drivers/char/drm/drm_fops.c - kernel/msm-4.19 - Gitiles

 /**
  * \file drm_fops.c
  * File operations for DRM
  *
  * \author Rickard E. (Rik) Faith <faith@valinux.com>
  * \author Daryll Strauss <daryll@valinux.com>
  * \author Gareth Hughes <gareth@valinux.com>
  */

 /*
  * Created: Mon Jan  4 08:58:31 1999 by faith@valinux.com
  *
  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
  * All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice (including the next
  * paragraph) shall be included in all copies or substantial portions of the
  * Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  * OTHER DEALINGS IN THE SOFTWARE.
  */

 #include "drmP.h"
 #include "drm_sarea.h"
 #include <linux/poll.h>

 static int drm_open_helper(struct inode *inode, struct file *filp,
 			   drm_device_t * dev);

 static int drm_setup(drm_device_t * dev)
 {
 	drm_local_map_t *map;
 	int i;
 	int ret;

 	if (dev->driver->firstopen) {
 		ret = dev->driver->firstopen(dev);
 		if (ret != 0)
 			return ret;
 	}

 	/* prebuild the SAREA */
 	i = drm_addmap(dev, 0, SAREA_MAX, _DRM_SHM, _DRM_CONTAINS_LOCK, &map);
 	if (i != 0)
 		return i;

 	atomic_set(&dev->ioctl_count, 0);
 	atomic_set(&dev->vma_count, 0);
 	dev->buf_use = 0;
 	atomic_set(&dev->buf_alloc, 0);

 	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA)) {
 		i = drm_dma_setup(dev);
 		if (i < 0)
 			return i;
 	}

 	for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
 		atomic_set(&dev->counts[i], 0);

 	for (i = 0; i < DRM_HASH_SIZE; i++) {
 		dev->magiclist[i].head = NULL;
 		dev->magiclist[i].tail = NULL;
 	}

 	dev->ctxlist = drm_alloc(sizeof(*dev->ctxlist), DRM_MEM_CTXLIST);
 	if (dev->ctxlist == NULL)
 		return -ENOMEM;
 	memset(dev->ctxlist, 0, sizeof(*dev->ctxlist));
 	INIT_LIST_HEAD(&dev->ctxlist->head);

 	dev->vmalist = NULL;
 	dev->sigdata.lock = dev->lock.hw_lock = NULL;
 	init_waitqueue_head(&dev->lock.lock_queue);
 	dev->queue_count = 0;
 	dev->queue_reserved = 0;
 	dev->queue_slots = 0;
 	dev->queuelist = NULL;
 	dev->irq_enabled = 0;
 	dev->context_flag = 0;
 	dev->interrupt_flag = 0;
 	dev->dma_flag = 0;
 	dev->last_context = 0;
 	dev->last_switch = 0;
 	dev->last_checked = 0;
 	init_waitqueue_head(&dev->context_wait);
 	dev->if_version = 0;

 	dev->ctx_start = 0;
 	dev->lck_start = 0;

 	dev->buf_async = NULL;
 	init_waitqueue_head(&dev->buf_readers);
 	init_waitqueue_head(&dev->buf_writers);

 	DRM_DEBUG("\n");

 	/*
 	 * The kernel's context could be created here, but is now created
 	 * in drm_dma_enqueue.  This is more resource-efficient for
 	 * hardware that does not do DMA, but may mean that
 	 * drm_select_queue fails between the time the interrupt is
 	 * initialized and the time the queues are initialized.
 	 */

 	return 0;
 }

 /**
  * Open file.
  *
  * \param inode device inode
  * \param filp file pointer.
  * \return zero on success or a negative number on failure.
  *
  * Searches the DRM device with the same minor number, calls open_helper(), and
  * increments the device open count. If the open count was previous at zero,
  * i.e., it's the first that the device is open, then calls setup().
  */
 int drm_open(struct inode *inode, struct file *filp)
 {
 	drm_device_t *dev = NULL;
 	int minor = iminor(inode);
 	int retcode = 0;

 	if (!((minor >= 0) && (minor < drm_cards_limit)))
 		return -ENODEV;

 	if (!drm_heads[minor])
 		return -ENODEV;

 	if (!(dev = drm_heads[minor]->dev))
 		return -ENODEV;

 	retcode = drm_open_helper(inode, filp, dev);
 	if (!retcode) {
 		atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
 		spin_lock(&dev->count_lock);
 		if (!dev->open_count++) {
 			spin_unlock(&dev->count_lock);
 			return drm_setup(dev);
 		}
 		spin_unlock(&dev->count_lock);
 	}

 	return retcode;
 }
 EXPORT_SYMBOL(drm_open);

