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