include/asm-generic/local64.h

   1 #ifndef _ASM_GENERIC_LOCAL64_H
   2 #define _ASM_GENERIC_LOCAL64_H
   3
   4 #include <linux/percpu.h>
   5 #include <asm/types.h>
   6
   7 /*
   8  * A signed long type for operations which are atomic for a single CPU.
   9  * Usually used in combination with per-cpu variables.
  10  *
  11  * This is the default implementation, which uses atomic64_t.  Which is
  12  * rather pointless.  The whole point behind local64_t is that some processors
  13  * can perform atomic adds and subtracts in a manner which is atomic wrt IRQs
  14  * running on this CPU.  local64_t allows exploitation of such capabilities.
  15  */
  16
  17 /* Implement in terms of atomics. */
  18
  19 #if BITS_PER_LONG == 64
  20
  21 #include <asm/local.h>
  22
  23 typedef struct {
  24         local_t a;
  25 } local64_t;
  26
  27 #define LOCAL64_INIT(i) { LOCAL_INIT(i) }
  28
  29 #define local64_read(l)         local_read(&(l)->a)
  30 #define local64_set(l,i)        local_set((&(l)->a),(i))
  31 #define local64_inc(l)          local_inc(&(l)->a)
  32 #define local64_dec(l)          local_dec(&(l)->a)
  33 #define local64_add(i,l)        local_add((i),(&(l)->a))
  34 #define local64_sub(i,l)        local_sub((i),(&(l)->a))
  35
  36 #define local64_sub_and_test(i, l) local_sub_and_test((i), (&(l)->a))
  37 #define local64_dec_and_test(l) local_dec_and_test(&(l)->a)
  38 #define local64_inc_and_test(l) local_inc_and_test(&(l)->a)
  39 #define local64_add_negative(i, l) local_add_negative((i), (&(l)->a))
  40 #define local64_add_return(i, l) local_add_return((i), (&(l)->a))
  41 #define local64_sub_return(i, l) local_sub_return((i), (&(l)->a))
  42 #define local64_inc_return(l)   local_inc_return(&(l)->a)
  43
  44 #define local64_cmpxchg(l, o, n) local_cmpxchg((&(l)->a), (o), (n))
  45 #define local64_xchg(l, n)      local_xchg((&(l)->a), (n))
  46 #define local64_add_unless(l, _a, u) local_add_unless((&(l)->a), (_a), (u))
  47 #define local64_inc_not_zero(l) local_inc_not_zero(&(l)->a)
  48
  49 /* Non-atomic variants, ie. preemption disabled and won't be touched
  50  * in interrupt, etc.  Some archs can optimize this case well. */
  51 #define __local64_inc(l)        local64_set((l), local64_read(l) + 1)
  52 #define __local64_dec(l)        local64_set((l), local64_read(l) - 1)
  53 #define __local64_add(i,l)      local64_set((l), local64_read(l) + (i))
  54 #define __local64_sub(i,l)      local64_set((l), local64_read(l) - (i))
  55
  56 #else /* BITS_PER_LONG != 64 */
  57
  58 #include <asm/atomic.h>
  59
  60 /* Don't use typedef: don't want them to be mixed with atomic_t's. */
  61 typedef struct {
  62         atomic64_t a;
  63 } local64_t;
  64
  65 #define LOCAL64_INIT(i) { ATOMIC_LONG_INIT(i) }
  66
  67 #define local64_read(l)         atomic64_read(&(l)->a)
  68 #define local64_set(l,i)        atomic64_set((&(l)->a),(i))
  69 #define local64_inc(l)          atomic64_inc(&(l)->a)
  70 #define local64_dec(l)          atomic64_dec(&(l)->a)
  71 #define local64_add(i,l)        atomic64_add((i),(&(l)->a))
  72 #define local64_sub(i,l)        atomic64_sub((i),(&(l)->a))
  73
  74 #define local64_sub_and_test(i, l) atomic64_sub_and_test((i), (&(l)->a))
  75 #define local64_dec_and_test(l) atomic64_dec_and_test(&(l)->a)
  76 #define local64_inc_and_test(l) atomic64_inc_and_test(&(l)->a)
  77 #define local64_add_negative(i, l) atomic64_add_negative((i), (&(l)->a))
  78 #define local64_add_return(i, l) atomic64_add_return((i), (&(l)->a))
  79 #define local64_sub_return(i, l) atomic64_sub_return((i), (&(l)->a))
  80 #define local64_inc_return(l)   atomic64_inc_return(&(l)->a)
  81
  82 #define local64_cmpxchg(l, o, n) atomic64_cmpxchg((&(l)->a), (o), (n))
  83 #define local64_xchg(l, n)      atomic64_xchg((&(l)->a), (n))
  84 #define local64_add_unless(l, _a, u) atomic64_add_unless((&(l)->a), (_a), (u))
  85 #define local64_inc_not_zero(l) atomic64_inc_not_zero(&(l)->a)
  86
  87 /* Non-atomic variants, ie. preemption disabled and won't be touched
  88  * in interrupt, etc.  Some archs can optimize this case well. */
  89 #define __local64_inc(l)        local64_set((l), local64_read(l) + 1)
  90 #define __local64_dec(l)        local64_set((l), local64_read(l) - 1)
  91 #define __local64_add(i,l)      local64_set((l), local64_read(l) + (i))
  92 #define __local64_sub(i,l)      local64_set((l), local64_read(l) - (i))
  93
  94 #endif /* BITS_PER_LONG != 64 */
  95
  96 #endif /* _ASM_GENERIC_LOCAL64_H */