sys/compat/linuxkpi/common/include/linux/kfifo.h

   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_*/