From: Didier Pallard Date: Fri, 19 Feb 2016 11:00:31 +0000 (+0100) Subject: hash: fix CRC32c computation X-Git-Tag: spdx-start~7574 X-Git-Url: http://git.droids-corp.org/?p=dpdk.git;a=commitdiff_plain;h=9792848c65a7cfcc97217bcaa104a0641112d61e hash: fix CRC32c computation Fix crc32c hash functions to return a valid crc32c value for data lengths not multiple of 4 bytes. ARM code is not tested. Fixes: af75078fece3 ("first public release") Signed-off-by: Didier Pallard Acked-by: David Marchand Acked-by: Pablo de Lara --- diff --git a/doc/guides/rel_notes/release_16_04.rst b/doc/guides/rel_notes/release_16_04.rst index 64e913d0c7..fd7dd1a682 100644 --- a/doc/guides/rel_notes/release_16_04.rst +++ b/doc/guides/rel_notes/release_16_04.rst @@ -87,6 +87,11 @@ Drivers Libraries ~~~~~~~~~ +* **hash: Fixed CRC32c hash computation for non multiple of 4 bytes sizes.** + + Fix crc32c hash functions to return a valid crc32c value for data lengths + not multiple of 4 bytes. + Examples ~~~~~~~~ diff --git a/lib/librte_hash/rte_crc_arm64.h b/lib/librte_hash/rte_crc_arm64.h index 02e26bcada..7dd6334eed 100644 --- a/lib/librte_hash/rte_crc_arm64.h +++ b/lib/librte_hash/rte_crc_arm64.h @@ -49,6 +49,28 @@ extern "C" { #include #include +static inline uint32_t +crc32c_arm64_u8(uint8_t data, uint32_t init_val) +{ + asm(".arch armv8-a+crc"); + __asm__ volatile( + "crc32cb %w[crc], %w[crc], %w[value]" + : [crc] "+r" (init_val) + : [value] "r" (data)); + return init_val; +} + +static inline uint32_t +crc32c_arm64_u16(uint16_t data, uint32_t init_val) +{ + asm(".arch armv8-a+crc"); + __asm__ volatile( + "crc32ch %w[crc], %w[crc], %w[value]" + : [crc] "+r" (init_val) + : [value] "r" (data)); + return init_val; +} + static inline uint32_t crc32c_arm64_u32(uint32_t data, uint32_t init_val) { @@ -102,6 +124,48 @@ rte_hash_crc_init_alg(void) rte_hash_crc_set_alg(CRC32_ARM64); } +/** + * Use single crc32 instruction to perform a hash on a 1 byte value. + * Fall back to software crc32 implementation in case arm64 crc intrinsics is + * not supported + * + * @param data + * Data to perform hash on. + * @param init_val + * Value to initialise hash generator. + * @return + * 32bit calculated hash value. + */ +static inline uint32_t +rte_hash_crc_1byte(uint8_t data, uint32_t init_val) +{ + if (likely(crc32_alg & CRC32_ARM64)) + return crc32c_arm64_u8(data, init_val); + + return crc32c_1byte(data, init_val); +} + +/** + * Use single crc32 instruction to perform a hash on a 2 bytes value. + * Fall back to software crc32 implementation in case arm64 crc intrinsics is + * not supported + * + * @param data + * Data to perform hash on. + * @param init_val + * Value to initialise hash generator. + * @return + * 32bit calculated hash value. + */ +static inline uint32_t +rte_hash_crc_2byte(uint16_t data, uint32_t init_val) +{ + if (likely(crc32_alg & CRC32_ARM64)) + return crc32c_arm64_u16(data, init_val); + + return crc32c_2bytes(data, init_val); +} + /** * Use single crc32 instruction to perform a hash on a 4 byte value. * Fall back to software crc32 implementation in case arm64 crc intrinsics is diff --git a/lib/librte_hash/rte_hash_crc.h b/lib/librte_hash/rte_hash_crc.h index 78a34b7642..63e74aa474 100644 --- a/lib/librte_hash/rte_hash_crc.h +++ b/lib/librte_hash/rte_hash_crc.h @@ -327,6 +327,28 @@ static const uint32_t crc32c_tables[8][256] = {{ (crc32c_tables[(n)][(crc) & 0xFF] ^ \ crc32c_tables[(n)-1][((crc) >> 8) & 0xFF]) +static inline uint32_t +crc32c_1byte(uint8_t data, uint32_t init_val) +{ + uint32_t crc; + crc = init_val; + crc ^= data; + + return crc32c_tables[0][crc & 