xref: /freebsd/sys/dev/drm2/drm_global.c (revision 3078531de10dcae44b253a35125c949ff4235284)
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 __FBSDID("$FreeBSD$");
33 
34 #include <dev/drm2/drmP.h>
35 #include <dev/drm2/drm_global.h>
36 
37 MALLOC_DEFINE(M_DRM_GLOBAL, "drm_global", "DRM Global Items");
38 
39 struct drm_global_item {
40 	struct sx mutex;
41 	void *object;
42 	int refcount;
43 };
44 
45 static struct drm_global_item glob[DRM_GLOBAL_NUM];
46 
47 void drm_global_init(void)
48 {
49 	int i;
50 
51 	for (i = 0; i < DRM_GLOBAL_NUM; ++i) {
52 		struct drm_global_item *item = &glob[i];
53 		sx_init(&item->mutex, "drmgi");
54 		item->object = NULL;
55 		item->refcount = 0;
56 	}
57 }
58 
59 void drm_global_release(void)
60 {
61 	int i;
62 	for (i = 0; i < DRM_GLOBAL_NUM; ++i) {
63 		struct drm_global_item *item = &glob[i];
64 		MPASS(item->object == NULL);
65 		MPASS(item->refcount == 0);
66 		sx_destroy(&item->mutex);
67 	}
68 }
69 
70 int drm_global_item_ref(struct drm_global_reference *ref)
71 {
72 	int ret;
73 	struct drm_global_item *item = &glob[ref->global_type];
74 
75 	sx_xlock(&item->mutex);
76 	if (item->refcount == 0) {
77 		item->object = malloc(ref->size, M_DRM_GLOBAL,
78 		    M_NOWAIT | M_ZERO);
79 		if (unlikely(item->object == NULL)) {
80 			ret = -ENOMEM;
81 			goto out_err;
82 		}
83 
84 		ref->object = item->object;
85 		ret = ref->init(ref);
86 		if (unlikely(ret != 0))
87 			goto out_err;
88 
89 	}
90 	++item->refcount;
91 	ref->object = item->object;
92 	sx_xunlock(&item->mutex);
93 	return 0;
94 out_err:
95 	sx_xunlock(&item->mutex);
96 	item->object = NULL;
97 	return ret;
98 }
99 EXPORT_SYMBOL(drm_global_item_ref);
100 
101 void drm_global_item_unref(struct drm_global_reference *ref)
102 {
103 	struct drm_global_item *item = &glob[ref->global_type];
104 
105 	sx_xlock(&item->mutex);
106 	MPASS(item->refcount != 0);
107 	MPASS(ref->object == item->object);
108 	if (--item->refcount == 0) {
109 		ref->release(ref);
110 		free(item->object, M_DRM_GLOBAL);
111 		item->object = NULL;
112 	}
113 	sx_xunlock(&item->mutex);
114 }
115 EXPORT_SYMBOL(drm_global_item_unref);
116