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1da177e4 LT |
1 | #ifndef _I386_BITOPS_H |
2 | #define _I386_BITOPS_H | |
3 | ||
4 | /* | |
5 | * Copyright 1992, Linus Torvalds. | |
6 | */ | |
7 | ||
1da177e4 LT |
8 | /** |
9 | * find_first_zero_bit - find the first zero bit in a memory region | |
10 | * @addr: The address to start the search at | |
11 | * @size: The maximum size to search | |
12 | * | |
ec12fa5c | 13 | * Returns the bit number of the first zero bit, not the number of the byte |
1da177e4 LT |
14 | * containing a bit. |
15 | */ | |
16 | static inline int find_first_zero_bit(const unsigned long *addr, unsigned size) | |
17 | { | |
18 | int d0, d1, d2; | |
19 | int res; | |
20 | ||
21 | if (!size) | |
22 | return 0; | |
23 | /* This looks at memory. Mark it volatile to tell gcc not to move it around */ | |
24 | __asm__ __volatile__( | |
25 | "movl $-1,%%eax\n\t" | |
26 | "xorl %%edx,%%edx\n\t" | |
27 | "repe; scasl\n\t" | |
28 | "je 1f\n\t" | |
29 | "xorl -4(%%edi),%%eax\n\t" | |
30 | "subl $4,%%edi\n\t" | |
31 | "bsfl %%eax,%%edx\n" | |
32 | "1:\tsubl %%ebx,%%edi\n\t" | |
33 | "shll $3,%%edi\n\t" | |
34 | "addl %%edi,%%edx" | |
35 | :"=d" (res), "=&c" (d0), "=&D" (d1), "=&a" (d2) | |
36 | :"1" ((size + 31) >> 5), "2" (addr), "b" (addr) : "memory"); | |
37 | return res; | |
38 | } | |
39 | ||
40 | /** | |
41 | * find_next_zero_bit - find the first zero bit in a memory region | |
42 | * @addr: The address to base the search on | |
ec12fa5c | 43 | * @offset: The bit number to start searching at |
1da177e4 LT |
44 | * @size: The maximum size to search |
45 | */ | |
46 | int find_next_zero_bit(const unsigned long *addr, int size, int offset); | |
47 | ||
cd85c8b4 SR |
48 | /** |
49 | * __ffs - find first bit in word. | |
50 | * @word: The word to search | |
51 | * | |
52 | * Undefined if no bit exists, so code should check against 0 first. | |
53 | */ | |
54 | static inline unsigned long __ffs(unsigned long word) | |
55 | { | |
56 | __asm__("bsfl %1,%0" | |
57 | :"=r" (word) | |
58 | :"rm" (word)); | |
59 | return word; | |
60 | } | |
61 | ||
1da177e4 LT |
62 | /** |
63 | * find_first_bit - find the first set bit in a memory region | |
64 | * @addr: The address to start the search at | |
65 | * @size: The maximum size to search | |
66 | * | |
ec12fa5c | 67 | * Returns the bit number of the first set bit, not the number of the byte |
1da177e4 LT |
68 | * containing a bit. |
69 | */ | |
d89c145c | 70 | static inline unsigned find_first_bit(const unsigned long *addr, unsigned size) |
1da177e4 | 71 | { |
d89c145c | 72 | unsigned x = 0; |
d6d2a2ab LT |
73 | |
74 | while (x < size) { | |
75 | unsigned long val = *addr++; | |
76 | if (val) | |
77 | return __ffs(val) + x; | |
cd85c8b4 | 78 | x += (sizeof(*addr)<<3); |
d6d2a2ab | 79 | } |
cd85c8b4 | 80 | return x; |
1da177e4 LT |
81 | } |
82 | ||
83 | /** | |
84 | * find_next_bit - find the first set bit in a memory region | |
85 | * @addr: The address to base the search on | |
ec12fa5c | 86 | * @offset: The bit number to start searching at |
1da177e4 LT |
87 | * @size: The maximum size to search |
88 | */ | |
89 | int find_next_bit(const unsigned long *addr, int size, int offset); | |
90 | ||
91 | /** | |
92 | * ffz - find first zero in word. | |
93 | * @word: The word to search | |
94 | * | |
95 | * Undefined if no zero exists, so code should check against ~0UL first. | |
96 | */ | |
97 | static inline unsigned long ffz(unsigned long word) | |
98 | { | |
99 | __asm__("bsfl %1,%0" | |
100 | :"=r" (word) | |
101 | :"r" (~word)); | |
102 | return word; | |
103 | } | |
104 | ||
1da177e4 LT |
105 | #ifdef __KERNEL__ |
106 | ||
1cc2b994 | 107 | #include <asm-generic/bitops/sched.h> |
1da177e4 LT |
108 | |
109 | /** | |
110 | * ffs - find first bit set | |
111 | * @x: the word to search | |
112 | * | |
113 | * This is defined the same way as | |
114 | * the libc and compiler builtin ffs routines, therefore | |
72fd4a35 | 115 | * differs in spirit from the above ffz() (man ffs). |
1da177e4 LT |
116 | */ |
117 | static inline int ffs(int x) | |
118 | { | |
119 | int r; | |
120 | ||
121 | __asm__("bsfl %1,%0\n\t" | |
122 | "jnz 1f\n\t" | |
123 | "movl $-1,%0\n" | |
124 | "1:" : "=r" (r) : "rm" (x)); | |
125 | return r+1; | |
126 | } | |
127 | ||
d832245d SH |
128 | /** |
129 | * fls - find last bit set | |
130 | * @x: the word to search | |
131 | * | |
72fd4a35 | 132 | * This is defined the same way as ffs(). |
d832245d SH |
133 | */ |
134 | static inline int fls(int x) | |
135 | { | |
136 | int r; | |
137 | ||
138 | __asm__("bsrl %1,%0\n\t" | |
139 | "jnz 1f\n\t" | |
140 | "movl $-1,%0\n" | |
141 | "1:" : "=r" (r) : "rm" (x)); | |
142 | return r+1; | |
143 | } | |
144 | ||
1cc2b994 | 145 | #include <asm-generic/bitops/hweight.h> |
1da177e4 LT |
146 | |
147 | #endif /* __KERNEL__ */ | |
148 | ||
1cc2b994 AM |
149 | #include <asm-generic/bitops/fls64.h> |
150 | ||
1da177e4 LT |
151 | #ifdef __KERNEL__ |
152 | ||
1cc2b994 AM |
153 | #include <asm-generic/bitops/ext2-non-atomic.h> |
154 | ||
ec12fa5c RD |
155 | #define ext2_set_bit_atomic(lock, nr, addr) \ |
156 | test_and_set_bit((nr), (unsigned long *)addr) | |
157 | #define ext2_clear_bit_atomic(lock, nr, addr) \ | |
158 | test_and_clear_bit((nr), (unsigned long *)addr) | |
1cc2b994 AM |
159 | |
160 | #include <asm-generic/bitops/minix.h> | |
1da177e4 LT |
161 | |
162 | #endif /* __KERNEL__ */ | |
163 | ||
164 | #endif /* _I386_BITOPS_H */ |