xref: /dpdk/drivers/mempool/stack/rte_mempool_stack.c (revision 25d11a86c56d50947af33d0b79ede622809bd8b9)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2016 Intel Corporation
3  */
4 
5 #include <stdio.h>
6 #include <rte_mempool.h>
7 #include <rte_malloc.h>
8 
9 struct rte_mempool_stack {
10 	rte_spinlock_t sl;
11 
12 	uint32_t size;
13 	uint32_t len;
14 	void *objs[];
15 };
16 
17 static int
18 stack_alloc(struct rte_mempool *mp)
19 {
20 	struct rte_mempool_stack *s;
21 	unsigned n = mp->size;
22 	int size = sizeof(*s) + (n+16)*sizeof(void *);
23 
24 	/* Allocate our local memory structure */
25 	s = rte_zmalloc_socket("mempool-stack",
26 			size,
27 			RTE_CACHE_LINE_SIZE,
28 			mp->socket_id);
29 	if (s == NULL) {
30 		RTE_LOG(ERR, MEMPOOL, "Cannot allocate stack!\n");
31 		return -ENOMEM;
32 	}
33 
34 	rte_spinlock_init(&s->sl);
35 
36 	s->size = n;
37 	mp->pool_data = s;
38 
39 	return 0;
40 }
41 
42 static int
43 stack_enqueue(struct rte_mempool *mp, void * const *obj_table,
44 		unsigned n)
45 {
46 	struct rte_mempool_stack *s = mp->pool_data;
47 	void **cache_objs;
48 	unsigned index;
49 
50 	rte_spinlock_lock(&s->sl);
51 	cache_objs = &s->objs[s->len];
52 
53 	/* Is there sufficient space in the stack ? */
54 	if ((s->len + n) > s->size) {
55 		rte_spinlock_unlock(&s->sl);
56 		return -ENOBUFS;
57 	}
58 
59 	/* Add elements back into the cache */
60 	for (index = 0; index < n; ++index, obj_table++)
61 		cache_objs[index] = *obj_table;
62 
63 	s->len += n;
64 
65 	rte_spinlock_unlock(&s->sl);
66 	return 0;
67 }
68 
69 static int
70 stack_dequeue(struct rte_mempool *mp, void **obj_table,
71 		unsigned n)
72 {
73 	struct rte_mempool_stack *s = mp->pool_data;
74 	void **cache_objs;
75 	unsigned index, len;
76 
77 	rte_spinlock_lock(&s->sl);
78 
79 	if (unlikely(n > s->len)) {
80 		rte_spinlock_unlock(&s->sl);
81 		return -ENOENT;
82 	}
83 
84 	cache_objs = s->objs;
85 
86 	for (index = 0, len = s->len - 1; index < n;
87 			++index, len--, obj_table++)
88 		*obj_table = cache_objs[len];
89 
90 	s->len -= n;
91 	rte_spinlock_unlock(&s->sl);
92 	return 0;
93 }
94 
95 static unsigned
96 stack_get_count(const struct rte_mempool *mp)
97 {
98 	struct rte_mempool_stack *s = mp->pool_data;
99 
100 	return s->len;
101 }
102 
103 static void
104 stack_free(struct rte_mempool *mp)
105 {
106 	rte_free((void *)(mp->pool_data));
107 }
108 
109 static struct rte_mempool_ops ops_stack = {
110 	.name = "stack",
111 	.alloc = stack_alloc,
112 	.free = stack_free,
113 	.enqueue = stack_enqueue,
114 	.dequeue = stack_dequeue,
115 	.get_count = stack_get_count
116 };
117 
118 MEMPOOL_REGISTER_OPS(ops_stack);
119