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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) 1999-2003 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__ void atomic_add(int i, atomic_t * v)
49{
50 __CS_LOOP(v, i, "ar");
51}
52static __inline__ int atomic_add_return(int i, atomic_t * v)
53{
54 return __CS_LOOP(v, i, "ar");
55}
56static __inline__ int atomic_add_negative(int i, atomic_t * v)
57{
58 return __CS_LOOP(v, i, "ar") < 0;
59}
60static __inline__ void atomic_sub(int i, atomic_t * v)
61{
62 __CS_LOOP(v, i, "sr");
63}
64static __inline__ int atomic_sub_return(int i, atomic_t * v)
65{
66 return __CS_LOOP(v, i, "sr");
67}
68static __inline__ void atomic_inc(volatile atomic_t * v)
69{
70 __CS_LOOP(v, 1, "ar");
71}
72static __inline__ int atomic_inc_return(volatile atomic_t * v)
73{
74 return __CS_LOOP(v, 1, "ar");
75}
76
77static __inline__ int atomic_inc_and_test(volatile atomic_t * v)
78{
79 return __CS_LOOP(v, 1, "ar") == 0;
80}
81static __inline__ void atomic_dec(volatile atomic_t * v)
82{
83 __CS_LOOP(v, 1, "sr");
84}
85static __inline__ int atomic_dec_return(volatile atomic_t * v)
86{
87 return __CS_LOOP(v, 1, "sr");
88}
89static __inline__ int atomic_dec_and_test(volatile atomic_t * v)
90{
91 return __CS_LOOP(v, 1, "sr") == 0;
92}
93static __inline__ void atomic_clear_mask(unsigned long mask, atomic_t * v)
94{
95 __CS_LOOP(v, ~mask, "nr");
96}
97static __inline__ void atomic_set_mask(unsigned long mask, atomic_t * v)
98{
99 __CS_LOOP(v, mask, "or");
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__ void atomic64_add(long long i, atomic64_t * v)
127{
128 __CSG_LOOP(v, i, "agr");
129}
130static __inline__ long long atomic64_add_return(long long i, atomic64_t * v)
131{
132 return __CSG_LOOP(v, i, "agr");
133}
134static __inline__ long long atomic64_add_negative(long long i, atomic64_t * v)
135{
136 return __CSG_LOOP(v, i, "agr") < 0;
137}
138static __inline__ void atomic64_sub(long long i, atomic64_t * v)
139{
140 __CSG_LOOP(v, i, "sgr");
141}
142static __inline__ void atomic64_inc(volatile atomic64_t * v)
143{
144 __CSG_LOOP(v, 1, "agr");
145}
146static __inline__ long long atomic64_inc_return(volatile atomic64_t * v)
147{
148 return __CSG_LOOP(v, 1, "agr");
149}
150static __inline__ long long atomic64_inc_and_test(volatile atomic64_t * v)
151{
152 return __CSG_LOOP(v, 1, "agr") == 0;
153}
154static __inline__ void atomic64_dec(volatile atomic64_t * v)
155{
156 __CSG_LOOP(v, 1, "sgr");
157}
158static __inline__ long long atomic64_dec_return(volatile atomic64_t * v)
159{
160 return __CSG_LOOP(v, 1, "sgr");
161}
162static __inline__ long long atomic64_dec_and_test(volatile atomic64_t * v)
163{
164 return __CSG_LOOP(v, 1, "sgr") == 0;
165}
166static __inline__ void atomic64_clear_mask(unsigned long mask, atomic64_t * v)
167{
168 __CSG_LOOP(v, ~mask, "ngr");
169}
170static __inline__ void atomic64_set_mask(unsigned long mask, atomic64_t * v)
171{
172 __CSG_LOOP(v, mask, "ogr");
173}
174
175#undef __CSG_LOOP
176#endif
177
178/*
179 returns 0 if expected_oldval==value in *v ( swap was successful )
180 returns 1 if unsuccessful.
181
182 This is non-portable, use bitops or spinlocks instead!
183*/
184static __inline__ int
185atomic_compare_and_swap(int expected_oldval,int new_val,atomic_t *v)
186{
187 int retval;
188
189 __asm__ __volatile__(
190 " lr %0,%3\n"
191 " cs %0,%4,0(%2)\n"
192 " ipm %0\n"
193 " srl %0,28\n"
194 "0:"
195 : "=&d" (retval), "=m" (v->counter)
196 : "a" (v), "d" (expected_oldval) , "d" (new_val),
197 "m" (v->counter) : "cc", "memory" );
198 return retval;
199}
200
201#define smp_mb__before_atomic_dec() smp_mb()
202#define smp_mb__after_atomic_dec() smp_mb()
203#define smp_mb__before_atomic_inc() smp_mb()
204#define smp_mb__after_atomic_inc() smp_mb()
205
206#endif /* __KERNEL__ */
207#endif /* __ARCH_S390_ATOMIC__ */