ceph/src/seastar/dpdk/lib/librte_hash/rte_crc_arm64.h

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2015 Cavium, Inc
   3  */
   4
   5 #ifndef _RTE_CRC_ARM64_H_
   6 #define _RTE_CRC_ARM64_H_
   7
   8 /**
   9  * @file
  10  *
  11  * RTE CRC arm64 Hash
  12  */
  13
  14 #ifdef __cplusplus
  15 extern "C" {
  16 #endif
  17
  18 #include <stdint.h>
  19 #include <rte_cpuflags.h>
  20 #include <rte_branch_prediction.h>
  21 #include <rte_common.h>
  22
  23 static inline uint32_t
  24 crc32c_arm64_u8(uint8_t data, uint32_t init_val)
  25 {
  26         __asm__ volatile(
  27                         "crc32cb %w[crc], %w[crc], %w[value]"
  28                         : [crc] "+r" (init_val)
  29                         : [value] "r" (data));
  30         return init_val;
  31 }
  32
  33 static inline uint32_t
  34 crc32c_arm64_u16(uint16_t data, uint32_t init_val)
  35 {
  36         __asm__ volatile(
  37                         "crc32ch %w[crc], %w[crc], %w[value]"
  38                         : [crc] "+r" (init_val)
  39                         : [value] "r" (data));
  40         return init_val;
  41 }
  42
  43 static inline uint32_t
  44 crc32c_arm64_u32(uint32_t data, uint32_t init_val)
  45 {
  46         __asm__ volatile(
  47                         "crc32cw %w[crc], %w[crc], %w[value]"
  48                         : [crc] "+r" (init_val)
  49                         : [value] "r" (data));
  50         return init_val;
  51 }
  52
  53 static inline uint32_t
  54 crc32c_arm64_u64(uint64_t data, uint32_t init_val)
  55 {
  56         __asm__ volatile(
  57                         "crc32cx %w[crc], %w[crc], %x[value]"
  58                         : [crc] "+r" (init_val)
  59                         : [value] "r" (data));
  60         return init_val;
  61 }
  62
  63 /**
  64  * Allow or disallow use of arm64 SIMD instrinsics for CRC32 hash
  65  * calculation.
  66  *
  67  * @param alg
  68  *   An OR of following flags:
  69  *   - (CRC32_SW) Don't use arm64 crc intrinsics
  70  *   - (CRC32_ARM64) Use ARMv8 CRC intrinsic if available
  71  *
  72  */
  73 static inline void
  74 rte_hash_crc_set_alg(uint8_t alg)
  75 {
  76         switch (alg) {
  77         case CRC32_ARM64:
  78                 if (!rte_cpu_get_flag_enabled(RTE_CPUFLAG_CRC32))
  79                         alg = CRC32_SW;
  80                 /* fall-through */
  81         case CRC32_SW:
  82                 crc32_alg = alg;
  83                 /* fall-through */
  84         default:
  85                 break;
  86         }
  87 }
  88
  89 /* Setting the best available algorithm */
  90 RTE_INIT(rte_hash_crc_init_alg)
  91 {
  92         rte_hash_crc_set_alg(CRC32_ARM64);
  93 }
  94
  95 /**
  96  * Use single crc32 instruction to perform a hash on a 1 byte value.
  97  * Fall back to software crc32 implementation in case arm64 crc intrinsics is
  98  * not supported
  99  *
 100  * @param data
 101  *   Data to perform hash on.
 102  * @param init_val
 103  *   Value to initialise hash generator.
 104  * @return
 105  *   32bit calculated hash value.
 106  */
 107 static inline uint32_t
 108 rte_hash_crc_1byte(uint8_t data, uint32_t init_val)
 109 {
 110         if (likely(crc32_alg & CRC32_ARM64))
 111                 return crc32c_arm64_u8(data, init_val);
 112
 113         return crc32c_1byte(data, init_val);
 114 }
 115
 116 /**
 117  * Use single crc32 instruction to perform a hash on a 2 bytes value.
 118  * Fall back to software crc32 implementation in case arm64 crc intrinsics is
 119  * not supported
 120  *
 121  * @param data
 122  *   Data to perform hash on.
 123  * @param init_val
 124  *   Value to initialise hash generator.
 125  * @return
 126  *   32bit calculated hash value.
 127  */
 128 static inline uint32_t
 129 rte_hash_crc_2byte(uint16_t data, uint32_t init_val)
 130 {
 131         if (likely(crc32_alg & CRC32_ARM64))
 132                 return crc32c_arm64_u16(data, init_val);
 133
 134         return crc32c_2bytes(data, init_val);
 135 }
 136
 137 /**
 138  * Use single crc32 instruction to perform a hash on a 4 byte value.
 139  * Fall back to software crc32 implementation in case arm64 crc intrinsics is
 140  * not supported
 141  *
 142  * @param data
 143  *   Data to perform hash on.
 144  * @param init_val
 145  *   Value to initialise hash generator.
 146  * @return
 147  *   32bit calculated hash value.
 148  */
 149 static inline uint32_t
 150 rte_hash_crc_4byte(uint32_t data, uint32_t init_val)
 151 {
 152         if (likely(crc32_alg & CRC32_ARM64))
 153                 return crc32c_arm64_u32(data, init_val);
 154
 155         return crc32c_1word(data, init_val);
 156 }
 157
 158 /**
 159  * Use single crc32 instruction to perform a hash on a 8 byte value.
 160  * Fall back to software crc32 implementation in case arm64 crc intrinsics is
 161  * not supported
 162  *
 163  * @param data
 164  *   Data to perform hash on.
 165  * @param init_val
 166  *   Value to initialise hash generator.
 167  * @return
 168  *   32bit calculated hash value.
 169  */
 170 static inline uint32_t
 171 rte_hash_crc_8byte(uint64_t data, uint32_t init_val)
 172 {
 173         if (likely(crc32_alg == CRC32_ARM64))
 174                 return crc32c_arm64_u64(data, init_val);
 175
 176         return crc32c_2words(data, init_val);
 177 }
 178
 179 #ifdef __cplusplus
 180 }
 181 #endif
 182
 183 #endif /* _RTE_CRC_ARM64_H_ */