 ba4420c224
			
		
	
	
	ba4420c224
	
	
	
		
			
			I wrote this for the prime sharing work, but I also noticed other external non-upstream drivers from a large company carrying a similiar patch, so I may as well ship it in master. Signed-off-by: Dave Airlie <airlied@redhat.com>
		
			
				
	
	
		
			112 lines
		
	
	
	
		
			3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			112 lines
		
	
	
	
		
			3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /**************************************************************************
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|  *
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|  * Copyright 2008-2009 VMware, Inc., Palo Alto, CA., USA
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|  * All Rights Reserved.
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|  *
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|  * Permission is hereby granted, free of charge, to any person obtaining a
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|  * copy of this software and associated documentation files (the
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|  * "Software"), to deal in the Software without restriction, including
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|  * without limitation the rights to use, copy, modify, merge, publish,
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|  * distribute, sub license, and/or sell copies of the Software, and to
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|  * permit persons to whom the Software is furnished to do so, subject to
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|  * the following conditions:
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|  *
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|  * The above copyright notice and this permission notice (including the
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|  * next paragraph) shall be included in all copies or substantial portions
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|  * of the Software.
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|  *
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|  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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|  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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|  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
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|  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
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|  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
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|  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
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|  * USE OR OTHER DEALINGS IN THE SOFTWARE.
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|  *
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|  **************************************************************************/
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| /*
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|  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
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|  */
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| 
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| #include <linux/mutex.h>
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| #include <linux/slab.h>
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| #include <linux/module.h>
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| #include "drm_global.h"
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| 
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| struct drm_global_item {
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| 	struct mutex mutex;
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| 	void *object;
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| 	int refcount;
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| };
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| 
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| static struct drm_global_item glob[DRM_GLOBAL_NUM];
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| 
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| void drm_global_init(void)
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| {
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| 	int i;
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| 
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| 	for (i = 0; i < DRM_GLOBAL_NUM; ++i) {
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| 		struct drm_global_item *item = &glob[i];
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| 		mutex_init(&item->mutex);
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| 		item->object = NULL;
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| 		item->refcount = 0;
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| 	}
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| }
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| 
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| void drm_global_release(void)
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| {
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| 	int i;
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| 	for (i = 0; i < DRM_GLOBAL_NUM; ++i) {
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| 		struct drm_global_item *item = &glob[i];
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| 		BUG_ON(item->object != NULL);
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| 		BUG_ON(item->refcount != 0);
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| 	}
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| }
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| 
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| int drm_global_item_ref(struct drm_global_reference *ref)
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| {
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| 	int ret;
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| 	struct drm_global_item *item = &glob[ref->global_type];
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| 	void *object;
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| 
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| 	mutex_lock(&item->mutex);
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| 	if (item->refcount == 0) {
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| 		item->object = kzalloc(ref->size, GFP_KERNEL);
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| 		if (unlikely(item->object == NULL)) {
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| 			ret = -ENOMEM;
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| 			goto out_err;
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| 		}
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| 
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| 		ref->object = item->object;
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| 		ret = ref->init(ref);
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| 		if (unlikely(ret != 0))
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| 			goto out_err;
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| 
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| 	}
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| 	++item->refcount;
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| 	ref->object = item->object;
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| 	object = item->object;
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| 	mutex_unlock(&item->mutex);
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| 	return 0;
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| out_err:
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| 	mutex_unlock(&item->mutex);
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| 	item->object = NULL;
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| 	return ret;
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| }
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| EXPORT_SYMBOL(drm_global_item_ref);
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| 
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| void drm_global_item_unref(struct drm_global_reference *ref)
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| {
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| 	struct drm_global_item *item = &glob[ref->global_type];
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| 
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| 	mutex_lock(&item->mutex);
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| 	BUG_ON(item->refcount == 0);
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| 	BUG_ON(ref->object != item->object);
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| 	if (--item->refcount == 0) {
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| 		ref->release(ref);
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| 		item->object = NULL;
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| 	}
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| 	mutex_unlock(&item->mutex);
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| }
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| EXPORT_SYMBOL(drm_global_item_unref);
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| 
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