arch/frv/include/asm/atomic.h

   1 /* atomic.h: atomic operation emulation for FR-V
   2  *
   3  * For an explanation of how atomic ops work in this arch, see:
   4  *   Documentation/frv/atomic-ops.txt
   5  *
   6  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
   7  * Written by David Howells (dhowells@redhat.com)
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation; either version
  12  * 2 of the License, or (at your option) any later version.
  13  */
  14 #ifndef _ASM_ATOMIC_H
  15 #define _ASM_ATOMIC_H
  16
  17 #include <linux/types.h>
  18 #include <asm/cmpxchg.h>
  19 #include <asm/barrier.h>
  20
  21 #ifdef CONFIG_SMP
  22 #error not SMP safe
  23 #endif
  24
  25 #include <asm/atomic_defs.h>
  26
  27 /*
  28  * Atomic operations that C can't guarantee us.  Useful for
  29  * resource counting etc..
  30  *
  31  * We do not have SMP systems, so we don't have to deal with that.
  32  */
  33
  34 #define ATOMIC_INIT(i)          { (i) }
  35 #define atomic_read(v)          READ_ONCE((v)->counter)
  36 #define atomic_set(v, i)        WRITE_ONCE(((v)->counter), (i))
  37
  38 static inline int atomic_inc_return(atomic_t *v)
  39 {
  40         return __atomic_add_return(1, &v->counter);
  41 }
  42
  43 static inline int atomic_dec_return(atomic_t *v)
  44 {
  45         return __atomic_sub_return(1, &v->counter);
  46 }
  47
  48 static inline int atomic_add_return(int i, atomic_t *v)
  49 {
  50         return __atomic_add_return(i, &v->counter);
  51 }
  52
  53 static inline int atomic_sub_return(int i, atomic_t *v)
  54 {
  55         return __atomic_sub_return(i, &v->counter);
  56 }
  57
  58 static inline int atomic_add_negative(int i, atomic_t *v)
  59 {
  60         return atomic_add_return(i, v) < 0;
  61 }
  62
  63 static inline void atomic_add(int i, atomic_t *v)
  64 {
  65         atomic_add_return(i, v);
  66 }
  67
  68 static inline void atomic_sub(int i, atomic_t *v)
  69 {
  70         atomic_sub_return(i, v);
  71 }
  72
  73 static inline void atomic_inc(atomic_t *v)
  74 {
  75         atomic_inc_return(v);
  76 }
  77
  78 static inline void atomic_dec(atomic_t *v)
  79 {
  80         atomic_dec_return(v);
  81 }
  82
  83 #define atomic_sub_and_test(i,v)        (atomic_sub_return((i), (v)) == 0)
  84 #define atomic_dec_and_test(v)          (atomic_sub_return(1, (v)) == 0)
  85 #define atomic_inc_and_test(v)          (atomic_add_return(1, (v)) == 0)
  86
  87 /*
  88  * 64-bit atomic ops
  89  */
  90 typedef struct {
  91         long long counter;
  92 } atomic64_t;
  93
  94 #define ATOMIC64_INIT(i)        { (i) }
  95
  96 static inline long long atomic64_read(const atomic64_t *v)
  97 {
  98         long long counter;
  99
 100         asm("ldd%I1 %M1,%0"
 101             : "=e"(counter)
 102             : "m"(v->counter));
 103
 104         return counter;
 105 }
 106
 107 static inline void atomic64_set(atomic64_t *v, long long i)
 108 {
 109         asm volatile("std%I0 %1,%M0"
 110                      : "=m"(v->counter)
 111                      : "e"(i));
 112 }
 113
 114 static inline long long atomic64_inc_return(atomic64_t *v)
 115 {
 116         return __atomic64_add_return(1, &v->counter);
 117 }
 118
 119 static inline long long atomic64_dec_return(atomic64_t *v)
 120 {
 121         return __atomic64_sub_return(1, &v->counter);
 122 }
 123
 124 static inline long long atomic64_add_return(long long i, atomic64_t *v)
 125 {
 126         return __atomic64_add_return(i, &v->counter);
 127 }
 128
 129 static inline long long atomic64_sub_return(long long i, atomic64_t *v)
 130 {
 131         return __atomic64_sub_return(i, &v->counter);
 132 }
 133
 134 static inline long long atomic64_add_negative(long long i, atomic64_t *v)
 135 {
 136         return atomic64_add_return(i, v) < 0;
 137 }
 138
 139 static inline void atomic64_add(long long i, atomic64_t *v)
 140 {
 141         atomic64_add_return(i, v);
 142 }
 143
 144 static inline void atomic64_sub(long long i, atomic64_t *v)
 145 {
 146         atomic64_sub_return(i, v);
 147 }
 148
 149 static inline void atomic64_inc(atomic64_t *v)
 150 {
 151         atomic64_inc_return(v);
 152 }
 153
 154 static inline void atomic64_dec(atomic64_t *v)
 155 {
 156         atomic64_dec_return(v);
 157 }
 158
 159 #define atomic64_sub_and_test(i,v)      (atomic64_sub_return((i), (v)) == 0)
 160 #define atomic64_dec_and_test(v)        (atomic64_dec_return((v)) == 0)
 161 #define atomic64_inc_and_test(v)        (atomic64_inc_return((v)) == 0)
 162
 163
 164 #define atomic_cmpxchg(v, old, new)     (cmpxchg(&(v)->counter, old, new))
 165 #define atomic_xchg(v, new)             (xchg(&(v)->counter, new))
 166 #define atomic64_cmpxchg(v, old, new)   (__cmpxchg_64(old, new, &(v)->counter))
 167 #define atomic64_xchg(v, new)           (__xchg_64(new, &(v)->counter))
 168
 169 static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
 170 {
 171         int c, old;
 172         c = atomic_read(v);
 173         for (;;) {
 174                 if (unlikely(c == (u)))
 175                         break;
 176                 old = atomic_cmpxchg((v), c, c + (a));
 177                 if (likely(old == c))
 178                         break;
 179                 c = old;
 180         }
 181         return c;
 182 }
 183
 184 #define ATOMIC_OP(op)                                                   \
 185 static inline void atomic_##op(int i, atomic_t *v)                      \
 186 {                                                                       \
 187         (void)__atomic32_fetch_##op(i, &v->counter);                    \
 188 }                                                                       \
 189                                                                         \
 190 static inline void atomic64_##op(long long i, atomic64_t *v)            \
 191 {                                                                       \
 192         (void)__atomic64_fetch_##op(i, &v->counter);                    \
 193 }
 194
 195 ATOMIC_OP(or)
 196 ATOMIC_OP(and)
 197 ATOMIC_OP(xor)
 198
 199 #undef ATOMIC_OP
 200
 201 #endif /* _ASM_ATOMIC_H */