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 ARCH_HAS_STRNCPY_FROM_USER 53 bool 54 55config ARCH_HAS_STRNLEN_USER 56 bool 57 58config GENERIC_STRNCPY_FROM_USER 59 def_bool !ARCH_HAS_STRNCPY_FROM_USER 60 61config GENERIC_STRNLEN_USER 62 def_bool !ARCH_HAS_STRNLEN_USER 63 64config GENERIC_NET_UTILS 65 bool 66 67source "lib/math/Kconfig" 68 69config NO_GENERIC_PCI_IOPORT_MAP 70 bool 71 72config GENERIC_PCI_IOMAP 73 bool 74 75config GENERIC_IOMAP 76 bool 77 select GENERIC_PCI_IOMAP 78 79config STMP_DEVICE 80 bool 81 82config ARCH_USE_CMPXCHG_LOCKREF 83 bool 84 85config ARCH_HAS_FAST_MULTIPLIER 86 bool 87 88config ARCH_USE_SYM_ANNOTATIONS 89 bool 90 91config INDIRECT_PIO 92 bool "Access I/O in non-MMIO mode" 93 depends on ARM64 94 help 95 On some platforms where no separate I/O space exists, there are I/O 96 hosts which can not be accessed in MMIO mode. Using the logical PIO 97 mechanism, the host-local I/O resource can be mapped into system 98 logic PIO space shared with MMIO hosts, such as PCI/PCIe, then the 99 system can access the I/O devices with the mapped-logic PIO through 100 I/O accessors. 101 102 This way has relatively little I/O performance cost. Please make 103 sure your devices really need this configure item enabled. 104 105 When in doubt, say N. 106 107config INDIRECT_IOMEM 108 bool 109 help 110 This is selected by other options/architectures to provide the 111 emulated iomem accessors. 112 113config INDIRECT_IOMEM_FALLBACK 114 bool 115 depends on INDIRECT_IOMEM 116 help 117 If INDIRECT_IOMEM is selected, this enables falling back to plain 118 mmio accesses when the IO memory address is not a registered 119 emulated region. 120 121source "lib/crypto/Kconfig" 122 123config LIB_MEMNEQ 124 bool 125 126config CRC_CCITT 127 tristate "CRC-CCITT functions" 128 help 129 This option is provided for the case where no in-kernel-tree 130 modules require CRC-CCITT functions, but a module built outside 131 the kernel tree does. Such modules that use library CRC-CCITT 132 functions require M here. 133 134config CRC16 135 tristate "CRC16 functions" 136 help 137 This option is provided for the case where no in-kernel-tree 138 modules require CRC16 functions, but a module built outside 139 the kernel tree does. Such modules that use library CRC16 140 functions require M here. 141 142config CRC_T10DIF 143 tristate "CRC calculation for the T10 Data Integrity Field" 144 select CRYPTO 145 select CRYPTO_CRCT10DIF 146 help 147 This option is only needed if a module that's not in the 148 kernel tree needs to calculate CRC checks for use with the 149 SCSI data integrity subsystem. 150 151config CRC64_ROCKSOFT 152 tristate "CRC calculation for the Rocksoft model CRC64" 153 select CRC64 154 select CRYPTO 155 select CRYPTO_CRC64_ROCKSOFT 156 help 157 This option provides a CRC64 API to a registered crypto driver. 158 This is used with the block layer's data integrity subsystem. 159 160config CRC_ITU_T 161 tristate "CRC ITU-T V.41 functions" 162 help 163 This option is provided for the case where no in-kernel-tree 164 modules require CRC ITU-T V.41 functions, but a module built outside 165 the kernel tree does. Such modules that use library CRC ITU-T V.41 166 functions require M here. 167 168config CRC32 169 tristate "CRC32/CRC32c functions" 170 default y 171 select BITREVERSE 172 help 173 This option is provided for the case where no in-kernel-tree 174 modules require CRC32/CRC32c functions, but a module built outside 175 the kernel tree does. Such modules that use library CRC32/CRC32c 176 functions require M here. 177 178config CRC32_SELFTEST 179 tristate "CRC32 perform self test on init" 180 depends on CRC32 181 help 182 This option enables the CRC32 library functions to perform a 183 self test on initialization. The self test computes crc32_le 184 and crc32_be over byte strings with random alignment and length 185 and computes the total elapsed time and number of bytes processed. 186 187choice 188 prompt "CRC32 implementation" 189 depends on CRC32 190 default CRC32_SLICEBY8 191 help 192 This option allows a kernel builder to override the default choice 193 of CRC32 algorithm. Choose the default ("slice by 8") unless you 194 know that you need one of the others. 195 196config CRC32_SLICEBY8 197 bool "Slice by 8 bytes" 198 help 199 Calculate checksum 8 bytes at a time with a clever slicing algorithm. 