1 /* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright(c) 2019 Intel Corporation
3 */
4
5 #ifndef _RTE_STACK_STD_H_
6 #define _RTE_STACK_STD_H_
7
8 #include <rte_branch_prediction.h>
9
10 /**
11 * @internal Push several objects on the stack (MT-safe).
12 *
13 * @param s
14 * A pointer to the stack structure.
15 * @param obj_table
16 * A pointer to a table of void * pointers (objects).
17 * @param n
18 * The number of objects to push on the stack from the obj_table.
19 * @return
20 * Actual number of objects pushed (either 0 or *n*).
21 */
22 static __rte_always_inline unsigned int
__rte_stack_std_push(struct rte_stack * s,void * const * obj_table,unsigned int n)23 __rte_stack_std_push(struct rte_stack *s, void * const *obj_table,
24 unsigned int n)
25 {
26 struct rte_stack_std *stack = &s->stack_std;
27 unsigned int index;
28 void **cache_objs;
29
30 rte_spinlock_lock(&stack->lock);
31 cache_objs = &stack->objs[stack->len];
32
33 /* Is there sufficient space in the stack? */
34 if ((stack->len + n) > s->capacity) {
35 rte_spinlock_unlock(&stack->lock);
36 return 0;
37 }
38
39 /* Add elements back into the cache */
40 for (index = 0; index < n; ++index, obj_table++)
41 cache_objs[index] = *obj_table;
42
43 stack->len += n;
44
45 rte_spinlock_unlock(&stack->lock);
46 return n;
47 }
48
49 /**
50 * @internal Pop several objects from the stack (MT-safe).
51 *
52 * @param s
53 * A pointer to the stack structure.
54 * @param obj_table
55 * A pointer to a table of void * pointers (objects).
56 * @param n
57 * The number of objects to pull from the stack.
58 * @return
59 * Actual number of objects popped (either 0 or *n*).
60 */
61 static __rte_always_inline unsigned int
__rte_stack_std_pop(struct rte_stack * s,void ** obj_table,unsigned int n)62 __rte_stack_std_pop(struct rte_stack *s, void **obj_table, unsigned int n)
63 {
64 struct rte_stack_std *stack = &s->stack_std;
65 unsigned int index, len;
66 void **cache_objs;
67
68 rte_spinlock_lock(&stack->lock);
69
70 if (unlikely(n > stack->len)) {
71 rte_spinlock_unlock(&stack->lock);
72 return 0;
73 }
74
75 cache_objs = stack->objs;
76
77 for (index = 0, len = stack->len - 1; index < n;
78 ++index, len--, obj_table++)
79 *obj_table = cache_objs[len];
80
81 stack->len -= n;
82 rte_spinlock_unlock(&stack->lock);
83
84 return n;
85 }
86
87 /**
88 * @internal Return the number of used entries in a stack.
89 *
90 * @param s
91 * A pointer to the stack structure.
92 * @return
93 * The number of used entries in the stack.
94 */
95 static __rte_always_inline unsigned int
__rte_stack_std_count(struct rte_stack * s)96 __rte_stack_std_count(struct rte_stack *s)
97 {
98 return (unsigned int)s->stack_std.len;
99 }
100
101 /**
102 * @internal Initialize a standard stack.
103 *
104 * @param s
105 * A pointer to the stack structure.
106 */
107 void
108 rte_stack_std_init(struct rte_stack *s);
109
110 /**
111 * @internal Return the memory required for a standard stack.
112 *
113 * @param count
114 * The size of the stack.
115 * @return
116 * The bytes to allocate for a standard stack.
117 */
118 ssize_t
119 rte_stack_std_get_memsize(unsigned int count);
120
121 #endif /* _RTE_STACK_STD_H_ */
122