lib/librte_table/rte_lru_arm64.h

   1 /*
   2  *   BSD LICENSE
   3  *
   4  *   Copyright (C) Cavium, Inc. 2017.
   5  *
   6  *   Redistribution and use in source and binary forms, with or without
   7  *   modification, are permitted provided that the following conditions
   8  *   are met:
   9  *
  10  *     * Redistributions of source code must retain the above copyright
  11  *       notice, this list of conditions and the following disclaimer.
  12  *     * Redistributions in binary form must reproduce the above copyright
  13  *       notice, this list of conditions and the following disclaimer in
  14  *       the documentation and/or other materials provided with the
  15  *       distribution.
  16  *     * Neither the name of Cavium, Inc nor the names of its
  17  *       contributors may be used to endorse or promote products derived
  18  *       from this software without specific prior written permission.
  19  *
  20  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  21  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  22  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  23  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  24  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  25  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  26  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  27  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  28  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  29  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  30  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31  */
  32
  33 #ifndef __RTE_LRU_ARM64_H__
  34 #define __RTE_LRU_ARM64_H__
  35
  36 #ifdef __cplusplus
  37 extern "C" {
  38 #endif
  39
  40 #include <stdint.h>
  41 #include <rte_vect.h>
  42
  43 #ifndef RTE_TABLE_HASH_LRU_STRATEGY
  44 #ifdef RTE_MACHINE_CPUFLAG_NEON
  45 #define RTE_TABLE_HASH_LRU_STRATEGY                        3
  46 #else /* if no NEON, use simple scalar version */
  47 #define RTE_TABLE_HASH_LRU_STRATEGY                        1
  48 #endif
  49 #endif
  50
  51 #if RTE_TABLE_HASH_LRU_STRATEGY == 3
  52
  53 #define lru_init(bucket)                                                \
  54         { bucket->lru_list = ~0LLU; }
  55
  56 static inline int
  57 f_lru_pos(uint64_t lru_list)
  58 {
  59         /* Compare the vector to zero vector */
  60         uint16x4_t lru_vec = vld1_u16((uint16_t *)&lru_list);
  61         uint16x4_t min_vec = vmov_n_u16(vminv_u16(lru_vec));
  62         uint64_t mask = vget_lane_u64(vreinterpret_u64_u16(
  63                         vceq_u16(min_vec, lru_vec)), 0);
  64         return __builtin_clzl(mask) >> 4;
  65 }
  66 #define lru_pos(bucket) f_lru_pos(bucket->lru_list)
  67
  68 #define lru_update(bucket, mru_val)                                     \
  69 do {                                                                    \
  70         const uint64_t orvals[] = {0xFFFFLLU, 0xFFFFLLU << 16,          \
  71                 0xFFFFLLU << 32, 0xFFFFLLU << 48, 0LLU};                \
  72         const uint64_t decs[] = {0x1000100010001LLU, 0};                \
  73         uint64x1_t lru = vdup_n_u64(bucket->lru_list);                  \
  74         uint64x1_t vdec = vdup_n_u64(decs[mru_val>>2]);                 \
  75         bucket->lru_list = vget_lane_u64(vreinterpret_u64_u16(          \
  76                                 vsub_u16(vreinterpret_u16_u64(lru),     \
  77                                         vreinterpret_u16_u64(vdec))),   \
  78                                 0);                                     \
  79         bucket->lru_list |= orvals[mru_val];                            \
  80 } while (0)
  81
  82 #endif
  83
  84 #ifdef __cplusplus
  85 }
  86 #endif
  87
  88 #endif