# SPDX-License-Identifier: GPL-2.0-only## Library configuration# config BINARY_PRINTF def_bool n menu "Library routines" config RAID6_PQ tristate config RAID6_PQ_BENCHMARK bool "Automatically choose fastest RAID6 PQ functions" depends on RAID6_PQ default y help Benchmark all available RAID6 PQ functions on init and choose the fastest one. config LINEAR_RANGES tristate config PACKING bool "Generic bitfield packing and unpacking" default n help This option provides the packing() helper function, which permits converting bitfields between a CPU-usable representation and a memory representation that can have any combination of these quirks: - Is little endian (bytes are reversed within a 32-bit group) - The least-significant 32-bit word comes first (within a 64-bit group) - The most significant bit of a byte is at its right (bit 0 of a register description is numerically 2^7). Drivers may use these helpers to match the bit indices as described in the data sheets of the peripherals they are in control of. When in doubt, say N. config BITREVERSE tristate config HAVE_ARCH_BITREVERSE bool default n depends on BITREVERSE help This option enables the use of hardware bit-reversal instructions on architectures which support such operations. config GENERIC_STRNCPY_FROM_USER bool config GENERIC_STRNLEN_USER bool config GENERIC_NET_UTILS bool config GENERIC_FIND_FIRST_BIT bool source "lib/math/Kconfig" config NO_GENERIC_PCI_IOPORT_MAP bool config GENERIC_PCI_IOMAP bool config GENERIC_IOMAP bool select GENERIC_PCI_IOMAP config STMP_DEVICE bool config ARCH_USE_CMPXCHG_LOCKREF bool config ARCH_HAS_FAST_MULTIPLIER bool config ARCH_USE_SYM_ANNOTATIONS bool config INDIRECT_PIO bool "Access I/O in non-MMIO mode" depends on ARM64 help On some platforms where no separate I/O space exists, there are I/O hosts which can not be accessed in MMIO mode. Using the logical PIO mechanism, the host-local I/O resource can be mapped into system logic PIO space shared with MMIO hosts, such as PCI/PCIe, then the system can access the I/O devices with the mapped-logic PIO through I/O accessors. This way has relatively little I/O performance cost. Please make sure your devices really need this configure item enabled. When in doubt, say N. config CRC_CCITT tristate "CRC-CCITT functions" help This option is provided for the case where no in-kernel-tree modules require CRC-CCITT functions, but a module built outside the kernel tree does. Such modules that use library CRC-CCITT functions require M here. config CRC16 tristate "CRC16 functions" help This option is provided for the case where no in-kernel-tree modules require CRC16 functions, but a module built outside the kernel tree does. Such modules that use library CRC16 functions require M here. config CRC_T10DIF tristate "CRC calculation for the T10 Data Integrity Field" select CRYPTO select CRYPTO_CRCT10DIF help This option is only needed if a module that's not in the kernel tree needs to calculate CRC checks for use with the SCSI data integrity subsystem. config CRC_ITU_T tristate "CRC ITU-T V.41 functions" help This option is provided for the case where no in-kernel-tree modules require CRC ITU-T V.41 functions, but a module built outside the kernel tree does. Such modules that use library CRC ITU-T V.41 functions require M here. config CRC32 tristate "CRC32/CRC32c functions" default y select BITREVERSE help This option is provided for the case where no in-kernel-tree modules require CRC32/CRC32c functions, but a module built outside the kernel tree does. Such modules that use library CRC32/CRC32c functions require M here. config CRC32_SELFTEST tristate "CRC32 perform self test on init" depends on CRC32 help This option enables the CRC32 library functions to perform a self test on initialization. The self test computes crc32_le and crc32_be over byte strings with random alignment and length and computes the total elapsed time and number of bytes processed. choice prompt "CRC32 implementation" depends on CRC32 default CRC32_SLICEBY8 help This option allows a kernel builder to override the default choice of CRC32 algorithm. Choose the default ("slice by 8") unless you know that you need one of the others. config CRC32_SLICEBY8 bool "Slice by 8 bytes" help Calculate checksum 8 bytes at a time with a clever slicing algorithm. This is the fastest algorithm, but comes with a 8KiB lookup table. Most modern processors