lib/Kconfig

   1 #
   2 # Library configuration
   3 #
   4
   5 config BINARY_PRINTF
   6         def_bool n
   7
   8 menu "Library routines"
   9
  10 config RAID6_PQ
  11         tristate
  12
  13 config BITREVERSE
  14         tristate
  15
  16 config 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
  24 config RATIONAL
  25         bool
  26
  27 config GENERIC_STRNCPY_FROM_USER
  28         bool
  29
  30 config GENERIC_STRNLEN_USER
  31         bool
  32
  33 config GENERIC_NET_UTILS
  34         bool
  35
  36 config GENERIC_FIND_FIRST_BIT
  37         bool
  38
  39 config NO_GENERIC_PCI_IOPORT_MAP
  40         bool
  41
  42 config GENERIC_PCI_IOMAP
  43         bool
  44
  45 config GENERIC_IOMAP
  46         bool
  47         select GENERIC_PCI_IOMAP
  48
  49 config STMP_DEVICE
  50         bool
  51
  52 config ARCH_USE_CMPXCHG_LOCKREF
  53         bool
  54
  55 config ARCH_HAS_FAST_MULTIPLIER
  56         bool
  57
  58 config 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
  74 config 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
  82 config 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
  90 config 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
  99 config 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
 107 config 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
 117 config 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
 126 choice
 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
 135 config 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
 146 config 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
 155 config 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
 163 config 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
 171 endchoice
 172
 173 config CRC64
 174         tristate "CRC64 functions"
 175         help
 176           This option is provided for the case where no in-kernel-tree
 177           modules require CRC64 functions, but a module built outside
 178           the kernel tree does. Such modules that use library CRC64
 179           functions require M here.
 180
 181 config CRC4
 182         tristate "CRC4 functions"
 183         help
 184           This option is provided for the case where no in-kernel-tree
 185           modules require CRC4 functions, but a module built outside
 186           the kernel tree does. Such modules that use library CRC4
 187           functions require M here.
 188
 189 config CRC7
 190         tristate "CRC7 functions"
 191         help
 192           This option is provided for the case where no in-kernel-tree
 193           modules require CRC7 functions, but a module built outside
 194           the kernel tree does. Such modules that use library CRC7
 195           functions require M here.
 196
 197 config LIBCRC32C
 198         tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check"
 199         select CRYPTO
 200         select CRYPTO_CRC32C
 201         help
 202           This option is provided for the case where no in-kernel-tree
 203           modules require CRC32c functions, but a module built outside the
 204           kernel tree does. Such modules that use library CRC32c functions
 205           require M here.  See Castagnoli93.
 206           Module will be libcrc32c.
 207
 208 config CRC8
 209         tristate "CRC8 function"
 210         help
 211           This option provides CRC8 function. Drivers may select this
 212           when they need to do cyclic redundancy check according CRC8
 213           algorithm. Module will be called crc8.
 214
 215 config XXHASH
 216         tristate
 217
 218 config AUDIT_GENERIC
 219         bool
 220         depends on AUDIT && !AUDIT_ARCH
 221         default y
 222
 223 config AUDIT_ARCH_COMPAT_GENERIC
 224         bool
 225         default n
 226
 227 config AUDIT_COMPAT_GENERIC
 228         bool
 229         depends on AUDIT_GENERIC && AUDIT_ARCH_COMPAT_GENERIC && COMPAT
 230         default y
 231
 232 config RANDOM32_SELFTEST
 233         bool "PRNG perform self test on init"
 234         help
 235           This option enables the 32 bit PRNG library functions to perform a
 236           self test on initialization.
 237
 238 #
 239 # compression support is select'ed if needed
 240 #
 241 config 842_COMPRESS
 242         select CRC32
 243         tristate
 244
 245 config 842_DECOMPRESS
 246         select CRC32
 247         tristate
 248
 249 config ZLIB_INFLATE
 250         tristate
 251
 252 config ZLIB_DEFLATE
 253         tristate
 254         select BITREVERSE
 255
 256 config LZO_COMPRESS
 257         tristate
 258
 259 config LZO_DECOMPRESS
 260         tristate
 261
 262 config LZ4_COMPRESS
 263         tristate
 264
 265 config LZ4HC_COMPRESS
 266         tristate
 267
 268 config LZ4_DECOMPRESS
 269         tristate
 270
 271 config ZSTD_COMPRESS
 272         select XXHASH
 273         tristate
 274
 275 config ZSTD_DECOMPRESS
 276         select XXHASH
 277         tristate
 278
 279 source "lib/xz/Kconfig"
 280
 281 #
 282 # These all provide a common interface (hence the apparent duplication with
 283 # ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.)
 284 #
 285 config DECOMPRESS_GZIP
 286         select ZLIB_INFLATE
 287         tristate
 288
 289 config DECOMPRESS_BZIP2
 290         tristate
 291
 292 config DECOMPRESS_LZMA
 293         tristate
 294
 295 config DECOMPRESS_XZ
 296         select XZ_DEC
 297         tristate
 298
 299 config DECOMPRESS_LZO
 300         select LZO_DECOMPRESS
 301         tristate
 302
 303 config DECOMPRESS_LZ4
 304         select LZ4_DECOMPRESS
 305         tristate
 306
 307 #
 308 # Generic allocator support is selected if needed
 309 #
 310 config GENERIC_ALLOCATOR
 311         bool
 312
 313 #
 314 # reed solomon support is select'ed if needed
 315 #
 316 config REED_SOLOMON
 317         tristate
 318
 319 config REED_SOLOMON_ENC8
 320         bool
 321
 322 config REED_SOLOMON_DEC8
 323         bool
 324
 325 config REED_SOLOMON_ENC16
 326         bool
 327
 328 config REED_SOLOMON_DEC16
 329         bool
 330
 331 #
 332 # BCH support is selected if needed
 333 #
 334 config BCH
 335         tristate
 336
 337 config BCH_CONST_PARAMS
 338         bool
 339         help
 340           Drivers may select this option to force specific constant
 341           values for parameters 'm' (Galois field order) and 't'
 342           (error correction capability). Those specific values must
 343           be set by declaring default values for symbols BCH_CONST_M
 344           and BCH_CONST_T.
