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 RAID6_PQ_BENCHMARK
  14         bool "Automatically choose fastest RAID6 PQ functions"
  15         depends on RAID6_PQ
  16         default y
  17         help
  18           Benchmark all available RAID6 PQ functions on init and choose the
  19           fastest one.
  20
  21 config BITREVERSE
  22         tristate
  23
  24 config HAVE_ARCH_BITREVERSE
  25         bool
  26         default n
  27         depends on BITREVERSE
  28         help
  29           This option enables the use of hardware bit-reversal instructions on
  30           architectures which support such operations.
  31
  32 config RATIONAL
  33         bool
  34
  35 config GENERIC_STRNCPY_FROM_USER
  36         bool
  37
  38 config GENERIC_STRNLEN_USER
  39         bool
  40
  41 config GENERIC_NET_UTILS
  42         bool
  43
  44 config GENERIC_FIND_FIRST_BIT
  45         bool
  46
  47 config NO_GENERIC_PCI_IOPORT_MAP
  48         bool
  49
  50 config GENERIC_PCI_IOMAP
  51         bool
  52
  53 config GENERIC_IOMAP
  54         bool
  55         select GENERIC_PCI_IOMAP
  56
  57 config STMP_DEVICE
  58         bool
  59
  60 config ARCH_USE_CMPXCHG_LOCKREF
  61         bool
  62
  63 config ARCH_HAS_FAST_MULTIPLIER
  64         bool
  65
  66 config INDIRECT_PIO
  67         bool "Access I/O in non-MMIO mode"
  68         depends on ARM64
  69         help
  70           On some platforms where no separate I/O space exists, there are I/O
  71           hosts which can not be accessed in MMIO mode. Using the logical PIO
  72           mechanism, the host-local I/O resource can be mapped into system
  73           logic PIO space shared with MMIO hosts, such as PCI/PCIe, then the
  74           system can access the I/O devices with the mapped-logic PIO through
  75           I/O accessors.
  76
  77           This way has relatively little I/O performance cost. Please make
  78           sure your devices really need this configure item enabled.
  79
  80           When in doubt, say N.
  81
  82 config CRC_CCITT
  83         tristate "CRC-CCITT functions"
  84         help
  85           This option is provided for the case where no in-kernel-tree
  86           modules require CRC-CCITT functions, but a module built outside
  87           the kernel tree does. Such modules that use library CRC-CCITT
  88           functions require M here.
  89
  90 config CRC16
  91         tristate "CRC16 functions"
  92         help
  93           This option is provided for the case where no in-kernel-tree
  94           modules require CRC16 functions, but a module built outside
  95           the kernel tree does. Such modules that use library CRC16
  96           functions require M here.
  97
  98 config CRC_T10DIF
  99         tristate "CRC calculation for the T10 Data Integrity Field"
 100         select CRYPTO
 101         select CRYPTO_CRCT10DIF
 102         help
 103           This option is only needed if a module that's not in the
 104           kernel tree needs to calculate CRC checks for use with the
 105           SCSI data integrity subsystem.
 106
 107 config CRC_ITU_T
 108         tristate "CRC ITU-T V.41 functions"
 109         help
 110           This option is provided for the case where no in-kernel-tree
 111           modules require CRC ITU-T V.41 functions, but a module built outside
 112           the kernel tree does. Such modules that use library CRC ITU-T V.41
 113           functions require M here.
 114
 115 config CRC32
 116         tristate "CRC32/CRC32c functions"
 117         default y
 118         select BITREVERSE
 119         help
 120           This option is provided for the case where no in-kernel-tree
 121           modules require CRC32/CRC32c functions, but a module built outside
 122           the kernel tree does. Such modules that use library CRC32/CRC32c
 123           functions require M here.
 124
 125 config CRC32_SELFTEST
 126         tristate "CRC32 perform self test on init"
 127         depends on CRC32
 128         help
 129           This option enables the CRC32 library functions to perform a
 130           self test on initialization. The self test computes crc32_le
 131           and crc32_be over byte strings with random alignment and length
 132           and computes the total elapsed time and number of bytes processed.
 133
 134 choice
 135         prompt "CRC32 implementation"
 136         depends on CRC32
 137         default CRC32_SLICEBY8
 138         help
 139           This option allows a kernel builder to override the default choice
 140           of CRC32 algorithm.  Choose the default ("slice by 8") unless you
 141           know that you need one of the others.
 142
 143 config CRC32_SLICEBY8
 144         bool "Slice by 8 bytes"
 145         help
 146           Calculate checksum 8 bytes at a time with a clever slicing algorithm.
 147           This is the fastest algorithm, but comes with a 8KiB lookup table.
 148           Most modern processors have enough cache to hold this table without
 149           thrashing the cache.