 /**
  * File \c open operation.
  *
  * \param inode device inode.
  * \param filp file pointer.
  *
  * Puts the dev->fops corresponding to the device minor number into
  * \p filp, call the \c open method, and restore the file operations.
  */
 int drm_stub_open(struct inode *inode, struct file *filp)
 {
 	drm_device_t *dev = NULL;
 	int minor = iminor(inode);
 	int err = -ENODEV;
 	const struct file_operations *old_fops;

 	DRM_DEBUG("\n");

 	if (!((minor >= 0) && (minor < drm_cards_limit)))
 		return -ENODEV;

 	if (!drm_heads[minor])
 		return -ENODEV;

 	if (!(dev = drm_heads[minor]->dev))
 		return -ENODEV;

 	old_fops = filp->f_op;
 	filp->f_op = fops_get(&dev->driver->fops);
 	if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
 		fops_put(filp->f_op);
 		filp->f_op = fops_get(old_fops);
 	}
 	fops_put(old_fops);

 	return err;
 }

 /**
  * Check whether DRI will run on this CPU.
  *
  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
  */
 static int drm_cpu_valid(void)
 {
 #if defined(__i386__)
 	if (boot_cpu_data.x86 == 3)
 		return 0;	/* No cmpxchg on a 386 */
 #endif
 #if defined(__sparc__) && !defined(__sparc_v9__)
 	return 0;		/* No cmpxchg before v9 sparc. */
 #endif
 	return 1;
 }

 /**
  * Called whenever a process opens /dev/drm.
  *
  * \param inode device inode.
  * \param filp file pointer.
  * \param dev device.
  * \return zero on success or a negative number on failure.
  *
  * Creates and initializes a drm_file structure for the file private data in \p
  * filp and add it into the double linked list in \p dev.
  */
 static int drm_open_helper(struct inode *inode, struct file *filp,
 			   drm_device_t * dev)
 {
 	int minor = iminor(inode);
 	drm_file_t *priv;
 	int ret;

 	if (filp->f_flags & O_EXCL)
 		return -EBUSY;	/* No exclusive opens */
 	if (!drm_cpu_valid())
 		return -EINVAL;

 	DRM_DEBUG("pid = %d, minor = %d\n", current->pid, minor);

 	priv = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
 	if (!priv)
 		return -ENOMEM;

 	memset(priv, 0, sizeof(*priv));
 	filp->private_data = priv;
 	priv->uid = current->euid;
 	priv->pid = current->pid;
 	priv->minor = minor;
 	priv->head = drm_heads[minor];
 	priv->ioctl_count = 0;
 	/* for compatibility root is always authenticated */
 	priv->authenticated = capable(CAP_SYS_ADMIN);
 	priv->lock_count = 0;

 	if (dev->driver->open) {
 		ret = dev->driver->open(dev, priv);
 		if (ret < 0)
 			goto out_free;
 	}

 	mutex_lock(&dev->struct_mutex);
 	if (!dev->file_last) {
 		priv->next = NULL;
 		priv->prev = NULL;
 		dev->file_first = priv;
 		dev->file_last = priv;
 		/* first opener automatically becomes master */
 		priv->master = 1;
 	} else {
 		priv->next = NULL;
 		priv->prev = dev->file_last;
 		dev->file_last->next = priv;
 		dev->file_last = priv;
 	}
 	mutex_unlock(&dev->struct_mutex);

