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 default n 28 help 29 This option provides the packing() helper function, which permits 30 converting bitfields between a CPU-usable representation and a 31 memory representation that can have any combination of these quirks: 32 - Is little endian (bytes are reversed within a 32-bit group) 33 - The least-significant 32-bit word comes first (within a 64-bit 34 group) 35 - The most significant bit of a byte is at its right (bit 0 of a 36 register description is numerically 2^7). 37 Drivers may use these helpers to match the bit indices as described 38 in the data sheets of the peripherals they are in control of. 39 40 When in doubt, say N. 41 42config BITREVERSE 43 tristate 44 45config HAVE_ARCH_BITREVERSE 46 bool 47 default n 48 help 49 This option enables the use of hardware bit-reversal instructions on 50 architectures which support such operations. 51 52config GENERIC_STRNCPY_FROM_USER 53 bool 54 55config GENERIC_STRNLEN_USER 56 bool 57 58config GENERIC_NET_UTILS 59 bool 60 61config GENERIC_FIND_FIRST_BIT 62 bool 63 64source "lib/math/Kconfig" 65 66config NO_GENERIC_PCI_IOPORT_MAP 67 bool 68 69config GENERIC_PCI_IOMAP 70 bool 71 72config GENERIC_IOMAP 73 bool 74 select GENERIC_PCI_IOMAP 75 76config STMP_DEVICE 77 bool 78 79config ARCH_USE_CMPXCHG_LOCKREF 80 bool 81 82config ARCH_HAS_FAST_MULTIPLIER 83 bool 84 85config ARCH_USE_SYM_ANNOTATIONS 86 bool 87 88config INDIRECT_PIO 89 bool "Access I/O in non-MMIO mode" 90 depends on ARM64 91 help 92 On some platforms where no separate I/O space exists, there are I/O 93 hosts which can not be accessed in MMIO mode. Using the logical PIO 94 mechanism, the host-local I/O resource can be mapped into system 95 logic PIO space shared with MMIO hosts, such as PCI/PCIe, then the 96 system can access the I/O devices with the mapped-logic PIO through 97 I/O accessors. 98 99 This way has relatively little I/O performance cost. Please make 100 sure your devices really need this configure item enabled. 101 102 When in doubt, say N. 103 104source "lib/crypto/Kconfig" 105 106config LIB_MEMNEQ 107 bool 108 109config CRC_CCITT 110 tristate "CRC-CCITT functions" 111 help 112 This option is provided for the case where no in-kernel-tree 113 modules require CRC-CCITT functions, but a module built outside 114 the kernel tree does. Such modules that use library CRC-CCITT 115 functions require M here. 116 117config CRC16 118 tristate "CRC16 functions" 119 help 120 This option is provided for the case where no in-kernel-tree 121 modules require CRC16 functions, but a module built outside 122 the kernel tree does. Such modules that use library CRC16 123 functions require M here. 124 125config CRC_T10DIF 126 tristate "CRC calculation for the T10 Data Integrity Field" 127 select CRYPTO 128 select CRYPTO_CRCT10DIF 129 help 130 This option is only needed if a module that's not in the 131 kernel tree needs to calculate CRC checks for use with the 132 SCSI data integrity subsystem. 133 134config CRC_ITU_T 135 tristate "CRC ITU-T V.41 functions" 136 help 137 This option is provided for the case where no in-kernel-tree 138 modules require CRC ITU-T V.41 functions, but a module built outside 139 the kernel tree does. Such modules that use library CRC ITU-T V.41 140 functions require M here. 141 142config CRC32 143 tristate "CRC32/CRC32c functions" 144 default y 145 select BITREVERSE 146 help 147 This option is provided for the case where no in-kernel-tree 148 modules require CRC32/CRC32c functions, but a module built outside 149 the kernel tree does. Such modules that use library CRC32/CRC32c 150 functions require M here. 151 152config CRC32_SELFTEST 153 tristate "CRC32 perform self test on init" 154 depends on CRC32 155 help 156 This option enables the CRC32 library functions to perform a 157 self test on initialization. The self test computes crc32_le 158 and crc32_be over byte strings with random alignment and length 159 and computes the total elapsed time and number of bytes processed. 160 161choice 162 prompt "CRC32 implementation" 163 depends on CRC32 164 default CRC32_SLICEBY8 165 help 166 This option allows a kernel builder to override the default choice 167 of CRC32 algorithm. Choose the default ("slice by 8") unless you 168 know that you need one of the others. 