blob: 74219c56a7f6d42685ad48db33a920280b2abef0 [file] [log] [blame]
Simon Glass744d9852011-10-10 08:22:14 +00001/*
2 * Copyright (c) 2011 The Chromium OS Authors.
3 *
4 * Copyright 1995, Russell King.
5 * Various bits and pieces copyrights include:
6 * Linus Torvalds (test_bit).
7 *
8 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
9 *
10 * Please note that the code in this file should never be included
11 * from user space. Many of these are not implemented in assembler
12 * since they would be too costly. Also, they require priviledged
13 * instructions (which are not available from user mode) to ensure
14 * that they are atomic.
15 */
16
17#ifndef __ASM_SANDBOX_BITOPS_H
18#define __ASM_SANDBOX_BITOPS_H
19
20#include <asm/system.h>
21
22#ifdef __KERNEL__
23
24#define smp_mb__before_clear_bit() do { } while (0)
25#define smp_mb__after_clear_bit() do { } while (0)
26
27/*
28 * Function prototypes to keep gcc -Wall happy.
29 */
30extern void set_bit(int nr, void *addr);
31
32extern void clear_bit(int nr, void *addr);
33
34extern void change_bit(int nr, void *addr);
35
36static inline void __change_bit(int nr, void *addr)
37{
38 unsigned long mask = BIT_MASK(nr);
39 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
40
41 *p ^= mask;
42}
43
44static inline int __test_and_set_bit(int nr, void *addr)
45{
46 unsigned long mask = BIT_MASK(nr);
47 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
48 unsigned long old = *p;
49
50 *p = old | mask;
51 return (old & mask) != 0;
52}
53
54static inline int test_and_set_bit(int nr, void *addr)
55{
56 unsigned long flags;
57 int out;
58
59 local_irq_save(flags);
60 out = __test_and_set_bit(nr, addr);
61 local_irq_restore(flags);
62
63 return out;
64}
65
66static inline int __test_and_clear_bit(int nr, void *addr)
67{
68 unsigned long mask = BIT_MASK(nr);
69 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
70 unsigned long old = *p;
71
72 *p = old & ~mask;
73 return (old & mask) != 0;
74}
75
76static inline int test_and_clear_bit(int nr, void *addr)
77{
78 unsigned long flags;
79 int out;
80
81 local_irq_save(flags);
82 out = __test_and_clear_bit(nr, addr);
83 local_irq_restore(flags);
84
85 return out;
86}
87
88extern int test_and_change_bit(int nr, void *addr);
89
90static inline int __test_and_change_bit(int nr, void *addr)
91{
92 unsigned long mask = BIT_MASK(nr);
93 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
94 unsigned long old = *p;
95
96 *p = old ^ mask;
97 return (old & mask) != 0;
98}
99
100extern int find_first_zero_bit(void *addr, unsigned size);
101extern int find_next_zero_bit(void *addr, int size, int offset);
102
103/*
104 * This routine doesn't need to be atomic.
105 */
106static inline int test_bit(int nr, const void *addr)
107{
108 return ((unsigned char *) addr)[nr >> 3] & (1U << (nr & 7));
109}
110
111/*
112 * ffz = Find First Zero in word. Undefined if no zero exists,
113 * so code should check against ~0UL first..
114 */
115static inline unsigned long ffz(unsigned long word)
116{
117 int k;
118
119 word = ~word;
120 k = 31;
121 if (word & 0x0000ffff) {
122 k -= 16; word <<= 16;
123 }
124 if (word & 0x00ff0000) {
125 k -= 8; word <<= 8;
126 }
127 if (word & 0x0f000000) {
128 k -= 4; word <<= 4;
129 }
130 if (word & 0x30000000) {
131 k -= 2; word <<= 2;
132 }
133 if (word & 0x40000000)
134 k -= 1;
135 return k;
136}
137
138/*
139 * hweightN: returns the hamming weight (i.e. the number
140 * of bits set) of a N-bit word
141 */
142
143#define hweight32(x) generic_hweight32(x)
144#define hweight16(x) generic_hweight16(x)
145#define hweight8(x) generic_hweight8(x)
146
147#define ext2_set_bit test_and_set_bit
148#define ext2_clear_bit test_and_clear_bit
149#define ext2_test_bit test_bit
150#define ext2_find_first_zero_bit find_first_zero_bit
151#define ext2_find_next_zero_bit find_next_zero_bit
152
153/* Bitmap functions for the minix filesystem. */
154#define minix_test_and_set_bit(nr, addr) test_and_set_bit(nr, addr)
155#define minix_set_bit(nr, addr) set_bit(nr, addr)
156#define minix_test_and_clear_bit(nr, addr) test_and_clear_bit(nr, addr)
157#define minix_test_bit(nr, addr) test_bit(nr, addr)
158#define minix_find_first_zero_bit(addr, size) find_first_zero_bit(addr, size)
159
160#endif /* __KERNEL__ */
161
162#endif /* _ARM_BITOPS_H */