LXR linux/arch/blackfin/include/asm/atomic.h

   1#ifndef __ARCH_BLACKFIN_ATOMIC__
   2#define __ARCH_BLACKFIN_ATOMIC__
   3
   4#include <asm/system.h> /* local_irq_XXX() */
   5
   6/*
   7 * Atomic operations that C can't guarantee us.  Useful for
   8 * resource counting etc..
   9 *
  10 * Generally we do not concern about SMP BFIN systems, so we don't have
  11 * to deal with that.
  12 *
  13 * Tony Kou (tonyko@lineo.ca)   Lineo Inc.   2001
  14 */
  15
  16typedef struct {
  17        int counter;
  18} atomic_t;
  19#define ATOMIC_INIT(i)  { (i) }
  20
  21#define atomic_read(v)          ((v)->counter)
  22#define atomic_set(v, i)        (((v)->counter) = i)
  23
  24static __inline__ void atomic_add(int i, atomic_t * v)
  25{
  26        long flags;
  27
  28        local_irq_save(flags);
  29        v->counter += i;
  30        local_irq_restore(flags);
  31}
  32
  33static __inline__ void atomic_sub(int i, atomic_t * v)
  34{
  35        long flags;
  36
  37        local_irq_save(flags);
  38        v->counter -= i;
  39        local_irq_restore(flags);
  40
  41}
  42
  43static inline int atomic_add_return(int i, atomic_t * v)
  44{
  45        int __temp = 0;
  46        long flags;
  47
  48        local_irq_save(flags);
  49        v->counter += i;
  50        __temp = v->counter;
  51        local_irq_restore(flags);
  52
  53
  54        return __temp;
  55}
  56
  57#define atomic_add_negative(a, v)       (atomic_add_return((a), (v)) < 0)
  58static inline int atomic_sub_return(int i, atomic_t * v)
  59{
  60        int __temp = 0;
  61        long flags;
  62
  63        local_irq_save(flags);
  64        v->counter -= i;
  65        __temp = v->counter;
  66        local_irq_restore(flags);
  67
  68        return __temp;
  69}
  70
  71static __inline__ void atomic_inc(volatile atomic_t * v)
  72{
  73        long flags;
  74
  75        local_irq_save(flags);
  76        v->counter++;
  77        local_irq_restore(flags);
  78}
  79
  80#define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
  81#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
  82
  83#define atomic_add_unless(v, a, u)                              \
  84({                                                              \
  85        int c, old;                                             \
  86        c = atomic_read(v);                                     \
  87        while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \
  88                c = old;                                        \
  89        c != (u);                                               \
  90})
  91#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
  92
  93static __inline__ void atomic_dec(volatile atomic_t * v)
  94{
  95        long flags;
  96
  97        local_irq_save(flags);
  98        v->counter--;
  99        local_irq_restore(flags);
 100}
 101
 102static __inline__ void atomic_clear_mask(unsigned int mask, atomic_t * v)
 103{
 104        long flags;
 105
 106        local_irq_save(flags);
 107        v->counter &= ~mask;
 108        local_irq_restore(flags);
 109}
 110
 111static __inline__ void atomic_set_mask(unsigned int mask, atomic_t * v)
 112{
 113        long flags;
 114
 115        local_irq_save(flags);
 116        v->counter |= mask;
 117        local_irq_restore(flags);
 118}
 119
 120/* Atomic operations are already serializing */
 121#define smp_mb__before_atomic_dec()    barrier()
 122#define smp_mb__after_atomic_dec() barrier()
 123#define smp_mb__before_atomic_inc()    barrier()
 124#define smp_mb__after_atomic_inc() barrier()
 125
 126#define atomic_dec_return(v) atomic_sub_return(1,(v))
 127#define atomic_inc_return(v) atomic_add_return(1,(v))
 128
 129/*
 130 * atomic_inc_and_test - increment and test
 131 * @v: pointer of type atomic_t
 132 *
 133 * Atomically increments @v by 1
 134 * and returns true if the result is zero, or false for all
 135 * other cases.
 136 */
 137#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
 138
 139#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
 140#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
 141
 142#include <asm-generic/atomic.h>
 143
 144#endif                          /* __ARCH_BLACKFIN_ATOMIC __ */
 145