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