have enough cache to hold this table without thrashing the cache. This is the default implementation choice. Choose this one unless you have a good reason not to. config CRC32_SLICEBY4 bool "Slice by 4 bytes" help Calculate checksum 4 bytes at a time with a clever slicing algorithm. This is a bit slower than slice by 8, but has a smaller 4KiB lookup table. Only choose this option if you know what you are doing. config CRC32_SARWATE bool "Sarwate's Algorithm (one byte at a time)" help Calculate checksum a byte at a time using Sarwate's algorithm. This is not particularly fast, but has a small 256 byte lookup table. Only choose this option if you know what you are doing. config CRC32_BIT bool "Classic Algorithm (one bit at a time)" help Calculate checksum one bit at a time. This is VERY slow, but has no lookup table. This is provided as a debugging option. Only choose this option if you are debugging crc32. endchoice config CRC64 tristate "CRC64 functions" help This option is provided for the case where no in-kernel-tree modules require CRC64 functions, but a module built outside the kernel tree does. Such modules that use library CRC64 functions require M here. config CRC4 tristate "CRC4 functions" help This option is provided for the case where no in-kernel-tree modules require CRC4 functions, but a module built outside the kernel tree does. Such modules that use library CRC4 functions require M here. config CRC7 tristate "CRC7 functions" help This option is provided for the case where no in-kernel-tree modules require CRC7 functions, but a module built outside the kernel tree does. Such modules that use library CRC7 functions require M here. config LIBCRC32C tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check" select CRYPTO select CRYPTO_CRC32C help This option is provided for the case where no in-kernel-tree modules require CRC32c functions, but a module built outside the kernel tree does. Such modules that use library CRC32c functions require M here. See Castagnoli93. Module will be libcrc32c. config CRC8 tristate "CRC8 function" help This option provides CRC8 function. Drivers may select this when they need to do cyclic redundancy check according CRC8 algorithm. Module will be called crc8. config XXHASH tristate config AUDIT_GENERIC bool depends on AUDIT && !AUDIT_ARCH default y config AUDIT_ARCH_COMPAT_GENERIC bool default n config AUDIT_COMPAT_GENERIC bool depends on AUDIT_GENERIC && AUDIT_ARCH_COMPAT_GENERIC && COMPAT default y config RANDOM32_SELFTEST bool "PRNG perform self test on init" help This option enables the 32 bit PRNG library functions to perform a self test on initialization. ## compression support is select'ed if needed#config 842_COMPRESS select CRC32 tristate config 842_DECOMPRESS select CRC32 tristate config ZLIB_INFLATE tristate config ZLIB_DEFLATE tristate select BITREVERSE config ZLIB_DFLTCC def_bool y depends on S390 prompt "Enable s390x DEFLATE CONVERSION CALL support for kernel zlib" help Enable s390x hardware support for zlib in the kernel. config LZO_COMPRESS tristate config LZO_DECOMPRESS tristate config LZ4_COMPRESS tristate config LZ4HC_COMPRESS tristate config LZ4_DECOMPRESS tristate config ZSTD_COMPRESS select XXHASH tristate config ZSTD_DECOMPRESS select XXHASH tristate source "lib/xz/Kconfig" ## These all provide a common interface (hence the apparent duplication with# ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.)#config DECOMPRESS_GZIP select ZLIB_INFLATE tristate config DECOMPRESS_BZIP2 tristate config DECOMPRESS_LZMA tristate config DECOMPRESS_XZ select XZ_DEC tristate config DECOMPRESS_LZO select LZO_DECOMPRESS tristate config DECOMPRESS_LZ4 select LZ4_DECOMPRESS tristate config DECOMPRESS_ZSTD select ZSTD_DECOMPRESS tristate ## Generic allocator support is selected if needed#config GENERIC_ALLOCATOR bool ## reed solomon support is select'ed if needed#config REED_SOLOMON tristate config REED_SOLOMON_ENC8 bool config REED_SOLOMON_DEC8 bool config REED_SOLOMON_ENC16 bool config REED_SOLOMON_DEC16 bool ## BCH support is selected if needed#config BCH tristate config BCH_CONST_PARAMS bool help Drivers may select this option to force specific constant values for parameters 'm' (Galois field order) and 't' (error correction capability). Those specific values must be set by declaring default values for symbols BCH_CONST_M and BCH_CONST_T. Doing so will enable extra