include/asm-blackfin/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
  16 typedef 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
  24 static __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
  33 static __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
  43 static 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)
  58 static 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
  71 static __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
  93 static __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
 102 static __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
 111 static __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 __ */