200 This is the fastest algorithm, but comes with a 8KiB lookup table. 201 Most modern processors have enough cache to hold this table without 202 thrashing the cache. 203 204 This is the default implementation choice. Choose this one unless 205 you have a good reason not to. 206 207config CRC32_SLICEBY4 208 bool "Slice by 4 bytes" 209 help 210 Calculate checksum 4 bytes at a time with a clever slicing algorithm. 211 This is a bit slower than slice by 8, but has a smaller 4KiB lookup 212 table. 213 214 Only choose this option if you know what you are doing. 215 216config CRC32_SARWATE 217 bool "Sarwate's Algorithm (one byte at a time)" 218 help 219 Calculate checksum a byte at a time using Sarwate's algorithm. This 220 is not particularly fast, but has a small 256 byte lookup table. 221 222 Only choose this option if you know what you are doing. 223 224config CRC32_BIT 225 bool "Classic Algorithm (one bit at a time)" 226 help 227 Calculate checksum one bit at a time. This is VERY slow, but has 228 no lookup table. This is provided as a debugging option. 229 230 Only choose this option if you are debugging crc32. 231 232endchoice 233 234config CRC64 235 tristate "CRC64 functions" 236 help 237 This option is provided for the case where no in-kernel-tree 238 modules require CRC64 functions, but a module built outside 239 the kernel tree does. Such modules that use library CRC64 240 functions require M here. 241 242config CRC4 243 tristate "CRC4 functions" 244 help 245 This option is provided for the case where no in-kernel-tree 246 modules require CRC4 functions, but a module built outside 247 the kernel tree does. Such modules that use library CRC4 248 functions require M here. 249 250config CRC7 251 tristate "CRC7 functions" 252 help 253 This option is provided for the case where no in-kernel-tree 254 modules require CRC7 functions, but a module built outside 255 the kernel tree does. Such modules that use library CRC7 256 functions require M here. 257 258config LIBCRC32C 259 tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check" 260 select CRYPTO 261 select CRYPTO_CRC32C 262 help 263 This option is provided for the case where no in-kernel-tree 264 modules require CRC32c functions, but a module built outside the 265 kernel tree does. Such modules that use library CRC32c functions 266 require M here. See Castagnoli93. 267 Module will be libcrc32c. 268 269config CRC8 270 tristate "CRC8 function" 271 help 272 This option provides CRC8 function. Drivers may select this 273 when they need to do cyclic redundancy check according CRC8 274 algorithm. Module will be called crc8. 275 276config XXHASH 277 tristate 278 279config AUDIT_GENERIC 280 bool 281 depends on AUDIT && !AUDIT_ARCH 282 default y 283 284config AUDIT_ARCH_COMPAT_GENERIC 285 bool 286 default n 287 288config AUDIT_COMPAT_GENERIC 289 bool 290 depends on AUDIT_GENERIC && AUDIT_ARCH_COMPAT_GENERIC && COMPAT 291 default y 292 293config RANDOM32_SELFTEST 294 bool "PRNG perform self test on init" 295 help 296 This option enables the 32 bit PRNG library functions to perform a 297 self test on initialization. 298 299# 300# compression support is select'ed if needed 301# 302config 842_COMPRESS 303 select CRC32 304 tristate 305 306config 842_DECOMPRESS 307 select CRC32 308 tristate 309 310config ZLIB_INFLATE 311 tristate 312 313config ZLIB_DEFLATE 314 tristate 315 select BITREVERSE 316 317config ZLIB_DFLTCC 318 def_bool y 319 depends on S390 320 prompt "Enable s390x DEFLATE CONVERSION CALL support for kernel zlib" 321 help 322 Enable s390x hardware support for zlib in the kernel. 323 324config LZO_COMPRESS 325 tristate 326 327config LZO_DECOMPRESS 328 tristate 329 330config LZ4_COMPRESS 331 tristate 332 333config LZ4HC_COMPRESS 334 tristate 335 336config LZ4_DECOMPRESS 337 tristate 338 339config ZSTD_COMPRESS 340 select XXHASH 341 tristate 342 343config ZSTD_DECOMPRESS 344 select XXHASH 345 tristate 346 347source "lib/xz/Kconfig" 348 349# 350# These all provide a common interface (hence the apparent duplication with 351# ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.) 