1 /* 2 * arch/arm/include/asm/byteorder.h 3 * 4 * ARM Endian-ness. In little endian mode, the data bus is connected such 5 * that byte accesses appear as: 6 * 0 = d0...d7, 1 = d8...d15, 2 = d16...d23, 3 = d24...d31 7 * and word accesses (data or instruction) appear as: 8 * d0...d31 9 * 10 * When in big endian mode, byte accesses appear as: 11 * 0 = d24...d31, 1 = d16...d23, 2 = d8...d15, 3 = d0...d7 12 * and word accesses (data or instruction) appear as: 13 * d0...d31 14 */ 15 #ifndef __ASM_ARM_SWAB_H 16 #define __ASM_ARM_SWAB_H 17 18 #include <uapi/asm/swab.h> 19 20 #if __LINUX_ARM_ARCH__ >= 6 21 22 static inline __attribute_const__ __u32 __arch_swahb32(__u32 x) 23 { 24 __asm__ ("rev16 %0, %1" : "=r" (x) : "r" (x)); 25 return x; 26 } 27 #define __arch_swahb32 __arch_swahb32 28 #define __arch_swab16(x) ((__u16)__arch_swahb32(x)) 29 30 static inline __attribute_const__ __u32 __arch_swab32(__u32 x) 31 { 32 __asm__ ("rev %0, %1" : "=r" (x) : "r" (x)); 33 return x; 34 } 35 #define __arch_swab32 __arch_swab32 36 37 #endif 38 #endif 39