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ba4e7d97 TH |
1 | /************************************************************************** |
2 | * | |
3 | * Copyright 2008-2009 VMware, Inc., Palo Alto, CA., USA | |
4 | * All Rights Reserved. | |
5 | * | |
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: | |
13 | * | |
14 | * The above copyright notice and this permission notice (including the | |
15 | * next paragraph) shall be included in all copies or substantial portions | |
16 | * of the Software. | |
17 | * | |
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. | |
25 | * | |
26 | **************************************************************************/ | |
27 | /* | |
28 | * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com> | |
29 | */ | |
30 | ||
ba4e7d97 TH |
31 | #include <linux/mutex.h> |
32 | #include <linux/slab.h> | |
33 | #include <linux/module.h> | |
760285e7 | 34 | #include <drm/drm_global.h> |
ba4e7d97 | 35 | |
ba4420c2 | 36 | struct drm_global_item { |
ba4e7d97 TH |
37 | struct mutex mutex; |
38 | void *object; | |
39 | int refcount; | |
40 | }; | |
41 | ||
ba4420c2 | 42 | static struct drm_global_item glob[DRM_GLOBAL_NUM]; |
ba4e7d97 | 43 | |
ba4420c2 | 44 | void drm_global_init(void) |
ba4e7d97 TH |
45 | { |
46 | int i; | |
47 | ||
ba4420c2 DA |
48 | for (i = 0; i < DRM_GLOBAL_NUM; ++i) { |
49 | struct drm_global_item *item = &glob[i]; | |
ba4e7d97 TH |
50 | mutex_init(&item->mutex); |
51 | item->object = NULL; | |
52 | item->refcount = 0; | |
53 | } | |
54 | } | |
55 | ||
ba4420c2 | 56 | void drm_global_release(void) |
ba4e7d97 TH |
57 | { |
58 | int i; | |
ba4420c2 DA |
59 | for (i = 0; i < DRM_GLOBAL_NUM; ++i) { |
60 | struct drm_global_item *item = &glob[i]; | |
ba4e7d97 TH |
61 | BUG_ON(item->object != NULL); |
62 | BUG_ON(item->refcount != 0); | |
63 | } | |
64 | } | |
65 | ||
b834ff86 GKB |
66 | /** |
67 | * drm_global_item_ref - Initialize and acquire reference to memory | |
68 | * object | |
69 | * @ref: Object for initialization | |
70 | * | |
71 | * This initializes a memory object, allocating memory and calling the | |
72 | * .init() hook. Further calls will increase the reference count for | |
73 | * that item. | |
74 | * | |
75 | * Returns: | |
76 | * Zero on success, non-zero otherwise. | |
77 | */ | |
ba4420c2 | 78 | int drm_global_item_ref(struct drm_global_reference *ref) |
ba4e7d97 | 79 | { |
d28d6e6f | 80 | int ret = 0; |
ba4420c2 | 81 | struct drm_global_item *item = &glob[ref->global_type]; |
ba4e7d97 TH |
82 | |
83 | mutex_lock(&item->mutex); | |
84 | if (item->refcount == 0) { | |
d28d6e6f HR |
85 | ref->object = kzalloc(ref->size, GFP_KERNEL); |
86 | if (unlikely(ref->object == NULL)) { | |
ba4e7d97 | 87 | ret = -ENOMEM; |
d28d6e6f | 88 | goto error_unlock; |
ba4e7d97 | 89 | } |
ba4e7d97 TH |
90 | ret = ref->init(ref); |
91 | if (unlikely(ret != 0)) | |
d28d6e6f | 92 | goto error_free; |
ba4e7d97 | 93 | |
d28d6e6f HR |
94 | item->object = ref->object; |
95 | } else { | |
96 | ref->object = item->object; | |
ba4e7d97 | 97 | } |
d28d6e6f | 98 | |
df748b02 | 99 | ++item->refcount; |
ba4e7d97 TH |
100 | mutex_unlock(&item->mutex); |
101 | return 0; | |
d28d6e6f HR |
102 | |
103 | error_free: | |
104 | kfree(ref->object); | |
105 | ref->object = NULL; | |
106 | error_unlock: | |
ba4e7d97 | 107 | mutex_unlock(&item->mutex); |
ba4e7d97 TH |
108 | return ret; |
109 | } | |
ba4420c2 | 110 | EXPORT_SYMBOL(drm_global_item_ref); |
ba4e7d97 | 111 | |
b834ff86 GKB |
112 | /** |
113 | * drm_global_item_unref - Drop reference to memory | |
114 | * object | |
115 | * @ref: Object being removed | |
116 | * | |
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 | |
120 | * | |
121 | */ | |
122 | ||
ba4420c2 | 123 | void drm_global_item_unref(struct drm_global_reference *ref) |
ba4e7d97 | 124 | { |
ba4420c2 | 125 | struct drm_global_item *item = &glob[ref->global_type]; |
ba4e7d97 TH |
126 | |
127 | mutex_lock(&item->mutex); | |
128 | BUG_ON(item->refcount == 0); | |
129 | BUG_ON(ref->object != item->object); | |
130 | if (--item->refcount == 0) { | |
131 | ref->release(ref); | |
ba4e7d97 TH |
132 | item->object = NULL; |
133 | } | |
134 | mutex_unlock(&item->mutex); | |
135 | } | |
ba4420c2 | 136 | EXPORT_SYMBOL(drm_global_item_unref); |
ba4e7d97 | 137 |