1#ifndef _LINUX_BITREV_H
2#define _LINUX_BITREV_H
3
4#include <linux/types.h>
5
6#ifdef CONFIG_HAVE_ARCH_BITREVERSE
7#include <asm/bitrev.h>
8
9#define __bitrev32 __arch_bitrev32
10#define __bitrev16 __arch_bitrev16
11#define __bitrev8 __arch_bitrev8
12
13#else
14extern u8 const byte_rev_table[256];
15static inline u8 __bitrev8(u8 byte)
16{
17	return byte_rev_table[byte];
18}
19
20static inline u16 __bitrev16(u16 x)
21{
22	return (__bitrev8(x & 0xff) << 8) | __bitrev8(x >> 8);
23}
24
25static inline u32 __bitrev32(u32 x)
26{
27	return (__bitrev16(x & 0xffff) << 16) | __bitrev16(x >> 16);
28}
29
30#endif /* CONFIG_HAVE_ARCH_BITREVERSE */
31
32#define __constant_bitrev32(x)	\
33({					\
34	u32 __x = x;			\
35	__x = (__x >> 16) | (__x << 16);	\
36	__x = ((__x & (u32)0xFF00FF00UL) >> 8) | ((__x & (u32)0x00FF00FFUL) << 8);	\
37	__x = ((__x & (u32)0xF0F0F0F0UL) >> 4) | ((__x & (u32)0x0F0F0F0FUL) << 4);	\
38	__x = ((__x & (u32)0xCCCCCCCCUL) >> 2) | ((__x & (u32)0x33333333UL) << 2);	\
39	__x = ((__x & (u32)0xAAAAAAAAUL) >> 1) | ((__x & (u32)0x55555555UL) << 1);	\
40	__x;								\
41})
42
43#define __constant_bitrev16(x)	\
44({					\
45	u16 __x = x;			\
46	__x = (__x >> 8) | (__x << 8);	\
47	__x = ((__x & (u16)0xF0F0U) >> 4) | ((__x & (u16)0x0F0FU) << 4);	\
48	__x = ((__x & (u16)0xCCCCU) >> 2) | ((__x & (u16)0x3333U) << 2);	\
49	__x = ((__x & (u16)0xAAAAU) >> 1) | ((__x & (u16)0x5555U) << 1);	\
50	__x;								\
51})
52
53#define __constant_bitrev8(x)	\
54({					\
55	u8 __x = x;			\
56	__x = (__x >> 4) | (__x << 4);	\
57	__x = ((__x & (u8)0xCCU) >> 2) | ((__x & (u8)0x33U) << 2);	\
58	__x = ((__x & (u8)0xAAU) >> 1) | ((__x & (u8)0x55U) << 1);	\
59	__x;								\
60})
61
62#define bitrev32(x) \
63({			\
64	u32 __x = x;	\
65	__builtin_constant_p(__x) ?	\
66	__constant_bitrev32(__x) :			\
67	__bitrev32(__x);				\
68})
69
70#define bitrev16(x) \
71({			\
72	u16 __x = x;	\
73	__builtin_constant_p(__x) ?	\
74	__constant_bitrev16(__x) :			\
75	__bitrev16(__x);				\
76 })
77
78#define bitrev8(x) \
79({			\
80	u8 __x = x;	\
81	__builtin_constant_p(__x) ?	\
82	__constant_bitrev8(__x) :			\
83	__bitrev8(__x)	;			\
84 })
85#endif /* _LINUX_BITREV_H */
86