ceph/src/dpdk/lib/librte_mempool/rte_mempool_stack.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2016 Intel Corporation. All rights reserved.
   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,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  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 <stdio.h>
  35 #include <rte_mempool.h>
  36 #include <rte_malloc.h>
  37
  38 struct rte_mempool_stack {
  39         rte_spinlock_t sl;
  40
  41         uint32_t size;
  42         uint32_t len;
  43         void *objs[];
  44 };
  45
  46 static int
  47 stack_alloc(struct rte_mempool *mp)
  48 {
  49         struct rte_mempool_stack *s;
  50         unsigned n = mp->size;
  51         int size = sizeof(*s) + (n+16)*sizeof(void *);
  52
  53         /* Allocate our local memory structure */
  54         s = rte_zmalloc_socket("mempool-stack",
  55                         size,
  56                         RTE_CACHE_LINE_SIZE,
  57                         mp->socket_id);
  58         if (s == NULL) {
  59                 RTE_LOG(ERR, MEMPOOL, "Cannot allocate stack!\n");
  60                 return -ENOMEM;
  61         }
  62
  63         rte_spinlock_init(&s->sl);
  64
  65         s->size = n;
  66         mp->pool_data = s;
  67
  68         return 0;
  69 }
  70
  71 static int
  72 stack_enqueue(struct rte_mempool *mp, void * const *obj_table,
  73                 unsigned n)
  74 {
  75         struct rte_mempool_stack *s = mp->pool_data;
  76         void **cache_objs;
  77         unsigned index;
  78
  79         rte_spinlock_lock(&s->sl);
  80         cache_objs = &s->objs[s->len];
  81
  82         /* Is there sufficient space in the stack ? */
  83         if ((s->len + n) > s->size) {
  84                 rte_spinlock_unlock(&s->sl);
  85                 return -ENOBUFS;
  86         }
  87
  88         /* Add elements back into the cache */
  89         for (index = 0; index < n; ++index, obj_table++)
  90                 cache_objs[index] = *obj_table;
  91
  92         s->len += n;
  93
  94         rte_spinlock_unlock(&s->sl);
  95         return 0;
  96 }
  97
  98 static int
  99 stack_dequeue(struct rte_mempool *mp, void **obj_table,
 100                 unsigned n)
 101 {
 102         struct rte_mempool_stack *s = mp->pool_data;
 103         void **cache_objs;
 104         unsigned index, len;
 105
 106         rte_spinlock_lock(&s->sl);
 107
 108         if (unlikely(n > s->len)) {
 109                 rte_spinlock_unlock(&s->sl);
 110                 return -ENOENT;
 111         }
 112
 113         cache_objs = s->objs;
 114
 115         for (index = 0, len = s->len - 1; index < n;
 116                         ++index, len--, obj_table++)
 117                 *obj_table = cache_objs[len];
 118
 119         s->len -= n;
 120         rte_spinlock_unlock(&s->sl);
 121         return n;
 122 }
 123
 124 static unsigned
 125 stack_get_count(const struct rte_mempool *mp)
 126 {
 127         struct rte_mempool_stack *s = mp->pool_data;
 128
 129         return s->len;
 130 }
 131
 132 static void
 133 stack_free(struct rte_mempool *mp)
 134 {
 135         rte_free((void *)(mp->pool_data));
 136 }
 137
 138 static struct rte_mempool_ops ops_stack = {
 139         .name = "stack",
 140         .alloc = stack_alloc,
 141         .free = stack_free,
 142         .enqueue = stack_enqueue,
 143         .dequeue = stack_dequeue,
 144         .get_count = stack_get_count
 145 };
 146
 147 MEMPOOL_REGISTER_OPS(ops_stack);