1 /* $NetBSD: ttm_module.c,v 1.3 2021/12/18 23:45:44 riastradh Exp $ */
2
3 /* SPDX-License-Identifier: GPL-2.0 OR MIT */
4 /**************************************************************************
5 *
6 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
7 * All Rights Reserved.
8 *
9 * Permission is hereby granted, free of charge, to any person obtaining a
10 * copy of this software and associated documentation files (the
11 * "Software"), to deal in the Software without restriction, including
12 * without limitation the rights to use, copy, modify, merge, publish,
13 * distribute, sub license, and/or sell copies of the Software, and to
14 * permit persons to whom the Software is furnished to do so, subject to
15 * the following conditions:
16 *
17 * The above copyright notice and this permission notice (including the
18 * next paragraph) shall be included in all copies or substantial portions
19 * of the Software.
20 *
21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
22 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
24 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
25 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
26 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
27 * USE OR OTHER DEALINGS IN THE SOFTWARE.
28 *
29 **************************************************************************/
30 /*
31 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
32 * Jerome Glisse
33 */
34 #include <sys/cdefs.h>
35 __KERNEL_RCSID(0, "$NetBSD: ttm_module.c,v 1.3 2021/12/18 23:45:44 riastradh Exp $");
36
37 #include <linux/module.h>
38 #include <linux/device.h>
39 #include <linux/sched.h>
40 #include <drm/ttm/ttm_module.h>
41 #include <drm/drm_sysfs.h>
42
43 static DECLARE_WAIT_QUEUE_HEAD(exit_q);
44 static atomic_t device_released;
45
46 static struct device_type ttm_drm_class_type = {
47 .name = "ttm",
48 /**
49 * Add pm ops here.
50 */
51 };
52
ttm_drm_class_device_release(struct device * dev)53 static void ttm_drm_class_device_release(struct device *dev)
54 {
55 atomic_set(&device_released, 1);
56 wake_up_all(&exit_q);
57 }
58
59 static struct device ttm_drm_class_device = {
60 .type = &ttm_drm_class_type,
61 .release = &ttm_drm_class_device_release
62 };
63
ttm_get_kobj(void)64 struct kobject *ttm_get_kobj(void)
65 {
66 struct kobject *kobj = &ttm_drm_class_device.kobj;
67 BUG_ON(kobj == NULL);
68 return kobj;
69 }
70
ttm_init(void)71 static int __init ttm_init(void)
72 {
73 int ret;
74
75 ret = dev_set_name(&ttm_drm_class_device, "ttm");
76 if (unlikely(ret != 0))
77 return ret;
78
79 atomic_set(&device_released, 0);
80 ret = drm_class_device_register(&ttm_drm_class_device);
81 if (unlikely(ret != 0))
82 goto out_no_dev_reg;
83
84 return 0;
85 out_no_dev_reg:
86 atomic_set(&device_released, 1);
87 wake_up_all(&exit_q);
88 return ret;
89 }
90
ttm_exit(void)91 static void __exit ttm_exit(void)
92 {
93 drm_class_device_unregister(&ttm_drm_class_device);
94
95 /**
96 * Refuse to unload until the TTM device is released.
97 * Not sure this is 100% needed.
98 */
99
100 wait_event(exit_q, atomic_read(&device_released) == 1);
101 }
102
103 module_init(ttm_init);
104 module_exit(ttm_exit);
105
106 MODULE_AUTHOR("Thomas Hellstrom, Jerome Glisse");
107 MODULE_DESCRIPTION("TTM memory manager subsystem (for DRM device)");
108 MODULE_LICENSE("GPL and additional rights");
109