include/asm-ia64/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  * On IA-64, counter must always be volatile to ensure that that the
  22  * memory accesses are ordered.
  23  */
  24 typedef struct { volatile __s32 counter; } atomic_t;
  25 typedef struct { volatile __s64 counter; } atomic64_t;
  26
  27 #define ATOMIC_INIT(i)          ((atomic_t) { (i) })
  28 #define ATOMIC64_INIT(i)        ((atomic64_t) { (i) })
  29
  30 #define atomic_read(v)          ((v)->counter)
  31 #define atomic64_read(v)        ((v)->counter)
  32
  33 #define atomic_set(v,i)         (((v)->counter) = (i))
  34 #define atomic64_set(v,i)       (((v)->counter) = (i))
  35
  36 static __inline__ int
  37 ia64_atomic_add (int i, atomic_t *v)
  38 {
  39         __s32 old, new;
  40         CMPXCHG_BUGCHECK_DECL
  41
  42         do {
  43                 CMPXCHG_BUGCHECK(v);
  44                 old = atomic_read(v);
  45                 new = old + i;
  46         } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic_t)) != old);
  47         return new;
  48 }
  49
  50 static __inline__ int
  51 ia64_atomic64_add (__s64 i, atomic64_t *v)
  52 {
  53         __s64 old, new;
  54         CMPXCHG_BUGCHECK_DECL
  55
  56         do {
  57                 CMPXCHG_BUGCHECK(v);
  58                 old = atomic64_read(v);
  59                 new = old + i;
  60         } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic64_t)) != old);
  61         return new;
  62 }
  63
  64 static __inline__ int
  65 ia64_atomic_sub (int i, atomic_t *v)
  66 {
  67         __s32 old, new;
  68         CMPXCHG_BUGCHECK_DECL
  69
  70         do {
  71                 CMPXCHG_BUGCHECK(v);
  72                 old = atomic_read(v);
  73                 new = old - i;
  74         } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic_t)) != old);
  75         return new;
  76 }
  77
  78 static __inline__ int
  79 ia64_atomic64_sub (__s64 i, atomic64_t *v)
  80 {
  81         __s64 old, new;
  82         CMPXCHG_BUGCHECK_DECL
  83
  84         do {
  85                 CMPXCHG_BUGCHECK(v);
  86                 old = atomic64_read(v);
  87                 new = old - i;
  88         } while (ia64_cmpxchg(acq, v, old, new, sizeof(atomic64_t)) != old);
  89         return new;
  90 }
  91
  92 #define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
  93 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
  94
  95 #define atomic64_cmpxchg(v, old, new) \
  96         (cmpxchg(&((v)->counter), old, new))
  97 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
  98
  99 static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
 100 {
 101         int c, old;
 102         c = atomic_read(v);
 103         for (;;) {
 104                 if (unlikely(c == (u)))
 105                         break;
 106                 old = atomic_cmpxchg((v), c, c + (a));
 107                 if (likely(old == c))
 108                         break;
 109                 c = old;
 110         }
 111         return c != (u);
 112 }
 113
 114 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
 115
 116 static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
 117 {
 118         long c, old;
 119         c = atomic64_read(v);
 120         for (;;) {
 121                 if (unlikely(c == (u)))
 122                         break;
 123                 old = atomic64_cmpxchg((v), c, c + (a));
 124                 if (likely(old == c))
 125                         break;
 126                 c = old;
 127         }
 128         return c != (u);
 129 }
 130
 131 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
 132
 133 #define atomic_add_return(i,v)                                          \
 134 ({                                                                      \
 135         int __ia64_aar_i = (i);                                         \
 136         (__builtin_constant_p(i)                                        \
 137          && (   (__ia64_aar_i ==  1) || (__ia64_aar_i ==   4)           \
 138              || (__ia64_aar_i ==  8) || (__ia64_aar_i ==  16)           \
 139              || (__ia64_aar_i == -1) || (__ia64_aar_i ==  -4)           \
 140              || (__ia64_aar_i == -8) || (__ia64_aar_i == -16)))         \
 141                 ? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter)       \
 142                 : ia64_atomic_add(__ia64_aar_i, v);                     \
 143 })
 144
 145 #define atomic64_add_return(i,v)                                        \
 146 ({                                                                      \
 147         long __ia64_aar_i = (i);                                        \
 148         (__builtin_constant_p(i)                                        \
 149          && (   (__ia64_aar_i ==  1) || (__ia64_aar_i ==   4)           \
 150              || (__ia64_aar_i ==  8) || (__ia64_aar_i ==  16)           \
 151              || (__ia64_aar_i == -1) || (__ia64_aar_i ==  -4)           \
 152              || (__ia64_aar_i == -8) || (__ia64_aar_i == -16)))         \
 153                 ? ia64_fetch_and_add(__ia64_aar_i, &(v)->counter)       \
 154                 : ia64_atomic64_add(__ia64_aar_i, v);                   \
 155 })
 156
 157 /*
 158  * Atomically add I to V and return TRUE if the resulting value is
 159  * negative.