 #ifdef __alpha__
 	/*
 	 * Default the hose
 	 */
 	if (!dev->hose) {
 		struct pci_dev *pci_dev;
 		pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
 		if (pci_dev) {
 			dev->hose = pci_dev->sysdata;
 			pci_dev_put(pci_dev);
 		}
 		if (!dev->hose) {
 			struct pci_bus *b = pci_bus_b(pci_root_buses.next);
 			if (b)
 				dev->hose = b->sysdata;
 		}
 	}
 #endif

 	return 0;
       out_free:
 	drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
 	filp->private_data = NULL;
 	return ret;
 }

 /** No-op. */
 int drm_fasync(int fd, struct file *filp, int on)
 {
 	drm_file_t *priv = filp->private_data;
 	drm_device_t *dev = priv->head->dev;
 	int retcode;

 	DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
 		  (long)old_encode_dev(priv->head->device));
 	retcode = fasync_helper(fd, filp, on, &dev->buf_async);
 	if (retcode < 0)
 		return retcode;
 	return 0;
 }
 EXPORT_SYMBOL(drm_fasync);

 /**
  * Release file.
  *
  * \param inode device inode
  * \param filp file pointer.
  * \return zero on success or a negative number on failure.
  *
  * If the hardware lock is held then free it, and take it again for the kernel
  * context since it's necessary to reclaim buffers. Unlink the file private
  * data from its list and free it. Decreases the open count and if it reaches
  * zero calls drm_lastclose().
  */
 int drm_release(struct inode *inode, struct file *filp)
 {
 	drm_file_t *priv = filp->private_data;
 	drm_device_t *dev;
 	int retcode = 0;

 	lock_kernel();
 	dev = priv->head->dev;

 	DRM_DEBUG("open_count = %d\n", dev->open_count);

 	if (dev->driver->preclose)
 		dev->driver->preclose(dev, filp);

 	/* ========================================================
 	 * Begin inline drm_release
 	 */

 	DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
 		  current->pid, (long)old_encode_dev(priv->head->device),
 		  dev->open_count);

 	if (priv->lock_count && dev->lock.hw_lock &&
 	    _DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock) &&
 	    dev->lock.filp == filp) {
 		DRM_DEBUG("File %p released, freeing lock for context %d\n",
 			  filp, _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));

 		if (dev->driver->reclaim_buffers_locked)
 			dev->driver->reclaim_buffers_locked(dev, filp);

 		drm_lock_free(dev, &dev->lock.hw_lock->lock,
 			      _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));

 		/* FIXME: may require heavy-handed reset of
 		   hardware at this point, possibly
 		   processed via a callback to the X
 		   server. */
 	} else if (dev->driver->reclaim_buffers_locked && priv->lock_count
 		   && dev->lock.hw_lock) {
 		/* The lock is required to reclaim buffers */
 		DECLARE_WAITQUEUE(entry, current);

 		add_wait_queue(&dev->lock.lock_queue, &entry);
 		for (;;) {
 			__set_current_state(TASK_INTERRUPTIBLE);
 			if (!dev->lock.hw_lock) {
 				/* Device has been unregistered */
 				retcode = -EINTR;
 				break;
 			}
 			if (drm_lock_take(&dev->lock.hw_lock->lock,
 					  DRM_KERNEL_CONTEXT)) {
 				dev->lock.filp = filp;
 				dev->lock.lock_time = jiffies;
 				atomic_inc(&dev->counts[_DRM_STAT_LOCKS]);
 				break;	/* Got lock */
 			}
 			/* Contention */
 			schedule();
 			if (signal_pending(current)) {
 				retcode = -ERESTARTSYS;
 				break;
 			}
 		}
 		__set_current_state(TASK_RUNNING);
 		remove_wait_queue(&dev->lock.lock_queue, &entry);
 		if (!retcode) {
 			dev->driver->reclaim_buffers_locked(dev, filp);
 			drm_lock_free(dev, &dev->lock.hw_lock->lock,
 				      DRM_KERNEL_CONTEXT);
 		}
 	}

