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_*/ 123