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>
32 #include <linux/mutex.h>
33 #include <linux/slab.h>
34 #include <linux/module.h>
35 #include <drm/drm_global.h>
37 struct drm_global_item {
43 static struct drm_global_item glob[DRM_GLOBAL_NUM];
45 void drm_global_init(void)
49 for (i = 0; i < DRM_GLOBAL_NUM; ++i) {
50 struct drm_global_item *item = &glob[i];
51 lockinit(&item->mutex, "drmgi", 0, LK_CANRECURSE);
57 void drm_global_release(void)
60 for (i = 0; i < DRM_GLOBAL_NUM; ++i) {
61 struct drm_global_item *item = &glob[i];
62 BUG_ON(item->object != NULL);
63 BUG_ON(item->refcount != 0);
68 * drm_global_item_ref - Initialize and acquire reference to memory
70 * @ref: Object for initialization
72 * This initializes a memory object, allocating memory and calling the
73 * .init() hook. Further calls will increase the reference count for
77 * Zero on success, non-zero otherwise.
79 int drm_global_item_ref(struct drm_global_reference *ref)
82 struct drm_global_item *item = &glob[ref->global_type];
84 mutex_lock(&item->mutex);
85 if (item->refcount == 0) {
86 ref->object = kzalloc(ref->size, GFP_KERNEL);
87 if (unlikely(ref->object == NULL)) {
92 if (unlikely(ret != 0))
95 item->object = ref->object;
97 ref->object = item->object;
101 mutex_unlock(&item->mutex);
108 mutex_unlock(&item->mutex);
111 EXPORT_SYMBOL(drm_global_item_ref);
114 * drm_global_item_unref - Drop reference to memory
116 * @ref: Object being removed
118 * Drop a reference to the memory object and eventually call the
119 * release() hook. The allocated object should be dropped in the
120 * release() hook or before calling this function
124 void drm_global_item_unref(struct drm_global_reference *ref)
126 struct drm_global_item *item = &glob[ref->global_type];
128 mutex_lock(&item->mutex);
129 BUG_ON(item->refcount == 0);
130 BUG_ON(ref->object != item->object);
131 if (--item->refcount == 0) {
135 mutex_unlock(&item->mutex);
137 EXPORT_SYMBOL(drm_global_item_unref);