linux/arch/ia64/include/asm/atomic.h
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   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
  19
  20#define ATOMIC_INIT(i)          { (i) }
  21#define ATOMIC64_INIT(i)        { (i) }
  22
  23#define atomic_read(v)          ACCESS_ONCE((v)->counter)
  24#define atomic64_read(v)        ACCESS_ONCE((v)->counter)
  25
  26#define atomic_set(v,i)         (((v)->counter) = (i))
  27#define atomic64_set(v,i)       (((v)->counter) = (i))
  28
  29static __inline__ int
  30ia64_atomic_add (int i, atomic_t *v)
  31{
  32        __s32 old, new;
  33        CMPXCHG_BUGCHECK_DECL
  34
  35        do {
  36                CMPXCHG_BUGCHECK(v);
  37                old = atomic_read(v);
  38                new = old + i;
  39        } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic_t)) != old);
  40        return new;
  41}
  42
  43static __inline__ long
  44ia64_atomic64_add (__s64 i, atomic64_t *v)
  45{
  46        __s64 old, new;
  47        CMPXCHG_BUGCHECK_DECL
  48
  49        do {
  50                CMPXCHG_BUGCHECK(v);
  51                old = atomic64_read(v);
  52                new = old + i;
  53        } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic64_t)) != old);
  54        return new;
  55}
  56
  57static __inline__ int
  58ia64_atomic_sub (int i, atomic_t *v)
  59{
  60        __s32 old, new;
  61        CMPXCHG_BUGCHECK_DECL
  62
  63        do {
  64                CMPXCHG_BUGCHECK(v);
  65                old = atomic_read(v);
  66                new = old - i;
  67        } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic_t)) != old);
  68        return new;
  69}
  70
  71static __inline__ long
  72ia64_atomic64_sub (__s64 i, atomic64_t *v)
  73{
  74        __s64 old, new;
  75        CMPXCHG_BUGCHECK_DECL
  76
  77        do {
  78                CMPXCHG_BUGCHECK(v);
  79                old = atomic64_read(v);
  80                new = old - i;
  81        } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic64_t)) != old);
  82        return new;
  83}
  84
  85#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
  86#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
  87
  88#define atomic64_cmpxchg(v, old, new) \
  89        (cmpxchg(&((v)->counter), old, new))
  90#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
  91
  92static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
  93{
  94        int c, old;
  95        c = atomic_read(v);
  96        for (;;) {
  97                if (unlikely(c == (u)))
  98                        break;
  99                old = atomic_cmpxchg((v), c, c + (a));
 100                if (likely(old == c))
 101                        break;
 102                c = old;
 103        }
 104        return c;
 105}
 106
 107
 108static __inline__ long atomic64_add_unless(atomic64_t *v, long a, long u)
 109{
 110        long c, old;
 111        c = atomic64_read(v);
 112        for (;;) {
 113                if (unlikely(c == (u)))
 114                        break;
 115                old = atomic64_cmpxchg((v), c, c + (a));
 116                if (likely(old == c))
 117                        break;
 118                c = old;
 119        }
 120        return c != (u);
 121}
 122
 123#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
 124
 125#define atomic_add_return(i,v)                                          \
 126({                                                                      \
 127        int __ia64_aar_i = (i);                                         \
 128        (__builtin_constant_p(i)                                        \
 129         && (   (__ia64_aar_i ==  1) || (__ia64_aar_i ==   4)           \
 130             || (__ia64_aar_i ==  8) || (__ia64_aar_i ==  16)           \
 131             || (__ia64_aar_i == -1) || (__ia64_aar_i ==  -4)           \
 132             || (__ia64_aar_i == -8) || (__ia64_aar_i == -16)))         \
 133                ? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter)       \
 134                : ia64_atomic_add(__ia64_aar_i, v);                     \
 135})
 136
 137#define atomic64_add_return(i,v)                                        \
 138({                                                                      \
 139        long __ia64_aar_i = (i);                                        \
 140        (__builtin_constant_p(i)                                        \
 141         && (   (__ia64_aar_i ==  1) || (__ia64_aar_i ==   4)           \
 142             || (__ia64_aar_i ==  8) || (__ia64_aar_i ==  16)           \
 143             || (__ia64_aar_i == -1) || (__ia64_aar_i ==  -4)           \
 144             || (__ia64_aar_i == -8) || (__ia64_aar_i == -16)))         \
 145                ? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter)       \
 146                : ia64_atomic64_add(__ia64_aar_i, v);                   \
 147})
 148
 149/*
 150 * Atomically add I to V and return TRUE if the resulting value is
 151 * negative.
