xref: /dragonfly/sys/dev/drm/drm_global.c (revision ef3ac1d1)
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14  * The above copyright notice and this permission notice (including the
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16  * of the Software.
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27 /*
28  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
29  * $FreeBSD: head/sys/dev/drm2/drm_global.c 248060 2013-03-08 18:11:02Z dumbbell $
30  */
31 
32 #include <drm/drmP.h>
33 #include <drm/drm_global.h>
34 
35 struct drm_global_item {
36 	struct lock mutex;
37 	void *object;
38 	int refcount;
39 };
40 
41 static struct drm_global_item glob[DRM_GLOBAL_NUM];
42 
43 void drm_global_init(void)
44 {
45 	int i;
46 
47 	for (i = 0; i < DRM_GLOBAL_NUM; ++i) {
48 		struct drm_global_item *item = &glob[i];
49 		lockinit(&item->mutex, "drmgi", 0, LK_CANRECURSE);
50 		item->object = NULL;
51 		item->refcount = 0;
52 	}
53 }
54 
55 void drm_global_release(void)
56 {
57 	int i;
58 	for (i = 0; i < DRM_GLOBAL_NUM; ++i) {
59 		struct drm_global_item *item = &glob[i];
60 		KKASSERT(item->object == NULL);
61 		KKASSERT(item->refcount == 0);
62 		lockuninit(&item->mutex);
63 	}
64 }
65 
66 int drm_global_item_ref(struct drm_global_reference *ref)
67 {
68 	int ret;
69 	struct drm_global_item *item = &glob[ref->global_type];
70 	void *object;
71 
72 	lockmgr(&item->mutex, LK_EXCLUSIVE);
73 	if (item->refcount == 0) {
74 		item->object = kmalloc(ref->size, M_DRM,
75 		    M_WAITOK | M_ZERO);
76 
77 		ref->object = item->object;
78 		ret = ref->init(ref);
79 		if (unlikely(ret != 0))
80 			goto out_err;
81 
82 	}
83 	++item->refcount;
84 	ref->object = item->object;
85 	object = item->object;
86 	lockmgr(&item->mutex, LK_RELEASE);
87 	return 0;
88 out_err:
89 	lockmgr(&item->mutex, LK_RELEASE);
90 	item->object = NULL;
91 	return ret;
92 }
93 
94 void drm_global_item_unref(struct drm_global_reference *ref)
95 {
96 	struct drm_global_item *item = &glob[ref->global_type];
97 
98 	lockmgr(&item->mutex, LK_EXCLUSIVE);
99 	KKASSERT(item->refcount != 0);
100 	KKASSERT(ref->object == item->object);
101 	if (--item->refcount == 0) {
102 		ref->release(ref);
103 		drm_free(item->object, M_DRM);
104 		item->object = NULL;
105 	}
106 	lockmgr(&item->mutex, LK_RELEASE);
107 }
108