0xff] ^ (crc >> 8); +} + +static inline uint32_t +crc32c_2bytes(uint16_t data, uint32_t init_val) +{ + uint32_t crc; + crc = init_val; + crc ^= data; + + crc = CRC32_UPD(crc, 1) ^ (crc >> 16); + + return crc; +} + static inline uint32_t crc32c_1word(uint32_t data, uint32_t init_val) { @@ -366,6 +388,26 @@ crc32c_2words(uint64_t data, uint32_t init_val) } #if defined(RTE_ARCH_I686) || defined(RTE_ARCH_X86_64) +static inline uint32_t +crc32c_sse42_u8(uint8_t data, uint32_t init_val) +{ + __asm__ volatile( + "crc32b %[data], %[init_val];" + : [init_val] "+r" (init_val) + : [data] "rm" (data)); + return init_val; +} + +static inline uint32_t +crc32c_sse42_u16(uint16_t data, uint32_t init_val) +{ + __asm__ volatile( + "crc32w %[data], %[init_val];" + : [init_val] "+r" (init_val) + : [data] "rm" (data)); + return init_val; +} + static inline uint32_t crc32c_sse42_u32(uint32_t data, uint32_t init_val) { @@ -452,6 +494,52 @@ rte_hash_crc_init_alg(void) rte_hash_crc_set_alg(CRC32_SSE42_x64); } +/** + * Use single crc32 instruction to perform a hash on a byte value. + * Fall back to software crc32 implementation in case SSE4.2 is + * not supported + * + * @param data + * Data to perform hash on. + * @param init_val + * Value to initialise hash generator. + * @return + * 32bit calculated hash value. + */ +static inline uint32_t +rte_hash_crc_1byte(uint8_t data, uint32_t init_val) +{ +#if defined RTE_ARCH_I686 || defined RTE_ARCH_X86_64 + if (likely(crc32_alg & CRC32_SSE42)) + return crc32c_sse42_u8(data, init_val); +#endif + + return crc32c_1byte(data, init_val); +} + +/** + * Use single crc32 instruction to perform a hash on a 2 bytes value. + * Fall back to software crc32 implementation in case SSE4.2 is + * not supported + * + * @param data + * Data to perform hash on. + * @param init_val + * Value to initialise hash generator. + * @return + * 32bit calculated hash value. + */ +static inline uint32_t +rte_hash_crc_2byte(uint16_t data, uint32_t init_val) +{ +#if defined RTE_ARCH_I686 || defined RTE_ARCH_X86_64 + if (likely(crc32_alg & CRC32_SSE42)) + return crc32c_sse42_u16(data, init_val); +#endif + + return crc32c_2bytes(data, init_val); +} + /** * Use single crc32 instruction to perform a hash on a 4 byte value. * Fall back to software crc32 implementation in case SSE4.2 is @@ -521,7 +609,6 @@ static inline uint32_t rte_hash_crc(const void *data, uint32_t data_len, uint32_t init_val) { unsigned i; - uint64_t temp = 0; uintptr_t pd = (uintptr_t) data; for (i = 0; i < data_len / 8; i++) { @@ -529,35 +616,19 @@ rte_hash_crc(const void *data, uint32_t data_len, uint32_t init_val) pd += 8; } - switch (7 - (data_len & 0x07)) { - case 0: - temp |= (uint64_t) *((const uint8_t *)pd + 6) << 48; - /* Fallthrough */ - case 1: - temp |= (uint64_t) *((const uint8_t *)pd + 5) << 40; - /* Fallthrough */ - case 2: - temp |= (uint64_t) *((const uint8_t *)pd + 4) << 32; - temp |= *(const uint32_t *)pd; - init_val = rte_hash_crc_8byte(temp, init_val); - break; - case 3: + if (data_len & 0x4) { init_val = rte_hash_crc_4byte(*(const uint32_t *)pd, init_val); - break; - case 4: - temp |= *((const uint8_t *)pd + 2) << 16; - /* Fallthrough */ - case 5: - temp |= *((const uint8_t *)pd + 1) << 8; - /* Fallthrough */ - case 6: - temp |= *(const uint8_t *)pd; - init_val = rte_hash_crc_4byte(temp, init_val); - /* Fallthrough */ - default: - break; + pd += 4; + } + + if (data_len & 0x2) { + init_val = rte_hash_crc_2byte(*(const uint16_t *)pd, init_val); + pd += 2; } + if (data_len & 0x1) + init_val = rte_hash_crc_1byte(*(const uint8_t *)pd, init_val); + return init_val; }