 	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
 	    !dev->driver->reclaim_buffers_locked) {
 		dev->driver->reclaim_buffers(dev, filp);
 	}

 	drm_fasync(-1, filp, 0);

 	mutex_lock(&dev->ctxlist_mutex);
 	if (dev->ctxlist && (!list_empty(&dev->ctxlist->head))) {
 		drm_ctx_list_t *pos, *n;

 		list_for_each_entry_safe(pos, n, &dev->ctxlist->head, head) {
 			if (pos->tag == priv &&
 			    pos->handle != DRM_KERNEL_CONTEXT) {
 				if (dev->driver->context_dtor)
 					dev->driver->context_dtor(dev,
 								  pos->handle);

 				drm_ctxbitmap_free(dev, pos->handle);

 				list_del(&pos->head);
 				drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
 				--dev->ctx_count;
 			}
 		}
 	}
 	mutex_unlock(&dev->ctxlist_mutex);

 	mutex_lock(&dev->struct_mutex);
 	if (priv->remove_auth_on_close == 1) {
 		drm_file_t *temp = dev->file_first;
 		while (temp) {
 			temp->authenticated = 0;
 			temp = temp->next;
 		}
 	}
 	if (priv->prev) {
 		priv->prev->next = priv->next;
 	} else {
 		dev->file_first = priv->next;
 	}
 	if (priv->next) {
 		priv->next->prev = priv->prev;
 	} else {
 		dev->file_last = priv->prev;
 	}
 	mutex_unlock(&dev->struct_mutex);

 	if (dev->driver->postclose)
 		dev->driver->postclose(dev, priv);
 	drm_free(priv, sizeof(*priv), DRM_MEM_FILES);

 	/* ========================================================
 	 * End inline drm_release
 	 */

 	atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
 	spin_lock(&dev->count_lock);
 	if (!--dev->open_count) {
 		if (atomic_read(&dev->ioctl_count) || dev->blocked) {
 			DRM_ERROR("Device busy: %d %d\n",
 				  atomic_read(&dev->ioctl_count), dev->blocked);
 			spin_unlock(&dev->count_lock);
 			unlock_kernel();
 			return -EBUSY;
 		}
 		spin_unlock(&dev->count_lock);
 		unlock_kernel();
 		return drm_lastclose(dev);
 	}
 	spin_unlock(&dev->count_lock);

 	unlock_kernel();

 	return retcode;
 }
 EXPORT_SYMBOL(drm_release);

 /** No-op. */
 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 {
 	return 0;
 }
 EXPORT_SYMBOL(drm_poll);
	/**
	* \file drm_fops.c
	* File operations for DRM
	*
	* \author Rickard E. (Rik) Faith <faith@valinux.com>
	* \author Daryll Strauss <daryll@valinux.com>
	* \author Gareth Hughes <gareth@valinux.com>
	*/

	/*
	* Created: Mon Jan 4 08:58:31 1999 by faith@valinux.com
	*
	* Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
	* Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
	* All Rights Reserved.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the "Software"),
	* to deal in the Software without restriction, including without limitation
	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	* and/or sell copies of the Software, and to permit persons to whom the
	* Software is furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice (including the next
	* paragraph) shall be included in all copies or substantial portions of the
	* Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
	* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
	* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
	* OTHER DEALINGS IN THE SOFTWARE.
	*/

	#include "drmP.h"
	#include "drm_sarea.h"
	#include <linux/poll.h>

	static int drm_open_helper(struct inode inode, struct file filp,
	drm_device_t * dev);

	static int drm_setup(drm_device_t * dev)
	{
	drm_local_map_t *map;
	int i;
	int ret;

	if (dev->driver->firstopen) {
	ret = dev->driver->firstopen(dev);
	if (ret != 0)
	return ret;
	}

	/* prebuild the SAREA */
	i = drm_addmap(dev, 0, SAREA_MAX, _DRM_SHM, _DRM_CONTAINS_LOCK, &map);
	if (i != 0)
	return i;

	atomic_set(&dev->ioctl_count, 0);
	atomic_set(&dev->vma_count, 0);
	dev->buf_use = 0;
	atomic_set(&dev->buf_alloc, 0);

