lib/librte_net/rte_net_crc.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2017 Intel Corporation
   3  */
   4
   5 #include <stddef.h>
   6 #include <string.h>
   7 #include <stdint.h>
   8
   9 #include <rte_cpuflags.h>
  10 #include <rte_common.h>
  11 #include <rte_net_crc.h>
  12
  13 #if defined(RTE_ARCH_X86_64) && defined(RTE_MACHINE_CPUFLAG_PCLMULQDQ)
  14 #define X86_64_SSE42_PCLMULQDQ     1
  15 #elif defined(RTE_ARCH_ARM64) && defined(RTE_MACHINE_CPUFLAG_PMULL)
  16 #define ARM64_NEON_PMULL           1
  17 #endif
  18
  19 #ifdef X86_64_SSE42_PCLMULQDQ
  20 #include <net_crc_sse.h>
  21 #elif defined ARM64_NEON_PMULL
  22 #include <net_crc_neon.h>
  23 #endif
  24
  25 /** CRC polynomials */
  26 #define CRC32_ETH_POLYNOMIAL 0x04c11db7UL
  27 #define CRC16_CCITT_POLYNOMIAL 0x1021U
  28
  29 #define CRC_LUT_SIZE 256
  30
  31 /* crc tables */
  32 static uint32_t crc32_eth_lut[CRC_LUT_SIZE];
  33 static uint32_t crc16_ccitt_lut[CRC_LUT_SIZE];
  34
  35 static uint32_t
  36 rte_crc16_ccitt_handler(const uint8_t *data, uint32_t data_len);
  37
  38 static uint32_t
  39 rte_crc32_eth_handler(const uint8_t *data, uint32_t data_len);
  40
  41 typedef uint32_t
  42 (*rte_net_crc_handler)(const uint8_t *data, uint32_t data_len);
  43
  44 static rte_net_crc_handler *handlers;
  45
  46 static rte_net_crc_handler handlers_scalar[] = {
  47         [RTE_NET_CRC16_CCITT] = rte_crc16_ccitt_handler,
  48         [RTE_NET_CRC32_ETH] = rte_crc32_eth_handler,
  49 };
  50
  51 #ifdef X86_64_SSE42_PCLMULQDQ
  52 static rte_net_crc_handler handlers_sse42[] = {
  53         [RTE_NET_CRC16_CCITT] = rte_crc16_ccitt_sse42_handler,
  54         [RTE_NET_CRC32_ETH] = rte_crc32_eth_sse42_handler,
  55 };
  56 #elif defined ARM64_NEON_PMULL
  57 static rte_net_crc_handler handlers_neon[] = {
  58         [RTE_NET_CRC16_CCITT] = rte_crc16_ccitt_neon_handler,
  59         [RTE_NET_CRC32_ETH] = rte_crc32_eth_neon_handler,
  60 };
  61 #endif
  62
  63 /**
  64  * Reflect the bits about the middle
  65  *
  66  * @param val
  67  *   value to be reflected
  68  *
  69  * @return
  70  *   reflected value
  71  */
  72 static uint32_t
  73 reflect_32bits(uint32_t val)
  74 {
  75         uint32_t i, res = 0;
  76
  77         for (i = 0; i < 32; i++)
  78                 if ((val & (1U << i)) != 0)
  79                         res |= (uint32_t)(1U << (31 - i));
  80
  81         return res;
  82 }
  83
  84 static void
  85 crc32_eth_init_lut(uint32_t poly,
  86         uint32_t *lut)
  87 {
  88         uint32_t i, j;
  89
  90         for (i = 0; i < CRC_LUT_SIZE; i++) {
  91                 uint32_t crc = reflect_32bits(i);
  92
  93                 for (j = 0; j < 8; j++) {
  94                         if (crc & 0x80000000L)
  95                                 crc = (crc << 1) ^ poly;
  96                         else
  97                                 crc <<= 1;
  98                 }
  99                 lut[i] = reflect_32bits(crc);
 100         }
 101 }
 102
 103 static __rte_always_inline uint32_t
 104 crc32_eth_calc_lut(const uint8_t *data,
 105         uint32_t data_len,
 106         uint32_t crc,
 107         const uint32_t *lut)
 108 {
 109         while (data_len--)
 110                 crc = lut[(crc ^ *data++) & 0xffL] ^ (crc >> 8);
 111
 112         return crc;
 113 }
 114
 115 static void
 116 rte_net_crc_scalar_init(void)
 117 {
 118         /* 32-bit crc init */
 119         crc32_eth_init_lut(CRC32_ETH_POLYNOMIAL, crc32_eth_lut);
 120
 121         /* 16-bit CRC init */
 122         crc32_eth_init_lut(CRC16_CCITT_POLYNOMIAL << 16, crc16_ccitt_lut);
 123 }
 124
 125 static inline uint32_t
 126 rte_crc16_ccitt_handler(const uint8_t *data, uint32_t data_len)
 127 {
 128         /* return 16-bit CRC value */
 129         return (uint16_t)~crc32_eth_calc_lut(data,
 130                 data_len,
 131                 0xffff,
 132                 crc16_ccitt_lut);
 133 }
 134
 135 static inline uint32_t
 136 rte_crc32_eth_handler(const uint8_t *data, uint32_t data_len)
 137 {
 138         /* return 32-bit CRC value */
 139         return ~crc32_eth_calc_lut(data,
 140                 data_len,
 141                 0xffffffffUL,
 142                 crc32_eth_lut);
 143 }
 144
 145 void
 146 rte_net_crc_set_alg(enum rte_net_crc_alg alg)
 147 {
 148         switch (alg) {
 149 #ifdef X86_64_SSE42_PCLMULQDQ
 150         case RTE_NET_CRC_SSE42:
 151                 handlers = handlers_sse42;
 152                 break;
 153 #elif defined ARM64_NEON_PMULL
 154                 /* fall-through */
 155         case RTE_NET_CRC_NEON:
 156                 if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_PMULL)) {
 157                         handlers = handlers_neon;
 158                         break;
 159                 }
 160 #endif
 161                 /* fall-through */
 162         case RTE_NET_CRC_SCALAR:
 163                 /* fall-through */
 164         default:
 165                 handlers = handlers_scalar;
 166                 break;
 167         }
 168 }
 169
 170 uint32_t
 171 rte_net_crc_calc(const void *data,
 172         uint32_t data_len,
 173         enum rte_net_crc_type type)
 174 {
 175         uint32_t ret;
 176         rte_net_crc_handler f_handle;
 177
 178         f_handle = handlers[type];
 179         ret = f_handle(data, data_len);
 180
 181         return ret;
 182 }
 183
 184 /* Select highest available crc algorithm as default one */
 185 RTE_INIT(rte_net_crc_init)
 186 {
 187         enum rte_net_crc_alg alg = RTE_NET_CRC_SCALAR;
 188
 189         rte_net_crc_scalar_init();
 190
 191 #ifdef X86_64_SSE42_PCLMULQDQ
 192         alg = RTE_NET_CRC_SSE42;
 193         rte_net_crc_sse42_init();
 194 #elif defined ARM64_NEON_PMULL
 195         if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_PMULL)) {
 196                 alg = RTE_NET_CRC_NEON;
 197                 rte_net_crc_neon_init();
 198         }
 199 #endif
 200
 201         rte_net_crc_set_alg(alg);
 202 }