/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
|
/*
|
* arch/arm/include/asm/byteorder.h
|
*
|
* ARM Endian-ness. In little endian mode, the data bus is connected such
|
* that byte accesses appear as:
|
* 0 = d0...d7, 1 = d8...d15, 2 = d16...d23, 3 = d24...d31
|
* and word accesses (data or instruction) appear as:
|
* d0...d31
|
*
|
* When in big endian mode, byte accesses appear as:
|
* 0 = d24...d31, 1 = d16...d23, 2 = d8...d15, 3 = d0...d7
|
* and word accesses (data or instruction) appear as:
|
* d0...d31
|
*/
|
#ifndef _UAPI__ASM_ARM_SWAB_H
|
#define _UAPI__ASM_ARM_SWAB_H
|
|
#include <linux/compiler.h>
|
#include <linux/types.h>
|
|
#if !defined(__STRICT_ANSI__) || defined(__KERNEL__)
|
# define __SWAB_64_THRU_32__
|
#endif
|
|
|
#if !defined(__KERNEL__) || __LINUX_ARM_ARCH__ < 6
|
static inline __attribute_const__ __u32 __arch_swab32(__u32 x)
|
{
|
__u32 t;
|
|
#ifndef __thumb__
|
if (!__builtin_constant_p(x)) {
|
/*
|
* The compiler needs a bit of a hint here to always do the
|
* right thing and not screw it up to different degrees
|
* depending on the gcc version.
|
*/
|
asm ("eor\t%0, %1, %1, ror #16" : "=r" (t) : "r" (x));
|
} else
|
#endif
|
t = x ^ ((x << 16) | (x >> 16)); /* eor r1,r0,r0,ror #16 */
|
|
x = (x << 24) | (x >> 8); /* mov r0,r0,ror #8 */
|
t &= ~0x00FF0000; /* bic r1,r1,#0x00FF0000 */
|
x ^= (t >> 8); /* eor r0,r0,r1,lsr #8 */
|
|
return x;
|
}
|
#define __arch_swab32 __arch_swab32
|
|
#endif
|
|
#endif /* _UAPI__ASM_ARM_SWAB_H */
|
