1/* $Id: atomic.h,v 1.1.1.1 2008/10/15 03:27:16 james26_jang Exp $ */
2
3#ifndef __ASM_CRIS_ATOMIC__
4#define __ASM_CRIS_ATOMIC__
5
6#include <asm/system.h>
7
8/*
9 * Atomic operations that C can't guarantee us.  Useful for
10 * resource counting etc..
11 */
12
13/*
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.
17 */
18
19#define __atomic_fool_gcc(x) (*(struct { int a[100]; } *)x)
20
21typedef struct { int counter; } atomic_t;
22
23#define ATOMIC_INIT(i)  { (i) }
24
25#define atomic_read(v) ((v)->counter)
26#define atomic_set(v,i) (((v)->counter) = (i))
27
28/* These should be written in asm but we do it in C for now. */
29
30static __inline__ void atomic_add(int i, volatile atomic_t *v)
31{
32	unsigned long flags;
33	save_flags(flags);
34	cli();
35	v->counter += i;
36	restore_flags(flags);
37}
38
39static __inline__ void atomic_sub(int i, volatile atomic_t *v)
40{
41	unsigned long flags;
42	save_flags(flags);
43	cli();
44	v->counter -= i;
45	restore_flags(flags);
46}
47
48static __inline__ int atomic_add_return(int i, volatile atomic_t *v)
49{
50	unsigned long flags;
51	int retval;
52	save_flags(flags);
53	cli();
54	retval = (v->counter += i);
55	restore_flags(flags);
56	return retval;
57}
58
59static __inline__ int atomic_sub_return(int i, volatile atomic_t *v)
60{
61	unsigned long flags;
62	int retval;
63	save_flags(flags);
64	cli();
65	retval = (v->counter -= i);
66	restore_flags(flags);
67	return retval;
68}
69
70static __inline__ int atomic_sub_and_test(int i, volatile atomic_t *v)
71{
72	int retval;
73	unsigned long flags;
74	save_flags(flags);
75	cli();
76	retval = (v->counter -= i) == 0;
77	restore_flags(flags);
78	return retval;
79}
80
81static __inline__ void atomic_inc(volatile atomic_t *v)
82{
83	unsigned long flags;
84	save_flags(flags);
85	cli();
86	(v->counter)++;
87	restore_flags(flags);
88}
89
90static __inline__ void atomic_dec(volatile atomic_t *v)
91{
92	unsigned long flags;
93	save_flags(flags);
94	cli();
95	(v->counter)--;
96	restore_flags(flags);
97}
98
99static __inline__ int atomic_inc_return(volatile atomic_t *v)
100{
101	unsigned long flags;
102	int retval;
103	save_flags(flags);
104	cli();
105	retval = (v->counter)++;
106	restore_flags(flags);
107	return retval;
108}
109
110static __inline__ int atomic_dec_return(volatile atomic_t *v)
111{
112	unsigned long flags;
113	int retval;
114	save_flags(flags);
115	cli();
116	retval = (v->counter)--;
117	restore_flags(flags);
118	return retval;
119}
120static __inline__ int atomic_dec_and_test(volatile atomic_t *v)
121{
122	int retval;
123	unsigned long flags;
124	save_flags(flags);
125	cli();
126	retval = --(v->counter) == 0;
127	restore_flags(flags);
128	return retval;
129}
130
131static __inline__ int atomic_inc_and_test(volatile atomic_t *v)
132{
133	int retval;
134	unsigned long flags;
135	save_flags(flags);
136	cli();
137	retval = ++(v->counter) == 0;
138	restore_flags(flags);
139	return retval;
140}
141
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()
147
148#endif
149