1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_BITREV_H
3#define _LINUX_BITREV_H
4
5#include <linux/types.h>
6
7#ifdef CONFIG_HAVE_ARCH_BITREVERSE
8#include <asm/bitrev.h>
9
10#define __bitrev32 __arch_bitrev32
11#define __bitrev16 __arch_bitrev16
12#define __bitrev8 __arch_bitrev8
13
14#else
15extern u8 const byte_rev_table[256];
16static inline u8 __bitrev8(u8 byte)
17{
18	return byte_rev_table[byte];
19}
20
21static inline u16 __bitrev16(u16 x)
22{
23	return (__bitrev8(x & 0xff) << 8) | __bitrev8(x >> 8);
24}
25
26static inline u32 __bitrev32(u32 x)
27{
28	return (__bitrev16(x & 0xffff) << 16) | __bitrev16(x >> 16);
29}
30
31#endif /* CONFIG_HAVE_ARCH_BITREVERSE */
32
33#define __bitrev8x4(x)	(__bitrev32(swab32(x)))
34
35#define __constant_bitrev32(x)	\
36({					\
37	u32 ___x = x;			\
38	___x = (___x >> 16) | (___x << 16);	\
39	___x = ((___x & (u32)0xFF00FF00UL) >> 8) | ((___x & (u32)0x00FF00FFUL) << 8);	\
40	___x = ((___x & (u32)0xF0F0F0F0UL) >> 4) | ((___x & (u32)0x0F0F0F0FUL) << 4);	\
41	___x = ((___x & (u32)0xCCCCCCCCUL) >> 2) | ((___x & (u32)0x33333333UL) << 2);	\
42	___x = ((___x & (u32)0xAAAAAAAAUL) >> 1) | ((___x & (u32)0x55555555UL) << 1);	\
43	___x;								\
44})
45
46#define __constant_bitrev16(x)	\
47({					\
48	u16 ___x = x;			\
49	___x = (___x >> 8) | (___x << 8);	\
50	___x = ((___x & (u16)0xF0F0U) >> 4) | ((___x & (u16)0x0F0FU) << 4);	\
51	___x = ((___x & (u16)0xCCCCU) >> 2) | ((___x & (u16)0x3333U) << 2);	\
52	___x = ((___x & (u16)0xAAAAU) >> 1) | ((___x & (u16)0x5555U) << 1);	\
53	___x;								\
54})
55
56#define __constant_bitrev8x4(x) \
57({			\
58	u32 ___x = x;	\
59	___x = ((___x & (u32)0xF0F0F0F0UL) >> 4) | ((___x & (u32)0x0F0F0F0FUL) << 4);	\
60	___x = ((___x & (u32)0xCCCCCCCCUL) >> 2) | ((___x & (u32)0x33333333UL) << 2);	\
61	___x = ((___x & (u32)0xAAAAAAAAUL) >> 1) | ((___x & (u32)0x55555555UL) << 1);	\
62	___x;								\
63})
64
65#define __constant_bitrev8(x)	\
66({					\
67	u8 ___x = x;			\
68	___x = (___x >> 4) | (___x << 4);	\
69	___x = ((___x & (u8)0xCCU) >> 2) | ((___x & (u8)0x33U) << 2);	\
70	___x = ((___x & (u8)0xAAU) >> 1) | ((___x & (u8)0x55U) << 1);	\
71	___x;								\
72})
73
74#define bitrev32(x) \
75({			\
76	u32 __x = x;	\
77	__builtin_constant_p(__x) ?	\
78	__constant_bitrev32(__x) :			\
79	__bitrev32(__x);				\
80})
81
82#define bitrev16(x) \
83({			\
84	u16 __x = x;	\
85	__builtin_constant_p(__x) ?	\
86	__constant_bitrev16(__x) :			\
87	__bitrev16(__x);				\
88 })
89
90#define bitrev8x4(x) \
91({			\
92	u32 __x = x;	\
93	__builtin_constant_p(__x) ?	\
94	__constant_bitrev8x4(__x) :			\
95	__bitrev8x4(__x);				\
96 })
97
98#define bitrev8(x) \
99({			\
100	u8 __x = x;	\
101	__builtin_constant_p(__x) ?	\
102	__constant_bitrev8(__x) :			\
103	__bitrev8(__x)	;			\
104 })
105#endif /* _LINUX_BITREV_H */
106