1#ifndef _ASM_IA64_ATOMIC_H
2#define _ASM_IA64_ATOMIC_H
3
4/*
5 * Atomic operations that C can't guarantee us.  Useful for
6 * resource counting etc..
7 *
8 * NOTE: don't mess with the types below!  The "unsigned long" and
9 * "int" types were carefully placed so as to ensure proper operation
10 * of the macros.
11 *
12 * Copyright (C) 1998, 1999, 2002-2003 Hewlett-Packard Co
13 *	David Mosberger-Tang <davidm@hpl.hp.com>
14 */
15#include <linux/types.h>
16
17#include <asm/intrinsics.h>
18#include <asm/barrier.h>
19
20
21#define ATOMIC_INIT(i)		{ (i) }
22#define ATOMIC64_INIT(i)	{ (i) }
23
24#define atomic_read(v)		ACCESS_ONCE((v)->counter)
25#define atomic64_read(v)	ACCESS_ONCE((v)->counter)
26
27#define atomic_set(v,i)		(((v)->counter) = (i))
28#define atomic64_set(v,i)	(((v)->counter) = (i))
29
30#define ATOMIC_OP(op, c_op)						\
31static __inline__ int							\
32ia64_atomic_##op (int i, atomic_t *v)					\
33{									\
34	__s32 old, new;							\
35	CMPXCHG_BUGCHECK_DECL						\
36									\
37	do {								\
38		CMPXCHG_BUGCHECK(v);					\
39		old = atomic_read(v);					\
40		new = old c_op i;					\
41	} while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic_t)) != old); \
42	return new;							\
43}
44
45ATOMIC_OP(add, +)
46ATOMIC_OP(sub, -)
47
48#undef ATOMIC_OP
49
50#define atomic_add_return(i,v)						\
51({									\
52	int __ia64_aar_i = (i);						\
53	(__builtin_constant_p(i)					\
54	 && (   (__ia64_aar_i ==  1) || (__ia64_aar_i ==   4)		\
55	     || (__ia64_aar_i ==  8) || (__ia64_aar_i ==  16)		\
56	     || (__ia64_aar_i == -1) || (__ia64_aar_i ==  -4)		\
57	     || (__ia64_aar_i == -8) || (__ia64_aar_i == -16)))		\
58		? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter)	\
59		: ia64_atomic_add(__ia64_aar_i, v);			\
60})
61
62#define atomic_sub_return(i,v)						\
63({									\
64	int __ia64_asr_i = (i);						\
65	(__builtin_constant_p(i)					\
66	 && (   (__ia64_asr_i ==   1) || (__ia64_asr_i ==   4)		\
67	     || (__ia64_asr_i ==   8) || (__ia64_asr_i ==  16)		\
68	     || (__ia64_asr_i ==  -1) || (__ia64_asr_i ==  -4)		\
69	     || (__ia64_asr_i ==  -8) || (__ia64_asr_i == -16)))	\
70		? ia64_fetch_and_add(-__ia64_asr_i, &(v)->counter)	\
71		: ia64_atomic_sub(__ia64_asr_i, v);			\
72})
73
74#define ATOMIC64_OP(op, c_op)						\
75static __inline__ long							\
76ia64_atomic64_##op (__s64 i, atomic64_t *v)				\
77{									\
78	__s64 old, new;							\
79	CMPXCHG_BUGCHECK_DECL						\
80									\
81	do {								\
82		CMPXCHG_BUGCHECK(v);					\
83		old = atomic64_read(v);					\
84		new = old c_op i;					\
85	} while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic64_t)) != old); \
86	return new;							\
87}
88
89ATOMIC64_OP(add, +)
90ATOMIC64_OP(sub, -)
91
92#undef ATOMIC64_OP
93
94#define atomic64_add_return(i,v)					\
95({									\
96	long __ia64_aar_i = (i);					\
97	(__builtin_constant_p(i)					\
98	 && (   (__ia64_aar_i ==  1) || (__ia64_aar_i ==   4)		\
99	     || (__ia64_aar_i ==  8) || (__ia64_aar_i ==  16)		\
100	     || (__ia64_aar_i == -1) || (__ia64_aar_i ==  -4)		\
101	     || (__ia64_aar_i == -8) || (__ia64_aar_i == -16)))		\
