xref: /freebsd/sys/dev/drm2/drm_global.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
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 
31 #include <sys/cdefs.h>
32 #include <dev/drm2/drmP.h>
33 #include <dev/drm2/drm_global.h>
34 
35 MALLOC_DEFINE(M_DRM_GLOBAL, "drm_global", "DRM Global Items");
36 
37 struct drm_global_item {
38 	struct sx mutex;
39 	void *object;
40 	int refcount;
41 };
42 
43 static struct drm_global_item glob[DRM_GLOBAL_NUM];
44 
45 void drm_global_init(void)
46 {
47 	int i;
48 
49 	for (i = 0; i < DRM_GLOBAL_NUM; ++i) {
50 		struct drm_global_item *item = &glob[i];
51 		sx_init(&item->mutex, "drmgi");
52 		item->object = NULL;
53 		item->refcount = 0;
54 	}
55 }
56 
57 void drm_global_release(void)
58 {
59 	int i;
60 	for (i = 0; i < DRM_GLOBAL_NUM; ++i) {
61 		struct drm_global_item *item = &glob[i];
62 		MPASS(item->object == NULL);
63 		MPASS(item->refcount == 0);
64 		sx_destroy(&item->mutex);
65 	}
66 }
67 
68 int drm_global_item_ref(struct drm_global_reference *ref)
69 {
70 	int ret;
71 	struct drm_global_item *item = &glob[ref->global_type];
72 
73 	sx_xlock(&item->mutex);
74 	if (item->refcount == 0) {
75 		item->object = malloc(ref->size, M_DRM_GLOBAL,
76 		    M_NOWAIT | M_ZERO);
77 		if (unlikely(item->object == NULL)) {
78 			ret = -ENOMEM;
79 			goto out_err;
80 		}
81 
82 		ref->object = item->object;
83 		ret = ref->init(ref);
84 		if (unlikely(ret != 0))
85 			goto out_err;
86 
87 	}
88 	++item->refcount;
89 	ref->object = item->object;
90 	sx_xunlock(&item->mutex);
91 	return 0;
92 out_err:
93 	sx_xunlock(&item->mutex);
94 	item->object = NULL;
95 	return ret;
96 }
97 EXPORT_SYMBOL(drm_global_item_ref);
98 
99 void drm_global_item_unref(struct drm_global_reference *ref)
100 {
101 	struct drm_global_item *item = &glob[ref->global_type];
102 
103 	sx_xlock(&item->mutex);
104 	MPASS(item->refcount != 0);
105 	MPASS(ref->object == item->object);
106 	if (--item->refcount == 0) {
107 		ref->release(ref);
108 		free(item->object, M_DRM_GLOBAL);
109 		item->object = NULL;
110 	}
111 	sx_xunlock(&item->mutex);
112 }
113 EXPORT_SYMBOL(drm_global_item_unref);
114