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