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
  24 typedef 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
  33 static 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
  46 static __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
  59 static __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
  92 static 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
 108 static 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__ */