	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA)) {
	i = drm_dma_setup(dev);
	if (i < 0)
	return i;
	}

	for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
	atomic_set(&dev->counts[i], 0);

	for (i = 0; i < DRM_HASH_SIZE; i++) {
	dev->magiclist[i].head = NULL;
	dev->magiclist[i].tail = NULL;
	}

	dev->ctxlist = drm_alloc(sizeof(*dev->ctxlist), DRM_MEM_CTXLIST);
	if (dev->ctxlist == NULL)
	return -ENOMEM;
	memset(dev->ctxlist, 0, sizeof(*dev->ctxlist));
	INIT_LIST_HEAD(&dev->ctxlist->head);

	dev->vmalist = NULL;
	dev->sigdata.lock = dev->lock.hw_lock = NULL;
	init_waitqueue_head(&dev->lock.lock_queue);
	dev->queue_count = 0;
	dev->queue_reserved = 0;
	dev->queue_slots = 0;
	dev->queuelist = NULL;
	dev->irq_enabled = 0;
	dev->context_flag = 0;
	dev->interrupt_flag = 0;
	dev->dma_flag = 0;
	dev->last_context = 0;
	dev->last_switch = 0;
	dev->last_checked = 0;
	init_waitqueue_head(&dev->context_wait);
	dev->if_version = 0;

	dev->ctx_start = 0;
	dev->lck_start = 0;

	dev->buf_async = NULL;
	init_waitqueue_head(&dev->buf_readers);
	init_waitqueue_head(&dev->buf_writers);

	DRM_DEBUG("\n");

	/*
	* The kernel's context could be created here, but is now created
	* in drm_dma_enqueue. This is more resource-efficient for
	* hardware that does not do DMA, but may mean that
	* drm_select_queue fails between the time the interrupt is
	* initialized and the time the queues are initialized.
	*/

	return 0;
	}

	/**
	* Open file.
	*
	* \param inode device inode
	* \param filp file pointer.
	* \return zero on success or a negative number on failure.
	*
	* Searches the DRM device with the same minor number, calls open_helper(), and
	* increments the device open count. If the open count was previous at zero,
	* i.e., it's the first that the device is open, then calls setup().
	*/
	int drm_open(struct inode inode, struct file filp)
	{
	drm_device_t *dev = NULL;
	int minor = iminor(inode);
	int retcode = 0;

	if (!((minor >= 0) && (minor < drm_cards_limit)))
	return -ENODEV;

	if (!drm_heads[minor])
	return -ENODEV;

	if (!(dev = drm_heads[minor]->dev))
	return -ENODEV;

	retcode = drm_open_helper(inode, filp, dev);
	if (!retcode) {
	atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
	spin_lock(&dev->count_lock);
	if (!dev->open_count++) {
	spin_unlock(&dev->count_lock);
	return drm_setup(dev);
	}
	spin_unlock(&dev->count_lock);
	}

	return retcode;
	}
	EXPORT_SYMBOL(drm_open);

	/**
	* File \c open operation.
	*
	* \param inode device inode.
	* \param filp file pointer.
	*
	* Puts the dev->fops corresponding to the device minor number into
	* \p filp, call the \c open method, and restore the file operations.
	*/
	int drm_stub_open(struct inode inode, struct file filp)
	{
	drm_device_t *dev = NULL;
	int minor = iminor(inode);
	int err = -ENODEV;
	const struct file_operations *old_fops;

	DRM_DEBUG("\n");

	if (!((minor >= 0) && (minor < drm_cards_limit)))
	return -ENODEV;

	if (!drm_heads[minor])
	return -ENODEV;

	if (!(dev = drm_heads[minor]->dev))
	return -ENODEV;

	old_fops = filp->f_op;
	filp->f_op = fops_get(&dev->driver->fops);
	if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
	fops_put(filp->f_op);
	filp->f_op = fops_get(old_fops);
	}
	fops_put(old_fops);

	return err;
	}

	/**
	* Check whether DRI will run on this CPU.
	*
	* \return non-zero if the DRI will run on this CPU, or zero otherwise.
	*/
	static int drm_cpu_valid(void)
	{
	#if defined(__i386__)
	if (boot_cpu_data.x86 == 3)
	return 0; /* No cmpxchg on a 386 */
	#endif
	#if defined(__sparc__) && !defined(__sparc_v9__)
	return 0; /* No cmpxchg before v9 sparc. */
	#endif
	return 1;
	}

