xref: /linux/drivers/gpu/drm/ttm/ttm_module.c (revision 44f57d78)
1 /* SPDX-License-Identifier: GPL-2.0 OR MIT */
2 /**************************************************************************
3  *
4  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
5  * All Rights Reserved.
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a
8  * copy of this software and associated documentation files (the
9  * "Software"), to deal in the Software without restriction, including
10  * without limitation the rights to use, copy, modify, merge, publish,
11  * distribute, sub license, and/or sell copies of the Software, and to
12  * permit persons to whom the Software is furnished to do so, subject to
13  * the following conditions:
14  *
15  * The above copyright notice and this permission notice (including the
16  * next paragraph) shall be included in all copies or substantial portions
17  * of the Software.
18  *
19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
22  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
23  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
24  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
25  * USE OR OTHER DEALINGS IN THE SOFTWARE.
26  *
27  **************************************************************************/
28 /*
29  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
30  * 	    Jerome Glisse
31  */
32 #include <linux/module.h>
33 #include <linux/device.h>
34 #include <linux/sched.h>
35 #include <drm/ttm/ttm_module.h>
36 #include <drm/drm_sysfs.h>
37 
38 static DECLARE_WAIT_QUEUE_HEAD(exit_q);
39 static atomic_t device_released;
40 
41 static struct device_type ttm_drm_class_type = {
42 	.name = "ttm",
43 	/**
44 	 * Add pm ops here.
45 	 */
46 };
47 
48 static void ttm_drm_class_device_release(struct device *dev)
49 {
50 	atomic_set(&device_released, 1);
51 	wake_up_all(&exit_q);
52 }
53 
54 static struct device ttm_drm_class_device = {
55 	.type = &ttm_drm_class_type,
56 	.release = &ttm_drm_class_device_release
57 };
58 
59 struct kobject *ttm_get_kobj(void)
60 {
61 	struct kobject *kobj = &ttm_drm_class_device.kobj;
62 	BUG_ON(kobj == NULL);
63 	return kobj;
64 }
65 
66 static int __init ttm_init(void)
67 {
68 	int ret;
69 
70 	ret = dev_set_name(&ttm_drm_class_device, "ttm");
71 	if (unlikely(ret != 0))
72 		return ret;
73 
74 	atomic_set(&device_released, 0);
75 	ret = drm_class_device_register(&ttm_drm_class_device);
76 	if (unlikely(ret != 0))
77 		goto out_no_dev_reg;
78 
79 	return 0;
80 out_no_dev_reg:
81 	atomic_set(&device_released, 1);
82 	wake_up_all(&exit_q);
83 	return ret;
84 }
85 
86 static void __exit ttm_exit(void)
87 {
88 	drm_class_device_unregister(&ttm_drm_class_device);
89 
90 	/**
91 	 * Refuse to unload until the TTM device is released.
92 	 * Not sure this is 100% needed.
93 	 */
94 
95 	wait_event(exit_q, atomic_read(&device_released) == 1);
96 }
97 
98 module_init(ttm_init);
99 module_exit(ttm_exit);
100 
101 MODULE_AUTHOR("Thomas Hellstrom, Jerome Glisse");
102 MODULE_DESCRIPTION("TTM memory manager subsystem (for DRM device)");
103 MODULE_LICENSE("GPL and additional rights");
104