1 /* asm/bitops.h for Linux/CRIS
3 * TODO: asm versions if speed is needed
5 * All bit operations return 0 if the bit was cleared before the
6 * operation and != 0 if it was not.
8 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
11 #ifndef _CRIS_BITOPS_H
12 #define _CRIS_BITOPS_H
14 /* Currently this is unsuitable for consumption outside the kernel. */
17 #include <asm/arch/bitops.h>
18 #include <asm/system.h>
19 #include <asm/atomic.h>
20 #include <linux/compiler.h>
23 * Some hacks to defeat gcc over-optimizations..
25 struct __dummy
{ unsigned long a
[100]; };
26 #define ADDR (*(struct __dummy *) addr)
27 #define CONST_ADDR (*(const struct __dummy *) addr)
30 * set_bit - Atomically set a bit in memory
32 * @addr: the address to start counting from
34 * This function is atomic and may not be reordered. See __set_bit()
35 * if you do not require the atomic guarantees.
36 * Note that @nr may be almost arbitrarily large; this function is not
37 * restricted to acting on a single-word quantity.
40 #define set_bit(nr, addr) (void)test_and_set_bit(nr, addr)
43 * clear_bit - Clears a bit in memory
45 * @addr: Address to start counting from
47 * clear_bit() is atomic and may not be reordered. However, it does
48 * not contain a memory barrier, so if it is used for locking purposes,
49 * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
50 * in order to ensure changes are visible on other processors.
53 #define clear_bit(nr, addr) (void)test_and_clear_bit(nr, addr)
56 * change_bit - Toggle a bit in memory
58 * @addr: Address to start counting from
60 * change_bit() is atomic and may not be reordered.
61 * Note that @nr may be almost arbitrarily large; this function is not
62 * restricted to acting on a single-word quantity.
65 #define change_bit(nr, addr) (void)test_and_change_bit(nr, addr)
68 * test_and_set_bit - Set a bit and return its old value
70 * @addr: Address to count from
72 * This operation is atomic and cannot be reordered.
73 * It also implies a memory barrier.
76 static inline int test_and_set_bit(int nr
, volatile unsigned long *addr
)
78 unsigned int mask
, retval
;
80 unsigned int *adr
= (unsigned int *)addr
;
83 mask
= 1 << (nr
& 0x1f);
84 cris_atomic_save(addr
, flags
);
85 retval
= (mask
& *adr
) != 0;
87 cris_atomic_restore(addr
, flags
);
92 * clear_bit() doesn't provide any barrier for the compiler.
94 #define smp_mb__before_clear_bit() barrier()
95 #define smp_mb__after_clear_bit() barrier()
98 * test_and_clear_bit - Clear a bit and return its old value
100 * @addr: Address to count from
102 * This operation is atomic and cannot be reordered.
103 * It also implies a memory barrier.
106 static inline int test_and_clear_bit(int nr
, volatile unsigned long *addr
)
108 unsigned int mask
, retval
;
110 unsigned int *adr
= (unsigned int *)addr
;
113 mask
= 1 << (nr
& 0x1f);
114 cris_atomic_save(addr
, flags
);
115 retval
= (mask
& *adr
) != 0;
117 cris_atomic_restore(addr
, flags
);
122 * test_and_change_bit - Change a bit and return its old value
124 * @addr: Address to count from
126 * This operation is atomic and cannot be reordered.
127 * It also implies a memory barrier.
130 static inline int test_and_change_bit(int nr
, volatile unsigned long *addr
)
132 unsigned int mask
, retval
;
134 unsigned int *adr
= (unsigned int *)addr
;
136 mask
= 1 << (nr
& 0x1f);
137 cris_atomic_save(addr
, flags
);
138 retval
= (mask
& *adr
) != 0;
140 cris_atomic_restore(addr
, flags
);
144 #include <asm-generic/bitops/non-atomic.h>
147 * Since we define it "external", it collides with the built-in
148 * definition, which doesn't have the same semantics. We don't want to
149 * use -fno-builtin, so just hide the name ffs.
151 #define ffs kernel_ffs
153 #include <asm-generic/bitops/fls.h>
154 #include <asm-generic/bitops/fls64.h>
155 #include <asm-generic/bitops/hweight.h>
156 #include <asm-generic/bitops/find.h>
157 #include <asm-generic/bitops/lock.h>
159 #include <asm-generic/bitops/ext2-non-atomic.h>
161 #define ext2_set_bit_atomic(l,n,a) test_and_set_bit(n,a)
162 #define ext2_clear_bit_atomic(l,n,a) test_and_clear_bit(n,a)
164 #include <asm-generic/bitops/minix.h>
165 #include <asm-generic/bitops/sched.h>
167 #endif /* __KERNEL__ */
169 #endif /* _CRIS_BITOPS_H */
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