arch/blackfin/include/asm/atomic.h

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