lib/ovs-atomic-locked.c

   1 /*
   2  * Copyright (c) 2013, 2014 Nicira, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include <config.h>
  18
  19 #include "ovs-atomic.h"
  20 #include "hash.h"
  21 #include "ovs-thread.h"
  22
  23 #ifdef OVS_ATOMIC_LOCKED_IMPL
  24 static struct ovs_mutex *
  25 mutex_for_pointer(void *p)
  26 {
  27     OVS_ALIGNED_STRUCT(CACHE_LINE_SIZE, aligned_mutex) {
  28         struct ovs_mutex mutex;
  29         char pad[PAD_SIZE(sizeof(struct ovs_mutex), CACHE_LINE_SIZE)];
  30     };
  31
  32     static struct aligned_mutex atomic_mutexes[] = {
  33 #define MUTEX_INIT { .mutex = OVS_MUTEX_INITIALIZER }
  34 #define MUTEX_INIT4  MUTEX_INIT,  MUTEX_INIT,  MUTEX_INIT,  MUTEX_INIT
  35 #define MUTEX_INIT16 MUTEX_INIT4, MUTEX_INIT4, MUTEX_INIT4, MUTEX_INIT4
  36         MUTEX_INIT16, MUTEX_INIT16,
  37     };
  38     BUILD_ASSERT_DECL(IS_POW2(ARRAY_SIZE(atomic_mutexes)));
  39
  40     uint32_t hash = hash_pointer(p, 0);
  41     uint32_t indx = hash & (ARRAY_SIZE(atomic_mutexes) - 1);
  42     return &atomic_mutexes[indx].mutex;
  43 }
  44
  45 void
  46 atomic_lock__(void *p)
  47     OVS_ACQUIRES(mutex_for_pointer(p))
  48 {
  49     ovs_mutex_lock(mutex_for_pointer(p));
  50 }
  51
  52 void
  53 atomic_unlock__(void *p)
  54     OVS_RELEASES(mutex_for_pointer(p))
  55 {
  56     ovs_mutex_unlock(mutex_for_pointer(p));
  57 }
  58 #endif /* OVS_ATOMIC_LOCKED_IMPL */