Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
1#ifndef _PERF_LINUX_BITOPS_H_
2#define _PERF_LINUX_BITOPS_H_
3
4#include <linux/kernel.h>
5#include <linux/compiler.h>
6#include <asm/hweight.h>
7
8#define BITS_PER_LONG __WORDSIZE
9#define BITS_PER_BYTE 8
10#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
11
12#define for_each_set_bit(bit, addr, size) \
13 for ((bit) = find_first_bit((addr), (size)); \
14 (bit) < (size); \
15 (bit) = find_next_bit((addr), (size), (bit) + 1))
16
17/* same as for_each_set_bit() but use bit as value to start with */
18#define for_each_set_bit_cont(bit, addr, size) \
19 for ((bit) = find_next_bit((addr), (size), (bit)); \
20 (bit) < (size); \
21 (bit) = find_next_bit((addr), (size), (bit) + 1))
22
23static inline void set_bit(int nr, unsigned long *addr)
24{
25 addr[nr / BITS_PER_LONG] |= 1UL << (nr % BITS_PER_LONG);
26}
27
28static inline void clear_bit(int nr, unsigned long *addr)
29{
30 addr[nr / BITS_PER_LONG] &= ~(1UL << (nr % BITS_PER_LONG));
31}
32
33static __always_inline int test_bit(unsigned int nr, const unsigned long *addr)
34{
35 return ((1UL << (nr % BITS_PER_LONG)) &
36 (((unsigned long *)addr)[nr / BITS_PER_LONG])) != 0;
37}
38
39static inline unsigned long hweight_long(unsigned long w)
40{
41 return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
42}
43
44#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG)
45
46/**
47 * __ffs - find first bit in word.
48 * @word: The word to search
49 *
50 * Undefined if no bit exists, so code should check against 0 first.
51 */
52static __always_inline unsigned long __ffs(unsigned long word)
53{
54 int num = 0;
55
56#if BITS_PER_LONG == 64
57 if ((word & 0xffffffff) == 0) {
58 num += 32;
59 word >>= 32;
60 }
61#endif
62 if ((word & 0xffff) == 0) {
63 num += 16;
64 word >>= 16;
65 }
66 if ((word & 0xff) == 0) {
67 num += 8;
68 word >>= 8;
69 }
70 if ((word & 0xf) == 0) {
71 num += 4;
72 word >>= 4;
73 }
74 if ((word & 0x3) == 0) {
75 num += 2;
76 word >>= 2;
77 }
78 if ((word & 0x1) == 0)
79 num += 1;
80 return num;
81}
82
83/*
84 * Find the first set bit in a memory region.
85 */
86static inline unsigned long
87find_first_bit(const unsigned long *addr, unsigned long size)
88{
89 const unsigned long *p = addr;
90 unsigned long result = 0;
91 unsigned long tmp;
92
93 while (size & ~(BITS_PER_LONG-1)) {
94 if ((tmp = *(p++)))
95 goto found;
96 result += BITS_PER_LONG;
97 size -= BITS_PER_LONG;
98 }
99 if (!size)
100 return result;
101
102 tmp = (*p) & (~0UL >> (BITS_PER_LONG - size));
103 if (tmp == 0UL) /* Are any bits set? */
104 return result + size; /* Nope. */
105found:
106 return result + __ffs(tmp);
107}
108
109/*
110 * Find the next set bit in a memory region.
111 */
112static inline unsigned long
113find_next_bit(const unsigned long *addr, unsigned long size, unsigned long offset)
114{
115 const unsigned long *p = addr + BITOP_WORD(offset);
116 unsigned long result = offset & ~(BITS_PER_LONG-1);
117 unsigned long tmp;
118
119 if (offset >= size)
120 return size;
121 size -= result;
122 offset %= BITS_PER_LONG;
123 if (offset) {
124 tmp = *(p++);
125 tmp &= (~0UL << offset);
126 if (size < BITS_PER_LONG)
127 goto found_first;
128 if (tmp)
129 goto found_middle;
130 size -= BITS_PER_LONG;
131 result += BITS_PER_LONG;
132 }
133 while (size & ~(BITS_PER_LONG-1)) {
134 if ((tmp = *(p++)))
135 goto found_middle;
136 result += BITS_PER_LONG;
137 size -= BITS_PER_LONG;
138 }
139 if (!size)
140 return result;
141 tmp = *p;
142
143found_first:
144 tmp &= (~0UL >> (BITS_PER_LONG - size));
145 if (tmp == 0UL) /* Are any bits set? */
146 return result + size; /* Nope. */
147found_middle:
148 return result + __ffs(tmp);
149}
150
151#endif