 150
 151           This is the default implementation choice.  Choose this one unless
 152           you have a good reason not to.
 153
 154 config CRC32_SLICEBY4
 155         bool "Slice by 4 bytes"
 156         help
 157           Calculate checksum 4 bytes at a time with a clever slicing algorithm.
 158           This is a bit slower than slice by 8, but has a smaller 4KiB lookup
 159           table.
 160
 161           Only choose this option if you know what you are doing.
 162
 163 config CRC32_SARWATE
 164         bool "Sarwate's Algorithm (one byte at a time)"
 165         help
 166           Calculate checksum a byte at a time using Sarwate's algorithm.  This
 167           is not particularly fast, but has a small 256 byte lookup table.
 168
 169           Only choose this option if you know what you are doing.
 170
 171 config CRC32_BIT
 172         bool "Classic Algorithm (one bit at a time)"
 173         help
 174           Calculate checksum one bit at a time.  This is VERY slow, but has
 175           no lookup table.  This is provided as a debugging option.
 176
 177           Only choose this option if you are debugging crc32.
 178
 179 endchoice
 180
 181 config CRC64
 182         tristate "CRC64 functions"
 183         help
 184           This option is provided for the case where no in-kernel-tree
 185           modules require CRC64 functions, but a module built outside
 186           the kernel tree does. Such modules that use library CRC64
 187           functions require M here.
 188
 189 config CRC4
 190         tristate "CRC4 functions"
 191         help
 192           This option is provided for the case where no in-kernel-tree
 193           modules require CRC4 functions, but a module built outside
 194           the kernel tree does. Such modules that use library CRC4
 195           functions require M here.
 196
 197 config CRC7
 198         tristate "CRC7 functions"
 199         help
 200           This option is provided for the case where no in-kernel-tree
 201           modules require CRC7 functions, but a module built outside
 202           the kernel tree does. Such modules that use library CRC7
 203           functions require M here.
 204
 205 config LIBCRC32C
 206         tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check"
 207         select CRYPTO
 208         select CRYPTO_CRC32C
 209         help
 210           This option is provided for the case where no in-kernel-tree
 211           modules require CRC32c functions, but a module built outside the
 212           kernel tree does. Such modules that use library CRC32c functions
 213           require M here.  See Castagnoli93.
 214           Module will be libcrc32c.
 215
 216 config CRC8
 217         tristate "CRC8 function"
 218         help
 219           This option provides CRC8 function. Drivers may select this
 220           when they need to do cyclic redundancy check according CRC8
 221           algorithm. Module will be called crc8.
 222
 223 config XXHASH
 224         tristate
 225
 226 config AUDIT_GENERIC
 227         bool
 228         depends on AUDIT && !AUDIT_ARCH
 229         default y
 230
 231 config AUDIT_ARCH_COMPAT_GENERIC
 232         bool
 233         default n
 234
 235 config AUDIT_COMPAT_GENERIC
 236         bool
 237         depends on AUDIT_GENERIC && AUDIT_ARCH_COMPAT_GENERIC && COMPAT
 238         default y
 239
 240 config RANDOM32_SELFTEST
 241         bool "PRNG perform self test on init"
 242         help
 243           This option enables the 32 bit PRNG library functions to perform a
 244           self test on initialization.
 245
 246 #
 247 # compression support is select'ed if needed
 248 #
 249 config 842_COMPRESS
 250         select CRC32
 251         tristate
 252
 253 config 842_DECOMPRESS
 254         select CRC32
 255         tristate
 256
 257 config ZLIB_INFLATE
 258         tristate
 259
 260 config ZLIB_DEFLATE
 261         tristate
 262         select BITREVERSE
 263
 264 config LZO_COMPRESS
 265         tristate
 266
 267 config LZO_DECOMPRESS
 268         tristate
 269
 270 config LZ4_COMPRESS
 271         tristate
 272
 273 config LZ4HC_COMPRESS
 274         tristate
 275
 276 config LZ4_DECOMPRESS
 277         tristate
 278
 279 config ZSTD_COMPRESS
 280         select XXHASH
 281         tristate
 282
 283 config ZSTD_DECOMPRESS
 284         select XXHASH
 285         tristate
 286
 287 source "lib/xz/Kconfig"
 288
 289 #
 290 # These all provide a common interface (hence the apparent duplication with
 291 # ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.)
