ceph/src/spdk/lib/util/crc32.c

   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,
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  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 void
  37 spdk_crc32_table_init(struct spdk_crc32_table *table, uint32_t polynomial_reflect)
  38 {
  39         int i, j;
  40         uint32_t val;
  41
  42         for (i = 0; i < 256; i++) {
  43                 val = i;
  44                 for (j = 0; j < 8; j++) {
  45                         if (val & 1) {
  46                                 val = (val >> 1) ^ polynomial_reflect;
  47                         } else {
  48                                 val = (val >> 1);
  49                         }
  50                 }
  51                 table->table[i] = val;
  52         }
  53 }
  54
  55 #ifdef SPDK_HAVE_ARM_CRC
  56
  57 uint32_t
  58 spdk_crc32_update(const struct spdk_crc32_table *table, const void *buf, size_t len, uint32_t crc)
  59 {
  60         size_t count;
  61         const uint64_t *dword_buf;
  62
  63         count = len & 7;
  64         while (count--) {
  65                 crc = __crc32b(crc, *(const uint8_t *)buf);
  66                 buf++;
  67         }
  68         dword_buf = (const uint64_t *)buf;
  69
  70         count = len / 8;
  71         while (count--) {
  72                 crc = __crc32d(crc, *dword_buf);
  73                 dword_buf++;
  74         }
  75
  76         return crc;
  77 }
  78
  79 #else
  80
  81 uint32_t
  82 spdk_crc32_update(const struct spdk_crc32_table *table, const void *buf, size_t len, uint32_t crc)
  83 {
  84         const uint8_t *buf_u8 = buf;
  85         size_t i;
  86
  87         for (i = 0; i < len; i++) {
  88                 crc = (crc >> 8) ^ table->table[(crc ^ buf_u8[i]) & 0xff];
  89         }
  90
  91         return crc;
  92 }
  93
  94 #endif