xref: /linux/lib/Kconfig (revision a8b70ccf10e38775785d9cb12ead916474549f99)
1#
2# Library configuration
3#
4
5config BINARY_PRINTF
6	def_bool n
7
8menu "Library routines"
9
10config RAID6_PQ
11	tristate
12
13config BITREVERSE
14	tristate
15
16config HAVE_ARCH_BITREVERSE
17	bool
18	default n
19	depends on BITREVERSE
20	help
21	  This option enables the use of hardware bit-reversal instructions on
22	  architectures which support such operations.
23
24config RATIONAL
25	bool
26
27config GENERIC_STRNCPY_FROM_USER
28	bool
29
30config GENERIC_STRNLEN_USER
31	bool
32
33config GENERIC_NET_UTILS
34	bool
35
36config GENERIC_FIND_FIRST_BIT
37	bool
38
39config NO_GENERIC_PCI_IOPORT_MAP
40	bool
41
42config GENERIC_PCI_IOMAP
43	bool
44
45config GENERIC_IOMAP
46	bool
47	select GENERIC_PCI_IOMAP
48
49config STMP_DEVICE
50	bool
51
52config ARCH_USE_CMPXCHG_LOCKREF
53	bool
54
55config ARCH_HAS_FAST_MULTIPLIER
56	bool
57
58config INDIRECT_PIO
59	bool "Access I/O in non-MMIO mode"
60	depends on ARM64
61	help
62	  On some platforms where no separate I/O space exists, there are I/O
63	  hosts which can not be accessed in MMIO mode. Using the logical PIO
64	  mechanism, the host-local I/O resource can be mapped into system
65	  logic PIO space shared with MMIO hosts, such as PCI/PCIe, then the
66	  system can access the I/O devices with the mapped-logic PIO through
67	  I/O accessors.
68
69	  This way has relatively little I/O performance cost. Please make
70	  sure your devices really need this configure item enabled.
71
72	  When in doubt, say N.
73
74config CRC_CCITT
75	tristate "CRC-CCITT functions"
76	help
77	  This option is provided for the case where no in-kernel-tree
78	  modules require CRC-CCITT functions, but a module built outside
79	  the kernel tree does. Such modules that use library CRC-CCITT
80	  functions require M here.
81
82config CRC16
83	tristate "CRC16 functions"
84	help
85	  This option is provided for the case where no in-kernel-tree
86	  modules require CRC16 functions, but a module built outside
87	  the kernel tree does. Such modules that use library CRC16
88	  functions require M here.
89
90config CRC_T10DIF
91	tristate "CRC calculation for the T10 Data Integrity Field"
92	select CRYPTO
93	select CRYPTO_CRCT10DIF
94	help
95	  This option is only needed if a module that's not in the
96	  kernel tree needs to calculate CRC checks for use with the
97	  SCSI data integrity subsystem.
98
99config CRC_ITU_T
100	tristate "CRC ITU-T V.41 functions"
101	help
102	  This option is provided for the case where no in-kernel-tree
103	  modules require CRC ITU-T V.41 functions, but a module built outside
104	  the kernel tree does. Such modules that use library CRC ITU-T V.41
105	  functions require M here.
106
107config CRC32
108	tristate "CRC32/CRC32c functions"
109	default y
110	select BITREVERSE
111	help
112	  This option is provided for the case where no in-kernel-tree
113	  modules require CRC32/CRC32c functions, but a module built outside
114	  the kernel tree does. Such modules that use library CRC32/CRC32c
115	  functions require M here.
116
117config CRC32_SELFTEST
118	tristate "CRC32 perform self test on init"
119	depends on CRC32
120	help
121	  This option enables the CRC32 library functions to perform a
122	  self test on initialization. The self test computes crc32_le
123	  and crc32_be over byte strings with random alignment and length
124	  and computes the total elapsed time and number of bytes processed.
125
126choice
127	prompt "CRC32 implementation"
128	depends on CRC32
129	default CRC32_SLICEBY8
130	help
131	  This option allows a kernel builder to override the default choice
132	  of CRC32 algorithm.  Choose the default ("slice by 8") unless you
133	  know that you need one of the others.
