1 /**************************************************************************
3 * Copyright 2008-2009 VMware, Inc., Palo Alto, CA., USA
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
26 **************************************************************************/
28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
31 #include <linux/mutex.h>
32 #include <linux/slab.h>
33 #include <linux/module.h>
34 #include <drm/drm_global.h>
36 struct drm_global_item {
42 static struct drm_global_item glob[DRM_GLOBAL_NUM];
44 void drm_global_init(void)
48 for (i = 0; i < DRM_GLOBAL_NUM; ++i) {
49 struct drm_global_item *item = &glob[i];
50 mutex_init(&item->mutex);
56 void drm_global_release(void)
59 for (i = 0; i < DRM_GLOBAL_NUM; ++i) {
60 struct drm_global_item *item = &glob[i];
61 BUG_ON(item->object != NULL);
62 BUG_ON(item->refcount != 0);
67 * drm_global_item_ref - Initialize and acquire reference to memory
69 * @ref: Object for initialization
71 * This initializes a memory object, allocating memory and calling the
72 * .init() hook. Further calls will increase the reference count for
76 * Zero on success, non-zero otherwise.
78 int drm_global_item_ref(struct drm_global_reference *ref)
81 struct drm_global_item *item = &glob[ref->global_type];
83 mutex_lock(&item->mutex);
84 if (item->refcount == 0) {
85 ref->object = kzalloc(ref->size, GFP_KERNEL);
86 if (unlikely(ref->object == NULL)) {
91 if (unlikely(ret != 0))
94 item->object = ref->object;
96 ref->object = item->object;
100 mutex_unlock(&item->mutex);
107 mutex_unlock(&item->mutex);
110 EXPORT_SYMBOL(drm_global_item_ref);
113 * drm_global_item_unref - Drop reference to memory
115 * @ref: Object being removed
117 * Drop a reference to the memory object and eventually call the
118 * release() hook. The allocated object should be dropped in the
119 * release() hook or before calling this function
123 void drm_global_item_unref(struct drm_global_reference *ref)
125 struct drm_global_item *item = &glob[ref->global_type];
127 mutex_lock(&item->mutex);
128 BUG_ON(item->refcount == 0);
129 BUG_ON(ref->object != item->object);
130 if (--item->refcount == 0) {
134 mutex_unlock(&item->mutex);
136 EXPORT_SYMBOL(drm_global_item_unref);