[net-next-2.6.git] / drivers / gpu / drm / drm_fops.c

/**
 * \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 <linux/poll.h>
#include <linux/smp_lock.h>

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

static int drm_setup(struct drm_device * dev)
{
	int i;
	int ret;

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

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

	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
	    !drm_core_check_feature(dev, DRIVER_MODESET)) {
		dev->buf_use = 0;
		atomic_set(&dev->buf_alloc, 0);

		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);

	dev->sigdata.lock = NULL;

	dev->queue_count = 0;
	dev->queue_reserved = 0;
	dev->queue_slots = 0;
	dev->queuelist = NULL;
	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)
{
	struct drm_device *dev = NULL;
	int minor_id = iminor(inode);
	struct drm_minor *minor;
	int retcode = 0;

	minor = idr_find(&drm_minors_idr, minor_id);
	if (!minor)
		return -ENODEV;

	if (!(dev = 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);
			retcode = drm_setup(dev);
			goto out;
		}
		spin_unlock(&dev->count_lock);
	}
out:
	mutex_lock(&dev->struct_mutex);
	if (minor->type == DRM_MINOR_LEGACY) {
		BUG_ON((dev->dev_mapping != NULL) &&
			(dev->dev_mapping != inode->i_mapping));
		if (dev->dev_mapping == NULL)
			dev->dev_mapping = inode->i_mapping;
	}
	mutex_unlock(&dev->struct_mutex);

	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)
{
	struct drm_device *dev = NULL;
	struct drm_minor *minor;
	int minor_id = iminor(inode);
	int err = -ENODEV;
	const struct file_operations *old_fops;

	DRM_DEBUG("\n");

	/* BKL pushdown: note that nothing else serializes idr_find() */
	lock_kernel();
	minor = idr_find(&drm_minors_idr, minor_id);
	if (!minor)
		goto out;

	if (!(dev = minor->dev))
		goto out;

	old_fops = filp->f_op;
	filp->f_op = fops_get(&dev->driver->fops);
	if (filp->f_op == NULL) {
		filp->f_op = old_fops;
		goto out;
	}
	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);

out:
	unlock_kernel();
	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,
			   struct drm_device * dev)
{
	int minor_id = iminor(inode);
	struct drm_file *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", task_pid_nr(current), minor_id);

	priv = kmalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	memset(priv, 0, sizeof(*priv));
	filp->private_data = priv;
	priv->filp = filp;
	priv->uid = current_euid();
	priv->pid = task_pid_nr(current);
	priv->minor = idr_find(&drm_minors_idr, minor_id);
	priv->ioctl_count = 0;
	/* for compatibility root is always authenticated */
	priv->authenticated = capable(CAP_SYS_ADMIN);
	priv->lock_count = 0;

	INIT_LIST_HEAD(&priv->lhead);
	INIT_LIST_HEAD(&priv->fbs);

	if (dev->driver->driver_features & DRIVER_GEM)
		drm_gem_open(dev, priv);

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


	/* if there is no current master make this fd it */
	mutex_lock(&dev->struct_mutex);
	if (!priv->minor->master) {
		/* create a new master */
		priv->minor->master = drm_master_create(priv->minor);
		if (!priv->minor->master) {
			mutex_unlock(&dev->struct_mutex);
			ret = -ENOMEM;
			goto out_free;
		}

		priv->is_master = 1;
		/* take another reference for the copy in the local file priv */
		priv->master = drm_master_get(priv->minor->master);

		priv->authenticated = 1;

		mutex_unlock(&dev->struct_mutex);
		if (dev->driver->master_create) {
			ret = dev->driver->master_create(dev, priv->master);
			if (ret) {
				mutex_lock(&dev->struct_mutex);
				/* drop both references if this fails */
				drm_master_put(&priv->minor->master);
				drm_master_put(&priv->master);
				mutex_unlock(&dev->struct_mutex);
				goto out_free;
			}
		}
	} else {
		/* get a reference to the master */
		priv->master = drm_master_get(priv->minor->master);
		mutex_unlock(&dev->struct_mutex);
	}

	mutex_lock(&dev->struct_mutex);
	list_add(&priv->lhead, &dev->filelist);
	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:
	kfree(priv);
	filp->private_data = NULL;
	return ret;
}

/** No-op. */
int drm_fasync(int fd, struct file *filp, int on)
{
	struct drm_file *priv = filp->private_data;
	struct drm_device *dev = priv->minor->dev;

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

/*
 * Reclaim locked buffers; note that this may be a bad idea if the current
 * context doesn't have the hw lock...
 */
static void drm_reclaim_locked_buffers(struct drm_device *dev, struct file *f)
{
	struct drm_file *file_priv = f->private_data;

	if (drm_i_have_hw_lock(dev, file_priv)) {
		dev->driver->reclaim_buffers_locked(dev, file_priv);
	} else {
		unsigned long _end = jiffies + 3 * DRM_HZ;
		int locked = 0;

		drm_idlelock_take(&file_priv->master->lock);