134
135config CRC32_SLICEBY8
136	bool "Slice by 8 bytes"
137	help
138	  Calculate checksum 8 bytes at a time with a clever slicing algorithm.
139	  This is the fastest algorithm, but comes with a 8KiB lookup table.
140	  Most modern processors have enough cache to hold this table without
141	  thrashing the cache.
142
143	  This is the default implementation choice.  Choose this one unless
144	  you have a good reason not to.
145
146config CRC32_SLICEBY4
147	bool "Slice by 4 bytes"
148	help
149	  Calculate checksum 4 bytes at a time with a clever slicing algorithm.
150	  This is a bit slower than slice by 8, but has a smaller 4KiB lookup
151	  table.
152
153	  Only choose this option if you know what you are doing.
154
155config CRC32_SARWATE
156	bool "Sarwate's Algorithm (one byte at a time)"
157	help
158	  Calculate checksum a byte at a time using Sarwate's algorithm.  This
159	  is not particularly fast, but has a small 256 byte lookup table.
160
161	  Only choose this option if you know what you are doing.
162
163config CRC32_BIT
164	bool "Classic Algorithm (one bit at a time)"
165	help
166	  Calculate checksum one bit at a time.  This is VERY slow, but has
167	  no lookup table.  This is provided as a debugging option.
168
169	  Only choose this option if you are debugging crc32.
170
171endchoice
172
173config CRC4
174	tristate "CRC4 functions"
175	help
176	  This option is provided for the case where no in-kernel-tree
177	  modules require CRC4 functions, but a module built outside
178	  the kernel tree does. Such modules that use library CRC4
179	  functions require M here.
180
181config CRC7
182	tristate "CRC7 functions"
183	help
184	  This option is provided for the case where no in-kernel-tree
185	  modules require CRC7 functions, but a module built outside
186	  the kernel tree does. Such modules that use library CRC7
187	  functions require M here.
188
189config LIBCRC32C
190	tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check"
191	select CRYPTO
192	select CRYPTO_CRC32C
193	help
194	  This option is provided for the case where no in-kernel-tree
195	  modules require CRC32c functions, but a module built outside the
196	  kernel tree does. Such modules that use library CRC32c functions
197	  require M here.  See Castagnoli93.
198	  Module will be libcrc32c.
199
200config CRC8
201	tristate "CRC8 function"
202	help
203	  This option provides CRC8 function. Drivers may select this
204	  when they need to do cyclic redundancy check according CRC8
205	  algorithm. Module will be called crc8.
206
207config XXHASH
208	tristate
209
210config AUDIT_GENERIC
211	bool
212	depends on AUDIT && !AUDIT_ARCH
213	default y
214
215config AUDIT_ARCH_COMPAT_GENERIC
216	bool
217	default n
218
219config AUDIT_COMPAT_GENERIC
220	bool
221	depends on AUDIT_GENERIC && AUDIT_ARCH_COMPAT_GENERIC && COMPAT
222	default y
223
224config RANDOM32_SELFTEST
225	bool "PRNG perform self test on init"
226	default n
227	help
228	  This option enables the 32 bit PRNG library functions to perform a
229	  self test on initialization.
230
231#
232# compression support is select'ed if needed
233#
234config 842_COMPRESS
235	select CRC32
236	tristate
237
238config 842_DECOMPRESS
239	select CRC32
240	tristate
241
242config ZLIB_INFLATE
243	tristate
244
245config ZLIB_DEFLATE
246	tristate
247	select BITREVERSE
248
249config LZO_COMPRESS
250	tristate
251
252config LZO_DECOMPRESS
253	tristate
254
255config LZ4_COMPRESS
256	tristate
257
258config LZ4HC_COMPRESS
259	tristate
260
261config LZ4_DECOMPRESS
262	tristate
263
264config ZSTD_COMPRESS
265	select XXHASH
266	tristate
267
268config ZSTD_DECOMPRESS
269	select XXHASH
270	tristate
271
272source "lib/xz/Kconfig"
273
274#
275# These all provide a common interface (hence the apparent duplication with
276# ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.)
