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/*-
* Copyright (c) 2021 Beckhoff Automation GmbH & Co. KG
* Copyright (c) 2022 Bjoern A. Zeeb
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#ifndef _LINUXKPI_LINUX_KFIFO_H_
#define _LINUXKPI_LINUX_KFIFO_H_
#include <sys/types.h>
#include <linux/slab.h>
#include <linux/gfp.h>
/*
* INIT_KFIFO() is used to initialize the structure declared with
* DECLARE_KFIFO(). It doesn't work with DECLARE_KFIFO_PTR().
*/
#define INIT_KFIFO(_kf) \
({ \
(_kf).total = nitems((_kf).head); \
(_kf).count = 0; \
(_kf).first = 0; \
(_kf).last = 0; \
})
#define DECLARE_KFIFO(_name, _type, _size) \
struct kfifo_ ## _name { \
size_t total; \
size_t count; \
size_t first; \
size_t last; \
_type head[_size]; \
} _name
#define DECLARE_KFIFO_PTR(_name, _type) \
struct kfifo_ ## _name { \
size_t total; \
size_t count; \
size_t first; \
size_t last; \
_type *head; \
} _name
#define kfifo_len(_kf) \
({ \
(_kf)->count; \
})
#define kfifo_is_empty(_kf) \
({ \
((_kf)->count == 0) ? true : false; \
})
#define kfifo_is_full(_kf) \
({ \
((_kf)->count == (_kf)->total) ? true : false; \
})
#define kfifo_put(_kf, _e) \
({ \
bool _rc; \
\
/* Would overflow. */ \
if (kfifo_is_full(_kf)) { \
_rc = false; \
} else { \
(_kf)->head[(_kf)->last] = (_e); \
(_kf)->count++; \
(_kf)->last++; \
if ((_kf)->last > (_kf)->total) \
(_kf)->last = 0; \
_rc = true; \
} \
\
_rc; \
})
#define kfifo_get(_kf, _e) \
({ \
bool _rc; \
\
if (kfifo_is_empty(_kf)) { \
_rc = false; \
} else { \
*(_e) = (_kf)->head[(_kf)->first]; \
(_kf)->count--; \
(_kf)->first++; \
if ((_kf)->first > (_kf)->total) \
(_kf)->first = 0; \
_rc = true; \
} \
\
_rc; \
})
#define kfifo_alloc(_kf, _s, _gfp) \
({ \
int _error; \
\
(_kf)->head = kmalloc(sizeof(__typeof(*(_kf)->head)) * (_s), _gfp); \
if ((_kf)->head == NULL) \
_error = ENOMEM; \
else { \
(_kf)->total = (_s); \
_error = 0; \
} \
\
_error; \
})
#define kfifo_free(_kf) \
({ \
kfree((_kf)->head); \
(_kf)->head = NULL; \
(_kf)->total = (_kf)->count = (_kf)->first = (_kf)->last = 0; \
})
#endif /* _LINUXKPI_LINUX_KFIFO_H_*/
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