sys/compat/linuxkpi/common/include/asm/atomic64.h

   1 /*-
   2  * Copyright (c) 2016 Mellanox Technologies, Ltd.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice unmodified, this list of conditions, and the following
  10  *    disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  * $FreeBSD$
  27  */
  28 #ifndef _ASM_ATOMIC64_H_
  29 #define _ASM_ATOMIC64_H_
  30
  31 #include <sys/cdefs.h>
  32 #include <sys/types.h>
  33 #include <machine/atomic.h>
  34
  35 typedef struct {
  36         volatile int64_t counter;
  37 } atomic64_t;
  38
  39 /*------------------------------------------------------------------------*
  40  *      64-bit atomic operations
  41  *------------------------------------------------------------------------*/
  42
  43 #define atomic64_add(i, v)              atomic64_add_return((i), (v))
  44 #define atomic64_sub(i, v)              atomic64_sub_return((i), (v))
  45 #define atomic64_inc_return(v)          atomic64_add_return(1, (v))
  46 #define atomic64_add_negative(i, v)     (atomic64_add_return((i), (v)) < 0)
  47 #define atomic64_add_and_test(i, v)     (atomic64_add_return((i), (v)) == 0)
  48 #define atomic64_sub_and_test(i, v)     (atomic64_sub_return((i), (v)) == 0)
  49 #define atomic64_dec_and_test(v)        (atomic64_sub_return(1, (v)) == 0)
  50 #define atomic64_inc_and_test(v)        (atomic64_add_return(1, (v)) == 0)
  51 #define atomic64_dec_return(v)          atomic64_sub_return(1, (v))
  52 #define atomic64_inc_not_zero(v)        atomic64_add_unless((v), 1, 0)
  53
  54 static inline int64_t
  55 atomic64_add_return(int64_t i, atomic64_t *v)
  56 {
  57         return i + atomic_fetchadd_64(&v->counter, i);
  58 }
  59
  60 static inline int64_t
  61 atomic64_sub_return(int64_t i, atomic64_t *v)
  62 {
  63         return atomic_fetchadd_64(&v->counter, -i) - i;
  64 }
  65
  66 static inline void
  67 atomic64_set(atomic64_t *v, int64_t i)
  68 {
  69         atomic_store_rel_64(&v->counter, i);
  70 }
  71
  72 static inline int64_t
  73 atomic64_read(atomic64_t *v)
  74 {
  75         return atomic_load_acq_64(&v->counter);
  76 }
  77
  78 static inline int64_t
  79 atomic64_inc(atomic64_t *v)
  80 {
  81         return atomic_fetchadd_64(&v->counter, 1) + 1;
  82 }
  83
  84 static inline int64_t
  85 atomic64_dec(atomic64_t *v)
  86 {
  87         return atomic_fetchadd_64(&v->counter, -1) - 1;
  88 }
  89
  90 static inline int64_t
  91 atomic64_add_unless(atomic64_t *v, int64_t a, int64_t u)
  92 {
  93         int64_t c;
  94
  95         for (;;) {
  96                 c = atomic64_read(v);
  97                 if (unlikely(c == u))
  98                         break;
  99                 if (likely(atomic_cmpset_64(&v->counter, c, c + a)))
 100                         break;
 101         }
 102         return (c != u);
 103 }
 104
 105 static inline int64_t
 106 atomic64_xchg(atomic64_t *v, int64_t i)
 107 {
 108 #if defined(__i386__) || defined(__amd64__) || \
 109     defined(__arm__) || defined(__aarch64__)
 110         return (atomic_swap_64(&v->counter, i));
 111 #else
 112         int64_t ret;
 113         for (;;) {
 114                 ret = atomic_load_acq_64(&v->counter);
 115                 if (atomic_cmpset_64(&v->counter, ret, i))
 116                         break;
 117         }
 118         return (ret);
 119 #endif
 120 }
 121
 122 static inline int64_t
 123 atomic64_cmpxchg(atomic64_t *v, int64_t old, int64_t new)
 124 {
 125         int64_t ret = old;
 126
 127         for (;;) {
 128                 if (atomic_cmpset_64(&v->counter, old, new))
 129                         break;
 130                 ret = atomic_load_acq_64(&v->counter);
 131                 if (ret != old)
 132                         break;
 133         }
 134         return (ret);
 135 }
 136
 137 #endif                                  /* _ASM_ATOMIC64_H_ */