LXR linux/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
  24typedef 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#define local64_cmpxchg(l, o, n) local_cmpxchg((&(l)->a), (o), (n))
  46#define local64_xchg(l, n)      local_xchg((&(l)->a), (n))
  47#define local64_add_unless(l, _a, u) local_add_unless((&(l)->a), (_a), (u))
  48#define local64_inc_not_zero(l) local_inc_not_zero(&(l)->a)
  49
  50/* Non-atomic variants, ie. preemption disabled and won't be touched
  51 * in interrupt, etc.  Some archs can optimize this case well. */
  52#define __local64_inc(l)        local64_set((l), local64_read(l) + 1)
  53#define __local64_dec(l)        local64_set((l), local64_read(l) - 1)
  54#define __local64_add(i,l)      local64_set((l), local64_read(l) + (i))
  55#define __local64_sub(i,l)      local64_set((l), local64_read(l) - (i))
  56
  57#else /* BITS_PER_LONG != 64 */
  58
  59#include <linux/atomic.h>
  60
  61/* Don't use typedef: don't want them to be mixed with atomic_t's. */
  62typedef struct {
  63        atomic64_t a;
  64} local64_t;
  65
  66#define LOCAL64_INIT(i) { ATOMIC_LONG_INIT(i) }
  67
  68#define local64_read(l)         atomic64_read(&(l)->a)
  69#define local64_set(l,i)        atomic64_set((&(l)->a),(i))
  70#define local64_inc(l)          atomic64_inc(&(l)->a)
  71#define local64_dec(l)          atomic64_dec(&(l)->a)
  72#define local64_add(i,l)        atomic64_add((i),(&(l)->a))
  73#define local64_sub(i,l)        atomic64_sub((i),(&(l)->a))
  74
  75#define local64_sub_and_test(i, l) atomic64_sub_and_test((i), (&(l)->a))
  76#define local64_dec_and_test(l) atomic64_dec_and_test(&(l)->a)
  77#define local64_inc_and_test(l) atomic64_inc_and_test(&(l)->a)
  78#define local64_add_negative(i, l) atomic64_add_negative((i), (&(l)->a))
  79#define local64_add_return(i, l) atomic64_add_return((i), (&(l)->a))
  80#define local64_sub_return(i, l) atomic64_sub_return((i), (&(l)->a))
  81#define local64_inc_return(l)   atomic64_inc_return(&(l)->a)
  82
  83#define local64_cmpxchg(l, o, n) atomic64_cmpxchg((&(l)->a), (o), (n))
  84#define local64_xchg(l, n)      atomic64_xchg((&(l)->a), (n))
  85#define local64_add_unless(l, _a, u) atomic64_add_unless((&(l)->a), (_a), (u))
  86#define local64_inc_not_zero(l) atomic64_inc_not_zero(&(l)->a)
  87
  88/* Non-atomic variants, ie. preemption disabled and won't be touched
  89 * in interrupt, etc.  Some archs can optimize this case well. */
  90#define __local64_inc(l)        local64_set((l), local64_read(l) + 1)
  91#define __local64_dec(l)        local64_set((l), local64_read(l) - 1)
  92#define __local64_add(i,l)      local64_set((l), local64_read(l) + (i))
  93#define __local64_sub(i,l)      local64_set((l), local64_read(l) - (i))
  94
  95#endif /* BITS_PER_LONG != 64 */
  96
  97#endif /* _ASM_GENERIC_LOCAL64_H */
  98