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 #include <linux/config.h>
  18
  19 #include <asm/system.h>
  20
  21 #ifdef CONFIG_SMP
  22 #error SMP not supported
  23 #endif
  24
  25 typedef struct { int counter; } atomic_t;
  26
  27 #define ATOMIC_INIT(i)  { (i) }
  28
  29 #ifdef __KERNEL__
  30
  31 #define atomic_read(v)          ((v)->counter)
  32 #define atomic_set(v,i)         (((v)->counter) = (i))
  33
  34 extern __inline__ int atomic_add_return (int i, volatile atomic_t *v)
  35 {
  36         unsigned long flags;
  37         int res;
  38
  39         local_irq_save (flags);
  40         res = v->counter + i;
  41         v->counter = res;
  42         local_irq_restore (flags);
  43
  44         return res;
  45 }
  46
  47 static __inline__ int atomic_sub_return (int i, volatile atomic_t *v)
  48 {
  49         unsigned long flags;
  50         int res;
  51
  52         local_irq_save (flags);
  53         res = v->counter - i;
  54         v->counter = res;
  55         local_irq_restore (flags);
  56
  57         return res;
  58 }
  59
  60 static __inline__ void atomic_clear_mask (unsigned long mask, unsigned long *addr)
  61 {
  62         unsigned long flags;
  63
  64         local_irq_save (flags);
  65         *addr &= ~mask;
  66         local_irq_restore (flags);
  67 }
  68
  69 #endif
  70
  71 #define atomic_add(i, v)        atomic_add_return ((i), (v))
  72 #define atomic_sub(i, v)        atomic_sub_return ((i), (v))
  73
  74 #define atomic_dec_return(v)    atomic_sub_return (1, (v))
  75 #define atomic_inc_return(v)    atomic_add_return (1, (v))
  76 #define atomic_inc(v)           atomic_inc_return (v)
  77 #define atomic_dec(v)           atomic_dec_return (v)
  78
  79 /*
  80  * atomic_inc_and_test - increment and test
  81  * @v: pointer of type atomic_t
  82  *
  83  * Atomically increments @v by 1
  84  * and returns true if the result is zero, or false for all
  85  * other cases.
  86  */
  87 #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
  88
  89 #define atomic_sub_and_test(i,v)        (atomic_sub_return ((i), (v)) == 0)
  90 #define atomic_dec_and_test(v)          (atomic_sub_return (1, (v)) == 0)
  91 #define atomic_add_negative(i,v)        (atomic_add_return ((i), (v)) < 0)
  92
  93 /* Atomic operations are already serializing on ARM */
  94 #define smp_mb__before_atomic_dec()     barrier()
  95 #define smp_mb__after_atomic_dec()      barrier()
  96 #define smp_mb__before_atomic_inc()     barrier()
  97 #define smp_mb__after_atomic_inc()      barrier()
  98
  99 #endif /* __V850_ATOMIC_H__ */