LXR linux/drivers/gpu/drm/ttm/ttm

   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
  38static DECLARE_WAIT_QUEUE_HEAD(exit_q);
  39static atomic_t device_released;
  40
  41static struct device_type ttm_drm_class_type = {
  42        .name = "ttm",
  43        /**
  44         * Add pm ops here.
  45         */
  46};
  47
  48static void ttm_drm_class_device_release(struct device *dev)
  49{
  50        atomic_set(&device_released, 1);
  51        wake_up_all(&exit_q);
  52}
  53
  54static struct device ttm_drm_class_device = {
  55        .type = &ttm_drm_class_type,
  56        .release = &ttm_drm_class_device_release
  57};
  58
  59struct 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
  66static 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;
  80out_no_dev_reg:
  81        atomic_set(&device_released, 1);
  82        wake_up_all(&exit_q);
  83        return ret;
  84}
  85
  86static 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
  98module_init(ttm_init);
  99module_exit(ttm_exit);
 100
 101MODULE_AUTHOR("Thomas Hellstrom, Jerome Glisse");
 102MODULE_DESCRIPTION("TTM memory manager subsystem (for DRM device)");
 103MODULE_LICENSE("GPL and additional rights");
 104