		/*
		 * Wait for a while.
		 */
		do {
			spin_lock_bh(&file_priv->master->lock.spinlock);
			locked = file_priv->master->lock.idle_has_lock;
			spin_unlock_bh(&file_priv->master->lock.spinlock);
			if (locked)
				break;
			schedule();
		} while (!time_after_eq(jiffies, _end));

		if (!locked) {
			DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
				  "\tdriver to use reclaim_buffers_idlelocked() instead.\n"
				  "\tI will go on reclaiming the buffers anyway.\n");
		}

		dev->driver->reclaim_buffers_locked(dev, file_priv);
		drm_idlelock_release(&file_priv->master->lock);
	}
}

static void drm_master_release(struct drm_device *dev, struct file *filp)
{
	struct drm_file *file_priv = filp->private_data;

	if (dev->driver->reclaim_buffers_locked &&
	    file_priv->master->lock.hw_lock)
		drm_reclaim_locked_buffers(dev, filp);

	if (dev->driver->reclaim_buffers_idlelocked &&
	    file_priv->master->lock.hw_lock) {
		drm_idlelock_take(&file_priv->master->lock);
		dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
		drm_idlelock_release(&file_priv->master->lock);
	}


	if (drm_i_have_hw_lock(dev, file_priv)) {
		DRM_DEBUG("File %p released, freeing lock for context %d\n",
			  filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
		drm_lock_free(&file_priv->master->lock,
			      _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
	}

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

/**
 * Release file.
 *
 * \param inode device inode
 * \param file_priv DRM file private.
 * \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)
{
	struct drm_file *file_priv = filp->private_data;
	struct drm_device *dev = file_priv->minor->dev;
	int retcode = 0;

	lock_kernel();

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

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

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

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

	/* if the master has gone away we can't do anything with the lock */
	if (file_priv->minor->master)
		drm_master_release(dev, filp);

	if (dev->driver->driver_features & DRIVER_GEM)
		drm_gem_release(dev, file_priv);

	if (dev->driver->driver_features & DRIVER_MODESET)
		drm_fb_release(file_priv);

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

		list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
			if (pos->tag == file_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);
				kfree(pos);
				--dev->ctx_count;
			}
		}
	}
	mutex_unlock(&dev->ctxlist_mutex);

	mutex_lock(&dev->struct_mutex);

	if (file_priv->is_master) {
		struct drm_master *master = file_priv->master;
		struct drm_file *temp;
		list_for_each_entry(temp, &dev->filelist, lhead) {
			if ((temp->master == file_priv->master) &&
			    (temp != file_priv))
				temp->authenticated = 0;
		}

		/**
		 * Since the master is disappearing, so is the
		 * possibility to lock.
		 */

		if (master->lock.hw_lock) {
			if (dev->sigdata.lock == master->lock.hw_lock)
				dev->sigdata.lock = NULL;
			master->lock.hw_lock = NULL;
			master->lock.file_priv = NULL;
			wake_up_interruptible_all(&master->lock.lock_queue);
		}

		if (file_priv->minor->master == file_priv->master) {
			/* drop the reference held my the minor */
			drm_master_put(&file_priv->minor->master);
		}
	}

	/* drop the reference held my the file priv */
	drm_master_put(&file_priv->master);
	file_priv->is_master = 0;
	list_del(&file_priv->lhead);
	mutex_unlock(&dev->struct_mutex);

	if (dev->driver->postclose)
		dev->driver->postclose(dev, file_priv);
	kfree(file_priv);

