tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#ifndef _ASM_X86_BYTEORDER_H
2#define _ASM_X86_BYTEORDER_H
3
4#include <asm/types.h>
5#include <linux/compiler.h>
6
7#ifdef __GNUC__
8
9#ifdef __i386__
10
11static inline __attribute_const__ __u32 ___arch__swab32(__u32 x)
12{
13#ifdef CONFIG_X86_BSWAP
14 asm("bswap %0" : "=r" (x) : "0" (x));
15#else
16 asm("xchgb %b0,%h0\n\t" /* swap lower bytes */
17 "rorl $16,%0\n\t" /* swap words */
18 "xchgb %b0,%h0" /* swap higher bytes */
19 : "=q" (x)
20 : "0" (x));
21#endif
22 return x;
23}
24
25static inline __attribute_const__ __u64 ___arch__swab64(__u64 val)
26{
27 union {
28 struct {
29 __u32 a;
30 __u32 b;
31 } s;
32 __u64 u;
33 } v;
34 v.u = val;
35#ifdef CONFIG_X86_BSWAP
36 asm("bswapl %0 ; bswapl %1 ; xchgl %0,%1"
37 : "=r" (v.s.a), "=r" (v.s.b)
38 : "0" (v.s.a), "1" (v.s.b));
39#else
40 v.s.a = ___arch__swab32(v.s.a);
41 v.s.b = ___arch__swab32(v.s.b);
42 asm("xchgl %0,%1"
43 : "=r" (v.s.a), "=r" (v.s.b)
44 : "0" (v.s.a), "1" (v.s.b));
45#endif
46 return v.u;
47}
48
49#else /* __i386__ */
50
51static inline __attribute_const__ __u64 ___arch__swab64(__u64 x)
52{
53 asm("bswapq %0"
54 : "=r" (x)
55 : "0" (x));
56 return x;
57}
58
59static inline __attribute_const__ __u32 ___arch__swab32(__u32 x)
60{
61 asm("bswapl %0"
62 : "=r" (x)
63 : "0" (x));
64 return x;
65}
66
67#endif
68
69/* Do not define swab16. Gcc is smart enough to recognize "C" version and
70 convert it into rotation or exhange. */
71
72#define __arch__swab64(x) ___arch__swab64(x)
73#define __arch__swab32(x) ___arch__swab32(x)
74
75#define __BYTEORDER_HAS_U64__
76
77#endif /* __GNUC__ */
78
79#include <linux/byteorder/little_endian.h>
80
81#endif /* _ASM_X86_BYTEORDER_H */