1 /* $Id: atomic.h,v 1.22 2001/07/11 23:56:07 davem Exp $
2 * atomic.h: Thankfully the V9 is at least reasonable for this
5 * Copyright (C) 1996, 1997, 2000 David S. Miller (davem@redhat.com)
8 #ifndef __ARCH_SPARC64_ATOMIC__
9 #define __ARCH_SPARC64_ATOMIC__
11 #include <linux/config.h>
13 typedef struct { volatile int counter; } atomic_t;
14 #define ATOMIC_INIT(i) { (i) }
16 #define atomic_read(v) ((v)->counter)
17 #define atomic_set(v, i) (((v)->counter) = i)
19 extern void atomic_add(int, atomic_t *);
20 extern void atomic_sub(int, atomic_t *);
22 extern int atomic_add_ret(int, atomic_t *);
23 extern int atomic_sub_ret(int, atomic_t *);
25 #define atomic_dec_return(v) atomic_sub_ret(1, v)
27 #define atomic_inc_return(v) atomic_add_ret(1, v)
29 #define atomic_sub_return(i, v) atomic_sub_ret(i, v)
31 #define atomic_add_return(i, v) atomic_add_ret(i, v)
34 * atomic_inc_and_test - increment and test
35 * @v: pointer of type atomic_t
37 * Atomically increments @v by 1
38 * and returns true if the result is zero, or false for all
41 #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
43 #define atomic_sub_and_test(i, v) (atomic_sub_ret(i, v) == 0)
45 #define atomic_dec_and_test(v) (atomic_sub_ret(1, v) == 0)
47 #define atomic_inc(v) atomic_add(1, v)
49 #define atomic_dec(v) atomic_sub(1, v)
51 #define atomic_add_negative(i, v) (atomic_add_ret(i, v) < 0)
53 /* Atomic operations are already serializing */
55 #define smp_mb__before_atomic_dec() membar_safe("#StoreLoad | #LoadLoad")
56 #define smp_mb__after_atomic_dec() membar_safe("#StoreLoad | #StoreStore")
57 #define smp_mb__before_atomic_inc() membar_safe("#StoreLoad | #LoadLoad")
58 #define smp_mb__after_atomic_inc() membar_safe("#StoreLoad | #StoreStore")
60 #define smp_mb__before_atomic_dec() barrier()
61 #define smp_mb__after_atomic_dec() barrier()
62 #define smp_mb__before_atomic_inc() barrier()
63 #define smp_mb__after_atomic_inc() barrier()
66 #endif /* !(__ARCH_SPARC64_ATOMIC__) */