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>
24 #include <asm-generic/bitops/fls.h>
25 #include <asm-generic/bitops/__fls.h>
26 #include <asm-generic/bitops/fls64.h>
27 #include <asm-generic/bitops/__ffs.h>
31 #define smp_mb__before_clear_bit() do { } while (0)
32 #define smp_mb__after_clear_bit() do { } while (0)
35 * Function prototypes to keep gcc -Wall happy.
37 extern void set_bit(int nr, void *addr);
39 extern void clear_bit(int nr, void *addr);
41 extern void change_bit(int nr, void *addr);
43 static inline void __change_bit(int nr, void *addr)
45 unsigned long mask = BIT_MASK(nr);
46 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
51 static inline int __test_and_set_bit(int nr, void *addr)
53 unsigned long mask = BIT_MASK(nr);
54 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
55 unsigned long old = *p;
58 return (old & mask) != 0;
61 static inline int test_and_set_bit(int nr, void *addr)
63 unsigned long __always_unused flags;
66 local_irq_save(flags);
67 out = __test_and_set_bit(nr, addr);
68 local_irq_restore(flags);
73 static inline int __test_and_clear_bit(int nr, void *addr)
75 unsigned long mask = BIT_MASK(nr);
76 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
77 unsigned long old = *p;
80 return (old & mask) != 0;
83 static inline int test_and_clear_bit(int nr, void *addr)
85 unsigned long __always_unused flags;
88 local_irq_save(flags);
89 out = __test_and_clear_bit(nr, addr);
90 local_irq_restore(flags);
95 extern int test_and_change_bit(int nr, void *addr);
97 static inline int __test_and_change_bit(int nr, void *addr)
99 unsigned long mask = BIT_MASK(nr);
100 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
101 unsigned long old = *p;
104 return (old & mask) != 0;
107 extern int find_first_zero_bit(void *addr, unsigned size);
108 extern int find_next_zero_bit(void *addr, int size, int offset);
111 * This routine doesn't need to be atomic.
113 static inline int test_bit(int nr, const void *addr)
115 return ((unsigned char *) addr)[nr >> 3] & (1U << (nr & 7));
119 * ffz = Find First Zero in word. Undefined if no zero exists,
120 * so code should check against ~0UL first..
122 static inline unsigned long ffz(unsigned long word)
128 if (word & 0x0000ffff) {
129 k -= 16; word <<= 16;
131 if (word & 0x00ff0000) {
134 if (word & 0x0f000000) {
137 if (word & 0x30000000) {
140 if (word & 0x40000000)
146 * hweightN: returns the hamming weight (i.e. the number
147 * of bits set) of a N-bit word
150 #define hweight32(x) generic_hweight32(x)
151 #define hweight16(x) generic_hweight16(x)
152 #define hweight8(x) generic_hweight8(x)
154 #define ext2_set_bit test_and_set_bit
155 #define ext2_clear_bit test_and_clear_bit
156 #define ext2_test_bit test_bit
157 #define ext2_find_first_zero_bit find_first_zero_bit
158 #define ext2_find_next_zero_bit find_next_zero_bit
160 /* Bitmap functions for the minix filesystem. */
161 #define minix_test_and_set_bit(nr, addr) test_and_set_bit(nr, addr)
162 #define minix_set_bit(nr, addr) set_bit(nr, addr)
163 #define minix_test_and_clear_bit(nr, addr) test_and_clear_bit(nr, addr)
164 #define minix_test_bit(nr, addr) test_bit(nr, addr)
165 #define minix_find_first_zero_bit(addr, size) find_first_zero_bit(addr, size)
167 #endif /* __KERNEL__ */
169 #endif /* _ARM_BITOPS_H */