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