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_arch(u32 crc, const u8 *p, size_t len); 12 u32 __pure crc32_le_base(u32 crc, const u8 *p, size_t len); 13 u32 __pure crc32_be_arch(u32 crc, const u8 *p, size_t len); 14 u32 __pure crc32_be_base(u32 crc, const u8 *p, size_t len); 15 u32 __pure crc32c_le_arch(u32 crc, const u8 *p, size_t len); 16 u32 __pure crc32c_le_base(u32 crc, const u8 *p, size_t len); 17 18 static inline u32 __pure crc32_le(u32 crc, const u8 *p, size_t len) 19 { 20 if (IS_ENABLED(CONFIG_CRC32_ARCH)) 21 return crc32_le_arch(crc, p, len); 22 return crc32_le_base(crc, p, len); 23 } 24 25 static inline u32 __pure crc32_be(u32 crc, const u8 *p, size_t len) 26 { 27 if (IS_ENABLED(CONFIG_CRC32_ARCH)) 28 return crc32_be_arch(crc, p, len); 29 return crc32_be_base(crc, p, len); 30 } 31 32 /* TODO: leading underscores should be dropped once callers have been updated */ 33 static inline u32 __pure __crc32c_le(u32 crc, const u8 *p, size_t len) 34 { 35 if (IS_ENABLED(CONFIG_CRC32_ARCH)) 36 return crc32c_le_arch(crc, p, len); 37 return crc32c_le_base(crc, p, len); 38 } 39 40 /* 41 * crc32_optimizations() returns flags that indicate which CRC32 library 42 * functions are using architecture-specific optimizations. Unlike 43 * IS_ENABLED(CONFIG_CRC32_ARCH) it takes into account the different CRC32 44 * variants and also whether any needed CPU features are available at runtime. 45 */ 46 #define CRC32_LE_OPTIMIZATION BIT(0) /* crc32_le() is optimized */ 47 #define CRC32_BE_OPTIMIZATION BIT(1) /* crc32_be() is optimized */ 48 #define CRC32C_OPTIMIZATION BIT(2) /* __crc32c_le() is optimized */ 49 #if IS_ENABLED(CONFIG_CRC32_ARCH) 50 u32 crc32_optimizations(void); 51 #else 52 static inline u32 crc32_optimizations(void) { return 0; } 53 #endif 54 55 /** 56 * crc32_le_combine - Combine two crc32 check values into one. For two 57 * sequences of bytes, seq1 and seq2 with lengths len1 58 * and len2, crc32_le() check values were calculated 59 * for each, crc1 and crc2. 60 * 61 * @crc1: crc32 of the first block 62 * @crc2: crc32 of the second block 63 * @len2: length of the second block 64 * 65 * Return: The crc32_le() check value of seq1 and seq2 concatenated, 66 * requiring only crc1, crc2, and len2. Note: If seq_full denotes 67 * the concatenated memory area of seq1 with seq2, and crc_full 68 * the crc32_le() value of seq_full, then crc_full == 69 * crc32_le_combine(crc1, crc2, len2) when crc_full was seeded 70 * with the same initializer as crc1, and crc2 seed was 0. See 71 * also crc32_combine_test(). 72 */ 73 u32 __attribute_const__ crc32_le_shift(u32 crc, size_t len); 74 75 static inline u32 crc32_le_combine(u32 crc1, u32 crc2, size_t len2) 76 { 77 return crc32_le_shift(crc1, len2) ^ crc2; 78 } 79 80 /** 81 * __crc32c_le_combine - Combine two crc32c check values into one. For two 82 * sequences of bytes, seq1 and seq2 with lengths len1 83 * and len2, __crc32c_le() check values were calculated 84 * for each, crc1 and crc2. 85 * 86 * @crc1: crc32c of the first block 87 * @crc2: crc32c of the second block 88 * @len2: length of the second block 89 * 90 * Return: The __crc32c_le() check value of seq1 and seq2 concatenated, 91 * requiring only crc1, crc2, and len2. Note: If seq_full denotes 92 * the concatenated memory area of seq1 with seq2, and crc_full 93 * the __crc32c_le() value of seq_full, then crc_full == 94 * __crc32c_le_combine(crc1, crc2, len2) when crc_full was 95 * seeded with the same initializer as crc1, and crc2 seed 96 * was 0. See also crc32c_combine_test(). 97 */ 98 u32 __attribute_const__ __crc32c_le_shift(u32 crc, size_t len); 99 100 static inline u32 __crc32c_le_combine(u32 crc1, u32 crc2, size_t len2) 101 { 102 return __crc32c_le_shift(crc1, len2) ^ crc2; 103 } 104 105 #define crc32(seed, data, length) crc32_le(seed, (unsigned char const *)(data), length) 106 107 /* 108 * Helpers for hash table generation of ethernet nics: 109 * 110 * Ethernet sends the least significant bit of a byte first, thus crc32_le 111 * is used. The output of crc32_le is bit reversed [most significant bit 112 * is in bit nr 0], thus it must be reversed before use. Except for 113 * nics that bit swap the result internally... 114 */ 115 #define ether_crc(length, data) bitrev32(crc32_le(~0, data, length)) 116 #define ether_crc_le(length, data) crc32_le(~0, data, length) 117 118 #endif /* _LINUX_CRC32_H */ 119