169 170config CRC32_SLICEBY8 171 bool "Slice by 8 bytes" 172 help 173 Calculate checksum 8 bytes at a time with a clever slicing algorithm. 174 This is the fastest algorithm, but comes with a 8KiB lookup table. 175 Most modern processors have enough cache to hold this table without 176 thrashing the cache. 177 178 This is the default implementation choice. Choose this one unless 179 you have a good reason not to. 180 181config CRC32_SLICEBY4 182 bool "Slice by 4 bytes" 183 help 184 Calculate checksum 4 bytes at a time with a clever slicing algorithm. 185 This is a bit slower than slice by 8, but has a smaller 4KiB lookup 186 table. 187 188 Only choose this option if you know what you are doing. 189 190config CRC32_SARWATE 191 bool "Sarwate's Algorithm (one byte at a time)" 192 help 193 Calculate checksum a byte at a time using Sarwate's algorithm. This 194 is not particularly fast, but has a small 256 byte lookup table. 195 196 Only choose this option if you know what you are doing. 197 198config CRC32_BIT 199 bool "Classic Algorithm (one bit at a time)" 200 help 201 Calculate checksum one bit at a time. This is VERY slow, but has 202 no lookup table. This is provided as a debugging option. 203 204 Only choose this option if you are debugging crc32. 205 206endchoice 207 208config CRC64 209 tristate "CRC64 functions" 210 help 211 This option is provided for the case where no in-kernel-tree 212 modules require CRC64 functions, but a module built outside 213 the kernel tree does. Such modules that use library CRC64 214 functions require M here. 215 216config CRC4 217 tristate "CRC4 functions" 218 help 219 This option is provided for the case where no in-kernel-tree 220 modules require CRC4 functions, but a module built outside 221 the kernel tree does. Such modules that use library CRC4 222 functions require M here. 223 224config CRC7 225 tristate "CRC7 functions" 226 help 227 This option is provided for the case where no in-kernel-tree 228 modules require CRC7 functions, but a module built outside 229 the kernel tree does. Such modules that use library CRC7 230 functions require M here. 231 232config LIBCRC32C 233 tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check" 234 select CRYPTO 235 select CRYPTO_CRC32C 236 help 237 This option is provided for the case where no in-kernel-tree 238 modules require CRC32c functions, but a module built outside the 239 kernel tree does. Such modules that use library CRC32c functions 240 require M here. See Castagnoli93. 241 Module will be libcrc32c. 242 243config CRC8 244 tristate "CRC8 function" 245 help 246 This option provides CRC8 function. Drivers may select this 247 when they need to do cyclic redundancy check according CRC8 248 algorithm. Module will be called crc8. 249 250config XXHASH 251 tristate 252 253config AUDIT_GENERIC 254 bool 255 depends on AUDIT && !AUDIT_ARCH 256 default y 257 258config AUDIT_ARCH_COMPAT_GENERIC 259 bool 260 default n 261 262config AUDIT_COMPAT_GENERIC 263 bool 264 depends on AUDIT_GENERIC && AUDIT_ARCH_COMPAT_GENERIC && COMPAT 265 default y 266 267config RANDOM32_SELFTEST 268 bool "PRNG perform self test on init" 269 help 270 This option enables the 32 bit PRNG library functions to perform a 271 self test on initialization. 272 273# 274# compression support is select'ed if needed 275# 276config 842_COMPRESS 277 select CRC32 278 tristate 279 280config 842_DECOMPRESS 281 select CRC32 282 tristate 283 284config ZLIB_INFLATE 285 tristate 286 287config ZLIB_DEFLATE 288 tristate 289 select BITREVERSE 290 291config ZLIB_DFLTCC 292 def_bool y 293 depends on S390 294 prompt "Enable s390x DEFLATE CONVERSION CALL support for kernel zlib" 295 help 296 Enable s390x hardware support for zlib in the kernel. 297 298config LZO_COMPRESS 299 tristate 300 301config LZO_DECOMPRESS 302 tristate 303 304config LZ4_COMPRESS 305 tristate 306 307config LZ4HC_COMPRESS 308 tristate 309 310config LZ4_DECOMPRESS 311 tristate 312 313config ZSTD_COMPRESS 314 select XXHASH 315 tristate 316 317config ZSTD_DECOMPRESS 318 select XXHASH 319 tristate 320 321source "lib/xz/Kconfig" 322 323# 324# These all provide a common interface (hence the apparent duplication with 325# ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.) 