diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/crc32.h | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/include/linux/crc32.h b/include/linux/crc32.h index a0033ffee91c..56c0645789a9 100644 --- a/include/linux/crc32.h +++ b/include/linux/crc32.h @@ -9,9 +9,19 @@ extern u32 crc32_le(u32 crc, unsigned char const *p, size_t len); extern u32 crc32_be(u32 crc, unsigned char const *p, size_t len); +extern u32 bitreverse(u32 in); #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) bitreverse(crc32_le(~0, data, length)) #define ether_crc_le(length, data) crc32_le(~0, data, length) -#define ether_crc(length, data) crc32_be(~0, data, length) #endif /* _LINUX_CRC32_H */ |