diff options
Diffstat (limited to 'lib/Kconfig')
| -rw-r--r-- | lib/Kconfig | 70 |
1 files changed, 66 insertions, 4 deletions
diff --git a/lib/Kconfig b/lib/Kconfig index 028aba9e72a..4a8aba2e5cc 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -29,6 +29,10 @@ config GENERIC_IOMAP bool select GENERIC_PCI_IOMAP +config GENERIC_IO + boolean + default n + config CRC_CCITT tristate "CRC-CCITT functions" help @@ -61,14 +65,71 @@ config CRC_ITU_T functions require M here. config CRC32 - tristate "CRC32 functions" + tristate "CRC32/CRC32c functions" default y select BITREVERSE help This option is provided for the case where no in-kernel-tree - modules require CRC32 functions, but a module built outside the - kernel tree does. Such modules that use library CRC32 functions - require M here. + 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 + bool "CRC32 perform self test on init" + default n + 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 CRC7 tristate "CRC7 functions" @@ -224,6 +285,7 @@ config BTREE config HAS_IOMEM boolean depends on !NO_IOMEM + select GENERIC_IO default y config HAS_IOPORT |