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wdenkb15cbc02000-08-21 15:05:47 +00001#ifndef _LINUX_BITOPS_H
2#define _LINUX_BITOPS_H
3
Simon Kagstrom02f99902009-08-24 09:09:50 +02004#include <asm/types.h>
wdenkb15cbc02000-08-21 15:05:47 +00005
6/*
7 * ffs: find first bit set. This is defined the same way as
8 * the libc and compiler builtin ffs routines, therefore
9 * differs in spirit from the above ffz (man ffs).
10 */
11
12static inline int generic_ffs(int x)
13{
14 int r = 1;
15
16 if (!x)
17 return 0;
18 if (!(x & 0xffff)) {
19 x >>= 16;
20 r += 16;
21 }
22 if (!(x & 0xff)) {
23 x >>= 8;
24 r += 8;
25 }
26 if (!(x & 0xf)) {
27 x >>= 4;
28 r += 4;
29 }
30 if (!(x & 3)) {
31 x >>= 2;
32 r += 2;
33 }
34 if (!(x & 1)) {
35 x >>= 1;
36 r += 1;
37 }
38 return r;
39}
40
Simon Kagstrom52d61222009-08-24 09:10:12 +020041/**
42 * fls - find last (most-significant) bit set
43 * @x: the word to search
44 *
45 * This is defined the same way as ffs.
46 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
47 */
48static inline int generic_fls(int x)
49{
50 int r = 32;
51
52 if (!x)
53 return 0;
54 if (!(x & 0xffff0000u)) {
55 x <<= 16;
56 r -= 16;
57 }
58 if (!(x & 0xff000000u)) {
59 x <<= 8;
60 r -= 8;
61 }
62 if (!(x & 0xf0000000u)) {
63 x <<= 4;
64 r -= 4;
65 }
66 if (!(x & 0xc0000000u)) {
67 x <<= 2;
68 r -= 2;
69 }
70 if (!(x & 0x80000000u)) {
71 x <<= 1;
72 r -= 1;
73 }
74 return r;
75}
76
77
wdenkb15cbc02000-08-21 15:05:47 +000078/*
79 * hweightN: returns the hamming weight (i.e. the number
80 * of bits set) of a N-bit word
81 */
82
83static inline unsigned int generic_hweight32(unsigned int w)
84{
wdenk8bde7f72003-06-27 21:31:46 +000085 unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555);
86 res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
87 res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F);
88 res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF);
89 return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF);
wdenkb15cbc02000-08-21 15:05:47 +000090}
91
92static inline unsigned int generic_hweight16(unsigned int w)
93{
wdenk8bde7f72003-06-27 21:31:46 +000094 unsigned int res = (w & 0x5555) + ((w >> 1) & 0x5555);
95 res = (res & 0x3333) + ((res >> 2) & 0x3333);
96 res = (res & 0x0F0F) + ((res >> 4) & 0x0F0F);
97 return (res & 0x00FF) + ((res >> 8) & 0x00FF);
wdenkb15cbc02000-08-21 15:05:47 +000098}
99
100static inline unsigned int generic_hweight8(unsigned int w)
101{
wdenk8bde7f72003-06-27 21:31:46 +0000102 unsigned int res = (w & 0x55) + ((w >> 1) & 0x55);
103 res = (res & 0x33) + ((res >> 2) & 0x33);
104 return (res & 0x0F) + ((res >> 4) & 0x0F);
wdenkb15cbc02000-08-21 15:05:47 +0000105}
106
Simon Kagstrom02f99902009-08-24 09:09:50 +0200107#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
108#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
109
wdenkb15cbc02000-08-21 15:05:47 +0000110#include <asm/bitops.h>
111
Simon Kagstrom02f99902009-08-24 09:09:50 +0200112/* linux/include/asm-generic/bitops/non-atomic.h */
113
Simon Kagstrom0413cfe2009-09-17 15:15:52 +0200114#ifndef PLATFORM__SET_BIT
Simon Kagstrom02f99902009-08-24 09:09:50 +0200115# define __set_bit generic_set_bit
116#endif
117
Simon Kagstrom0413cfe2009-09-17 15:15:52 +0200118#ifndef PLATFORM__CLEAR_BIT
Simon Kagstrom02f99902009-08-24 09:09:50 +0200119# define __clear_bit generic_clear_bit
120#endif
121
Simon Kagstrom0413cfe2009-09-17 15:15:52 +0200122#ifndef PLATFORM_FFS
Simon Kagstrom52d61222009-08-24 09:10:12 +0200123# define ffs generic_ffs
124#endif
125
Simon Kagstrom0413cfe2009-09-17 15:15:52 +0200126#ifndef PLATFORM_FLS
Simon Kagstrom52d61222009-08-24 09:10:12 +0200127# define fls generic_fls
128#endif
129
Simon Kagstrom02f99902009-08-24 09:09:50 +0200130/**
131 * __set_bit - Set a bit in memory
132 * @nr: the bit to set
133 * @addr: the address to start counting from
134 *
135 * Unlike set_bit(), this function is non-atomic and may be reordered.
136 * If it's called on the same region of memory simultaneously, the effect
137 * may be that only one operation succeeds.
138 */
139static inline void generic_set_bit(int nr, volatile unsigned long *addr)
140{
141 unsigned long mask = BIT_MASK(nr);
142 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
143
144 *p |= mask;
145}
146
147static inline void generic_clear_bit(int nr, volatile unsigned long *addr)
148{
149 unsigned long mask = BIT_MASK(nr);
150 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
151
152 *p &= ~mask;
153}
wdenkb15cbc02000-08-21 15:05:47 +0000154
155#endif