ref: e9ca4a2d382afa8efd6fe54c869904ba99ed1d76
dir: /include/ext4_misc.h/
/*
* Copyright (c) 2015 Grzegorz Kostka (kostka.grzegorz@gmail.com)
* Copyright (c) 2015 Kaho Ng (ngkaho1234@gmail.com)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
*/
/** @addtogroup lwext4
* @{
*/
/**
* @file ext4_misc.h
* @brief Miscellaneous helpers.
*/
#ifndef EXT4_MISC_H_
#define EXT4_MISC_H_
#ifdef __cplusplus
extern "C" {
#endif
#include <stdint.h>
/**************************************************************/
#define EXT4_DIV_ROUND_UP(x, y) (((x) + (y) - 1)/(y))
#define EXT4_ALIGN(x, y) ((y) * EXT4_DIV_ROUND_UP((x), (y)))
/****************************Endian conversion*****************/
static inline uint64_t reorder64(uint64_t n)
{
return ((n & 0xff) << 56) |
((n & 0xff00) << 40) |
((n & 0xff0000) << 24) |
((n & 0xff000000LL) << 8) |
((n & 0xff00000000LL) >> 8) |
((n & 0xff0000000000LL) >> 24) |
((n & 0xff000000000000LL) >> 40) |
((n & 0xff00000000000000LL) >> 56);
}
static inline uint32_t reorder32(uint32_t n)
{
return ((n & 0xff) << 24) |
((n & 0xff00) << 8) |
((n & 0xff0000) >> 8) |
((n & 0xff000000) >> 24);
}
static inline uint16_t reorder16(uint16_t n)
{
return ((n & 0xff) << 8) |
((n & 0xff00) >> 8);
}
#ifdef CONFIG_BIG_ENDIAN
#define to_le64(_n) reorder64(_n)
#define to_le32(_n) reorder32(_n)
#define to_le16(_n) reorder16(_n)
#define to_be64(_n) _n
#define to_be32(_n) _n
#define to_be16(_n) _n
#else
#define to_le64(_n) _n
#define to_le32(_n) _n
#define to_le16(_n) _n
#define to_be64(_n) reorder64(_n)
#define to_be32(_n) reorder32(_n)
#define to_be16(_n) reorder16(_n)
#endif
/****************************Access macros to ext4 structures*****************/
#define ext4_get32(s, f) to_le32((s)->f)
#define ext4_get16(s, f) to_le16((s)->f)
#define ext4_get8(s, f) (s)->f
#define ext4_set32(s, f, v) \
do { \
(s)->f = to_le32(v); \
} while (0)
#define ext4_set16(s, f, v) \
do { \
(s)->f = to_le16(v); \
} while (0)
#define ext4_set8 \
(s, f, v) do { (s)->f = (v); } \
while (0)
/****************************Access macros to jbd2 structures*****************/
#define jbd_get32(s, f) to_be32((s)->f)
#define jbd_get16(s, f) to_be16((s)->f)
#define jbd_get8(s, f) (s)->f
#define jbd_set32(s, f, v) \
do { \
(s)->f = to_be32(v); \
} while (0)
#define jbd_set16(s, f, v) \
do { \
(s)->f = to_be16(v); \
} while (0)
#define jbd_set8 \
(s, f, v) do { (s)->f = (v); } \
while (0)
#ifdef __GNUC__
#ifndef __unused
#define __unused __attribute__ ((__unused__))
#endif
#else
#define __unused
#endif
#ifndef offsetof
#define offsetof(type, field) \
((size_t)(&(((type *)0)->field)))
#endif
#ifdef __cplusplus
}
#endif
#endif /* EXT4_MISC_H_ */
/**
* @}
*/