lib/librte_table/rte_lru_arm64.h

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2017 Cavium, Inc
   3  */
   4
   5 #ifndef __RTE_LRU_ARM64_H__
   6 #define __RTE_LRU_ARM64_H__
   7
   8 #ifdef __cplusplus
   9 extern "C" {
  10 #endif
  11
  12 #include <stdint.h>
  13 #include <rte_vect.h>
  14
  15 #ifndef RTE_TABLE_HASH_LRU_STRATEGY
  16 #ifdef RTE_MACHINE_CPUFLAG_NEON
  17 #define RTE_TABLE_HASH_LRU_STRATEGY                        3
  18 #else /* if no NEON, use simple scalar version */
  19 #define RTE_TABLE_HASH_LRU_STRATEGY                        1
  20 #endif
  21 #endif
  22
  23 #if RTE_TABLE_HASH_LRU_STRATEGY == 3
  24
  25 #define lru_init(bucket)                                                \
  26         { bucket->lru_list = ~0LLU; }
  27
  28 static inline int
  29 f_lru_pos(uint64_t lru_list)
  30 {
  31         /* Compare the vector to zero vector */
  32         uint16x4_t lru_vec = vld1_u16((uint16_t *)&lru_list);
  33         uint16x4_t min_vec = vmov_n_u16(vminv_u16(lru_vec));
  34         uint64_t mask = vget_lane_u64(vreinterpret_u64_u16(
  35                         vceq_u16(min_vec, lru_vec)), 0);
  36         return __builtin_clzl(mask) >> 4;
  37 }
  38 #define lru_pos(bucket) f_lru_pos(bucket->lru_list)
  39
  40 #define lru_update(bucket, mru_val)                                     \
  41 do {                                                                    \
  42         const uint64_t orvals[] = {0xFFFFLLU, 0xFFFFLLU << 16,          \
  43                 0xFFFFLLU << 32, 0xFFFFLLU << 48, 0LLU};                \
  44         const uint64_t decs[] = {0x1000100010001LLU, 0};                \
  45         uint64x1_t lru = vdup_n_u64(bucket->lru_list);                  \
  46         uint64x1_t vdec = vdup_n_u64(decs[mru_val>>2]);                 \
  47         bucket->lru_list = vget_lane_u64(vreinterpret_u64_u16(          \
  48                                 vsub_u16(vreinterpret_u16_u64(lru),     \
  49                                         vreinterpret_u16_u64(vdec))),   \
  50                                 0);                                     \
  51         bucket->lru_list |= orvals[mru_val];                            \
  52 } while (0)
  53
  54 #endif
  55
  56 #ifdef __cplusplus
  57 }
  58 #endif
  59
  60 #endif