326# 327config DECOMPRESS_GZIP 328 select ZLIB_INFLATE 329 tristate 330 331config DECOMPRESS_BZIP2 332 tristate 333 334config DECOMPRESS_LZMA 335 tristate 336 337config DECOMPRESS_XZ 338 select XZ_DEC 339 tristate 340 341config DECOMPRESS_LZO 342 select LZO_DECOMPRESS 343 tristate 344 345config DECOMPRESS_LZ4 346 select LZ4_DECOMPRESS 347 tristate 348 349config DECOMPRESS_ZSTD 350 select ZSTD_DECOMPRESS 351 tristate 352 353# 354# Generic allocator support is selected if needed 355# 356config GENERIC_ALLOCATOR 357 bool 358 359# 360# reed solomon support is select'ed if needed 361# 362config REED_SOLOMON 363 tristate 364 365config REED_SOLOMON_ENC8 366 bool 367 368config REED_SOLOMON_DEC8 369 bool 370 371config REED_SOLOMON_ENC16 372 bool 373 374config REED_SOLOMON_DEC16 375 bool 376 377# 378# BCH support is selected if needed 379# 380config BCH 381 tristate 382 383config BCH_CONST_PARAMS 384 bool 385 help 386 Drivers may select this option to force specific constant 387 values for parameters 'm' (Galois field order) and 't' 388 (error correction capability). Those specific values must 389 be set by declaring default values for symbols BCH_CONST_M 390 and BCH_CONST_T. 391 Doing so will enable extra compiler optimizations, 392 improving encoding and decoding performance up to 2x for 393 usual (m,t) values (typically such that m*t < 200). 394 When this option is selected, the BCH library supports 395 only a single (m,t) configuration. This is mainly useful 396 for NAND flash board drivers requiring known, fixed BCH 397 parameters. 398 399config BCH_CONST_M 400 int 401 range 5 15 402 help 403 Constant value for Galois field order 'm'. If 'k' is the 404 number of data bits to protect, 'm' should be chosen such 405 that (k + m*t) <= 2**m - 1. 406 Drivers should declare a default value for this symbol if 407 they select option BCH_CONST_PARAMS. 408 409config BCH_CONST_T 410 int 411 help 412 Constant value for error correction capability in bits 't'. 413 Drivers should declare a default value for this symbol if 414 they select option BCH_CONST_PARAMS. 415 416# 417# Textsearch support is select'ed if needed 418# 419config TEXTSEARCH 420 bool 421 422config TEXTSEARCH_KMP 423 tristate 424 425config TEXTSEARCH_BM 426 tristate 427 428config TEXTSEARCH_FSM 429 tristate 430 431config BTREE 432 bool 433 434config INTERVAL_TREE 435 bool 436 help 437 Simple, embeddable, interval-tree. Can find the start of an 438 overlapping range in log(n) time and then iterate over all 439 overlapping nodes. The algorithm is implemented as an 440 augmented rbtree. 441 442 See: 443 444 Documentation/core-api/rbtree.rst 445 446 for more information. 447 448config XARRAY_MULTI 449 bool 450 help 451 Support entries which occupy multiple consecutive indices in the 452 XArray. 453 454config ASSOCIATIVE_ARRAY 455 bool 456 help 457 Generic associative array. Can be searched and iterated over whilst 458 it is being modified. It is also reasonably quick to search and 459 modify. The algorithms are non-recursive, and the trees are highly 460 capacious. 461 462 See: 463 464 Documentation/core-api/assoc_array.rst 465 466 for more information. 467 468config HAS_IOMEM 469 bool 470 depends on !NO_IOMEM 471 default y 472 473config HAS_IOPORT_MAP 474 bool 475 depends on HAS_IOMEM && !NO_IOPORT_MAP 476 default y 477 478source "kernel/dma/Kconfig" 479 480config SGL_ALLOC 481 bool 482 default n 483 484config IOMMU_HELPER 485 bool 486 487config CHECK_SIGNATURE 488 bool 489 490config CPUMASK_OFFSTACK 491 bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS 492 help 493 Use dynamic allocation for cpumask_var_t, instead of putting 494 them on the stack. This is a bit more expensive, but avoids 495 stack overflow. 496 497config CPU_RMAP 498 bool 499 depends on SMP 500 501config DQL 502 bool 503 504config GLOB 505 bool 506# This actually supports modular compilation, but the module overhead 507# is ridiculous for the amount of code involved. Until an out-of-tree 508# driver asks for it, we'll just link it directly it into the kernel 509# when required. Since we're ignoring out-of-tree users, there's also 510# no need bother prompting for a manual decision: 511# prompt "glob_match() function" 512 help 513 This option provides a glob_match function for performing 514 simple text pattern matching. It originated in the ATA code 515 to blacklist particular drive models, but other device drivers 516 may need similar functionality. 