 160  */
 161 static __inline__ int
 162 atomic_add_negative (int i, atomic_t *v)
 163 {
 164         return atomic_add_return(i, v) < 0;
 165 }
 166
 167 static __inline__ int
 168 atomic64_add_negative (__s64 i, atomic64_t *v)
 169 {
 170         return atomic64_add_return(i, v) < 0;
 171 }
 172
 173 #define atomic_sub_return(i,v)                                          \
 174 ({                                                                      \
 175         int __ia64_asr_i = (i);                                         \
 176         (__builtin_constant_p(i)                                        \
 177          && (   (__ia64_asr_i ==   1) || (__ia64_asr_i ==   4)          \
 178              || (__ia64_asr_i ==   8) || (__ia64_asr_i ==  16)          \
 179              || (__ia64_asr_i ==  -1) || (__ia64_asr_i ==  -4)          \
 180              || (__ia64_asr_i ==  -8) || (__ia64_asr_i == -16)))        \
 181                 ? ia64_fetch_and_add(-__ia64_asr_i, &(v)->counter)      \
 182                 : ia64_atomic_sub(__ia64_asr_i, v);                     \
 183 })
 184
 185 #define atomic64_sub_return(i,v)                                        \
 186 ({                                                                      \
 187         long __ia64_asr_i = (i);                                        \
 188         (__builtin_constant_p(i)                                        \
 189          && (   (__ia64_asr_i ==   1) || (__ia64_asr_i ==   4)          \
 190              || (__ia64_asr_i ==   8) || (__ia64_asr_i ==  16)          \
 191              || (__ia64_asr_i ==  -1) || (__ia64_asr_i ==  -4)          \
 192              || (__ia64_asr_i ==  -8) || (__ia64_asr_i == -16)))        \
 193                 ? ia64_fetch_and_add(-__ia64_asr_i, &(v)->counter)      \
 194                 : ia64_atomic64_sub(__ia64_asr_i, v);                   \
 195 })
 196
 197 #define atomic_dec_return(v)            atomic_sub_return(1, (v))
 198 #define atomic_inc_return(v)            atomic_add_return(1, (v))
 199 #define atomic64_dec_return(v)          atomic64_sub_return(1, (v))
 200 #define atomic64_inc_return(v)          atomic64_add_return(1, (v))
 201
 202 #define atomic_sub_and_test(i,v)        (atomic_sub_return((i), (v)) == 0)
 203 #define atomic_dec_and_test(v)          (atomic_sub_return(1, (v)) == 0)
 204 #define atomic_inc_and_test(v)          (atomic_add_return(1, (v)) == 0)
 205 #define atomic64_sub_and_test(i,v)      (atomic64_sub_return((i), (v)) == 0)
 206 #define atomic64_dec_and_test(v)        (atomic64_sub_return(1, (v)) == 0)
 207 #define atomic64_inc_and_test(v)        (atomic64_add_return(1, (v)) == 0)
 208
 209 #define atomic_add(i,v)                 atomic_add_return((i), (v))
 210 #define atomic_sub(i,v)                 atomic_sub_return((i), (v))
 211 #define atomic_inc(v)                   atomic_add(1, (v))
 212 #define atomic_dec(v)                   atomic_sub(1, (v))
 213
 214 #define atomic64_add(i,v)               atomic64_add_return((i), (v))
 215 #define atomic64_sub(i,v)               atomic64_sub_return((i), (v))
 216 #define atomic64_inc(v)                 atomic64_add(1, (v))
 217 #define atomic64_dec(v)                 atomic64_sub(1, (v))
 218
 219 /* Atomic operations are already serializing */
 220 #define smp_mb__before_atomic_dec()     barrier()
 221 #define smp_mb__after_atomic_dec()      barrier()
 222 #define smp_mb__before_atomic_inc()     barrier()
 223 #define smp_mb__after_atomic_inc()      barrier()
 224
 225 #include <asm-generic/atomic.h>
 226 #endif /* _ASM_IA64_ATOMIC_H */