352# 353config DECOMPRESS_GZIP 354 select ZLIB_INFLATE 355 tristate 356 357config DECOMPRESS_BZIP2 358 tristate 359 360config DECOMPRESS_LZMA 361 tristate 362 363config DECOMPRESS_XZ 364 select XZ_DEC 365 tristate 366 367config DECOMPRESS_LZO 368 select LZO_DECOMPRESS 369 tristate 370 371config DECOMPRESS_LZ4 372 select LZ4_DECOMPRESS 373 tristate 374 375config DECOMPRESS_ZSTD 376 select ZSTD_DECOMPRESS 377 tristate 378 379# 380# Generic allocator support is selected if needed 381# 382config GENERIC_ALLOCATOR 383 bool 384 385# 386# reed solomon support is select'ed if needed 387# 388config REED_SOLOMON 389 tristate 390 391config REED_SOLOMON_ENC8 392 bool 393 394config REED_SOLOMON_DEC8 395 bool 396 397config REED_SOLOMON_ENC16 398 bool 399 400config REED_SOLOMON_DEC16 401 bool 402 403# 404# BCH support is selected if needed 405# 406config BCH 407 tristate 408 409config BCH_CONST_PARAMS 410 bool 411 help 412 Drivers may select this option to force specific constant 413 values for parameters 'm' (Galois field order) and 't' 414 (error correction capability). Those specific values must 415 be set by declaring default values for symbols BCH_CONST_M 416 and BCH_CONST_T. 417 Doing so will enable extra compiler optimizations, 418 improving encoding and decoding performance up to 2x for 419 usual (m,t) values (typically such that m*t < 200). 420 When this option is selected, the BCH library supports 421 only a single (m,t) configuration. This is mainly useful 422 for NAND flash board drivers requiring known, fixed BCH 423 parameters. 424 425config BCH_CONST_M 426 int 427 range 5 15 428 help 429 Constant value for Galois field order 'm'. If 'k' is the 430 number of data bits to protect, 'm' should be chosen such 431 that (k + m*t) <= 2**m - 1. 432 Drivers should declare a default value for this symbol if 433 they select option BCH_CONST_PARAMS. 434 435config BCH_CONST_T 436 int 437 help 438 Constant value for error correction capability in bits 't'. 439 Drivers should declare a default value for this symbol if 440 they select option BCH_CONST_PARAMS. 441 442# 443# Textsearch support is select'ed if needed 444# 445config TEXTSEARCH 446 bool 447 448config TEXTSEARCH_KMP 449 tristate 450 451config TEXTSEARCH_BM 452 tristate 453 454config TEXTSEARCH_FSM 455 tristate 456 457config BTREE 458 bool 459 460config INTERVAL_TREE 461 bool 462 help 463 Simple, embeddable, interval-tree. Can find the start of an 464 overlapping range in log(n) time and then iterate over all 465 overlapping nodes. The algorithm is implemented as an 466 augmented rbtree. 467 468 See: 469 470 Documentation/core-api/rbtree.rst 471 472 for more information. 473 474config XARRAY_MULTI 475 bool 476 help 477 Support entries which occupy multiple consecutive indices in the 478 XArray. 479 480config ASSOCIATIVE_ARRAY 481 bool 482 help 483 Generic associative array. Can be searched and iterated over whilst 484 it is being modified. It is also reasonably quick to search and 485 modify. The algorithms are non-recursive, and the trees are highly 486 capacious. 487 488 See: 489 490 Documentation/core-api/assoc_array.rst 491 492 for more information. 493 494config HAS_IOMEM 495 bool 496 depends on !NO_IOMEM 497 default y 498 499config HAS_IOPORT_MAP 500 bool 501 depends on HAS_IOMEM && !NO_IOPORT_MAP 502 default y 503 504source "kernel/dma/Kconfig" 505 506config SGL_ALLOC 507 bool 508 default n 509 510config IOMMU_HELPER 511 bool 512 513config CHECK_SIGNATURE 514 bool 515 516config CPUMASK_OFFSTACK 517 bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS 518 help 519 Use dynamic allocation for cpumask_var_t, instead of putting 520 them on the stack. This is a bit more expensive, but avoids 521 stack overflow. 522 523config CPU_RMAP 524 bool 525 depends on SMP 526 527config DQL 528 bool 529 530config GLOB 531 bool 532# This actually supports modular compilation, but the module overhead 533# is ridiculous for the amount of code involved. Until an out-of-tree 534# driver asks for it, we'll just link it directly it into the kernel 535# when required. Since we're ignoring out-of-tree users, there's also 536# no need bother prompting for a manual decision: 537# prompt "glob_match() function" 538 help 539 This option provides a glob_match function for performing 540 simple text pattern matching. It originated in the ATA code 541 to blacklist particular drive models, but other device drivers 542 may need similar functionality. 