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1da177e4 LT |
1 | /* |
2 | * linux/include/asm-arm/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_BYTEORDER_H | |
16 | #define __ASM_ARM_BYTEORDER_H | |
17 | ||
fe5dd7c7 | 18 | #include <linux/compiler.h> |
1da177e4 LT |
19 | #include <asm/types.h> |
20 | ||
6351610d AM |
21 | static inline __attribute_const__ __u32 ___arch__swab32(__u32 x) |
22 | { | |
23 | __u32 t; | |
24 | ||
441ff855 PA |
25 | #ifndef __thumb__ |
26 | if (!__builtin_constant_p(x)) { | |
a3e49436 NP |
27 | /* |
28 | * The compiler needs a bit of a hint here to always do the | |
29 | * right thing and not screw it up to different degrees | |
30 | * depending on the gcc version. | |
31 | */ | |
32 | asm ("eor\t%0, %1, %1, ror #16" : "=r" (t) : "r" (x)); | |
441ff855 PA |
33 | } else |
34 | #endif | |
35 | t = x ^ ((x << 16) | (x >> 16)); /* eor r1,r0,r0,ror #16 */ | |
36 | ||
6351610d AM |
37 | x = (x << 24) | (x >> 8); /* mov r0,r0,ror #8 */ |
38 | t &= ~0x00FF0000; /* bic r1,r1,#0x00FF0000 */ | |
39 | x ^= (t >> 8); /* eor r0,r0,r1,lsr #8 */ | |
40 | ||
41 | return x; | |
42 | } | |
43 | ||
44 | #define __arch__swab32(x) ___arch__swab32(x) | |
45 | ||
1da177e4 LT |
46 | #if !defined(__STRICT_ANSI__) || defined(__KERNEL__) |
47 | # define __BYTEORDER_HAS_U64__ | |
48 | # define __SWAB_64_THRU_32__ | |
49 | #endif | |
50 | ||
51 | #ifdef __ARMEB__ | |
52 | #include <linux/byteorder/big_endian.h> | |
53 | #else | |
54 | #include <linux/byteorder/little_endian.h> | |
55 | #endif | |
56 | ||
57 | #endif | |
58 |