include/asm-generic/local64.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_GENERIC_LOCAL64_H
   3 #define _ASM_GENERIC_LOCAL64_H
   4
   5 #include <linux/percpu.h>
   6 #include <asm/types.h>
   7
   8 /*
   9  * A signed long type for operations which are atomic for a single CPU.
  10  * Usually used in combination with per-cpu variables.
  11  *
  12  * This is the default implementation, which uses atomic64_t.  Which is
  13  * rather pointless.  The whole point behind local64_t is that some processors
  14  * can perform atomic adds and subtracts in a manner which is atomic wrt IRQs
  15  * running on this CPU.  local64_t allows exploitation of such capabilities.
  16  */
  17
  18 /* Implement in terms of atomics. */
  19
  20 #if BITS_PER_LONG == 64
  21
  22 #include <asm/local.h>
  23
  24 typedef struct {
  25         local_t a;
  26 } local64_t;
  27
  28 #define LOCAL64_INIT(i) { LOCAL_INIT(i) }
  29
  30 #define local64_read(l)         local_read(&(l)->a)
  31 #define local64_set(l,i)        local_set((&(l)->a),(i))
  32 #define local64_inc(l)          local_inc(&(l)->a)
  33 #define local64_dec(l)          local_dec(&(l)->a)
  34 #define local64_add(i,l)        local_add((i),(&(l)->a))
  35 #define local64_sub(i,l)        local_sub((i),(&(l)->a))
  36
  37 #define local64_sub_and_test(i, l) local_sub_and_test((i), (&(l)->a))
  38 #define local64_dec_and_test(l) local_dec_and_test(&(l)->a)
  39 #define local64_inc_and_test(l) local_inc_and_test(&(l)->a)
  40 #define local64_add_negative(i, l) local_add_negative((i), (&(l)->a))
  41 #define local64_add_return(i, l) local_add_return((i), (&(l)->a))
  42 #define local64_sub_return(i, l) local_sub_return((i), (&(l)->a))
  43 #define local64_inc_return(l)   local_inc_return(&(l)->a)
  44
  45 static inline s64 local64_cmpxchg(local64_t *l, s64 old, s64 new)
  46 {
  47         return local_cmpxchg(&l->a, old, new);
  48 }
  49
  50 static inline bool local64_try_cmpxchg(local64_t *l, s64 *old, s64 new)
  51 {
  52         return local_try_cmpxchg(&l->a, (long *)old, new);
  53 }
  54
  55 #define local64_xchg(l, n)      local_xchg((&(l)->a), (n))
  56 #define local64_add_unless(l, _a, u) local_add_unless((&(l)->a), (_a), (u))
  57 #define local64_inc_not_zero(l) local_inc_not_zero(&(l)->a)
  58
  59 /* Non-atomic variants, ie. preemption disabled and won't be touched
  60  * in interrupt, etc.  Some archs can optimize this case well. */
  61 #define __local64_inc(l)        local64_set((l), local64_read(l) + 1)
  62 #define __local64_dec(l)        local64_set((l), local64_read(l) - 1)
  63 #define __local64_add(i,l)      local64_set((l), local64_read(l) + (i))
  64 #define __local64_sub(i,l)      local64_set((l), local64_read(l) - (i))
  65
  66 #else /* BITS_PER_LONG != 64 */
  67
  68 #include <linux/atomic.h>
  69
  70 /* Don't use typedef: don't want them to be mixed with atomic_t's. */
  71 typedef struct {
  72         atomic64_t a;
  73 } local64_t;
  74
  75 #define LOCAL64_INIT(i) { ATOMIC_LONG_INIT(i) }
  76
  77 #define local64_read(l)         atomic64_read(&(l)->a)
  78 #define local64_set(l,i)        atomic64_set((&(l)->a),(i))
  79 #define local64_inc(l)          atomic64_inc(&(l)->a)
  80 #define local64_dec(l)          atomic64_dec(&(l)->a)
  81 #define local64_add(i,l)        atomic64_add((i),(&(l)->a))
  82 #define local64_sub(i,l)        atomic64_sub((i),(&(l)->a))
  83
  84 #define local64_sub_and_test(i, l) atomic64_sub_and_test((i), (&(l)->a))
  85 #define local64_dec_and_test(l) atomic64_dec_and_test(&(l)->a)
  86 #define local64_inc_and_test(l) atomic64_inc_and_test(&(l)->a)
  87 #define local64_add_negative(i, l) atomic64_add_negative((i), (&(l)->a))
  88 #define local64_add_return(i, l) atomic64_add_return((i), (&(l)->a))
  89 #define local64_sub_return(i, l) atomic64_sub_return((i), (&(l)->a))
  90 #define local64_inc_return(l)   atomic64_inc_return(&(l)->a)
  91
  92 #define local64_cmpxchg(l, o, n) atomic64_cmpxchg((&(l)->a), (o), (n))
  93 #define local64_try_cmpxchg(l, po, n) atomic64_try_cmpxchg((&(l)->a), (po), (n))
  94 #define local64_xchg(l, n)      atomic64_xchg((&(l)->a), (n))
  95 #define local64_add_unless(l, _a, u) atomic64_add_unless((&(l)->a), (_a), (u))
  96 #define local64_inc_not_zero(l) atomic64_inc_not_zero(&(l)->a)
  97
  98 /* Non-atomic variants, ie. preemption disabled and won't be touched
  99  * in interrupt, etc.  Some archs can optimize this case well. */
 100 #define __local64_inc(l)        local64_set((l), local64_read(l) + 1)
 101 #define __local64_dec(l)        local64_set((l), local64_read(l) - 1)
 102 #define __local64_add(i,l)      local64_set((l), local64_read(l) + (i))
 103 #define __local64_sub(i,l)      local64_set((l), local64_read(l) - (i))
 104
 105 #endif /* BITS_PER_LONG != 64 */
 106
 107 #endif /* _ASM_GENERIC_LOCAL64_H */