543 544 All drivers in the Linux kernel tree that require this function 545 should automatically select this option. Say N unless you 546 are compiling an out-of tree driver which tells you that it 547 depends on this. 548 549config GLOB_SELFTEST 550 tristate "glob self-test on init" 551 depends on GLOB 552 help 553 This option enables a simple self-test of the glob_match 554 function on startup. It is primarily useful for people 555 working on the code to ensure they haven't introduced any 556 regressions. 557 558 It only adds a little bit of code and slows kernel boot (or 559 module load) by a small amount, so you're welcome to play with 560 it, but you probably don't need it. 561 562# 563# Netlink attribute parsing support is select'ed if needed 564# 565config NLATTR 566 bool 567 568# 569# Generic 64-bit atomic support is selected if needed 570# 571config GENERIC_ATOMIC64 572 bool 573 574config LRU_CACHE 575 tristate 576 577config CLZ_TAB 578 bool 579 580config IRQ_POLL 581 bool "IRQ polling library" 582 help 583 Helper library to poll interrupt mitigation using polling. 584 585config MPILIB 586 tristate 587 select CLZ_TAB 588 help 589 Multiprecision maths library from GnuPG. 590 It is used to implement RSA digital signature verification, 591 which is used by IMA/EVM digital signature extension. 592 593config SIGNATURE 594 tristate 595 depends on KEYS 596 select CRYPTO 597 select CRYPTO_SHA1 598 select MPILIB 599 help 600 Digital signature verification. Currently only RSA is supported. 601 Implementation is done using GnuPG MPI library 602 603config DIMLIB 604 bool 605 help 606 Dynamic Interrupt Moderation library. 607 Implements an algorithm for dynamically changing CQ moderation values 608 according to run time performance. 609 610# 611# libfdt files, only selected if needed. 612# 613config LIBFDT 614 bool 615 616config OID_REGISTRY 617 tristate 618 help 619 Enable fast lookup object identifier registry. 620 621config UCS2_STRING 622 tristate 623 624# 625# generic vdso 626# 627source "lib/vdso/Kconfig" 628 629source "lib/fonts/Kconfig" 630 631config SG_SPLIT 632 def_bool n 633 help 634 Provides a helper to split scatterlists into chunks, each chunk being 635 a scatterlist. This should be selected by a driver or an API which 636 whishes to split a scatterlist amongst multiple DMA channels. 637 638config SG_POOL 639 def_bool n 640 help 641 Provides a helper to allocate chained scatterlists. This should be 642 selected by a driver or an API which whishes to allocate chained 643 scatterlist. 644 645# 646# sg chaining option 647# 648 649config ARCH_NO_SG_CHAIN 650 def_bool n 651 652config ARCH_HAS_PMEM_API 653 bool 654 655config MEMREGION 656 bool 657 658config ARCH_HAS_MEMREMAP_COMPAT_ALIGN 659 bool 660 661# use memcpy to implement user copies for nommu architectures 662config UACCESS_MEMCPY 663 bool 664 665config ARCH_HAS_UACCESS_FLUSHCACHE 666 bool 667 668# arch has a concept of a recoverable synchronous exception due to a 669# memory-read error like x86 machine-check or ARM data-abort, and 670# implements copy_mc_to_{user,kernel} to abort and report 671# 'bytes-transferred' if that exception fires when accessing the source 672# buffer. 673config ARCH_HAS_COPY_MC 674 bool 675 676# Temporary. Goes away when all archs are cleaned up 677config ARCH_STACKWALK 678 bool 679 680config STACKDEPOT 681 bool 682 select STACKTRACE 683 684config STACKDEPOT_ALWAYS_INIT 685 bool 686 select STACKDEPOT 687 688config STACK_HASH_ORDER 689 int "stack depot hash size (12 => 4KB, 20 => 1024KB)" 690 range 12 20 691 default 20 692 depends on STACKDEPOT 693 help 694 Select the hash size as a power of 2 for the stackdepot hash table. 695 Choose a lower value to reduce the memory impact. 696 697config REF_TRACKER 698 bool 699 depends on STACKTRACE_SUPPORT 700 select STACKDEPOT 701 702config SBITMAP 703 bool 704 705config PARMAN 706 tristate "parman" if COMPILE_TEST 707 708config OBJAGG 709 tristate "objagg" if COMPILE_TEST 710 711endmenu 712 713config GENERIC_IOREMAP 714 bool 715 716config GENERIC_LIB_ASHLDI3 717 bool 718 719config GENERIC_LIB_ASHRDI3 720 bool 721 722config GENERIC_LIB_LSHRDI3 723 bool 724 725config GENERIC_LIB_MULDI3 726 bool 727 728config GENERIC_LIB_CMPDI2 729 bool 730 731config GENERIC_LIB_UCMPDI2 732 bool 733 734config GENERIC_LIB_DEVMEM_IS_ALLOWED 735 bool 736 737config PLDMFW 738 bool 739 default n 740 741config ASN1_ENCODER 742 tristate 743 744config POLYNOMIAL 745 tristate 746