1 /* $Id: atomic.h,v 1.3 2001/07/25 16:15:19 bjornw Exp $ */
3 #ifndef __ASM_CRIS_ATOMIC__
4 #define __ASM_CRIS_ATOMIC__
6 #include <asm/system.h>
9 * Atomic operations that C can't guarantee us. Useful for
10 * resource counting etc..
14 * Make sure gcc doesn't try to be clever and move things around
15 * on us. We need to use _exactly_ the address the user gave us,
16 * not some alias that contains the same information.
19 #define __atomic_fool_gcc(x) (*(struct { int a[100]; } *)x)
21 typedef struct { int counter; } atomic_t;
23 #define ATOMIC_INIT(i) { (i) }
25 #define atomic_read(v) ((v)->counter)
26 #define atomic_set(v,i) (((v)->counter) = (i))
28 /* These should be written in asm but we do it in C for now. */
30 extern __inline__ void atomic_add(int i, volatile atomic_t *v)
33 local_save_flags(flags);
36 local_irq_restore(flags);
39 extern __inline__ void atomic_sub(int i, volatile atomic_t *v)
42 local_save_flags(flags);
45 local_irq_restore(flags);
48 extern __inline__ int atomic_add_return(int i, volatile atomic_t *v)
52 local_save_flags(flags);
54 retval = (v->counter += i);
55 local_irq_restore(flags);
59 extern __inline__ int atomic_sub_return(int i, volatile atomic_t *v)
63 local_save_flags(flags);
65 retval = (v->counter -= i);
66 local_irq_restore(flags);
70 extern __inline__ int atomic_sub_and_test(int i, volatile atomic_t *v)
74 local_save_flags(flags);
76 retval = (v->counter -= i) == 0;
77 local_irq_restore(flags);
81 extern __inline__ void atomic_inc(volatile atomic_t *v)
84 local_save_flags(flags);
87 local_irq_restore(flags);
90 extern __inline__ void atomic_dec(volatile atomic_t *v)
93 local_save_flags(flags);
96 local_irq_restore(flags);
99 extern __inline__ int atomic_inc_return(volatile atomic_t *v)
103 local_save_flags(flags);
105 retval = (v->counter)++;
106 local_irq_restore(flags);
110 extern __inline__ int atomic_dec_return(volatile atomic_t *v)
114 local_save_flags(flags);
116 retval = (v->counter)--;
117 local_irq_restore(flags);
120 extern __inline__ int atomic_dec_and_test(volatile atomic_t *v)
124 local_save_flags(flags);
126 retval = --(v->counter) == 0;
127 local_irq_restore(flags);
131 extern __inline__ int atomic_inc_and_test(volatile atomic_t *v)
135 local_save_flags(flags);
137 retval = ++(v->counter) == 0;
138 local_irq_restore(flags);
142 /* Atomic operations are already serializing */
143 #define smp_mb__before_atomic_dec() barrier()
144 #define smp_mb__after_atomic_dec() barrier()
145 #define smp_mb__before_atomic_inc() barrier()
146 #define smp_mb__after_atomic_inc() barrier()