102		? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter)	\
103		: ia64_atomic64_add(__ia64_aar_i, v);			\
104})
105
106#define atomic64_sub_return(i,v)					\
107({									\
108	long __ia64_asr_i = (i);					\
109	(__builtin_constant_p(i)					\
110	 && (   (__ia64_asr_i ==   1) || (__ia64_asr_i ==   4)		\
111	     || (__ia64_asr_i ==   8) || (__ia64_asr_i ==  16)		\
112	     || (__ia64_asr_i ==  -1) || (__ia64_asr_i ==  -4)		\
113	     || (__ia64_asr_i ==  -8) || (__ia64_asr_i == -16)))	\
114		? ia64_fetch_and_add(-__ia64_asr_i, &(v)->counter)	\
115		: ia64_atomic64_sub(__ia64_asr_i, v);			\
116})
117
118#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
119#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
120
121#define atomic64_cmpxchg(v, old, new) \
122	(cmpxchg(&((v)->counter), old, new))
123#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
124
125static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
126{
127	int c, old;
128	c = atomic_read(v);
129	for (;;) {
130		if (unlikely(c == (u)))
131			break;
132		old = atomic_cmpxchg((v), c, c + (a));
133		if (likely(old == c))
134			break;
135		c = old;
136	}
137	return c;
138}
139
140
141static __inline__ long atomic64_add_unless(atomic64_t *v, long a, long u)
142{
143	long c, old;
144	c = atomic64_read(v);
145	for (;;) {
146		if (unlikely(c == (u)))
147			break;
148		old = atomic64_cmpxchg((v), c, c + (a));
149		if (likely(old == c))
150			break;
151		c = old;
152	}
153	return c != (u);
154}
155
156#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
157
158/*
159 * Atomically add I to V and return TRUE if the resulting value is
160 * negative.
161 */
162static __inline__ int
163atomic_add_negative (int i, atomic_t *v)
164{
165	return atomic_add_return(i, v) < 0;
166}
167
168static __inline__ long
169atomic64_add_negative (__s64 i, atomic64_t *v)
170{
171	return atomic64_add_return(i, v) < 0;
172}
173
174#define atomic_dec_return(v)		atomic_sub_return(1, (v))
175#define atomic_inc_return(v)		atomic_add_return(1, (v))
176#define atomic64_dec_return(v)		atomic64_sub_return(1, (v))
177#define atomic64_inc_return(v)		atomic64_add_return(1, (v))
178
179#define atomic_sub_and_test(i,v)	(atomic_sub_return((i), (v)) == 0)
180#define atomic_dec_and_test(v)		(atomic_sub_return(1, (v)) == 0)
181#define atomic_inc_and_test(v)		(atomic_add_return(1, (v)) == 0)
182#define atomic64_sub_and_test(i,v)	(atomic64_sub_return((i), (v)) == 0)
183#define atomic64_dec_and_test(v)	(atomic64_sub_return(1, (v)) == 0)
184#define atomic64_inc_and_test(v)	(atomic64_add_return(1, (v)) == 0)
185
186#define atomic_add(i,v)			(void)atomic_add_return((i), (v))
187#define atomic_sub(i,v)			(void)atomic_sub_return((i), (v))
188#define atomic_inc(v)			atomic_add(1, (v))
189#define atomic_dec(v)			atomic_sub(1, (v))
190
191#define atomic64_add(i,v)		(void)atomic64_add_return((i), (v))
192#define atomic64_sub(i,v)		(void)atomic64_sub_return((i), (v))
193#define atomic64_inc(v)			atomic64_add(1, (v))
194#define atomic64_dec(v)			atomic64_sub(1, (v))
195
196#endif /* _ASM_IA64_ATOMIC_H */
197