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 #ifndef _LINUX_BITOPS_H
18 #error only <linux/bitops.h> can be included directly
21 #include <asm/arch/bitops.h>
22 #include <asm/system.h>
23 #include <asm/atomic.h>
24 #include <linux/compiler.h>
27 * Some hacks to defeat gcc over-optimizations..
29 struct __dummy
{ unsigned long a
[100]; };
30 #define ADDR (*(struct __dummy *) addr)
31 #define CONST_ADDR (*(const struct __dummy *) addr)
34 * set_bit - Atomically set a bit in memory
36 * @addr: the address to start counting from
38 * This function is atomic and may not be reordered. See __set_bit()
39 * if you do not require the atomic guarantees.
40 * Note that @nr may be almost arbitrarily large; this function is not
41 * restricted to acting on a single-word quantity.
44 #define set_bit(nr, addr) (void)test_and_set_bit(nr, addr)
47 * clear_bit - Clears a bit in memory
49 * @addr: Address to start counting from
51 * clear_bit() is atomic and may not be reordered. However, it does
52 * not contain a memory barrier, so if it is used for locking purposes,
53 * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
54 * in order to ensure changes are visible on other processors.
57 #define clear_bit(nr, addr) (void)test_and_clear_bit(nr, addr)
60 * change_bit - Toggle a bit in memory
62 * @addr: Address to start counting from
64 * change_bit() is atomic and may not be reordered.
65 * Note that @nr may be almost arbitrarily large; this function is not
66 * restricted to acting on a single-word quantity.
69 #define change_bit(nr, addr) (void)test_and_change_bit(nr, addr)
72 * test_and_set_bit - Set a bit and return its old value
74 * @addr: Address to count from
76 * This operation is atomic and cannot be reordered.
77 * It also implies a memory barrier.
80 static inline int test_and_set_bit(int nr
, volatile unsigned long *addr
)
82 unsigned int mask
, retval
;
84 unsigned int *adr
= (unsigned int *)addr
;
87 mask
= 1 << (nr
& 0x1f);
88 cris_atomic_save(addr
, flags
);
89 retval
= (mask
& *adr
) != 0;
91 cris_atomic_restore(addr
, flags
);
96 * clear_bit() doesn't provide any barrier for the compiler.
98 #define smp_mb__before_clear_bit() barrier()
99 #define smp_mb__after_clear_bit() barrier()
102 * test_and_clear_bit - Clear a bit and return its old value
104 * @addr: Address to count from
106 * This operation is atomic and cannot be reordered.
107 * It also implies a memory barrier.
110 static inline int test_and_clear_bit(int nr
, volatile unsigned long *addr
)
112 unsigned int mask
, retval
;
114 unsigned int *adr
= (unsigned int *)addr
;
117 mask
= 1 << (nr
& 0x1f);
118 cris_atomic_save(addr
, flags
);
119 retval
= (mask
& *adr
) != 0;
121 cris_atomic_restore(addr
, flags
);
126 * test_and_change_bit - Change a bit and return its old value
128 * @addr: Address to count from
130 * This operation is atomic and cannot be reordered.
131 * It also implies a memory barrier.
134 static inline int test_and_change_bit(int nr
, volatile unsigned long *addr
)
136 unsigned int mask
, retval
;
138 unsigned int *adr
= (unsigned int *)addr
;
140 mask
= 1 << (nr
& 0x1f);
141 cris_atomic_save(addr
, flags
);
142 retval
= (mask
& *adr
) != 0;
144 cris_atomic_restore(addr
, flags
);
148 #include <asm-generic/bitops/non-atomic.h>
151 * Since we define it "external", it collides with the built-in
152 * definition, which doesn't have the same semantics. We don't want to
153 * use -fno-builtin, so just hide the name ffs.
155 #define ffs kernel_ffs
157 #include <asm-generic/bitops/fls.h>
158 #include <asm-generic/bitops/fls64.h>
159 #include <asm-generic/bitops/hweight.h>
160 #include <asm-generic/bitops/find.h>
161 #include <asm-generic/bitops/lock.h>
163 #include <asm-generic/bitops/ext2-non-atomic.h>
165 #define ext2_set_bit_atomic(l,n,a) test_and_set_bit(n,a)
166 #define ext2_clear_bit_atomic(l,n,a) test_and_clear_bit(n,a)
168 #include <asm-generic/bitops/minix.h>
169 #include <asm-generic/bitops/sched.h>
171 #endif /* __KERNEL__ */
173 #endif /* _CRIS_BITOPS_H */
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