linux/arch/alpha/include/asm/atomic.h
<<
>>
Prefs
   1#ifndef _ALPHA_ATOMIC_H
   2#define _ALPHA_ATOMIC_H
   3
   4#include <linux/types.h>
   5#include <asm/barrier.h>
   6#include <asm/system.h>
   7
   8/*
   9 * Atomic operations that C can't guarantee us.  Useful for
  10 * resource counting etc...
  11 *
  12 * But use these as seldom as possible since they are much slower
  13 * than regular operations.
  14 */
  15
  16
  17#define ATOMIC_INIT(i)          ( (atomic_t) { (i) } )
  18#define ATOMIC64_INIT(i)        ( (atomic64_t) { (i) } )
  19
  20#define atomic_read(v)          ((v)->counter + 0)
  21#define atomic64_read(v)        ((v)->counter + 0)
  22
  23#define atomic_set(v,i)         ((v)->counter = (i))
  24#define atomic64_set(v,i)       ((v)->counter = (i))
  25
  26/*
  27 * To get proper branch prediction for the main line, we must branch
  28 * forward to code at the end of this object's .text section, then
  29 * branch back to restart the operation.
  30 */
  31
  32static __inline__ void atomic_add(int i, atomic_t * v)
  33{
  34        unsigned long temp;
  35        __asm__ __volatile__(
  36        "1:     ldl_l %0,%1\n"
  37        "       addl %0,%2,%0\n"
  38        "       stl_c %0,%1\n"
  39        "       beq %0,2f\n"
  40        ".subsection 2\n"
  41        "2:     br 1b\n"
  42        ".previous"
  43        :"=&r" (temp), "=m" (v->counter)
  44        :"Ir" (i), "m" (v->counter));
  45}
  46
  47static __inline__ void atomic64_add(long i, atomic64_t * v)
  48{
  49        unsigned long temp;
  50        __asm__ __volatile__(
  51        "1:     ldq_l %0,%1\n"
  52        "       addq %0,%2,%0\n"
  53        "       stq_c %0,%1\n"
  54        "       beq %0,2f\n"
  55        ".subsection 2\n"
  56        "2:     br 1b\n"
  57        ".previous"
  58        :"=&r" (temp), "=m" (v->counter)
  59        :"Ir" (i), "m" (v->counter));
  60}
  61
  62static __inline__ void atomic_sub(int i, atomic_t * v)
  63{
  64        unsigned long temp;
  65        __asm__ __volatile__(
  66        "1:     ldl_l %0,%1\n"
  67        "       subl %0,%2,%0\n"
  68        "       stl_c %0,%1\n"
  69        "       beq %0,2f\n"
  70        ".subsection 2\n"
  71        "2:     br 1b\n"
  72        ".previous"
  73        :"=&r" (temp), "=m" (v->counter)
  74        :"Ir" (i), "m" (v->counter));
  75}
  76
  77static __inline__ void atomic64_sub(long i, atomic64_t * v)
  78{
  79        unsigned long temp;
  80        __asm__ __volatile__(
  81        "1:     ldq_l %0,%1\n"
  82        "       subq %0,%2,%0\n"
  83        "       stq_c %0,%1\n"
  84        "       beq %0,2f\n"
  85        ".subsection 2\n"
  86        "2:     br 1b\n"
  87        ".previous"
  88        :"=&r" (temp), "=m" (v->counter)
  89        :"Ir" (i), "m" (v->counter));
  90}
  91
  92
  93/*
  94 * Same as above, but return the result value
  95 */
  96static inline int atomic_add_return(int i, atomic_t *v)
  97{
  98        long temp, result;
  99        smp_mb();
 100        __asm__ __volatile__(
 101        "1:     ldl_l %0,%1\n"
 102        "       addl %0,%3,%2\n"
 103        "       addl %0,%3,%0\n"
 104        "       stl_c %0,%1\n"
 105        "       beq %0,2f\n"
 106        ".subsection 2\n"
 107        "2:     br 1b\n"
 108        ".previous"
 109        :"=&r" (temp), "=m" (v->counter), "=&r" (result)
 110        :"Ir" (i), "m" (v->counter) : "memory");
 111        smp_mb();
 112        return result;
 113}
 114
 115static __inline__ long atomic64_add_return(long i, atomic64_t * v)
 116{
 117        long temp, result;
 118        smp_mb();
 119        __asm__ __volatile__(
 120        "1:     ldq_l %0,%1\n"
 121        "       addq %0,%3,%2\n"
 122        "       addq %0,%3,%0\n"
 123        "       stq_c %0,%1\n"
 124        "       beq %0,2f\n"
 125        ".subsection 2\n"
 126        "2:     br 1b\n"
 127        ".previous"
 128        :"=&r" (temp), "=m" (v->counter), "=&r" (result)
 129        :"Ir" (i), "m" (v->counter) : "memory");
 130        smp_mb();
 131        return result;
 132}
 133
 134static __inline__ long atomic_sub_return(int i, atomic_t * v)
 135{
 136        long temp, result;
 137        smp_mb();
 138        __asm__ __volatile__(
