mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-28 07:04:00 +08:00
d28d6e6fa5
In previous drm_global_item_ref, there are two times of writing ref->object if item->refcount is 0. So this patch does a minor update to put alloc and init ref firstly, and then to modify the item of glob array. Use "else" to avoid two times of writing ref->object. It can make the code logic more clearly. Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Huang Rui <ray.huang@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
115 lines
3.0 KiB
C
115 lines
3.0 KiB
C
/**************************************************************************
|
|
*
|
|
* 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 <linux/mutex.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/module.h>
|
|
#include <drm/drm_global.h>
|
|
|
|
struct drm_global_item {
|
|
struct mutex mutex;
|
|
void *object;
|
|
int refcount;
|
|
};
|
|
|
|
static struct drm_global_item glob[DRM_GLOBAL_NUM];
|
|
|
|
void drm_global_init(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < DRM_GLOBAL_NUM; ++i) {
|
|
struct drm_global_item *item = &glob[i];
|
|
mutex_init(&item->mutex);
|
|
item->object = NULL;
|
|
item->refcount = 0;
|
|
}
|
|
}
|
|
|
|
void drm_global_release(void)
|
|
{
|
|
int i;
|
|
for (i = 0; i < DRM_GLOBAL_NUM; ++i) {
|
|
struct drm_global_item *item = &glob[i];
|
|
BUG_ON(item->object != NULL);
|
|
BUG_ON(item->refcount != 0);
|
|
}
|
|
}
|
|
|
|
int drm_global_item_ref(struct drm_global_reference *ref)
|
|
{
|
|
int ret = 0;
|
|
struct drm_global_item *item = &glob[ref->global_type];
|
|
|
|
mutex_lock(&item->mutex);
|
|
if (item->refcount == 0) {
|
|
ref->object = kzalloc(ref->size, GFP_KERNEL);
|
|
if (unlikely(ref->object == NULL)) {
|
|
ret = -ENOMEM;
|
|
goto error_unlock;
|
|
}
|
|
ret = ref->init(ref);
|
|
if (unlikely(ret != 0))
|
|
goto error_free;
|
|
|
|
item->object = ref->object;
|
|
} else {
|
|
ref->object = item->object;
|
|
}
|
|
|
|
++item->refcount;
|
|
mutex_unlock(&item->mutex);
|
|
return 0;
|
|
|
|
error_free:
|
|
kfree(ref->object);
|
|
ref->object = NULL;
|
|
error_unlock:
|
|
mutex_unlock(&item->mutex);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(drm_global_item_ref);
|
|
|
|
void drm_global_item_unref(struct drm_global_reference *ref)
|
|
{
|
|
struct drm_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(drm_global_item_unref);
|
|
|