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