2 * Copyright (c) 2011 The Chromium OS Authors.
4 * Copyright 1995, Russell King.
5 * Various bits and pieces copyrights include:
6 * Linus Torvalds (test_bit).
8 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
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.
17 #ifndef __ASM_SANDBOX_BITOPS_H
18 #define __ASM_SANDBOX_BITOPS_H
20 #include <linux/compiler.h>
21 #include <asm/system.h>
25 #define smp_mb__before_clear_bit() do { } while (0)
26 #define smp_mb__after_clear_bit() do { } while (0)
29 * Function prototypes to keep gcc -Wall happy.
31 extern void set_bit(int nr, void *addr);
33 extern void clear_bit(int nr, void *addr);
35 extern void change_bit(int nr, void *addr);
37 static inline void __change_bit(int nr, void *addr)
39 unsigned long mask = BIT_MASK(nr);
40 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
45 static inline int __test_and_set_bit(int nr, void *addr)
47 unsigned long mask = BIT_MASK(nr);
48 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
49 unsigned long old = *p;
52 return (old & mask) != 0;
55 static inline int test_and_set_bit(int nr, void *addr)
57 unsigned long __always_unused flags;
60 local_irq_save(flags);
61 out = __test_and_set_bit(nr, addr);
62 local_irq_restore(flags);
67 static inline int __test_and_clear_bit(int nr, void *addr)
69 unsigned long mask = BIT_MASK(nr);
70 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
71 unsigned long old = *p;
74 return (old & mask) != 0;
77 static inline int test_and_clear_bit(int nr, void *addr)
79 unsigned long __always_unused flags;
82 local_irq_save(flags);
83 out = __test_and_clear_bit(nr, addr);
84 local_irq_restore(flags);
89 extern int test_and_change_bit(int nr, void *addr);
91 static inline int __test_and_change_bit(int nr, void *addr)
93 unsigned long mask = BIT_MASK(nr);
94 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
95 unsigned long old = *p;
98 return (old & mask) != 0;
101 extern int find_first_zero_bit(void *addr, unsigned size);
102 extern int find_next_zero_bit(void *addr, int size, int offset);
105 * This routine doesn't need to be atomic.
107 static inline int test_bit(int nr, const void *addr)
109 return ((unsigned char *) addr)[nr >> 3] & (1U << (nr & 7));
113 * ffz = Find First Zero in word. Undefined if no zero exists,
114 * so code should check against ~0UL first..
116 static inline unsigned long ffz(unsigned long word)
122 if (word & 0x0000ffff) {
123 k -= 16; word <<= 16;
125 if (word & 0x00ff0000) {
128 if (word & 0x0f000000) {
131 if (word & 0x30000000) {
134 if (word & 0x40000000)
140 * hweightN: returns the hamming weight (i.e. the number
141 * of bits set) of a N-bit word
144 #define hweight32(x) generic_hweight32(x)
145 #define hweight16(x) generic_hweight16(x)
146 #define hweight8(x) generic_hweight8(x)
148 #define ext2_set_bit test_and_set_bit
149 #define ext2_clear_bit test_and_clear_bit
150 #define ext2_test_bit test_bit
151 #define ext2_find_first_zero_bit find_first_zero_bit
152 #define ext2_find_next_zero_bit find_next_zero_bit
154 /* Bitmap functions for the minix filesystem. */
155 #define minix_test_and_set_bit(nr, addr) test_and_set_bit(nr, addr)
156 #define minix_set_bit(nr, addr) set_bit(nr, addr)
157 #define minix_test_and_clear_bit(nr, addr) test_and_clear_bit(nr, addr)
158 #define minix_test_bit(nr, addr) test_bit(nr, addr)
159 #define minix_find_first_zero_bit(addr, size) find_first_zero_bit(addr, size)
161 #endif /* __KERNEL__ */
163 #endif /* _ARM_BITOPS_H */