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