1 /*-
2 * Copyright (c) 2021 Beckhoff Automation GmbH & Co. KG
3 * Copyright (c) 2022 Bjoern A. Zeeb
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 */
27
28 #ifndef _LINUXKPI_LINUX_KFIFO_H_
29 #define _LINUXKPI_LINUX_KFIFO_H_
30
31 #include <sys/types.h>
32
33 #include <linux/slab.h>
34 #include <linux/gfp.h>
35
36 #define INIT_KFIFO(x) 0
37 #define DECLARE_KFIFO(x, y, z)
38
39 #define DECLARE_KFIFO_PTR(_name, _type) \
40 struct kfifo_ ## _name { \
41 size_t total; \
42 size_t count; \
43 size_t first; \
44 size_t last; \
45 _type *head; \
46 } _name
47
48 #define kfifo_len(_kf) \
49 ({ \
50 (_kf)->count; \
51 })
52
53 #define kfifo_is_empty(_kf) \
54 ({ \
55 ((_kf)->count == 0) ? true : false; \
56 })
57
58 #define kfifo_is_full(_kf) \
59 ({ \
60 ((_kf)->count == (_kf)->total) ? true : false; \
61 })
62
63 #define kfifo_put(_kf, _e) \
64 ({ \
65 bool _rc; \
66 \
67 /* Would overflow. */ \
68 if (kfifo_is_full(_kf)) { \
69 _rc = false; \
70 } else { \
71 (_kf)->head[(_kf)->last] = (_e); \
72 (_kf)->count++; \
73 (_kf)->last++; \
74 if ((_kf)->last > (_kf)->total) \
75 (_kf)->last = 0; \
76 _rc = true; \
77 } \
78 \
79 _rc; \
80 })
81
82 #define kfifo_get(_kf, _e) \
83 ({ \
84 bool _rc; \
85 \
86 if (kfifo_is_empty(_kf)) { \
87 _rc = false; \
88 } else { \
89 *(_e) = (_kf)->head[(_kf)->first]; \
90 (_kf)->count--; \
91 (_kf)->first++; \
92 if ((_kf)->first > (_kf)->total) \
93 (_kf)->first = 0; \
94 _rc = true; \
95 } \
96 \
97 _rc; \
98 })
99
100 #define kfifo_alloc(_kf, _s, _gfp) \
101 ({ \
102 int _error; \
103 \
104 (_kf)->head = kmalloc(sizeof(__typeof(*(_kf)->head)) * (_s), _gfp); \
105 if ((_kf)->head == NULL) \
106 _error = ENOMEM; \
107 else { \
108 (_kf)->total = (_s); \
109 _error = 0; \
110 } \
111 \
112 _error; \
113 })
114
115 #define kfifo_free(_kf) \
116 ({ \
117 kfree((_kf)->head); \
118 (_kf)->head = NULL; \
119 (_kf)->total = (_kf)->count = (_kf)->first = (_kf)->last = 0; \
120 })
121
122 #endif /* _LINUXKPI_LINUX_KFIFO_H_*/
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