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
15 extern u8 const byte_rev_table[256];
16 static inline u8 __bitrev8(u8 byte)
17 {
18 return byte_rev_table[byte];
19 }
20
21 static inline u16 __bitrev16(u16 x)
22 {
23 return (__bitrev8(x & 0xff) << 8) | __bitrev8(x >> 8);
24 }
25
26 static 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
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