LXR linux/arch/arm/include/asm/swab.h

   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
  22static 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
  30static 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