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/**************************************************************************
*
* Copyright 2008-2009 VMware, Inc., Palo Alto, CA., USA
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sub license, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
* USE OR OTHER DEALINGS IN THE SOFTWARE.
*
**************************************************************************/
/*
* Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
*/
#include "ttm/ttm_module.h"
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/module.h>
struct ttm_global_item {
struct mutex mutex;
void *object;
int refcount;
};
static struct ttm_global_item glob[TTM_GLOBAL_NUM];
void ttm_global_init(void)
{
int i;
for (i = 0; i < TTM_GLOBAL_NUM; ++i) {
struct ttm_global_item *item = &glob[i];
mutex_init(&item->mutex);
item->object = NULL;
item->refcount = 0;
}
}
void ttm_global_release(void)
{
int i;
for (i = 0; i < TTM_GLOBAL_NUM; ++i) {
struct ttm_global_item *item = &glob[i];
BUG_ON(item->object != NULL);
BUG_ON(item->refcount != 0);
}
}
int ttm_global_item_ref(struct ttm_global_reference *ref)
{
int ret;
struct ttm_global_item *item = &glob[ref->global_type];
void *object;
mutex_lock(&item->mutex);
if (item->refcount == 0) {
item->object = kzalloc(ref->size, GFP_KERNEL);
if (unlikely(item->object == NULL)) {
ret = -ENOMEM;
goto out_err;
}
ref->object = item->object;
ret = ref->init(ref);
if (unlikely(ret != 0))
goto out_err;
++item->refcount;
}
ref->object = item->object;
object = item->object;
mutex_unlock(&item->mutex);
return 0;
out_err:
mutex_unlock(&item->mutex);
item->object = NULL;
return ret;
}
EXPORT_SYMBOL(ttm_global_item_ref);
void ttm_global_item_unref(struct ttm_global_reference *ref)
{
struct ttm_global_item *item = &glob[ref->global_type];
mutex_lock(&item->mutex);
BUG_ON(item->refcount == 0);
BUG_ON(ref->object != item->object);
if (--item->refcount == 0) {
ref->release(ref);
item->object = NULL;
}
mutex_unlock(&item->mutex);
}
EXPORT_SYMBOL(ttm_global_item_unref);
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