LXR linux/include/asm-generic/atomic64.h

   1/*
   2 * Generic implementation of 64-bit atomics using spinlocks,
   3 * useful on processors that don't have 64-bit atomic instructions.
   4 *
   5 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License
   9 * as published by the Free Software Foundation; either version
  10 * 2 of the License, or (at your option) any later version.
  11 */
  12#ifndef _ASM_GENERIC_ATOMIC64_H
  13#define _ASM_GENERIC_ATOMIC64_H
  14
  15typedef struct {
  16        long long counter;
  17} atomic64_t;
  18
  19#define ATOMIC64_INIT(i)        { (i) }
  20
  21extern long long atomic64_read(const atomic64_t *v);
  22extern void      atomic64_set(atomic64_t *v, long long i);
  23
  24#define atomic64_set_release(v, i)      atomic64_set((v), (i))
  25
  26#define ATOMIC64_OP(op)                                                 \
  27extern void      atomic64_##op(long long a, atomic64_t *v);
  28
  29#define ATOMIC64_OP_RETURN(op)                                          \
  30extern long long atomic64_##op##_return(long long a, atomic64_t *v);
  31
  32#define ATOMIC64_FETCH_OP(op)                                           \
  33extern long long atomic64_fetch_##op(long long a, atomic64_t *v);
  34
  35#define ATOMIC64_OPS(op)        ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op) ATOMIC64_FETCH_OP(op)
  36
  37ATOMIC64_OPS(add)
  38ATOMIC64_OPS(sub)
  39
  40#undef ATOMIC64_OPS
  41#define ATOMIC64_OPS(op)        ATOMIC64_OP(op) ATOMIC64_FETCH_OP(op)
  42
  43ATOMIC64_OPS(and)
  44ATOMIC64_OPS(or)
  45ATOMIC64_OPS(xor)
  46
  47#undef ATOMIC64_OPS
  48#undef ATOMIC64_FETCH_OP
  49#undef ATOMIC64_OP_RETURN
  50#undef ATOMIC64_OP
  51
  52extern long long atomic64_dec_if_positive(atomic64_t *v);
  53extern long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n);
  54extern long long atomic64_xchg(atomic64_t *v, long long new);
  55extern int       atomic64_add_unless(atomic64_t *v, long long a, long long u);
  56
  57#define atomic64_add_negative(a, v)     (atomic64_add_return((a), (v)) < 0)
  58#define atomic64_inc(v)                 atomic64_add(1LL, (v))
  59#define atomic64_inc_return(v)          atomic64_add_return(1LL, (v))
  60#define atomic64_inc_and_test(v)        (atomic64_inc_return(v) == 0)
  61#define atomic64_sub_and_test(a, v)     (atomic64_sub_return((a), (v)) == 0)
  62#define atomic64_dec(v)                 atomic64_sub(1LL, (v))
  63#define atomic64_dec_return(v)          atomic64_sub_return(1LL, (v))
  64#define atomic64_dec_and_test(v)        (atomic64_dec_return((v)) == 0)
  65#define atomic64_inc_not_zero(v)        atomic64_add_unless((v), 1LL, 0LL)
  66
  67#endif  /*  _ASM_GENERIC_ATOMIC64_H  */
  68