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ttm_module.c revision 1.1.1.1.36.1 
      1 /*	$NetBSD: ttm_module.c,v 1.1.1.1.36.1 2018/09/06 06:56:34 pgoyette Exp $	*/
      2 
      3 /**************************************************************************
      4  *
      5  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
      6  * All Rights Reserved.
      7  *
      8  * Permission is hereby granted, free of charge, to any person obtaining a
      9  * copy of this software and associated documentation files (the
     10  * "Software"), to deal in the Software without restriction, including
     11  * without limitation the rights to use, copy, modify, merge, publish,
     12  * distribute, sub license, and/or sell copies of the Software, and to
     13  * permit persons to whom the Software is furnished to do so, subject to
     14  * the following conditions:
     15  *
     16  * The above copyright notice and this permission notice (including the
     17  * next paragraph) shall be included in all copies or substantial portions
     18  * of the Software.
     19  *
     20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     22  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
     23  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
     24  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
     25  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
     26  * USE OR OTHER DEALINGS IN THE SOFTWARE.
     27  *
     28  **************************************************************************/
     29 /*
     30  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
     31  * 	    Jerome Glisse
     32  */
     33 #include <sys/cdefs.h>
     34 __KERNEL_RCSID(0, "$NetBSD: ttm_module.c,v 1.1.1.1.36.1 2018/09/06 06:56:34 pgoyette Exp $");
     35 
     36 #include <linux/module.h>
     37 #include <linux/device.h>
     38 #include <linux/sched.h>
     39 #include <drm/ttm/ttm_module.h>
     40 #include <drm/drm_sysfs.h>
     41 
     42 static DECLARE_WAIT_QUEUE_HEAD(exit_q);
     43 static atomic_t device_released;
     44 
     45 static struct device_type ttm_drm_class_type = {
     46 	.name = "ttm",
     47 	/**
     48 	 * Add pm ops here.
     49 	 */
     50 };
     51 
     52 static void ttm_drm_class_device_release(struct device *dev)
     53 {
     54 	atomic_set(&device_released, 1);
     55 	wake_up_all(&exit_q);
     56 }
     57 
     58 static struct device ttm_drm_class_device = {
     59 	.type = &ttm_drm_class_type,
     60 	.release = &ttm_drm_class_device_release
     61 };
     62 
     63 struct kobject *ttm_get_kobj(void)
     64 {
     65 	struct kobject *kobj = &ttm_drm_class_device.kobj;
     66 	BUG_ON(kobj == NULL);
     67 	return kobj;
     68 }
     69 
     70 static int __init ttm_init(void)
     71 {
     72 	int ret;
     73 
     74 	ret = dev_set_name(&ttm_drm_class_device, "ttm");
     75 	if (unlikely(ret != 0))
     76 		return ret;
     77 
     78 	atomic_set(&device_released, 0);
     79 	ret = drm_class_device_register(&ttm_drm_class_device);
     80 	if (unlikely(ret != 0))
     81 		goto out_no_dev_reg;
     82 
     83 	return 0;
     84 out_no_dev_reg:
     85 	atomic_set(&device_released, 1);
     86 	wake_up_all(&exit_q);
     87 	return ret;
     88 }
     89 
     90 static void __exit ttm_exit(void)
     91 {
     92 	drm_class_device_unregister(&ttm_drm_class_device);
     93 
     94 	/**
     95 	 * Refuse to unload until the TTM device is released.
     96 	 * Not sure this is 100% needed.
     97 	 */
     98 
     99 	wait_event(exit_q, atomic_read(&device_released) == 1);
    100 }
    101 
    102 module_init(ttm_init);
    103 module_exit(ttm_exit);
    104 
    105 MODULE_AUTHOR("Thomas Hellstrom, Jerome Glisse");
    106 MODULE_DESCRIPTION("TTM memory manager subsystem (for DRM device)");
    107 MODULE_LICENSE("GPL and additional rights");
    108