2 # Library configuration
8 menu "Library routines"
13 config RAID6_PQ_BENCHMARK
14 bool "Automatically choose fastest RAID6 PQ functions"
18 Benchmark all available RAID6 PQ functions on init and choose the
24 config HAVE_ARCH_BITREVERSE
29 This option enables the use of hardware bit-reversal instructions on
30 architectures which support such operations.
35 config GENERIC_STRNCPY_FROM_USER
38 config GENERIC_STRNLEN_USER
41 config GENERIC_NET_UTILS
44 config GENERIC_FIND_FIRST_BIT
47 config NO_GENERIC_PCI_IOPORT_MAP
50 config GENERIC_PCI_IOMAP
55 select GENERIC_PCI_IOMAP
64 config ARCH_USE_CMPXCHG_LOCKREF
67 config ARCH_HAS_FAST_MULTIPLIER
71 tristate "CRC-CCITT functions"
73 This option is provided for the case where no in-kernel-tree
74 modules require CRC-CCITT functions, but a module built outside
75 the kernel tree does. Such modules that use library CRC-CCITT
76 functions require M here.
79 tristate "CRC16 functions"
81 This option is provided for the case where no in-kernel-tree
82 modules require CRC16 functions, but a module built outside
83 the kernel tree does. Such modules that use library CRC16
84 functions require M here.
87 tristate "CRC calculation for the T10 Data Integrity Field"
89 select CRYPTO_CRCT10DIF
91 This option is only needed if a module that's not in the
92 kernel tree needs to calculate CRC checks for use with the
93 SCSI data integrity subsystem.
96 tristate "CRC ITU-T V.41 functions"
98 This option is provided for the case where no in-kernel-tree
99 modules require CRC ITU-T V.41 functions, but a module built outside
100 the kernel tree does. Such modules that use library CRC ITU-T V.41
101 functions require M here.
104 tristate "CRC32/CRC32c functions"
108 This option is provided for the case where no in-kernel-tree
109 modules require CRC32/CRC32c functions, but a module built outside
110 the kernel tree does. Such modules that use library CRC32/CRC32c
111 functions require M here.
113 config CRC32_SELFTEST
114 bool "CRC32 perform self test on init"
118 This option enables the CRC32 library functions to perform a
119 self test on initialization. The self test computes crc32_le
120 and crc32_be over byte strings with random alignment and length
121 and computes the total elapsed time and number of bytes processed.
124 prompt "CRC32 implementation"
126 default CRC32_SLICEBY8
128 This option allows a kernel builder to override the default choice
129 of CRC32 algorithm. Choose the default ("slice by 8") unless you
130 know that you need one of the others.
132 config CRC32_SLICEBY8
133 bool "Slice by 8 bytes"
135 Calculate checksum 8 bytes at a time with a clever slicing algorithm.
136 This is the fastest algorithm, but comes with a 8KiB lookup table.
137 Most modern processors have enough cache to hold this table without
140 This is the default implementation choice. Choose this one unless
141 you have a good reason not to.
143 config CRC32_SLICEBY4
144 bool "Slice by 4 bytes"
146 Calculate checksum 4 bytes at a time with a clever slicing algorithm.
147 This is a bit slower than slice by 8, but has a smaller 4KiB lookup
150 Only choose this option if you know what you are doing.
153 bool "Sarwate's Algorithm (one byte at a time)"
155 Calculate checksum a byte at a time using Sarwate's algorithm. This
156 is not particularly fast, but has a small 256 byte lookup table.
158 Only choose this option if you know what you are doing.
161 bool "Classic Algorithm (one bit at a time)"
163 Calculate checksum one bit at a time. This is VERY slow, but has
164 no lookup table. This is provided as a debugging option.
166 Only choose this option if you are debugging crc32.
171 tristate "CRC7 functions"
173 This option is provided for the case where no in-kernel-tree
174 modules require CRC7 functions, but a module built outside
175 the kernel tree does. Such modules that use library CRC7
176 functions require M here.
179 tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check"
183 This option is provided for the case where no in-kernel-tree
184 modules require CRC32c functions, but a module built outside the
185 kernel tree does. Such modules that use library CRC32c functions
186 require M here. See Castagnoli93.
187 Module will be libcrc32c.
190 tristate "CRC8 function"
192 This option provides CRC8 function. Drivers may select this
193 when they need to do cyclic redundancy check according CRC8
194 algorithm. Module will be called crc8.
201 depends on AUDIT && !AUDIT_ARCH
204 config AUDIT_ARCH_COMPAT_GENERIC
208 config AUDIT_COMPAT_GENERIC
210 depends on AUDIT_GENERIC && AUDIT_ARCH_COMPAT_GENERIC && COMPAT
213 config RANDOM32_SELFTEST
214 bool "PRNG perform self test on init"
217 This option enables the 32 bit PRNG library functions to perform a
218 self test on initialization.
221 # compression support is select'ed if needed
227 config 842_DECOMPRESS
241 config LZO_DECOMPRESS
247 config LZ4HC_COMPRESS
250 config LZ4_DECOMPRESS
257 config ZSTD_DECOMPRESS
261 source "lib/xz/Kconfig"
264 # These all provide a common interface (hence the apparent duplication with
265 # ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.)
