diff options
Diffstat (limited to 'arch/arm/include/asm/swab.h')
| -rw-r--r-- | arch/arm/include/asm/swab.h | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/arch/arm/include/asm/swab.h b/arch/arm/include/asm/swab.h new file mode 100644 index 0000000000..c605182304 --- /dev/null +++ b/arch/arm/include/asm/swab.h @@ -0,0 +1,39 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * 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 __ASM_ARM_SWAB_H +#define __ASM_ARM_SWAB_H + +#include <uapi/asm/swab.h> + +#if __LINUX_ARM_ARCH__ >= 6 + +static inline __attribute_const__ __u32 __arch_swahb32(__u32 x) +{ + __asm__ ("rev16 %0, %1" : "=r" (x) : "r" (x)); + return x; +} +#define __arch_swahb32 __arch_swahb32 +#define __arch_swab16(x) ((__u16)__arch_swahb32(x)) + +static inline __attribute_const__ __u32 __arch_swab32(__u32 x) +{ + __asm__ ("rev %0, %1" : "=r" (x) : "r" (x)); + return x; +} +#define __arch_swab32 __arch_swab32 + +#endif +#endif |