drivers/gpu/drm/ttm/ttm_module.c

   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");