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Diffstat (limited to 'kernel/include/linux/crc32.h')
-rw-r--r-- | kernel/include/linux/crc32.h | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/kernel/include/linux/crc32.h b/kernel/include/linux/crc32.h new file mode 100644 index 000000000..9e8a032c1 --- /dev/null +++ b/kernel/include/linux/crc32.h @@ -0,0 +1,79 @@ +/* + * crc32.h + * See linux/lib/crc32.c for license and changes + */ +#ifndef _LINUX_CRC32_H +#define _LINUX_CRC32_H + +#include <linux/types.h> +#include <linux/bitrev.h> + +u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len); +u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len); + +/** + * crc32_le_combine - Combine two crc32 check values into one. For two + * sequences of bytes, seq1 and seq2 with lengths len1 + * and len2, crc32_le() check values were calculated + * for each, crc1 and crc2. + * + * @crc1: crc32 of the first block + * @crc2: crc32 of the second block + * @len2: length of the second block + * + * Return: The crc32_le() check value of seq1 and seq2 concatenated, + * requiring only crc1, crc2, and len2. Note: If seq_full denotes + * the concatenated memory area of seq1 with seq2, and crc_full + * the crc32_le() value of seq_full, then crc_full == + * crc32_le_combine(crc1, crc2, len2) when crc_full was seeded + * with the same initializer as crc1, and crc2 seed was 0. See + * also crc32_combine_test(). + */ +u32 __attribute_const__ crc32_le_shift(u32 crc, size_t len); + +static inline u32 crc32_le_combine(u32 crc1, u32 crc2, size_t len2) +{ + return crc32_le_shift(crc1, len2) ^ crc2; +} + +u32 __pure __crc32c_le(u32 crc, unsigned char const *p, size_t len); + +/** + * __crc32c_le_combine - Combine two crc32c check values into one. For two + * sequences of bytes, seq1 and seq2 with lengths len1 + * and len2, __crc32c_le() check values were calculated + * for each, crc1 and crc2. + * + * @crc1: crc32c of the first block + * @crc2: crc32c of the second block + * @len2: length of the second block + * + * Return: The __crc32c_le() check value of seq1 and seq2 concatenated, + * requiring only crc1, crc2, and len2. Note: If seq_full denotes + * the concatenated memory area of seq1 with seq2, and crc_full + * the __crc32c_le() value of seq_full, then crc_full == + * __crc32c_le_combine(crc1, crc2, len2) when crc_full was + * seeded with the same initializer as crc1, and crc2 seed + * was 0. See also crc32c_combine_test(). + */ +u32 __attribute_const__ __crc32c_le_shift(u32 crc, size_t len); + +static inline u32 __crc32c_le_combine(u32 crc1, u32 crc2, size_t len2) +{ + return __crc32c_le_shift(crc1, len2) ^ crc2; +} + +#define crc32(seed, data, length) crc32_le(seed, (unsigned char const *)(data), length) + +/* + * Helpers for hash table generation of ethernet nics: + * + * Ethernet sends the least significant bit of a byte first, thus crc32_le + * is used. The output of crc32_le is bit reversed [most significant bit + * is in bit nr 0], thus it must be reversed before use. Except for + * nics that bit swap the result internally... + */ +#define ether_crc(length, data) bitrev32(crc32_le(~0, data, length)) +#define ether_crc_le(length, data) crc32_le(~0, data, length) + +#endif /* _LINUX_CRC32_H */ |