277#
278config DECOMPRESS_GZIP
279	select ZLIB_INFLATE
280	tristate
281
282config DECOMPRESS_BZIP2
283	tristate
284
285config DECOMPRESS_LZMA
286	tristate
287
288config DECOMPRESS_XZ
289	select XZ_DEC
290	tristate
291
292config DECOMPRESS_LZO
293	select LZO_DECOMPRESS
294	tristate
295
296config DECOMPRESS_LZ4
297	select LZ4_DECOMPRESS
298	tristate
299
300#
301# Generic allocator support is selected if needed
302#
303config GENERIC_ALLOCATOR
304	bool
305
306#
307# reed solomon support is select'ed if needed
308#
309config REED_SOLOMON
310	tristate
311
312config REED_SOLOMON_ENC8
313	bool
314
315config REED_SOLOMON_DEC8
316	bool
317
318config REED_SOLOMON_ENC16
319	bool
320
321config REED_SOLOMON_DEC16
322	bool
323
324#
325# BCH support is selected if needed
326#
327config BCH
328	tristate
329
330config BCH_CONST_PARAMS
331	bool
332	help
333	  Drivers may select this option to force specific constant
334	  values for parameters 'm' (Galois field order) and 't'
335	  (error correction capability). Those specific values must
336	  be set by declaring default values for symbols BCH_CONST_M
337	  and BCH_CONST_T.
338	  Doing so will enable extra compiler optimizations,
339	  improving encoding and decoding performance up to 2x for
340	  usual (m,t) values (typically such that m*t < 200).
341	  When this option is selected, the BCH library supports
342	  only a single (m,t) configuration. This is mainly useful
343	  for NAND flash board drivers requiring known, fixed BCH
344	  parameters.
345
346config BCH_CONST_M
347	int
348	range 5 15
349	help
350	  Constant value for Galois field order 'm'. If 'k' is the
351	  number of data bits to protect, 'm' should be chosen such
352	  that (k + m*t) <= 2**m - 1.
353	  Drivers should declare a default value for this symbol if
354	  they select option BCH_CONST_PARAMS.
355
356config BCH_CONST_T
357	int
358	help
359	  Constant value for error correction capability in bits 't'.
360	  Drivers should declare a default value for this symbol if
361	  they select option BCH_CONST_PARAMS.
362
363#
364# Textsearch support is select'ed if needed
365#
366config TEXTSEARCH
367	bool
368
369config TEXTSEARCH_KMP
370	tristate
371
372config TEXTSEARCH_BM
373	tristate
374
375config TEXTSEARCH_FSM
376	tristate
377
378config BTREE
379	bool
380
381config INTERVAL_TREE
382	bool
383	help
384	  Simple, embeddable, interval-tree. Can find the start of an
385	  overlapping range in log(n) time and then iterate over all
386	  overlapping nodes. The algorithm is implemented as an
387	  augmented rbtree.
388
389	  See:
390
391		Documentation/rbtree.txt
392
393	  for more information.
394
395config RADIX_TREE_MULTIORDER
396	bool
397
398config ASSOCIATIVE_ARRAY
399	bool
400	help
401	  Generic associative array.  Can be searched and iterated over whilst
402	  it is being modified.  It is also reasonably quick to search and
403	  modify.  The algorithms are non-recursive, and the trees are highly
404	  capacious.
405
406	  See:
407
408		Documentation/assoc_array.txt
409
410	  for more information.
411
412config HAS_IOMEM
413	bool
414	depends on !NO_IOMEM
415	select GENERIC_IO
416	default y
417
418config HAS_IOPORT_MAP
419	bool
420	depends on HAS_IOMEM && !NO_IOPORT_MAP
421	default y
422
423config HAS_DMA
424	bool
425	depends on !NO_DMA
426	default y
427
428config SGL_ALLOC
429	bool
430	default n
431
432config DMA_DIRECT_OPS
433	bool
434	depends on HAS_DMA && (!64BIT || ARCH_DMA_ADDR_T_64BIT)
435	default n
436
437config DMA_VIRT_OPS
438	bool
439	depends on HAS_DMA && (!64BIT || ARCH_DMA_ADDR_T_64BIT)
440	default n
441
442config CHECK_SIGNATURE
443	bool
444
445config CPUMASK_OFFSTACK
446	bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
447	help
448	  Use dynamic allocation for cpumask_var_t, instead of putting
449	  them on the stack.  This is a bit more expensive, but avoids
450	  stack overflow.