 292 #
 293 config DECOMPRESS_GZIP
 294         select ZLIB_INFLATE
 295         tristate
 296
 297 config DECOMPRESS_BZIP2
 298         tristate
 299
 300 config DECOMPRESS_LZMA
 301         tristate
 302
 303 config DECOMPRESS_XZ
 304         select XZ_DEC
 305         tristate
 306
 307 config DECOMPRESS_LZO
 308         select LZO_DECOMPRESS
 309         tristate
 310
 311 config DECOMPRESS_LZ4
 312         select LZ4_DECOMPRESS
 313         tristate
 314
 315 #
 316 # Generic allocator support is selected if needed
 317 #
 318 config GENERIC_ALLOCATOR
 319         bool
 320
 321 #
 322 # reed solomon support is select'ed if needed
 323 #
 324 config REED_SOLOMON
 325         tristate
 326
 327 config REED_SOLOMON_ENC8
 328         bool
 329
 330 config REED_SOLOMON_DEC8
 331         bool
 332
 333 config REED_SOLOMON_ENC16
 334         bool
 335
 336 config REED_SOLOMON_DEC16
 337         bool
 338
 339 #
 340 # BCH support is selected if needed
 341 #
 342 config BCH
 343         tristate
 344
 345 config BCH_CONST_PARAMS
 346         bool
 347         help
 348           Drivers may select this option to force specific constant
 349           values for parameters 'm' (Galois field order) and 't'
 350           (error correction capability). Those specific values must
 351           be set by declaring default values for symbols BCH_CONST_M
 352           and BCH_CONST_T.
 353           Doing so will enable extra compiler optimizations,
 354           improving encoding and decoding performance up to 2x for
 355           usual (m,t) values (typically such that m*t < 200).
 356           When this option is selected, the BCH library supports
 357           only a single (m,t) configuration. This is mainly useful
 358           for NAND flash board drivers requiring known, fixed BCH
 359           parameters.
 360
 361 config BCH_CONST_M
 362         int
 363         range 5 15
 364         help
 365           Constant value for Galois field order 'm'. If 'k' is the
 366           number of data bits to protect, 'm' should be chosen such
 367           that (k + m*t) <= 2**m - 1.
 368           Drivers should declare a default value for this symbol if
 369           they select option BCH_CONST_PARAMS.
 370
 371 config BCH_CONST_T
 372         int
 373         help
 374           Constant value for error correction capability in bits 't'.
 375           Drivers should declare a default value for this symbol if
 376           they select option BCH_CONST_PARAMS.
 377
 378 #
 379 # Textsearch support is select'ed if needed
 380 #
 381 config TEXTSEARCH
 382         bool
 383
 384 config TEXTSEARCH_KMP
 385         tristate
 386
 387 config TEXTSEARCH_BM
 388         tristate
 389
 390 config TEXTSEARCH_FSM
 391         tristate
 392
 393 config BTREE
 394         bool
 395
 396 config INTERVAL_TREE
 397         bool
 398         help
 399           Simple, embeddable, interval-tree. Can find the start of an
 400           overlapping range in log(n) time and then iterate over all
 401           overlapping nodes. The algorithm is implemented as an
 402           augmented rbtree.
 403
 404           See:
 405
 406                 Documentation/rbtree.txt
 407
 408           for more information.
 409
 410 config XARRAY_MULTI
 411         bool
 412         help
 413           Support entries which occupy multiple consecutive indices in the
 414           XArray.
 415
 416 config ASSOCIATIVE_ARRAY
 417         bool
 418         help
 419           Generic associative array.  Can be searched and iterated over whilst
 420           it is being modified.  It is also reasonably quick to search and
 421           modify.  The algorithms are non-recursive, and the trees are highly
 422           capacious.
 423
 424           See:
 425
 426                 Documentation/core-api/assoc_array.rst
 427
 428           for more information.
 429
 430 config HAS_IOMEM
 431         bool
 432         depends on !NO_IOMEM
 433         select GENERIC_IO
 434         default y
 435
 436 config HAS_IOPORT_MAP
 437         bool
 438         depends on HAS_IOMEM && !NO_IOPORT_MAP
 439         default y
 440
 441 source "kernel/dma/Kconfig"
 442
 443 config SGL_ALLOC
 444         bool
 445         default n
 446
 447 config IOMMU_HELPER
 448         bool
 449
 450 config CHECK_SIGNATURE
 451         bool
 452
 453 config CPUMASK_OFFSTACK
 454         bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
 455         help
 456           Use dynamic allocation for cpumask_var_t, instead of putting
 457           them on the stack.  This is a bit more expensive, but avoids
 458           stack overflow.
 459
 460 config CPU_RMAP
 461         bool
 462         depends on SMP
 463
 464 config DQL
 465         bool
 466
 467 config GLOB
 468         bool
 469 #       This actually supports modular compilation, but the module overhead
 470 #       is ridiculous for the amount of code involved.  Until an out-of-tree
 471 #       driver asks for it, we'll just link it directly it into the kernel
 472 #       when required.  Since we're ignoring out-of-tree users, there's also
 473 #       no need bother prompting for a manual decision:
 474 #       prompt "glob_match() function"
 475         help
 476           This option provides a glob_match function for performing
 477           simple text pattern matching.  It originated in the ATA code
 478           to blacklist particular drive models, but other device drivers
 479           may need similar functionality.