	/**
	* Called whenever a process opens /dev/drm.
	*
	* \param inode device inode.
	* \param filp file pointer.
	* \param dev device.
	* \return zero on success or a negative number on failure.
	*
	* Creates and initializes a drm_file structure for the file private data in \p
	* filp and add it into the double linked list in \p dev.
	*/
	static int drm_open_helper(struct inode inode, struct file filp,
	drm_device_t * dev)
	{
	int minor = iminor(inode);
	drm_file_t *priv;
	int ret;

	if (filp->f_flags & O_EXCL)
	return -EBUSY; /* No exclusive opens */
	if (!drm_cpu_valid())
	return -EINVAL;

	DRM_DEBUG("pid = %d, minor = %d\n", current->pid, minor);

	priv = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
	if (!priv)
	return -ENOMEM;

	memset(priv, 0, sizeof(*priv));
	filp->private_data = priv;
	priv->uid = current->euid;
	priv->pid = current->pid;
	priv->minor = minor;
	priv->head = drm_heads[minor];
	priv->ioctl_count = 0;
	/* for compatibility root is always authenticated */
	priv->authenticated = capable(CAP_SYS_ADMIN);
	priv->lock_count = 0;

	if (dev->driver->open) {
	ret = dev->driver->open(dev, priv);
	if (ret < 0)
	goto out_free;
	}

	mutex_lock(&dev->struct_mutex);
	if (!dev->file_last) {
	priv->next = NULL;
	priv->prev = NULL;
	dev->file_first = priv;
	dev->file_last = priv;
	/* first opener automatically becomes master */
	priv->master = 1;
	} else {
	priv->next = NULL;
	priv->prev = dev->file_last;
	dev->file_last->next = priv;
	dev->file_last = priv;
	}
	mutex_unlock(&dev->struct_mutex);

	#ifdef __alpha__
	/*
	* Default the hose
	*/
	if (!dev->hose) {
	struct pci_dev *pci_dev;
	pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
	if (pci_dev) {
	dev->hose = pci_dev->sysdata;
	pci_dev_put(pci_dev);
	}
	if (!dev->hose) {
	struct pci_bus *b = pci_bus_b(pci_root_buses.next);
	if (b)
	dev->hose = b->sysdata;
	}
	}
	#endif

	return 0;
	out_free:
	drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
	filp->private_data = NULL;
	return ret;
	}

	/** No-op. */
	int drm_fasync(int fd, struct file *filp, int on)
	{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->head->dev;
	int retcode;

	DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
	(long)old_encode_dev(priv->head->device));
	retcode = fasync_helper(fd, filp, on, &dev->buf_async);
	if (retcode < 0)
	return retcode;
	return 0;
	}
	EXPORT_SYMBOL(drm_fasync);

	/**
	* Release file.
	*
	* \param inode device inode
	* \param filp file pointer.
	* \return zero on success or a negative number on failure.
	*
	* If the hardware lock is held then free it, and take it again for the kernel
	* context since it's necessary to reclaim buffers. Unlink the file private
	* data from its list and free it. Decreases the open count and if it reaches
	* zero calls drm_lastclose().
	*/
	int drm_release(struct inode inode, struct file filp)
	{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev;
	int retcode = 0;

	lock_kernel();
	dev = priv->head->dev;

	DRM_DEBUG("open_count = %d\n", dev->open_count);

	if (dev->driver->preclose)
	dev->driver->preclose(dev, filp);

	/* ========================================================
	* Begin inline drm_release
	*/

	DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
	current->pid, (long)old_encode_dev(priv->head->device),
	dev->open_count);

	if (priv->lock_count && dev->lock.hw_lock &&
	_DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock) &&
	dev->lock.filp == filp) {
	DRM_DEBUG("File %p released, freeing lock for context %d\n",
	filp, _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));

	if (dev->driver->reclaim_buffers_locked)
	dev->driver->reclaim_buffers_locked(dev, filp);

	drm_lock_free(dev, &dev->lock.hw_lock->lock,
	_DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));