 152 */
 153static __inline__ int
 154atomic_add_negative (int i, atomic_t *v)
 155{
 156        return atomic_add_return(i, v) < 0;
 157}
 158
 159static __inline__ long
 160atomic64_add_negative (__s64 i, atomic64_t *v)
 161{
 162        return atomic64_add_return(i, v) < 0;
 163}
 164
 165#define atomic_sub_return(i,v)                                          \
 166({                                                                      \
 167        int __ia64_asr_i = (i);                                         \
 168        (__builtin_constant_p(i)                                        \
 169         && (   (__ia64_asr_i ==   1) || (__ia64_asr_i ==   4)          \
 170             || (__ia64_asr_i ==   8) || (__ia64_asr_i ==  16)          \
 171             || (__ia64_asr_i ==  -1) || (__ia64_asr_i ==  -4)          \
 172             || (__ia64_asr_i ==  -8) || (__ia64_asr_i == -16)))        \
 173                ? ia64_fetch_and_add(-__ia64_asr_i, &(v)->counter)      \
 174                : ia64_atomic_sub(__ia64_asr_i, v);                     \
 175})
 176
 177#define atomic64_sub_return(i,v)                                        \
 178({                                                                      \
 179        long __ia64_asr_i = (i);                                        \
 180        (__builtin_constant_p(i)                                        \
 181         && (   (__ia64_asr_i ==   1) || (__ia64_asr_i ==   4)          \
 182             || (__ia64_asr_i ==   8) || (__ia64_asr_i ==  16)          \
 183             || (__ia64_asr_i ==  -1) || (__ia64_asr_i ==  -4)          \
 184             || (__ia64_asr_i ==  -8) || (__ia64_asr_i == -16)))        \
 185                ? ia64_fetch_and_add(-__ia64_asr_i, &(v)->counter)      \
 186                : ia64_atomic64_sub(__ia64_asr_i, v);                   \
 187})
 188
 189#define atomic_dec_return(v)            atomic_sub_return(1, (v))
 190#define atomic_inc_return(v)            atomic_add_return(1, (v))
 191#define atomic64_dec_return(v)          atomic64_sub_return(1, (v))
 192#define atomic64_inc_return(v)          atomic64_add_return(1, (v))
 193
 194#define atomic_sub_and_test(i,v)        (atomic_sub_return((i), (v)) == 0)
 195#define atomic_dec_and_test(v)          (atomic_sub_return(1, (v)) == 0)
 196#define atomic_inc_and_test(v)          (atomic_add_return(1, (v)) == 0)
 197#define atomic64_sub_and_test(i,v)      (atomic64_sub_return((i), (v)) == 0)
 198#define atomic64_dec_and_test(v)        (atomic64_sub_return(1, (v)) == 0)
 199#define atomic64_inc_and_test(v)        (atomic64_add_return(1, (v)) == 0)
 200
 201#define atomic_add(i,v)                 atomic_add_return((i), (v))
 202#define atomic_sub(i,v)                 atomic_sub_return((i), (v))
 203#define atomic_inc(v)                   atomic_add(1, (v))
 204#define atomic_dec(v)                   atomic_sub(1, (v))
 205
 206#define atomic64_add(i,v)               atomic64_add_return((i), (v))
 207#define atomic64_sub(i,v)               atomic64_sub_return((i), (v))
 208#define atomic64_inc(v)                 atomic64_add(1, (v))
 209#define atomic64_dec(v)                 atomic64_sub(1, (v))
 210
 211/* Atomic operations are already serializing */
 212#define smp_mb__before_atomic_dec()     barrier()
 213#define smp_mb__after_atomic_dec()      barrier()
 214#define smp_mb__before_atomic_inc()     barrier()
 215#define smp_mb__after_atomic_inc()      barrier()
 216
 217#endif /* _ASM_IA64_ATOMIC_H */
 218