swab.h 966 B

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  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. #include <uapi/asm/swab.h>
  18. #if __LINUX_ARM_ARCH__ >= 6
  19. static inline __attribute_const__ __u32 __arch_swahb32(__u32 x)
  20. {
  21. __asm__ ("rev16 %0, %1" : "=r" (x) : "r" (x));
  22. return x;
  23. }
  24. #define __arch_swahb32 __arch_swahb32
  25. #define __arch_swab16(x) ((__u16)__arch_swahb32(x))
  26. static inline __attribute_const__ __u32 __arch_swab32(__u32 x)
  27. {
  28. __asm__ ("rev %0, %1" : "=r" (x) : "r" (x));
  29. return x;
  30. }
  31. #define __arch_swab32 __arch_swab32
  32. #endif
  33. #endif