 139        "1:     ldl_l %0,%1\n"
 140        "       subl %0,%3,%2\n"
 141        "       subl %0,%3,%0\n"
 142        "       stl_c %0,%1\n"
 143        "       beq %0,2f\n"
 144        ".subsection 2\n"
 145        "2:     br 1b\n"
 146        ".previous"
 147        :"=&r" (temp), "=m" (v->counter), "=&r" (result)
 148        :"Ir" (i), "m" (v->counter) : "memory");
 149        smp_mb();
 150        return result;
 151}
 152
 153static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
 154{
 155        long temp, result;
 156        smp_mb();
 157        __asm__ __volatile__(
 158        "1:     ldq_l %0,%1\n"
 159        "       subq %0,%3,%2\n"
 160        "       subq %0,%3,%0\n"
 161        "       stq_c %0,%1\n"
 162        "       beq %0,2f\n"
 163        ".subsection 2\n"
 164        "2:     br 1b\n"
 165        ".previous"
 166        :"=&r" (temp), "=m" (v->counter), "=&r" (result)
 167        :"Ir" (i), "m" (v->counter) : "memory");
 168        smp_mb();
 169        return result;
 170}
 171
 172#define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
 173#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
 174
 175#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
 176#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 177
 178/**
 179 * atomic_add_unless - add unless the number is a given value
 180 * @v: pointer of type atomic_t
 181 * @a: the amount to add to v...
 182 * @u: ...unless v is equal to u.
 183 *
 184 * Atomically adds @a to @v, so long as it was not @u.
 185 * Returns non-zero if @v was not @u, and zero otherwise.
 186 */
 187static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
 188{
 189        int c, old;
 190        c = atomic_read(v);
 191        for (;;) {
 192                if (unlikely(c == (u)))
 193                        break;
 194                old = atomic_cmpxchg((v), c, c + (a));
 195                if (likely(old == c))
 196                        break;
 197                c = old;
 198        }
 199        return c != (u);
 200}
 201
 202#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
 203
 204/**
 205 * atomic64_add_unless - add unless the number is a given value
 206 * @v: pointer of type atomic64_t
 207 * @a: the amount to add to v...
 208 * @u: ...unless v is equal to u.
 209 *
 210 * Atomically adds @a to @v, so long as it was not @u.
 211 * Returns non-zero if @v was not @u, and zero otherwise.
 212 */
 213static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
 214{
 215        long c, old;
 216        c = atomic64_read(v);
 217        for (;;) {
 218                if (unlikely(c == (u)))
 219                        break;
 220                old = atomic64_cmpxchg((v), c, c + (a));
 221                if (likely(old == c))
 222                        break;
 223                c = old;
 224        }
 225        return c != (u);
 226}
 227
 228#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
 229
 230#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
 231#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
 232
 233#define atomic_dec_return(v) atomic_sub_return(1,(v))
 234#define atomic64_dec_return(v) atomic64_sub_return(1,(v))
 235
 236#define atomic_inc_return(v) atomic_add_return(1,(v))
 237#define atomic64_inc_return(v) atomic64_add_return(1,(v))
 238
 239#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
 240#define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)
 241
 242#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
 243#define atomic64_inc_and_test(v) (atomic64_add_return(1, (v)) == 0)
 244
 245#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
 246#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
 247
 248#define atomic_inc(v) atomic_add(1,(v))
 249#define atomic64_inc(v) atomic64_add(1,(v))
 250
 251#define atomic_dec(v) atomic_sub(1,(v))
 252#define atomic64_dec(v) atomic64_sub(1,(v))
 253
 254#define smp_mb__before_atomic_dec()     smp_mb()
 255#define smp_mb__after_atomic_dec()      smp_mb()
 256#define smp_mb__before_atomic_inc()     smp_mb()
 257#define smp_mb__after_atomic_inc()      smp_mb()
 258
 259#include <asm-generic/atomic-long.h>
 260#endif /* _ALPHA_ATOMIC_H */
 261