1 /* atomic.h: These still suck, but the I-cache hit rate is higher.
2  *
3  * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
4  * Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com.au)
5  * Copyright (C) 2007 Kyle McMartin (kyle@parisc-linux.org)
6  *
7  * Additions by Keith M Wesolowski (wesolows@foobazco.org) based
8  * on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>.
9  */
10 
11 #ifndef __ARCH_SPARC_ATOMIC__
12 #define __ARCH_SPARC_ATOMIC__
13 
14 #include <linux/types.h>
15 
16 #include <asm/cmpxchg.h>
17 #include <asm-generic/atomic64.h>
18 
19 
20 #define ATOMIC_INIT(i)  { (i) }
21 
22 extern int __atomic_add_return(int, atomic_t *);
23 extern int atomic_cmpxchg(atomic_t *, int, int);
24 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
25 extern int __atomic_add_unless(atomic_t *, int, int);
26 extern void atomic_set(atomic_t *, int);
27 
28 #define atomic_read(v)          (*(volatile int *)&(v)->counter)
29 
30 #define atomic_add(i, v)	((void)__atomic_add_return( (int)(i), (v)))
31 #define atomic_sub(i, v)	((void)__atomic_add_return(-(int)(i), (v)))
32 #define atomic_inc(v)		((void)__atomic_add_return(        1, (v)))
33 #define atomic_dec(v)		((void)__atomic_add_return(       -1, (v)))
34 
35 #define atomic_add_return(i, v)	(__atomic_add_return( (int)(i), (v)))
36 #define atomic_sub_return(i, v)	(__atomic_add_return(-(int)(i), (v)))
37 #define atomic_inc_return(v)	(__atomic_add_return(        1, (v)))
38 #define atomic_dec_return(v)	(__atomic_add_return(       -1, (v)))
39 
40 #define atomic_add_negative(a, v)	(atomic_add_return((a), (v)) < 0)
41 
42 /*
43  * atomic_inc_and_test - increment and test
44  * @v: pointer of type atomic_t
45  *
46  * Atomically increments @v by 1
47  * and returns true if the result is zero, or false for all
48  * other cases.
49  */
50 #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
51 
52 #define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
53 #define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
54 
55 /* Atomic operations are already serializing */
56 #define smp_mb__before_atomic_dec()	barrier()
57 #define smp_mb__after_atomic_dec()	barrier()
58 #define smp_mb__before_atomic_inc()	barrier()
59 #define smp_mb__after_atomic_inc()	barrier()
60 
61 #endif /* !(__ARCH_SPARC_ATOMIC__) */
62