Linux kernel mirror (for testing)
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1/* asm/bitops.h for Linux/CRIS
2 *
3 * TODO: asm versions if speed is needed
4 *
5 * All bit operations return 0 if the bit was cleared before the
6 * operation and != 0 if it was not.
7 *
8 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
9 */
10
11#ifndef _CRIS_BITOPS_H
12#define _CRIS_BITOPS_H
13
14/* Currently this is unsuitable for consumption outside the kernel. */
15#ifdef __KERNEL__
16
17#ifndef _LINUX_BITOPS_H
18#error only <linux/bitops.h> can be included directly
19#endif
20
21#include <arch/bitops.h>
22#include <linux/atomic.h>
23#include <linux/compiler.h>
24
25/*
26 * set_bit - Atomically set a bit in memory
27 * @nr: the bit to set
28 * @addr: the address to start counting from
29 *
30 * This function is atomic and may not be reordered. See __set_bit()
31 * if you do not require the atomic guarantees.
32 * Note that @nr may be almost arbitrarily large; this function is not
33 * restricted to acting on a single-word quantity.
34 */
35
36#define set_bit(nr, addr) (void)test_and_set_bit(nr, addr)
37
38/*
39 * clear_bit - Clears a bit in memory
40 * @nr: Bit to clear
41 * @addr: Address to start counting from
42 *
43 * clear_bit() is atomic and may not be reordered. However, it does
44 * not contain a memory barrier, so if it is used for locking purposes,
45 * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
46 * in order to ensure changes are visible on other processors.
47 */
48
49#define clear_bit(nr, addr) (void)test_and_clear_bit(nr, addr)
50
51/*
52 * change_bit - Toggle a bit in memory
53 * @nr: Bit to change
54 * @addr: Address to start counting from
55 *
56 * change_bit() is atomic and may not be reordered.
57 * Note that @nr may be almost arbitrarily large; this function is not
58 * restricted to acting on a single-word quantity.
59 */
60
61#define change_bit(nr, addr) (void)test_and_change_bit(nr, addr)
62
63/**
64 * test_and_set_bit - Set a bit and return its old value
65 * @nr: Bit to set
66 * @addr: Address to count from
67 *
68 * This operation is atomic and cannot be reordered.
69 * It also implies a memory barrier.
70 */
71
72static inline int test_and_set_bit(int nr, volatile unsigned long *addr)
73{
74 unsigned int mask, retval;
75 unsigned long flags;
76 unsigned int *adr = (unsigned int *)addr;
77
78 adr += nr >> 5;
79 mask = 1 << (nr & 0x1f);
80 cris_atomic_save(addr, flags);
81 retval = (mask & *adr) != 0;
82 *adr |= mask;
83 cris_atomic_restore(addr, flags);
84 return retval;
85}
86
87/*
88 * clear_bit() doesn't provide any barrier for the compiler.
89 */
90#define smp_mb__before_clear_bit() barrier()
91#define smp_mb__after_clear_bit() barrier()
92
93/**
94 * test_and_clear_bit - Clear a bit and return its old value
95 * @nr: Bit to clear
96 * @addr: Address to count from
97 *
98 * This operation is atomic and cannot be reordered.
99 * It also implies a memory barrier.
100 */
101
102static inline int test_and_clear_bit(int nr, volatile unsigned long *addr)
103{
104 unsigned int mask, retval;
105 unsigned long flags;
106 unsigned int *adr = (unsigned int *)addr;
107
108 adr += nr >> 5;
109 mask = 1 << (nr & 0x1f);
110 cris_atomic_save(addr, flags);
111 retval = (mask & *adr) != 0;
112 *adr &= ~mask;
113 cris_atomic_restore(addr, flags);
114 return retval;
115}
116
117/**
118 * test_and_change_bit - Change a bit and return its old value
119 * @nr: Bit to change
120 * @addr: Address to count from
121 *
122 * This operation is atomic and cannot be reordered.
123 * It also implies a memory barrier.
124 */
125
126static inline int test_and_change_bit(int nr, volatile unsigned long *addr)
127{
128 unsigned int mask, retval;
129 unsigned long flags;
130 unsigned int *adr = (unsigned int *)addr;
131 adr += nr >> 5;
132 mask = 1 << (nr & 0x1f);
133 cris_atomic_save(addr, flags);
134 retval = (mask & *adr) != 0;
135 *adr ^= mask;
136 cris_atomic_restore(addr, flags);
137 return retval;
138}
139
140#include <asm-generic/bitops/non-atomic.h>
141
142/*
143 * Since we define it "external", it collides with the built-in
144 * definition, which doesn't have the same semantics. We don't want to
145 * use -fno-builtin, so just hide the name ffs.
146 */
147#define ffs kernel_ffs
148
149#include <asm-generic/bitops/fls.h>
150#include <asm-generic/bitops/__fls.h>
151#include <asm-generic/bitops/fls64.h>
152#include <asm-generic/bitops/hweight.h>
153#include <asm-generic/bitops/find.h>
154#include <asm-generic/bitops/lock.h>
155
156#include <asm-generic/bitops/le.h>
157
158#include <asm-generic/bitops/ext2-atomic-setbit.h>
159
160#include <asm-generic/bitops/sched.h>
161
162#endif /* __KERNEL__ */
163
164#endif /* _CRIS_BITOPS_H */