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