517 518 All drivers in the Linux kernel tree that require this function 519 should automatically select this option. Say N unless you 520 are compiling an out-of tree driver which tells you that it 521 depends on this. 522 523config GLOB_SELFTEST 524 tristate "glob self-test on init" 525 depends on GLOB 526 help 527 This option enables a simple self-test of the glob_match 528 function on startup. It is primarily useful for people 529 working on the code to ensure they haven't introduced any 530 regressions. 531 532 It only adds a little bit of code and slows kernel boot (or 533 module load) by a small amount, so you're welcome to play with 534 it, but you probably don't need it. 535 536# 537# Netlink attribute parsing support is select'ed if needed 538# 539config NLATTR 540 bool 541 542# 543# Generic 64-bit atomic support is selected if needed 544# 545config GENERIC_ATOMIC64 546 bool 547 548config LRU_CACHE 549 tristate 550 551config CLZ_TAB 552 bool 553 554config IRQ_POLL 555 bool "IRQ polling library" 556 help 557 Helper library to poll interrupt mitigation using polling. 558 559config MPILIB 560 tristate 561 select CLZ_TAB 562 help 563 Multiprecision maths library from GnuPG. 564 It is used to implement RSA digital signature verification, 565 which is used by IMA/EVM digital signature extension. 566 567config SIGNATURE 568 tristate 569 depends on KEYS 570 select CRYPTO 571 select CRYPTO_SHA1 572 select MPILIB 573 help 574 Digital signature verification. Currently only RSA is supported. 575 Implementation is done using GnuPG MPI library 576 577config DIMLIB 578 bool 579 help 580 Dynamic Interrupt Moderation library. 581 Implements an algorithm for dynamically changing CQ moderation values 582 according to run time performance. 583 584# 585# libfdt files, only selected if needed. 586# 587config LIBFDT 588 bool 589 590config OID_REGISTRY 591 tristate 592 help 593 Enable fast lookup object identifier registry. 594 595config UCS2_STRING 596 tristate 597 598# 599# generic vdso 600# 601source "lib/vdso/Kconfig" 602 603source "lib/fonts/Kconfig" 604 605config SG_SPLIT 606 def_bool n 607 help 608 Provides a helper to split scatterlists into chunks, each chunk being 609 a scatterlist. This should be selected by a driver or an API which 610 whishes to split a scatterlist amongst multiple DMA channels. 611 612config SG_POOL 613 def_bool n 614 help 615 Provides a helper to allocate chained scatterlists. This should be 616 selected by a driver or an API which whishes to allocate chained 617 scatterlist. 618 619# 620# sg chaining option 621# 622 623config ARCH_NO_SG_CHAIN 624 def_bool n 625 626config ARCH_HAS_PMEM_API 627 bool 628 629config MEMREGION 630 bool 631 632config ARCH_HAS_MEMREMAP_COMPAT_ALIGN 633 bool 634 635# use memcpy to implement user copies for nommu architectures 636config UACCESS_MEMCPY 637 bool 638 639config ARCH_HAS_UACCESS_FLUSHCACHE 640 bool 641 642# arch has a concept of a recoverable synchronous exception due to a 643# memory-read error like x86 machine-check or ARM data-abort, and 644# implements copy_mc_to_{user,kernel} to abort and report 645# 'bytes-transferred' if that exception fires when accessing the source 646# buffer. 647config ARCH_HAS_COPY_MC 648 bool 649 650# Temporary. Goes away when all archs are cleaned up 651config ARCH_STACKWALK 652 bool 653 654config STACKDEPOT 655 bool 656 select STACKTRACE 657 658config STACK_HASH_ORDER 659 int "stack depot hash size (12 => 4KB, 20 => 1024KB)" 660 range 12 20 661 default 20 662 depends on STACKDEPOT 663 help 664 Select the hash size as a power of 2 for the stackdepot hash table. 665 Choose a lower value to reduce the memory impact. 666 667config SBITMAP 668 bool 669 670config PARMAN 671 tristate "parman" if COMPILE_TEST 672 673config OBJAGG 674 tristate "objagg" if COMPILE_TEST 675 676config STRING_SELFTEST 677 tristate "Test string functions" 678 679endmenu 680 681config GENERIC_IOREMAP 682 bool 683 684config GENERIC_LIB_ASHLDI3 685 bool 686 687config GENERIC_LIB_ASHRDI3 688 bool 689 690config GENERIC_LIB_LSHRDI3 691 bool 692 693config GENERIC_LIB_MULDI3 694 bool 695 696config GENERIC_LIB_CMPDI2 697 bool 698 699config GENERIC_LIB_UCMPDI2 700 bool 701 702config PLDMFW 703 bool 704 default n 705