diff options
Diffstat (limited to 'lib/Kconfig')
| -rw-r--r-- | lib/Kconfig | 121 |
1 files changed, 88 insertions, 33 deletions
diff --git a/lib/Kconfig b/lib/Kconfig index 5a318f753b2f..a78d22c6507f 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -156,13 +156,43 @@ config CRC16 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 ARCH_HAS_CRC_T10DIF + bool + +choice + prompt "CRC-T10DIF implementation" + depends on CRC_T10DIF + default CRC_T10DIF_IMPL_ARCH if ARCH_HAS_CRC_T10DIF + default CRC_T10DIF_IMPL_GENERIC if !ARCH_HAS_CRC_T10DIF + help + This option allows you to override the default choice of CRC-T10DIF + implementation. + +config CRC_T10DIF_IMPL_ARCH + bool "Architecture-optimized" if ARCH_HAS_CRC_T10DIF + help + Use the optimized implementation of CRC-T10DIF for the selected + architecture. It is recommended to keep this enabled, as it can + greatly improve CRC-T10DIF performance. + +config CRC_T10DIF_IMPL_GENERIC + bool "Generic implementation" + help + Use the generic table-based implementation of CRC-T10DIF. Selecting + this will reduce code size slightly but can greatly reduce CRC-T10DIF + performance. + +endchoice + +config CRC_T10DIF_ARCH + tristate + default CRC_T10DIF if CRC_T10DIF_IMPL_ARCH + config CRC64_ROCKSOFT tristate "CRC calculation for the Rocksoft model CRC64" select CRC64 @@ -190,36 +220,45 @@ config CRC32 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. +config ARCH_HAS_CRC32 + bool choice prompt "CRC32 implementation" depends on CRC32 - default CRC32_SLICEBY8 + default CRC32_IMPL_ARCH_PLUS_SLICEBY8 if ARCH_HAS_CRC32 + default CRC32_IMPL_SLICEBY8 if !ARCH_HAS_CRC32 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. + This option allows you to override the default choice of CRC32 + implementation. Choose the default unless you know that you need one + of the others. -config CRC32_SLICEBY8 +config CRC32_IMPL_ARCH_PLUS_SLICEBY8 + bool "Arch-optimized, with fallback to slice-by-8" if ARCH_HAS_CRC32 + help + Use architecture-optimized implementation of CRC32. Fall back to + slice-by-8 in cases where the arch-optimized implementation cannot be + used, e.g. if the CPU lacks support for the needed instructions. + + This is the default when an arch-optimized implementation exists. + +config CRC32_IMPL_ARCH_PLUS_SLICEBY1 + bool "Arch-optimized, with fallback to slice-by-1" if ARCH_HAS_CRC32 + help + Use architecture-optimized implementation of CRC32, but fall back to + slice-by-1 instead of slice-by-8 in order to reduce the binary size. + +config CRC32_IMPL_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. + This is much slower than the architecture-optimized implementation of + CRC32 (if the selected arch has one), but it is portable and is the + fastest implementation when no arch-optimized implementation is + available. It uses an 8KiB lookup table. Most modern processors have + enough cache to hold this table without thrashing the cache. -config CRC32_SLICEBY4 +config CRC32_IMPL_SLICEBY4 bool "Slice by 4 bytes" help Calculate checksum 4 bytes at a time with a clever slicing algorithm. @@ -228,15 +267,15 @@ config CRC32_SLICEBY4 Only choose this option if you know what you are doing. -config CRC32_SARWATE - bool "Sarwate's Algorithm (one byte at a time)" +config CRC32_IMPL_SLICEBY1 + bool "Slice by 1 byte (Sarwate's algorithm)" 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. + is not particularly fast, but has a small 1KiB lookup table. Only choose this option if you know what you are doing. -config CRC32_BIT +config CRC32_IMPL_BIT bool "Classic Algorithm (one bit at a time)" help Calculate checksum one bit at a time. This is VERY slow, but has @@ -246,6 +285,26 @@ config CRC32_BIT endchoice +config CRC32_ARCH + tristate + default CRC32 if CRC32_IMPL_ARCH_PLUS_SLICEBY8 || CRC32_IMPL_ARCH_PLUS_SLICEBY1 + +config CRC32_SLICEBY8 + bool + default y if CRC32_IMPL_SLICEBY8 || CRC32_IMPL_ARCH_PLUS_SLICEBY8 + +config CRC32_SLICEBY4 + bool + default y if CRC32_IMPL_SLICEBY4 + +config CRC32_SARWATE + bool + default y if CRC32_IMPL_SLICEBY1 || CRC32_IMPL_ARCH_PLUS_SLICEBY1 + +config CRC32_BIT + bool + default y if CRC32_IMPL_BIT + config CRC64 tristate "CRC64 functions" help @@ -272,14 +331,10 @@ config CRC7 config LIBCRC32C tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check" - select CRYPTO - select CRYPTO_CRC32C + select CRC32 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. + This option just selects CRC32 and is provided for compatibility + purposes until the users are updated to select CRC32 directly. config CRC8 tristate "CRC8 function" |