1 /* 2 * crc32.h 3 * See linux/lib/crc32.c for license and changes 4 */ 5 #ifndef _LINUX_CRC32_H 6 #define _LINUX_CRC32_H 7 8 #include <linux/types.h> 9 #include <linux/bitrev.h> 10 11 u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len); 12 u32 __pure crc32_le_base(u32 crc, unsigned char const *p, size_t len); 13 u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len); 14 u32 __pure crc32_be_base(u32 crc, unsigned char const *p, size_t len); 15 16 /** 17 * crc32_le_combine - Combine two crc32 check values into one. For two 18 * sequences of bytes, seq1 and seq2 with lengths len1 19 * and len2, crc32_le() check values were calculated 20 * for each, crc1 and crc2. 21 * 22 * @crc1: crc32 of the first block 23 * @crc2: crc32 of the second block 24 * @len2: length of the second block 25 * 26 * Return: The crc32_le() check value of seq1 and seq2 concatenated, 27 * requiring only crc1, crc2, and len2. Note: If seq_full denotes 28 * the concatenated memory area of seq1 with seq2, and crc_full 29 * the crc32_le() value of seq_full, then crc_full == 30 * crc32_le_combine(crc1, crc2, len2) when crc_full was seeded 31 * with the same initializer as crc1, and crc2 seed was 0. See 32 * also crc32_combine_test(). 33 */ 34 u32 __attribute_const__ crc32_le_shift(u32 crc, size_t len); 35 crc32_le_combine(u32 crc1,u32 crc2,size_t len2)36 static inline u32 crc32_le_combine(u32 crc1, u32 crc2, size_t len2) 37 { 38 return crc32_le_shift(crc1, len2) ^ crc2; 39 } 40 41 u32 __pure __crc32c_le(u32 crc, unsigned char const *p, size_t len); 42 u32 __pure __crc32c_le_base(u32 crc, unsigned char const *p, size_t len); 43 44 /** 45 * __crc32c_le_combine - Combine two crc32c check values into one. For two 46 * sequences of bytes, seq1 and seq2 with lengths len1 47 * and len2, __crc32c_le() check values were calculated 48 * for each, crc1 and crc2. 49 * 50 * @crc1: crc32c of the first block 51 * @crc2: crc32c of the second block 52 * @len2: length of the second block 53 * 54 * Return: The __crc32c_le() check value of seq1 and seq2 concatenated, 55 * requiring only crc1, crc2, and len2. Note: If seq_full denotes 56 * the concatenated memory area of seq1 with seq2, and crc_full 57 * the __crc32c_le() value of seq_full, then crc_full == 58 * __crc32c_le_combine(crc1, crc2, len2) when crc_full was 59 * seeded with the same initializer as crc1, and crc2 seed 60 * was 0. See also crc32c_combine_test(). 61 */ 62 u32 __attribute_const__ __crc32c_le_shift(u32 crc, size_t len); 63 __crc32c_le_combine(u32 crc1,u32 crc2,size_t len2)64 static inline u32 __crc32c_le_combine(u32 crc1, u32 crc2, size_t len2) 65 { 66 return __crc32c_le_shift(crc1, len2) ^ crc2; 67 } 68 69 #define crc32(seed, data, length) crc32_le(seed, (unsigned char const *)(data), length) 70 71 /* 72 * Helpers for hash table generation of ethernet nics: 73 * 74 * Ethernet sends the least significant bit of a byte first, thus crc32_le 75 * is used. The output of crc32_le is bit reversed [most significant bit 76 * is in bit nr 0], thus it must be reversed before use. Except for 77 * nics that bit swap the result internally... 78 */ 79 #define ether_crc(length, data) bitrev32(crc32_le(~0, data, length)) 80 #define ether_crc_le(length, data) crc32_le(~0, data, length) 81 82 #endif /* _LINUX_CRC32_H */ 83