projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| af8e24e9 HH |
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 <linux/compiler.h> | |
| e42ec241 | 19 | #include <linux/types.h> |
| af8e24e9 HH |
20 | |
| 21 | #if !defined(__STRICT_ANSI__) || defined(__KERNEL__) | |
| 22 | # define __SWAB_64_THRU_32__ | |
| 23 | #endif | |
| 24 | ||
| 40f5b078 RV |
25 | #if defined(__KERNEL__) && __LINUX_ARM_ARCH__ >= 6 |
| 26 | ||
| 27 | static inline __attribute_const__ __u16 __arch_swab16(__u16 x) | |
| 28 | { | |
| 29 | __asm__ ("rev16 %0, %1" : "=r" (x) : "r" (x)); | |
| 30 | return x; | |
| 31 | } | |
| 32 | #define __arch_swab16 __arch_swab16 | |
| 33 | ||
| 34 | static inline __attribute_const__ __u32 __arch_swab32(__u32 x) | |
| 35 | { | |
| 36 | __asm__ ("rev %0, %1" : "=r" (x) : "r" (x)); | |
| 37 | return x; | |
| 38 | } | |
| 39 | #define __arch_swab32 __arch_swab32 | |
| 40 | ||
| 41 | #else | |
| 42 | ||
| af8e24e9 HH |
43 | static inline __attribute_const__ __u32 __arch_swab32(__u32 x) |
| 44 | { | |
| 45 | __u32 t; | |
| 46 | ||
| 47 | #ifndef __thumb__ | |
| 48 | if (!__builtin_constant_p(x)) { | |
| 49 | /* | |
| 50 | * The compiler needs a bit of a hint here to always do the | |
| 51 | * right thing and not screw it up to different degrees | |
| 52 | * depending on the gcc version. | |
| 53 | */ | |
| 54 | asm ("eor\t%0, %1, %1, ror #16" : "=r" (t) : "r" (x)); | |
| 55 | } else | |
| 56 | #endif | |
| 57 | t = x ^ ((x << 16) | (x >> 16)); /* eor r1,r0,r0,ror #16 */ | |
| 58 | ||
| 59 | x = (x << 24) | (x >> 8); /* mov r0,r0,ror #8 */ | |
| 60 | t &= ~0x00FF0000; /* bic r1,r1,#0x00FF0000 */ | |
| 61 | x ^= (t >> 8); /* eor r0,r0,r1,lsr #8 */ | |
| 62 | ||
| 63 | return x; | |
| 64 | } | |
| 65 | #define __arch_swab32 __arch_swab32 | |
| 66 | ||
| 67 | #endif | |
| 68 | ||
| 40f5b078 | 69 | #endif |