1 /*- 2 * BSD LICENSE 3 * 4 * Copyright (c) Intel Corporation. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * * Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * * Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * * Neither the name of Intel Corporation nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 24 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 25 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 27 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #include "spdk/crc32.h" 35 36 #ifdef SPDK_HAVE_SSE4_2 37 38 uint32_t 39 spdk_crc32c_update(const void *buf, size_t len, uint32_t crc) 40 { 41 uint64_t crc_tmp64; 42 size_t count; 43 44 /* _mm_crc32_u64() needs a 64-bit intermediate value */ 45 crc_tmp64 = crc; 46 47 /* Process as much of the buffer as possible in 64-bit blocks. */ 48 count = len / 8; 49 while (count--) { 50 uint64_t block; 51 52 /* 53 * Use memcpy() to avoid unaligned loads, which are undefined behavior in C. 54 * The compiler will optimize out the memcpy() in release builds. 55 */ 56 memcpy(&block, buf, sizeof(block)); 57 crc_tmp64 = _mm_crc32_u64(crc_tmp64, block); 58 buf += sizeof(block); 59 } 60 crc = (uint32_t)crc_tmp64; 61 62 /* Handle any trailing bytes. */ 63 count = len & 7; 64 while (count--) { 65 crc = _mm_crc32_u8(crc, *(const uint8_t *)buf); 66 buf++; 67 } 68 69 return crc; 70 } 71 72 #elif defined(SPDK_HAVE_ARM_CRC) 73 74 uint32_t 75 spdk_crc32c_update(const void *buf, size_t len, uint32_t crc) 76 { 77 size_t count; 78 79 count = len / 8; 80 while (count--) { 81 uint64_t block; 82 83 memcpy(&block, buf, sizeof(block)); 84 crc = __crc32cd(crc, block); 85 buf += sizeof(block); 86 } 87 88 count = len & 7; 89 while (count--) { 90 crc = __crc32cb(crc, *(const uint8_t *)buf); 91 buf++; 92 } 93 94 return crc; 95 } 96 97 #else /* Neither SSE 4.2 nor ARM CRC32 instructions available */ 98 99 static struct spdk_crc32_table g_crc32c_table; 100 101 __attribute__((constructor)) static void 102 spdk_crc32c_init(void) 103 { 104 spdk_crc32_table_init(&g_crc32c_table, SPDK_CRC32C_POLYNOMIAL_REFLECT); 105 } 106 107 uint32_t 108 spdk_crc32c_update(const void *buf, size_t len, uint32_t crc) 109 { 110 return spdk_crc32_update(&g_crc32c_table, buf, len, crc); 111 } 112 113 #endif 114