 480
 481           All drivers in the Linux kernel tree that require this function
 482           should automatically select this option.  Say N unless you
 483           are compiling an out-of tree driver which tells you that it
 484           depends on this.
 485
 486 config GLOB_SELFTEST
 487         tristate "glob self-test on init"
 488         depends on GLOB
 489         help
 490           This option enables a simple self-test of the glob_match
 491           function on startup.  It is primarily useful for people
 492           working on the code to ensure they haven't introduced any
 493           regressions.
 494
 495           It only adds a little bit of code and slows kernel boot (or
 496           module load) by a small amount, so you're welcome to play with
 497           it, but you probably don't need it.
 498
 499 #
 500 # Netlink attribute parsing support is select'ed if needed
 501 #
 502 config NLATTR
 503         bool
 504
 505 #
 506 # Generic 64-bit atomic support is selected if needed
 507 #
 508 config GENERIC_ATOMIC64
 509        bool
 510
 511 config LRU_CACHE
 512         tristate
 513
 514 config CLZ_TAB
 515         bool
 516
 517 config CORDIC
 518         tristate "CORDIC algorithm"
 519         help
 520           This option provides an implementation of the CORDIC algorithm;
 521           calculations are in fixed point. Module will be called cordic.
 522
 523 config DDR
 524         bool "JEDEC DDR data"
 525         help
 526           Data from JEDEC specs for DDR SDRAM memories,
 527           particularly the AC timing parameters and addressing
 528           information. This data is useful for drivers handling
 529           DDR SDRAM controllers.
 530
 531 config IRQ_POLL
 532         bool "IRQ polling library"
 533         help
 534           Helper library to poll interrupt mitigation using polling.
 535
 536 config MPILIB
 537         tristate
 538         select CLZ_TAB
 539         help
 540           Multiprecision maths library from GnuPG.
 541           It is used to implement RSA digital signature verification,
 542           which is used by IMA/EVM digital signature extension.
 543
 544 config SIGNATURE
 545         tristate
 546         depends on KEYS
 547         select CRYPTO
 548         select CRYPTO_SHA1
 549         select MPILIB
 550         help
 551           Digital signature verification. Currently only RSA is supported.
 552           Implementation is done using GnuPG MPI library
 553
 554 #
 555 # libfdt files, only selected if needed.
 556 #
 557 config LIBFDT
 558         bool
 559
 560 config OID_REGISTRY
 561         tristate
 562         help
 563           Enable fast lookup object identifier registry.
 564
 565 config UCS2_STRING
 566         tristate
 567
 568 source "lib/fonts/Kconfig"
 569
 570 config SG_SPLIT
 571         def_bool n
 572         help
 573          Provides a helper to split scatterlists into chunks, each chunk being
 574          a scatterlist. This should be selected by a driver or an API which
 575          whishes to split a scatterlist amongst multiple DMA channels.
 576
 577 config SG_POOL
 578         def_bool n
 579         help
 580          Provides a helper to allocate chained scatterlists. This should be
 581          selected by a driver or an API which whishes to allocate chained
 582          scatterlist.
 583
 584 #
 585 # sg chaining option
 586 #
 587
 588 config ARCH_NO_SG_CHAIN
 589         def_bool n
 590
 591 config ARCH_HAS_PMEM_API
 592         bool
 593
 594 config ARCH_HAS_UACCESS_FLUSHCACHE
 595         bool
 596
 597 config ARCH_HAS_UACCESS_MCSAFE
 598         bool
 599
 600 config STACKDEPOT
 601         bool
 602         select STACKTRACE
 603
 604 config SBITMAP
 605         bool
 606
 607 config PARMAN
 608         tristate "parman" if COMPILE_TEST
 609
 610 config PRIME_NUMBERS
 611         tristate
 612
 613 config STRING_SELFTEST
 614         tristate "Test string functions"
 615
 616 endmenu
 617
 618 config GENERIC_LIB_ASHLDI3
 619         bool
 620
 621 config GENERIC_LIB_ASHRDI3
 622         bool
 623
 624 config GENERIC_LIB_LSHRDI3
 625         bool
 626
 627 config GENERIC_LIB_MULDI3
 628         bool
 629
 630 config GENERIC_LIB_CMPDI2
 631         bool
 632
 633 config GENERIC_LIB_UCMPDI2
 634         bool
 635
 636 config OBJAGG
 637         tristate "objagg" if COMPILE_TEST