	/* FIXME: may require heavy-handed reset of
	hardware at this point, possibly
	processed via a callback to the X
	server. */
	} else if (dev->driver->reclaim_buffers_locked && priv->lock_count
	&& dev->lock.hw_lock) {
	/* The lock is required to reclaim buffers */
	DECLARE_WAITQUEUE(entry, current);

	add_wait_queue(&dev->lock.lock_queue, &entry);
	for (;;) {
	__set_current_state(TASK_INTERRUPTIBLE);
	if (!dev->lock.hw_lock) {
	/* Device has been unregistered */
	retcode = -EINTR;
	break;
	}
	if (drm_lock_take(&dev->lock.hw_lock->lock,
	DRM_KERNEL_CONTEXT)) {
	dev->lock.filp = filp;
	dev->lock.lock_time = jiffies;
	atomic_inc(&dev->counts[_DRM_STAT_LOCKS]);
	break; /* Got lock */
	}
	/* Contention */
	schedule();
	if (signal_pending(current)) {
	retcode = -ERESTARTSYS;
	break;
	}
	}
	__set_current_state(TASK_RUNNING);
	remove_wait_queue(&dev->lock.lock_queue, &entry);
	if (!retcode) {
	dev->driver->reclaim_buffers_locked(dev, filp);
	drm_lock_free(dev, &dev->lock.hw_lock->lock,
	DRM_KERNEL_CONTEXT);
	}
	}

	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
	!dev->driver->reclaim_buffers_locked) {
	dev->driver->reclaim_buffers(dev, filp);
	}

	drm_fasync(-1, filp, 0);

	mutex_lock(&dev->ctxlist_mutex);
	if (dev->ctxlist && (!list_empty(&dev->ctxlist->head))) {
	drm_ctx_list_t pos, n;

	list_for_each_entry_safe(pos, n, &dev->ctxlist->head, head) {
	if (pos->tag == priv &&
	pos->handle != DRM_KERNEL_CONTEXT) {
	if (dev->driver->context_dtor)
	dev->driver->context_dtor(dev,
	pos->handle);

	drm_ctxbitmap_free(dev, pos->handle);

	list_del(&pos->head);
	drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST);
	--dev->ctx_count;
	}
	}
	}
	mutex_unlock(&dev->ctxlist_mutex);

	mutex_lock(&dev->struct_mutex);
	if (priv->remove_auth_on_close == 1) {
	drm_file_t *temp = dev->file_first;
	while (temp) {
	temp->authenticated = 0;
	temp = temp->next;
	}
	}
	if (priv->prev) {
	priv->prev->next = priv->next;
	} else {
	dev->file_first = priv->next;
	}
	if (priv->next) {
	priv->next->prev = priv->prev;
	} else {
	dev->file_last = priv->prev;
	}
	mutex_unlock(&dev->struct_mutex);

	if (dev->driver->postclose)
	dev->driver->postclose(dev, priv);
	drm_free(priv, sizeof(*priv), DRM_MEM_FILES);

	/* ========================================================
	* End inline drm_release
	*/

	atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
	spin_lock(&dev->count_lock);
	if (!--dev->open_count) {
	if (atomic_read(&dev->ioctl_count) \|\| dev->blocked) {
	DRM_ERROR("Device busy: %d %d\n",
	atomic_read(&dev->ioctl_count), dev->blocked);
	spin_unlock(&dev->count_lock);
	unlock_kernel();
	return -EBUSY;
	}
	spin_unlock(&dev->count_lock);
	unlock_kernel();
	return drm_lastclose(dev);
	}
	spin_unlock(&dev->count_lock);

	unlock_kernel();

	return retcode;
	}
	EXPORT_SYMBOL(drm_release);

	/** No-op. */
	unsigned int drm_poll(struct file filp, struct poll_table_struct wait)
	{
	return 0;
	}
	EXPORT_SYMBOL(drm_poll);