LXR linux/include/asm-v850/atomic.h

   1/*
   2 * include/asm-v850/atomic.h -- Atomic operations
   3 *
   4 *  Copyright (C) 2001,02  NEC Corporation
   5 *  Copyright (C) 2001,02  Miles Bader <miles@gnu.org>
   6 *
   7 * This file is subject to the terms and conditions of the GNU General
   8 * Public License.  See the file COPYING in the main directory of this
   9 * archive for more details.
  10 *
  11 * Written by Miles Bader <miles@gnu.org>
  12 */
  13
  14#ifndef __V850_ATOMIC_H__
  15#define __V850_ATOMIC_H__
  16
  17
  18#include <asm/system.h>
  19
  20#ifdef CONFIG_SMP
  21#error SMP not supported
  22#endif
  23
  24typedef struct { int counter; } atomic_t;
  25
  26#define ATOMIC_INIT(i)  { (i) }
  27
  28#ifdef __KERNEL__
  29
  30#define atomic_read(v)          ((v)->counter)
  31#define atomic_set(v,i)         (((v)->counter) = (i))
  32
  33static inline int atomic_add_return (int i, volatile atomic_t *v)
  34{
  35        unsigned long flags;
  36        int res;
  37
  38        local_irq_save (flags);
  39        res = v->counter + i;
  40        v->counter = res;
  41        local_irq_restore (flags);
  42
  43        return res;
  44}
  45
  46static __inline__ int atomic_sub_return (int i, volatile atomic_t *v)
  47{
  48        unsigned long flags;
  49        int res;
  50
  51        local_irq_save (flags);
  52        res = v->counter - i;
  53        v->counter = res;
  54        local_irq_restore (flags);
  55
  56        return res;
  57}
  58
  59static __inline__ void atomic_clear_mask (unsigned long mask, unsigned long *addr)
  60{
  61        unsigned long flags;
  62
  63        local_irq_save (flags);
  64        *addr &= ~mask;
  65        local_irq_restore (flags);
  66}
  67
  68#endif
  69
  70#define atomic_add(i, v)        atomic_add_return ((i), (v))
  71#define atomic_sub(i, v)        atomic_sub_return ((i), (v))
  72
  73#define atomic_dec_return(v)    atomic_sub_return (1, (v))
  74#define atomic_inc_return(v)    atomic_add_return (1, (v))
  75#define atomic_inc(v)           atomic_inc_return (v)
  76#define atomic_dec(v)           atomic_dec_return (v)
  77
  78/*
  79 * atomic_inc_and_test - increment and test
  80 * @v: pointer of type atomic_t
  81 *
  82 * Atomically increments @v by 1
  83 * and returns true if the result is zero, or false for all
  84 * other cases.
  85 */
  86#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
  87
  88#define atomic_sub_and_test(i,v)        (atomic_sub_return ((i), (v)) == 0)
  89#define atomic_dec_and_test(v)          (atomic_sub_return (1, (v)) == 0)
  90#define atomic_add_negative(i,v)        (atomic_add_return ((i), (v)) < 0)
  91
  92static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
  93{
  94        int ret;
  95        unsigned long flags;
  96
  97        local_irq_save(flags);
  98        ret = v->counter;
  99        if (likely(ret == old))
 100                v->counter = new;
 101        local_irq_restore(flags);
 102
 103        return ret;
 104}
 105
 106#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 107
 108static inline int atomic_add_unless(atomic_t *v, int a, int u)
 109{
 110        int ret;
 111        unsigned long flags;
 112
 113        local_irq_save(flags);
 114        ret = v->counter;
 115        if (ret != u)
 116                v->counter += a;
 117        local_irq_restore(flags);
 118
 119        return ret != u;
 120}
 121
 122#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
 123
 124/* Atomic operations are already serializing on ARM */
 125#define smp_mb__before_atomic_dec()     barrier()
 126#define smp_mb__after_atomic_dec()      barrier()
 127#define smp_mb__before_atomic_inc()     barrier()
 128#define smp_mb__after_atomic_inc()      barrier()
 129
 130#include <asm-generic/atomic.h>
 131#endif /* __V850_ATOMIC_H__ */
 132