compiler optimizations, improving encoding and decoding performance up to 2x for usual (m,t) values (typically such that m*t < 200). When this option is selected, the BCH library supports only a single (m,t) configuration. This is mainly useful for NAND flash board drivers requiring known, fixed BCH parameters. config BCH_CONST_M int range 5 15 help Constant value for Galois field order 'm'. If 'k' is the number of data bits to protect, 'm' should be chosen such that (k + m*t) <= 2**m - 1. Drivers should declare a default value for this symbol if they select option BCH_CONST_PARAMS. config BCH_CONST_T int help Constant value for error correction capability in bits 't'. Drivers should declare a default value for this symbol if they select option BCH_CONST_PARAMS. ## Textsearch support is select'ed if needed#config TEXTSEARCH bool config TEXTSEARCH_KMP tristate config TEXTSEARCH_BM tristate config TEXTSEARCH_FSM tristate config BTREE bool config INTERVAL_TREE bool help Simple, embeddable, interval-tree. Can find the start of an overlapping range in log(n) time and then iterate over all overlapping nodes. The algorithm is implemented as an augmented rbtree. See: Documentation/core-api/rbtree.rst for more information. config XARRAY_MULTI bool help Support entries which occupy multiple consecutive indices in the XArray. config ASSOCIATIVE_ARRAY bool help Generic associative array. Can be searched and iterated over whilst it is being modified. It is also reasonably quick to search and modify. The algorithms are non-recursive, and the trees are highly capacious. See: Documentation/core-api/assoc_array.rst for more information. config HAS_IOMEM bool depends on !NO_IOMEM default y config HAS_IOPORT_MAP bool depends on HAS_IOMEM && !NO_IOPORT_MAP default y source "kernel/dma/Kconfig" config SGL_ALLOC bool default n config IOMMU_HELPER bool config CHECK_SIGNATURE bool config CPUMASK_OFFSTACK bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS help Use dynamic allocation for cpumask_var_t, instead of putting them on the stack. This is a bit more expensive, but avoids stack overflow. config CPU_RMAP bool depends on SMP config DQL bool config GLOBLines 1–500 of 686. Load more
# SPDX-License-Identifier: GPL-2.0-only # # Library configuration # config BINARY_PRINTF def_bool n menu "Library routines" config RAID6_PQ tristate config RAID6_PQ_BENCHMARK bool "Automatically choose fastest RAID6 PQ functions" depends on RAID6_PQ default y help Benchmark all available RAID6 PQ functions on init and choose the fastest one. config LINEAR_RANGES tristate config PACKING bool "Generic bitfield packing and unpacking" default n help This option provides the packing() helper function, which permits converting bitfields between a CPU-usable representation and a memory representation that can have any combination of these quirks: - Is little endian (bytes are reversed within a 32-bit group) - The least-significant 32-bit word comes first (within a 64-bit group) - The most significant bit of a byte is at its right (bit 0 of a register description is numerically 2^7). Drivers may use these helpers to match the bit indices as described in the data sheets of the peripherals they are in control of. When in doubt, say N. config BITREVERSE tristate config HAVE_ARCH_BITREVERSE bool default n depends on BITREVERSE help This option enables the use of hardware bit-reversal instructions on architectures which support such operations. config GENERIC_STRNCPY_FROM_USER bool config GENERIC_STRNLEN_USER bool config GENERIC_NET_UTILS bool config GENERIC_FIND_FIRST_BIT bool source "lib/math/Kconfig" config NO_GENERIC_PCI_IOPORT_MAP bool config GENERIC_PCI_IOMAP bool config GENERIC_IOMAP bool select GENERIC_PCI_IOMAP config STMP_DEVICE bool config ARCH_USE_CMPXCHG_LOCKREF bool config ARCH_HAS_FAST_MULTIPLIER bool config ARCH_USE_SYM_ANNOTATIONS bool config INDIRECT_PIO bool "Access I/O in non-MMIO mode" depends on ARM64 help On some platforms where no separate I/O space exists, there are I/O hosts which can not be accessed in MMIO mode. Using the logical PIO mechanism, the host-local I/O resource can be mapped into system logic PIO space shared with MMIO hosts, such as PCI/PCIe, then the system can access the I/O devices with the mapped-logic PIO through I/O accessors. This way has relatively little I/O performance cost. Please make sure your devices really need this