1 /* SPDX-License-Identifier: (BSD-3-Clause OR LGPL-2.1)
2 * Copyright(c) 2010-2013 Intel Corporation.
3 * Copyright(c) 2013-2017 Wind River Systems, Inc.
4 */
5
6 #ifndef _RTE_AVP_FIFO_H_
7 #define _RTE_AVP_FIFO_H_
8
9 #include "rte_avp_common.h"
10
11 #ifdef __cplusplus
12 extern "C" {
13 #endif
14
15 #ifdef __KERNEL__
16 /* Write memory barrier for kernel compiles */
17 #define AVP_WMB() smp_wmb()
18 /* Read memory barrier for kernel compiles */
19 #define AVP_RMB() smp_rmb()
20 #else
21 /* Write memory barrier for userspace compiles */
22 #define AVP_WMB() rte_wmb()
23 /* Read memory barrier for userspace compiles */
24 #define AVP_RMB() rte_rmb()
25 #endif
26
27 #ifndef __KERNEL__
28 #include <rte_debug.h>
29
30 /**
31 * Initializes the avp fifo structure
32 */
33 static inline void
avp_fifo_init(struct rte_avp_fifo * fifo,unsigned int size)34 avp_fifo_init(struct rte_avp_fifo *fifo, unsigned int size)
35 {
36 /* Ensure size is power of 2 */
37 if (size & (size - 1))
38 rte_panic("AVP fifo size must be power of 2\n");
39
40 fifo->write = 0;
41 fifo->read = 0;
42 fifo->len = size;
43 fifo->elem_size = sizeof(void *);
44 }
45 #endif
46
47 /**
48 * Adds num elements into the fifo. Return the number actually written
49 */
50 static inline unsigned
avp_fifo_put(struct rte_avp_fifo * fifo,void ** data,unsigned int num)51 avp_fifo_put(struct rte_avp_fifo *fifo, void **data, unsigned int num)
52 {
53 unsigned int i = 0;
54 unsigned int fifo_write = fifo->write;
55 unsigned int fifo_read = fifo->read;
56 unsigned int new_write = fifo_write;
57
58 for (i = 0; i < num; i++) {
59 new_write = (new_write + 1) & (fifo->len - 1);
60
61 if (new_write == fifo_read)
62 break;
63 fifo->buffer[fifo_write] = data[i];
64 fifo_write = new_write;
65 }
66 AVP_WMB();
67 fifo->write = fifo_write;
68 return i;
69 }
70
71 /**
72 * Get up to num elements from the fifo. Return the number actually read
73 */
74 static inline unsigned int
avp_fifo_get(struct rte_avp_fifo * fifo,void ** data,unsigned int num)75 avp_fifo_get(struct rte_avp_fifo *fifo, void **data, unsigned int num)
76 {
77 unsigned int i = 0;
78 unsigned int new_read = fifo->read;
79 unsigned int fifo_write = fifo->write;
80
81 if (new_read == fifo_write)
82 return 0; /* empty */
83
84 for (i = 0; i < num; i++) {
85 if (new_read == fifo_write)
86 break;
87
88 data[i] = fifo->buffer[new_read];
89 new_read = (new_read + 1) & (fifo->len - 1);
90 }
91 AVP_RMB();
92 fifo->read = new_read;
93 return i;
94 }
95
96 /**
97 * Get the num of elements in the fifo
98 */
99 static inline unsigned int
avp_fifo_count(struct rte_avp_fifo * fifo)100 avp_fifo_count(struct rte_avp_fifo *fifo)
101 {
102 return (fifo->len + fifo->write - fifo->read) & (fifo->len - 1);
103 }
104
105 /**
106 * Get the num of available elements in the fifo
107 */
108 static inline unsigned int
avp_fifo_free_count(struct rte_avp_fifo * fifo)109 avp_fifo_free_count(struct rte_avp_fifo *fifo)
110 {
111 return (fifo->read - fifo->write - 1) & (fifo->len - 1);
112 }
113
114 #ifdef __cplusplus
115 }
116 #endif
117
118 #endif /* _RTE_AVP_FIFO_H_ */
119