2 * Copyright (c) 2011 The Chromium OS Authors.
4 * Modified from Linux arch/arm/include/asm/bitops.h
6 * Copyright 1995, Russell King.
7 * Various bits and pieces copyrights include:
8 * Linus Torvalds (test_bit).
10 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
12 * Please note that the code in this file should never be included
13 * from user space. Many of these are not implemented in assembler
14 * since they would be too costly. Also, they require priviledged
15 * instructions (which are not available from user mode) to ensure
16 * that they are atomic.
19 #ifndef __ASM_SANDBOX_BITOPS_H
20 #define __ASM_SANDBOX_BITOPS_H
22 #include <linux/compiler.h>
23 #include <asm/system.h>
27 #define smp_mb__before_clear_bit() do { } while (0)
28 #define smp_mb__after_clear_bit() do { } while (0)
31 * Function prototypes to keep gcc -Wall happy.
33 extern void set_bit(int nr, void *addr);
35 extern void clear_bit(int nr, void *addr);
37 extern void change_bit(int nr, void *addr);
39 static inline void __change_bit(int nr, void *addr)
41 unsigned long mask = BIT_MASK(nr);
42 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
47 static inline int __test_and_set_bit(int nr, void *addr)
49 unsigned long mask = BIT_MASK(nr);
50 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
51 unsigned long old = *p;
54 return (old & mask) != 0;
57 static inline int test_and_set_bit(int nr, void *addr)
59 unsigned long __always_unused flags;
62 local_irq_save(flags);
63 out = __test_and_set_bit(nr, addr);
64 local_irq_restore(flags);
69 static inline int __test_and_clear_bit(int nr, void *addr)
71 unsigned long mask = BIT_MASK(nr);
72 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
73 unsigned long old = *p;
76 return (old & mask) != 0;
79 static inline int test_and_clear_bit(int nr, void *addr)
81 unsigned long __always_unused flags;
84 local_irq_save(flags);
85 out = __test_and_clear_bit(nr, addr);
86 local_irq_restore(flags);
91 extern int test_and_change_bit(int nr, void *addr);
93 static inline int __test_and_change_bit(int nr, void *addr)
95 unsigned long mask = BIT_MASK(nr);
96 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
97 unsigned long old = *p;
100 return (old & mask) != 0;
103 extern int find_first_zero_bit(void *addr, unsigned size);
104 extern int find_next_zero_bit(void *addr, int size, int offset);
107 * This routine doesn't need to be atomic.
109 static inline int test_bit(int nr, const void *addr)
111 return ((unsigned char *) addr)[nr >> 3] & (1U << (nr & 7));
115 * ffz = Find First Zero in word. Undefined if no zero exists,
116 * so code should check against ~0UL first..
118 static inline unsigned long ffz(unsigned long word)
124 if (word & 0x0000ffff) {
125 k -= 16; word <<= 16;
127 if (word & 0x00ff0000) {
130 if (word & 0x0f000000) {
133 if (word & 0x30000000) {
136 if (word & 0x40000000)
142 * hweightN: returns the hamming weight (i.e. the number
143 * of bits set) of a N-bit word
146 #define hweight32(x) generic_hweight32(x)
147 #define hweight16(x) generic_hweight16(x)
148 #define hweight8(x) generic_hweight8(x)
150 #define ext2_set_bit test_and_set_bit
151 #define ext2_clear_bit test_and_clear_bit
152 #define ext2_test_bit test_bit
153 #define ext2_find_first_zero_bit find_first_zero_bit
154 #define ext2_find_next_zero_bit find_next_zero_bit
156 /* Bitmap functions for the minix filesystem. */
157 #define minix_test_and_set_bit(nr, addr) test_and_set_bit(nr, addr)
158 #define minix_set_bit(nr, addr) set_bit(nr, addr)
159 #define minix_test_and_clear_bit(nr, addr) test_and_clear_bit(nr, addr)
160 #define minix_test_bit(nr, addr) test_bit(nr, addr)
161 #define minix_find_first_zero_bit(addr, size) find_first_zero_bit(addr, size)
163 #endif /* __KERNEL__ */
165 #endif /* _ARM_BITOPS_H */