xref: /dpdk/drivers/mempool/stack/rte_mempool_stack.c (revision f8244c6399d9fae6afab6770ae367aef38742ea5)
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 0;
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);
148