267 config DECOMPRESS_GZIP
271 config DECOMPRESS_BZIP2
274 config DECOMPRESS_LZMA
281 config DECOMPRESS_LZO
282 select LZO_DECOMPRESS
285 config DECOMPRESS_LZ4
286 select LZ4_DECOMPRESS
290 # Generic allocator support is selected if needed
292 config GENERIC_ALLOCATOR
296 # reed solomon support is select'ed if needed
301 config REED_SOLOMON_ENC8
304 config REED_SOLOMON_DEC8
307 config REED_SOLOMON_ENC16
310 config REED_SOLOMON_DEC16
314 # BCH support is selected if needed
319 config BCH_CONST_PARAMS
322 Drivers may select this option to force specific constant
323 values for parameters 'm' (Galois field order) and 't'
324 (error correction capability). Those specific values must
325 be set by declaring default values for symbols BCH_CONST_M
327 Doing so will enable extra compiler optimizations,
328 improving encoding and decoding performance up to 2x for
329 usual (m,t) values (typically such that m*t < 200).
330 When this option is selected, the BCH library supports
331 only a single (m,t) configuration. This is mainly useful
332 for NAND flash board drivers requiring known, fixed BCH
339 Constant value for Galois field order 'm'. If 'k' is the
340 number of data bits to protect, 'm' should be chosen such
341 that (k + m*t) <= 2**m - 1.
342 Drivers should declare a default value for this symbol if
343 they select option BCH_CONST_PARAMS.
348 Constant value for error correction capability in bits 't'.
349 Drivers should declare a default value for this symbol if
350 they select option BCH_CONST_PARAMS.
353 # Textsearch support is select'ed if needed
358 config TEXTSEARCH_KMP
364 config TEXTSEARCH_FSM
373 Simple, embeddable, interval-tree. Can find the start of an
374 overlapping range in log(n) time and then iterate over all
375 overlapping nodes. The algorithm is implemented as an
380 Documentation/rbtree.txt
382 for more information.
384 config RADIX_TREE_MULTIORDER
387 config ASSOCIATIVE_ARRAY
390 Generic associative array. Can be searched and iterated over whilst
391 it is being modified. It is also reasonably quick to search and
392 modify. The algorithms are non-recursive, and the trees are highly
397 Documentation/assoc_array.txt
399 for more information.
407 config HAS_IOPORT_MAP
409 depends on HAS_IOMEM && !NO_IOPORT_MAP
417 config CHECK_SIGNATURE
420 config CPUMASK_OFFSTACK
421 bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
423 Use dynamic allocation for cpumask_var_t, instead of putting
424 them on the stack. This is a bit more expensive, but avoids
436 # This actually supports modular compilation, but the module overhead
437 # is ridiculous for the amount of code involved. Until an out-of-tree
438 # driver asks for it, we'll just link it directly it into the kernel
439 # when required. Since we're ignoring out-of-tree users, there's also
440 # no need bother prompting for a manual decision:
441 # prompt "glob_match() function"
443 This option provides a glob_match function for performing
444 simple text pattern matching. It originated in the ATA code
445 to blacklist particular drive models, but other device drivers
446 may need similar functionality.
448 All drivers in the Linux kernel tree that require this function
449 should automatically select this option. Say N unless you
450 are compiling an out-of tree driver which tells you that it
454 bool "glob self-test on init"
458 This option enables a simple self-test of the glob_match
459 function on startup. It is primarily useful for people
460 working on the code to ensure they haven't introduced any
463 It only adds a little bit of code and slows kernel boot (or
464 module load) by a small amount, so you're welcome to play with
465 it, but you probably don't need it.
468 # Netlink attribute parsing support is select'ed if needed
474 # Generic 64-bit atomic support is selected if needed
476 config GENERIC_ATOMIC64
486 tristate "CORDIC algorithm"
488 This option provides an implementation of the CORDIC algorithm;
489 calculations are in fixed point. Module will be called cordic.
492 bool "JEDEC DDR data"
494 Data from JEDEC specs for DDR SDRAM memories,
495 particularly the AC timing parameters and addressing
496 information. This data is useful for drivers handling
497 DDR SDRAM controllers.
500 bool "IRQ polling library"
502 Helper library to poll interrupt mitigation using polling.
508 Multiprecision maths library from GnuPG.
509 It is used to implement RSA digital signature verification,
510 which is used by IMA/EVM digital signature extension.
519 Digital signature verification. Currently only RSA is supported.
520 Implementation is done using GnuPG MPI library
523 # libfdt files, only selected if needed.
531 Enable fast lookup object identifier registry.
536 source "lib/fonts/Kconfig"
541 Provides a helper to split scatterlists into chunks, each chunk being
542 a scatterlist. This should be selected by a driver or an API which
543 whishes to split a scatterlist amongst multiple DMA channels.
548 Provides a helper to allocate chained scatterlists. This should be
549 selected by a driver or an API which whishes to allocate chained
556 config ARCH_HAS_SG_CHAIN
559 config ARCH_HAS_PMEM_API
562 config ARCH_HAS_MMIO_FLUSH