 345           Doing so will enable extra compiler optimizations,
 346           improving encoding and decoding performance up to 2x for
 347           usual (m,t) values (typically such that m*t < 200).
 348           When this option is selected, the BCH library supports
 349           only a single (m,t) configuration. This is mainly useful
 350           for NAND flash board drivers requiring known, fixed BCH
 351           parameters.
 352
 353 config BCH_CONST_M
 354         int
 355         range 5 15
 356         help
 357           Constant value for Galois field order 'm'. If 'k' is the
 358           number of data bits to protect, 'm' should be chosen such
 359           that (k + m*t) <= 2**m - 1.
 360           Drivers should declare a default value for this symbol if
 361           they select option BCH_CONST_PARAMS.
 362
 363 config BCH_CONST_T
 364         int
 365         help
 366           Constant value for error correction capability in bits 't'.
 367           Drivers should declare a default value for this symbol if
 368           they select option BCH_CONST_PARAMS.
 369
 370 #
 371 # Textsearch support is select'ed if needed
 372 #
 373 config TEXTSEARCH
 374         bool
 375
 376 config TEXTSEARCH_KMP
 377         tristate
 378
 379 config TEXTSEARCH_BM
 380         tristate
 381
 382 config TEXTSEARCH_FSM
 383         tristate
 384
 385 config BTREE
 386         bool
 387
 388 config INTERVAL_TREE
 389         bool
 390         help
 391           Simple, embeddable, interval-tree. Can find the start of an
 392           overlapping range in log(n) time and then iterate over all
 393           overlapping nodes. The algorithm is implemented as an
 394           augmented rbtree.
 395
 396           See:
 397
 398                 Documentation/rbtree.txt
 399
 400           for more information.
 401
 402 config XARRAY_MULTI
 403         bool
 404         help
 405           Support entries which occupy multiple consecutive indices in the
 406           XArray.
 407
 408 config ASSOCIATIVE_ARRAY
 409         bool
 410         help
 411           Generic associative array.  Can be searched and iterated over whilst
 412           it is being modified.  It is also reasonably quick to search and
 413           modify.  The algorithms are non-recursive, and the trees are highly
 414           capacious.
 415
 416           See:
 417
 418                 Documentation/core-api/assoc_array.rst
 419
 420           for more information.
 421
 422 config HAS_IOMEM
 423         bool
 424         depends on !NO_IOMEM
 425         select GENERIC_IO
 426         default y
 427
 428 config HAS_IOPORT_MAP
 429         bool
 430         depends on HAS_IOMEM && !NO_IOPORT_MAP
 431         default y
 432
 433 source "kernel/dma/Kconfig"
 434
 435 config SGL_ALLOC
 436         bool
 437         default n
 438
 439 config IOMMU_HELPER
 440         bool
 441
 442 config CHECK_SIGNATURE
 443         bool
 444
 445 config 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
 452 config CPU_RMAP
 453         bool
 454         depends on SMP
 455
 456 config DQL
 457         bool
 458
 459 config 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
 478 config 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 #
 494 config NLATTR
 495         bool
 496
 497 #
 498 # Generic 64-bit atomic support is selected if needed
 499 #
 500 config GENERIC_ATOMIC64
 501        bool
 502
 503 config LRU_CACHE
 504         tristate
 505
 506 config CLZ_TAB
 507         bool
 508
 509 config 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
 515 config 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
 523 config IRQ_POLL
 524         bool "IRQ polling library"
 525         help
 526           Helper library to poll interrupt mitigation using polling.
 527
 528 config 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
 536 config 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 #
 549 config LIBFDT
 550         bool
 551
 552 config OID_REGISTRY
 553         tristate
 554         help
 555           Enable fast lookup object identifier registry.
 556
 557 config UCS2_STRING
 558         tristate
 559
 560 source "lib/fonts/Kconfig"
 561
 562 config 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
 569 config 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
 580 config ARCH_NO_SG_CHAIN
 581         def_bool n
 582
 583 config ARCH_HAS_PMEM_API
 584         bool
 585
 586 config ARCH_HAS_UACCESS_FLUSHCACHE
 587         bool
 588
 589 config ARCH_HAS_UACCESS_MCSAFE
 590         bool
 591
 592 config STACKDEPOT
 593         bool
 594         select STACKTRACE
 595
 596 config SBITMAP
 597         bool
 598
 599 config PARMAN
 600         tristate "parman" if COMPILE_TEST
 601
 602 config PRIME_NUMBERS
 603         tristate
 604
 605 config STRING_SELFTEST
 606         tristate "Test string functions"
 607
 608 endmenu
 609
 610 config GENERIC_LIB_ASHLDI3
 611         bool
 612
 613 config GENERIC_LIB_ASHRDI3
 614         bool
 615
 616 config GENERIC_LIB_LSHRDI3
 617         bool
 618
 619 config GENERIC_LIB_MULDI3
 620         bool
 621
 622 config GENERIC_LIB_CMPDI2
 623         bool
 624
 625 config GENERIC_LIB_UCMPDI2
 626         bool
 627
 628 config OBJAGG
 629         tristate "objagg" if COMPILE_TEST