configure item enabled. When in doubt, say N. config CRC_CCITT tristate "CRC-CCITT functions" help This option is provided for the case where no in-kernel-tree modules require CRC-CCITT functions, but a module built outside the kernel tree does. Such modules that use library CRC-CCITT functions require M here. config CRC16 tristate "CRC16 functions" help This option is provided for the case where no in-kernel-tree modules require CRC16 functions, but a module built outside the kernel tree does. Such modules that use library CRC16 functions require M here. config CRC_T10DIF tristate "CRC calculation for the T10 Data Integrity Field" select CRYPTO select CRYPTO_CRCT10DIF help This option is only needed if a module that's not in the kernel tree needs to calculate CRC checks for use with the SCSI data integrity subsystem. config CRC_ITU_T tristate "CRC ITU-T V.41 functions" help This option is provided for the case where no in-kernel-tree modules require CRC ITU-T V.41 functions, but a module built outside the kernel tree does. Such modules that use library CRC ITU-T V.41 functions require M here. config CRC32 tristate "CRC32/CRC32c functions" default y select BITREVERSE help This option is provided for the case where no in-kernel-tree modules require CRC32/CRC32c functions, but a module built outside the kernel tree does. Such modules that use library CRC32/CRC32c functions require M here. config CRC32_SELFTEST tristate "CRC32 perform self test on init" depends on CRC32 help This option enables the CRC32 library functions to perform a self test on initialization. The self test computes crc32_le and crc32_be over byte strings with random alignment and length and computes the total elapsed time and number of bytes processed. choice prompt "CRC32 implementation" depends on CRC32 default CRC32_SLICEBY8 help This option allows a kernel builder to override the default choice of CRC32 algorithm. Choose the default ("slice by 8") unless you know that you need one of the others. config CRC32_SLICEBY8 bool "Slice by 8 bytes" help Calculate checksum 8 bytes at a time with a clever slicing algorithm. This is the fastest algorithm, but comes with a 8KiB lookup table. Most modern processors have enough cache to hold this table without thrashing the cache. This is the default implementation choice. Choose this one unless you have a good reason not to. config CRC32_SLICEBY4 bool "Slice by 4 bytes" help Calculate checksum 4 bytes at a time with a clever slicing algorithm. This is a bit slower than slice by 8, but has a smaller 4KiB lookup table. Only choose this option if you know what you are doing. config CRC32_SARWATE bool "Sarwate's Algorithm (one byte at a time)" help Calculate checksum a byte at a time using Sarwate's algorithm. This is not particularly fast, but has a small 256 byte lookup table. Only choose this option if you know what you are doing. config CRC32_BIT bool "Classic Algorithm (one bit at a time)" help Calculate checksum one bit at a time. This is VERY slow, but has no lookup table. This is provided as a debugging option. Only choose this option if you are debugging crc32. endchoice config CRC64 tristate "CRC64 functions" help This option is provided for the case where no in-kernel-tree modules require CRC64 functions, but a module built outside the kernel tree does. Such modules that use library CRC64 functions require M here. config CRC4 tristate "CRC4 functions" help This option is provided for the case where no in-kernel-tree modules require CRC4 functions, but a module built outside the kernel tree does. Such modules that use library CRC4 functions require M here. config CRC7 tristate "CRC7 functions" help This option is provided for the case where no in-kernel-tree modules require CRC7 functions, but a module built outside the kernel tree does. Such modules that use library CRC7 functions require M here. config LIBCRC32C tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check" select CRYPTO select CRYPTO_CRC32C help This option is provided for the case where no in-kernel-tree modules require CRC32c functions, but a module built outside the kernel tree does. Such modules that use library CRC32c functions require M here. See Castagnoli93. Module will be libcrc32c. config CRC8 tristate "CRC8 function" help This option provides CRC8 function. Drivers may select this when they need to do cyclic redundancy check