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1#ifndef __ARCH_S390_ATOMIC__
2#define __ARCH_S390_ATOMIC__
3
4/*
5 * include/asm-s390/atomic.h
6 *
7 * S390 version
8 * Copyright (C) 1999-2005 IBM Deutschland Entwicklung GmbH, IBM Corporation
9 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
10 * Denis Joseph Barrow,
11 * Arnd Bergmann (arndb@de.ibm.com)
12 *
13 * Derived from "include/asm-i386/bitops.h"
14 * Copyright (C) 1992, Linus Torvalds
15 *
16 */
17
18/*
19 * Atomic operations that C can't guarantee us. Useful for
20 * resource counting etc..
21 * S390 uses 'Compare And Swap' for atomicity in SMP enviroment
22 */
23
24typedef struct {
25 volatile int counter;
26} __attribute__ ((aligned (4))) atomic_t;
27#define ATOMIC_INIT(i) { (i) }
28
29#ifdef __KERNEL__
30
31#define __CS_LOOP(ptr, op_val, op_string) ({ \
32 typeof(ptr->counter) old_val, new_val; \
33 __asm__ __volatile__(" l %0,0(%3)\n" \
34 "0: lr %1,%0\n" \
35 op_string " %1,%4\n" \
36 " cs %0,%1,0(%3)\n" \
37 " jl 0b" \
38 : "=&d" (old_val), "=&d" (new_val), \
39 "=m" (((atomic_t *)(ptr))->counter) \
40 : "a" (ptr), "d" (op_val), \
41 "m" (((atomic_t *)(ptr))->counter) \
42 : "cc", "memory" ); \
43 new_val; \
44})
45#define atomic_read(v) ((v)->counter)
46#define atomic_set(v,i) (((v)->counter) = (i))
47
48static __inline__ int atomic_add_return(int i, atomic_t * v)
49{
50 return __CS_LOOP(v, i, "ar");
51}
52#define atomic_add(_i, _v) atomic_add_return(_i, _v)
53#define atomic_add_negative(_i, _v) (atomic_add_return(_i, _v) < 0)
54#define atomic_inc(_v) atomic_add_return(1, _v)
55#define atomic_inc_return(_v) atomic_add_return(1, _v)
56#define atomic_inc_and_test(_v) (atomic_add_return(1, _v) == 0)
57
58static __inline__ int atomic_sub_return(int i, atomic_t * v)
59{
60 return __CS_LOOP(v, i, "sr");
61}
62#define atomic_sub(_i, _v) atomic_sub_return(_i, _v)
63#define atomic_sub_and_test(_i, _v) (atomic_sub_return(_i, _v) == 0)
64#define atomic_dec(_v) atomic_sub_return(1, _v)
65#define atomic_dec_return(_v) atomic_sub_return(1, _v)
66#define atomic_dec_and_test(_v) (atomic_sub_return(1, _v) == 0)
67
68static __inline__ void atomic_clear_mask(unsigned long mask, atomic_t * v)
69{
70 __CS_LOOP(v, ~mask, "nr");
71}
72
73static __inline__ void atomic_set_mask(unsigned long mask, atomic_t * v)
74{
75 __CS_LOOP(v, mask, "or");
76}
77
78#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
79
80static __inline__ int atomic_cmpxchg(atomic_t *v, int old, int new)
81{
82 __asm__ __volatile__(" cs %0,%3,0(%2)\n"
83 : "+d" (old), "=m" (v->counter)
84 : "a" (v), "d" (new), "m" (v->counter)
85 : "cc", "memory" );
86 return old;
87}
88
89static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
90{
91 int c, old;
92
93 c = atomic_read(v);
94 while (c != u && (old = atomic_cmpxchg(v, c, c + a)) != c)
95 c = old;
96 return c != u;
97}
98
99#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
100
101#undef __CS_LOOP
102
103#ifdef __s390x__
104typedef struct {
105 volatile long long counter;
106} __attribute__ ((aligned (8))) atomic64_t;
107#define ATOMIC64_INIT(i) { (i) }
108
109#define __CSG_LOOP(ptr, op_val, op_string) ({ \
110 typeof(ptr->counter) old_val, new_val; \
111 __asm__ __volatile__(" lg %0,0(%3)\n" \
112 "0: lgr %1,%0\n" \
113 op_string " %1,%4\n" \
114 " csg %0,%1,0(%3)\n" \
115 " jl 0b" \
116 : "=&d" (old_val), "=&d" (new_val), \
117 "=m" (((atomic_t *)(ptr))->counter) \
118 : "a" (ptr), "d" (op_val), \
119 "m" (((atomic_t *)(ptr))->counter) \
120 : "cc", "memory" ); \
121 new_val; \
122})
123#define atomic64_read(v) ((v)->counter)
124#define atomic64_set(v,i) (((v)->counter) = (i))
125
126static __inline__ long long atomic64_add_return(long long i, atomic64_t * v)
127{
128 return __CSG_LOOP(v, i, "agr");
129}
130#define atomic64_add(_i, _v) atomic64_add_return(_i, _v)
131#define atomic64_add_negative(_i, _v) (atomic64_add_return(_i, _v) < 0)
132#define atomic64_inc(_v) atomic64_add_return(1, _v)
133#define atomic64_inc_return(_v) atomic64_add_return(1, _v)
134#define atomic64_inc_and_test(_v) (atomic64_add_return(1, _v) == 0)
135
136static __inline__ long long atomic64_sub_return(long long i, atomic64_t * v)
137{
138 return __CSG_LOOP(v, i, "sgr");
139}
140#define atomic64_sub(_i, _v) atomic64_sub_return(_i, _v)
141#define atomic64_sub_and_test(_i, _v) (atomic64_sub_return(_i, _v) == 0)
142#define atomic64_dec(_v) atomic64_sub_return(1, _v)
143#define atomic64_dec_return(_v) atomic64_sub_return(1, _v)
144#define atomic64_dec_and_test(_v) (atomic64_sub_return(1, _v) == 0)
145
146static __inline__ void atomic64_clear_mask(unsigned long mask, atomic64_t * v)
147{
148 __CSG_LOOP(v, ~mask, "ngr");
149}
150
151static __inline__ void atomic64_set_mask(unsigned long mask, atomic64_t * v)
152{
153 __CSG_LOOP(v, mask, "ogr");
154}
155
156static __inline__ long long atomic64_cmpxchg(atomic64_t *v,
157 long long old, long long new)
158{
159 __asm__ __volatile__(" csg %0,%3,0(%2)\n"
160 : "+d" (old), "=m" (v->counter)
161 : "a" (v), "d" (new), "m" (v->counter)
162 : "cc", "memory" );
163 return old;
164}
165
166static __inline__ int atomic64_add_unless(atomic64_t *v,
167 long long a, long long u)
168{
169 long long c, old;
170
171 c = atomic64_read(v);
172 while (c != u && (old = atomic64_cmpxchg(v, c, c + a)) != c)
173 c = old;
174 return c != u;
175}
176
177#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
178
179#undef __CSG_LOOP
180#endif
181
182#define smp_mb__before_atomic_dec() smp_mb()
183#define smp_mb__after_atomic_dec() smp_mb()
184#define smp_mb__before_atomic_inc() smp_mb()
185#define smp_mb__after_atomic_inc() smp_mb()
186
187#include <asm-generic/atomic.h>
188#endif /* __KERNEL__ */
189#endif /* __ARCH_S390_ATOMIC__ */