algorithms are non-recursive, and the trees are highly
500	  capacious.
501
502	  See:
503
504		Documentation/core-api/assoc_array.rst
505
506	  for more information.
507
508config HAS_IOMEM
509	bool
510	depends on !NO_IOMEM
511	default y
512
513config HAS_IOPORT
514	bool
515
516config HAS_IOPORT_MAP
517	bool
518	depends on HAS_IOMEM && !NO_IOPORT_MAP
519	default y
520
521source "kernel/dma/Kconfig"
522
523config SGL_ALLOC
524	bool
525	default n
526
527config IOMMU_HELPER
528	bool
529
530config CHECK_SIGNATURE
531	bool
532
533config CPUMASK_OFFSTACK
534	bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
535	help
536	  Use dynamic allocation for cpumask_var_t, instead of putting
537	  them on the stack.  This is a bit more expensive, but avoids
538	  stack overflow.
539
540config FORCE_NR_CPUS
541       bool "Set number of CPUs at compile time"
542       depends on SMP && EXPERT && !COMPILE_TEST
543       help
544         Say Yes if you have NR_CPUS set to an actual number of possible
545         CPUs in your system, not to a default value. This forces the core
546         code to rely on compile-time value and optimize kernel routines
547         better.
548
549config CPU_RMAP
550	bool
551	depends on SMP
552
553config DQL
554	bool
555
556config GLOB
557	bool
558#	This actually supports modular compilation, but the module overhead
559#	is ridiculous for the amount of code involved.	Until an out-of-tree
560#	driver asks for it, we'll just link it directly it into the kernel
561#	when required.  Since we're ignoring out-of-tree users,	there's also
562#	no need bother prompting for a manual decision:
563#	prompt "glob_match() function"
564	help
565	  This option provides a glob_match function for performing
566	  simple text pattern matching.  It originated in the ATA code
567	  to blacklist particular drive models, but other device drivers
568	  may need similar functionality.
569
570	  All drivers in the Linux kernel tree that require this function
571	  should automatically select this option.  Say N unless you
572	  are compiling an out-of tree driver which tells you that it
573	  depends on this.
574
575config GLOB_SELFTEST
576	tristate "glob self-test on init"
577	depends on GLOB
578	help
579	  This option enables a simple self-test of the glob_match
580	  function on startup.	It is primarily useful for people
581	  working on the code to ensure they haven't introduced any
582	  regressions.
583
584	  It only adds a little bit of code and slows kernel boot (or
585	  module load) by a small amount, so you're welcome to play with
586	  it, but you probably don't need it.
587
588#
589# Netlink attribute parsing support is select'ed if needed
590#
591config NLATTR
592	bool
593
594#
595# Generic 64-bit atomic support is selected if needed
596#
597config GENERIC_ATOMIC64
598       bool
599
600config LRU_CACHE
601	tristate
602
603config CLZ_TAB
604	bool
605
606config IRQ_POLL
607	bool "IRQ polling library"
608	help
609	  Helper library to poll interrupt mitigation using polling.
610
611config MPILIB
612	tristate
613	select CLZ_TAB
614	help
615	  Multiprecision maths library from GnuPG.
616	  It is used to implement RSA digital signature verification,
617	  which is used by IMA/EVM digital signature extension.
618
619config SIGNATURE
620	tristate
621	depends on KEYS
622	select CRYPTO
623	select CRYPTO_SHA1
624	select MPILIB
625	help
626	  Digital signature verification. Currently only RSA is supported.
627	  Implementation is done using GnuPG MPI library
628
629config DIMLIB
630	bool
631	help
632	  Dynamic Interrupt Moderation library.
633	  Implements an algorithm for dynamically changing CQ moderation values
634	  according to run time performance.
635
636#
637# libfdt files, only selected if needed.
638#
639config LIBFDT
640	bool
641
642config OID_REGISTRY
643	tristate
644	help
645	  Enable fast lookup object identifier registry.
646
647config UCS2_STRING
648	tristate
649
650#
651# generic vdso
652#
653source "lib/vdso/Kconfig"
654
655source "lib/fonts/Kconfig"
656
657config SG_SPLIT
658	def_bool n
659	help
660	 Provides a helper to split scatterlists into chunks, each chunk being
661	 a scatterlist. This should be selected by a driver or an API which
662	 whishes to split a scatterlist amongst multiple DMA channels.
663
664config SG_POOL
665	def_bool n
666	help
667	 Provides a helper to allocate chained scatterlists. This should be
668	 selected by a driver or an API which whishes to allocate chained
669	 scatterlist.
670
671#
672# sg chaining option
673#
674
675config ARCH_NO_SG_CHAIN
676	def_bool n
677
678config ARCH_HAS_PMEM_API
679	bool
680
681config MEMREGION
682	bool
683
684config ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
685	bool
686
687config ARCH_HAS_MEMREMAP_COMPAT_ALIGN
688	bool
689
690# use memcpy to implement user copies for nommu architectures
691config UACCESS_MEMCPY
692	bool
693
694config ARCH_HAS_UACCESS_FLUSHCACHE
695	bool
696
697# arch has a concept of a recoverable synchronous exception due to a
698# memory-read error like x86 machine-check or ARM data-abort, and
699# implements copy_mc_to_{user,kernel} to abort and report
700# 'bytes-transferred' if that exception fires when accessing the source
701# buffer.
702config ARCH_HAS_COPY_MC
703	bool
704
705# Temporary. Goes away when all archs are cleaned up
706config ARCH_STACKWALK
707       bool
708
709config STACKDEPOT
710	bool
711	select STACKTRACE
712
713config STACKDEPOT_ALWAYS_INIT
714	bool
715	select STACKDEPOT
716
717config REF_TRACKER
718	bool
719	depends on STACKTRACE_SUPPORT
720	select STACKDEPOT
721
722config SBITMAP
723	bool
724
725config PARMAN
726	tristate "parman" if COMPILE_TEST
727
728config OBJAGG
729	tristate "objagg" if COMPILE_TEST
730
731endmenu
732
733config GENERIC_IOREMAP
734	bool
735
736config GENERIC_LIB_ASHLDI3
737	bool
738
739config GENERIC_LIB_ASHRDI3
740	bool
741
742config GENERIC_LIB_LSHRDI3
743	bool
744
745config GENERIC_LIB_MULDI3
746	bool
747
748config GENERIC_LIB_CMPDI2
749	bool
750
751config GENERIC_LIB_UCMPDI2
752	bool
753
754config GENERIC_LIB_DEVMEM_IS_ALLOWED
755	bool
756
757config PLDMFW
758	bool
759	default n
760
761config ASN1_ENCODER
762       tristate
763
764config POLYNOMIAL
765       tristate
766