according CRC8 algorithm. Module will be called crc8. config XXHASH tristate config AUDIT_GENERIC bool depends on AUDIT && !AUDIT_ARCH default y config AUDIT_ARCH_COMPAT_GENERIC bool default n config AUDIT_COMPAT_GENERIC bool depends on AUDIT_GENERIC && AUDIT_ARCH_COMPAT_GENERIC && COMPAT default y config RANDOM32_SELFTEST bool "PRNG perform self test on init" help This option enables the 32 bit PRNG library functions to perform a self test on initialization. # # compression support is select'ed if needed # config 842_COMPRESS select CRC32 tristate config 842_DECOMPRESS select CRC32 tristate config ZLIB_INFLATE tristate config ZLIB_DEFLATE tristate select BITREVERSE config ZLIB_DFLTCC def_bool y depends on S390 prompt "Enable s390x DEFLATE CONVERSION CALL support for kernel zlib" help Enable s390x hardware support for zlib in the kernel. config LZO_COMPRESS tristate config LZO_DECOMPRESS tristate config LZ4_COMPRESS tristate config LZ4HC_COMPRESS tristate config LZ4_DECOMPRESS tristate config ZSTD_COMPRESS select XXHASH tristate config ZSTD_DECOMPRESS select XXHASH tristate source "lib/xz/Kconfig" # # These all provide a common interface (hence the apparent duplication with # ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.) # config DECOMPRESS_GZIP select ZLIB_INFLATE tristate config DECOMPRESS_BZIP2 tristate config DECOMPRESS_LZMA tristate config DECOMPRESS_XZ select XZ_DEC tristate config DECOMPRESS_LZO select LZO_DECOMPRESS tristate config DECOMPRESS_LZ4 select LZ4_DECOMPRESS tristate config DECOMPRESS_ZSTD select ZSTD_DECOMPRESS tristate # # Generic allocator support is selected if needed # config GENERIC_ALLOCATOR bool # # reed solomon support is select'ed if needed # config REED_SOLOMON tristate config REED_SOLOMON_ENC8 bool config REED_SOLOMON_DEC8 bool config REED_SOLOMON_ENC16 bool config REED_SOLOMON_DEC16 bool # # BCH support is selected if needed # config BCH tristate config BCH_CONST_PARAMS bool help Drivers may select this option to force specific constant values for parameters 'm' (Galois field order) and 't' (error correction capability). Those specific values must be set by declaring default values for symbols BCH_CONST_M and BCH_CONST_T. Doing so will enable extra compiler optimizations, improving encoding and decoding performance up to 2x for usual (m,t) values (typically such that m*t < 200). When this option is selected, the BCH library supports only a single (m,t) configuration. This is mainly useful for NAND flash board drivers requiring known, fixed BCH parameters. config BCH_CONST_M int range 5 15 help Constant value for Galois field order 'm'. If 'k' is the number of data bits to protect, 'm' should be chosen such that (k + m*t) <= 2**m - 1. Drivers should declare a default value for this symbol if they select option BCH_CONST_PARAMS. config BCH_CONST_T int help Constant value for error correction capability in bits 't'. Drivers should declare a default value for this symbol if they select option BCH_CONST_PARAMS. # # Textsearch support is select'ed if needed # config TEXTSEARCH bool config TEXTSEARCH_KMP tristate config TEXTSEARCH_BM tristate config TEXTSEARCH_FSM tristate config BTREE bool config INTERVAL_TREE bool help Simple, embeddable, interval-tree. Can find the start of an overlapping range in log(n) time and then iterate over all overlapping nodes. The algorithm is implemented as an augmented rbtree. See: Documentation/core-api/rbtree.rst for more information. config XARRAY_MULTI bool help Support entries which occupy multiple consecutive indices in the XArray. config ASSOCIATIVE_ARRAY bool help Generic associative array. Can be searched and iterated over whilst it is being modified. It is also reasonably quick to search and modify. The algorithms are non-recursive, and the trees are highly capacious. See: Documentation/core-api/assoc_array.rst for more information. config HAS_IOMEM bool depends on !NO_IOMEM default y config HAS_IOPORT_MAP bool depends on HAS_IOMEM && !NO_IOPORT_MAP default y source "kernel/dma/Kconfig" config SGL_ALLOC bool default n config IOMMU_HELPER bool config CHECK_SIGNATURE bool config CPUMASK_OFFSTACK bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS help Use dynamic allocation for cpumask_var_t, instead of putting them on the stack. This is a bit more expensive, but avoids stack overflow. config CPU_RMAP bool depends on SMP config DQL bool config GLOB