arch/ia64/include/asm/atomic.h

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