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