451
452config CPU_RMAP
453	bool
454	depends on SMP
455
456config DQL
457	bool
458
459config GLOB
460	bool
461#	This actually supports modular compilation, but the module overhead
462#	is ridiculous for the amount of code involved.	Until an out-of-tree
463#	driver asks for it, we'll just link it directly it into the kernel
464#	when required.  Since we're ignoring out-of-tree users,	there's also
465#	no need bother prompting for a manual decision:
466#	prompt "glob_match() function"
467	help
468	  This option provides a glob_match function for performing
469	  simple text pattern matching.  It originated in the ATA code
470	  to blacklist particular drive models, but other device drivers
471	  may need similar functionality.
472
473	  All drivers in the Linux kernel tree that require this function
474	  should automatically select this option.  Say N unless you
475	  are compiling an out-of tree driver which tells you that it
476	  depends on this.
477
478config GLOB_SELFTEST
479	tristate "glob self-test on init"
480	depends on GLOB
481	help
482	  This option enables a simple self-test of the glob_match
483	  function on startup.	It is primarily useful for people
484	  working on the code to ensure they haven't introduced any
485	  regressions.
486
487	  It only adds a little bit of code and slows kernel boot (or
488	  module load) by a small amount, so you're welcome to play with
489	  it, but you probably don't need it.
490
491#
492# Netlink attribute parsing support is select'ed if needed
493#
494config NLATTR
495	bool
496
497#
498# Generic 64-bit atomic support is selected if needed
499#
500config GENERIC_ATOMIC64
501       bool
502
503config LRU_CACHE
504	tristate
505
506config CLZ_TAB
507	bool
508
509config CORDIC
510	tristate "CORDIC algorithm"
511	help
512	  This option provides an implementation of the CORDIC algorithm;
513	  calculations are in fixed point. Module will be called cordic.
514
515config DDR
516	bool "JEDEC DDR data"
517	help
518	  Data from JEDEC specs for DDR SDRAM memories,
519	  particularly the AC timing parameters and addressing
520	  information. This data is useful for drivers handling
521	  DDR SDRAM controllers.
522
523config IRQ_POLL
524	bool "IRQ polling library"
525	help
526	  Helper library to poll interrupt mitigation using polling.
527
528config MPILIB
529	tristate
530	select CLZ_TAB
531	help
532	  Multiprecision maths library from GnuPG.
533	  It is used to implement RSA digital signature verification,
534	  which is used by IMA/EVM digital signature extension.
535
536config SIGNATURE
537	tristate
538	depends on KEYS
539	select CRYPTO
540	select CRYPTO_SHA1
541	select MPILIB
542	help
543	  Digital signature verification. Currently only RSA is supported.
544	  Implementation is done using GnuPG MPI library
545
546#
547# libfdt files, only selected if needed.
548#
549config LIBFDT
550	bool
551
552config OID_REGISTRY
553	tristate
554	help
555	  Enable fast lookup object identifier registry.
556
557config UCS2_STRING
558        tristate
559
560source "lib/fonts/Kconfig"
561
562config SG_SPLIT
563	def_bool n
564	help
565	 Provides a helper to split scatterlists into chunks, each chunk being
566	 a scatterlist. This should be selected by a driver or an API which
567	 whishes to split a scatterlist amongst multiple DMA channels.
568
569config SG_POOL
570	def_bool n
571	help
572	 Provides a helper to allocate chained scatterlists. This should be
573	 selected by a driver or an API which whishes to allocate chained
574	 scatterlist.
575
576#
577# sg chaining option
578#
579
580config ARCH_HAS_SG_CHAIN
581	def_bool n
582
583config ARCH_HAS_PMEM_API
584	bool
585
586config ARCH_HAS_UACCESS_FLUSHCACHE
587	bool
588
589config STACKDEPOT
590	bool
591	select STACKTRACE
592
593config SBITMAP
594	bool
595
596config PARMAN
597	tristate "parman" if COMPILE_TEST
598
599config PRIME_NUMBERS
600	tristate
601
602config STRING_SELFTEST
603	tristate "Test string functions"
604
605endmenu
606
607config GENERIC_ASHLDI3
608	bool
609
610config GENERIC_ASHRDI3
611	bool
612
613config GENERIC_LSHRDI3
614	bool
615
616config GENERIC_MULDI3
617	bool
618
619config GENERIC_CMPDI2
620	bool
621
622config GENERIC_UCMPDI2
623	bool
624