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
  15 typedef struct {
  16         long long counter;
  17 } atomic64_t;
  18
  19 #define ATOMIC64_INIT(i)        { (i) }
  20
  21 extern long long atomic64_read(const atomic64_t *v);
  22 extern 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)                                                 \
  27 extern void      atomic64_##op(long long a, atomic64_t *v);
  28
  29 #define ATOMIC64_OP_RETURN(op)                                          \
  30 extern long long atomic64_##op##_return(long long a, atomic64_t *v);
  31
  32 #define ATOMIC64_FETCH_OP(op)                                           \
  33 extern 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
  37 ATOMIC64_OPS(add)
  38 ATOMIC64_OPS(sub)
  39
  40 #undef ATOMIC64_OPS
  41 #define ATOMIC64_OPS(op)        ATOMIC64_OP(op) ATOMIC64_FETCH_OP(op)
  42
  43 ATOMIC64_OPS(and)
  44 ATOMIC64_OPS(or)
  45 ATOMIC64_OPS(xor)
  46
  47 #undef ATOMIC64_OPS
  48 #undef ATOMIC64_FETCH_OP
  49 #undef ATOMIC64_OP_RETURN
  50 #undef ATOMIC64_OP
  51
  52 extern long long atomic64_dec_if_positive(atomic64_t *v);
  53 extern long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n);
  54 extern long long atomic64_xchg(atomic64_t *v, long long new);
  55 extern 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  */