	/* ========================================================
	 * 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)) {
			DRM_ERROR("Device busy: %d\n",
				  atomic_read(&dev->ioctl_count));
			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);
Commit	Line	Data
1da177e4	1	/**
b5e89ed5	2	* \file drm_fops.c
1da177e4	3	* File operations for DRM
b5e89ed5	4	*
1da177e4 LT	5	* \author Rickard E. (Rik) Faith <faith@valinux.com>
	6	* \author Daryll Strauss <daryll@valinux.com>
	7	* \author Gareth Hughes <gareth@valinux.com>
	8	*/
	9
	10	/*
	11	* Created: Mon Jan 4 08:58:31 1999 by faith@valinux.com
	12	*
	13	* Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
	14	* Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
	15	* All Rights Reserved.
	16	*
	17	* Permission is hereby granted, free of charge, to any person obtaining a
	18	* copy of this software and associated documentation files (the "Software"),
	19	* to deal in the Software without restriction, including without limitation
	20	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	21	* and/or sell copies of the Software, and to permit persons to whom the
	22	* Software is furnished to do so, subject to the following conditions:
	23	*
	24	* The above copyright notice and this permission notice (including the next
	25	* paragraph) shall be included in all copies or substantial portions of the
	26	* Software.
	27	*
	28	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	29	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	30	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	31	* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
	32	* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
	33	* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
	34	* OTHER DEALINGS IN THE SOFTWARE.
	35	*/
	36
	37	#include "drmP.h"
	38	#include <linux/poll.h>
70ffa16e	39	#include <linux/smp_lock.h>
1da177e4	40
b5e89ed5	41	static int drm_open_helper(struct inode inode, struct file filp,
84b1fd10	42	struct drm_device * dev);
c94f7029	43
84b1fd10	44	static int drm_setup(struct drm_device * dev)
1da177e4 LT	45	{
	46	int i;
	47	int ret;
	48
22eae947 DA	49	if (dev->driver->firstopen) {
22eae947 DA	50	ret = dev->driver->firstopen(dev);
b5e89ed5	51	if (ret != 0)
1da177e4 LT	52	return ret;
	53	}
	54
b5e89ed5 DA	55	atomic_set(&dev->ioctl_count, 0);
b5e89ed5 DA	56	atomic_set(&dev->vma_count, 0);
1da177e4	57
f453ba04 DA	58	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
	59	!drm_core_check_feature(dev, DRIVER_MODESET)) {
	60	dev->buf_use = 0;
	61	atomic_set(&dev->buf_alloc, 0);
	62
b5e89ed5 DA	63	i = drm_dma_setup(dev);
b5e89ed5 DA	64	if (i < 0)
1da177e4 LT	65	return i;
	66	}
	67
3d77461e	68	for (i = 0; i < ARRAY_SIZE(dev->counts); i++)
b5e89ed5	69	atomic_set(&dev->counts[i], 0);
1da177e4	70
11d9c2fd	71	dev->sigdata.lock = NULL;
7c1c2871	72
1da177e4 LT	73	dev->queue_count = 0;
	74	dev->queue_reserved = 0;
	75	dev->queue_slots = 0;
	76	dev->queuelist = NULL;
1da177e4 LT	77	dev->context_flag = 0;
	78	dev->interrupt_flag = 0;
	79	dev->dma_flag = 0;
	80	dev->last_context = 0;
	81	dev->last_switch = 0;
	82	dev->last_checked = 0;
b5e89ed5	83	init_waitqueue_head(&dev->context_wait);
1da177e4 LT	84	dev->if_version = 0;
	85
	86	dev->ctx_start = 0;
	87	dev->lck_start = 0;
	88
1da177e4	89	dev->buf_async = NULL;
b5e89ed5 DA	90	init_waitqueue_head(&dev->buf_readers);
b5e89ed5 DA	91	init_waitqueue_head(&dev->buf_writers);
1da177e4	92
b5e89ed5	93	DRM_DEBUG("\n");
1da177e4 LT	94
	95	/*
	96	* The kernel's context could be created here, but is now created
b5e89ed5	97	* in drm_dma_enqueue. This is more resource-efficient for
1da177e4 LT	98	* hardware that does not do DMA, but may mean that
	99	* drm_select_queue fails between the time the interrupt is
	100	* initialized and the time the queues are initialized.
	101	*/
1da177e4 LT	102
	103	return 0;
	104	}
	105
	106	/**
	107	* Open file.
b5e89ed5	108	*
1da177e4 LT	109	* \param inode device inode
	110	* \param filp file pointer.
	111	* \return zero on success or a negative number on failure.
	112	*
	113	* Searches the DRM device with the same minor number, calls open_helper(), and
	114	* increments the device open count. If the open count was previous at zero,
	115	* i.e., it's the first that the device is open, then calls setup().
	116	*/
b5e89ed5	117	int drm_open(struct inode inode, struct file filp)
1da177e4	118	{
84b1fd10	119	struct drm_device *dev = NULL;
2c14f28b DA	120	int minor_id = iminor(inode);
2c14f28b DA	121	struct drm_minor *minor;
1da177e4 LT	122	int retcode = 0;
1da177e4 LT	123
2c14f28b DA	124	minor = idr_find(&drm_minors_idr, minor_id);
2c14f28b DA	125	if (!minor)
1da177e4	126	return -ENODEV;
b5e89ed5	127
2c14f28b	128	if (!(dev = minor->dev))
1da177e4	129	return -ENODEV;
b5e89ed5 DA	130
	131	retcode = drm_open_helper(inode, filp, dev);
	132	if (!retcode) {
	133	atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
	134	spin_lock(&dev->count_lock);
	135	if (!dev->open_count++) {
	136	spin_unlock(&dev->count_lock);
a2c0a97b JB	137	retcode = drm_setup(dev);
a2c0a97b JB	138	goto out;
1da177e4	139	}
b5e89ed5	140	spin_unlock(&dev->count_lock);
1da177e4	141	}
a2c0a97b JB	142	out:
a2c0a97b JB	143	mutex_lock(&dev->struct_mutex);
f453ba04 DA	144	if (minor->type == DRM_MINOR_LEGACY) {
	145	BUG_ON((dev->dev_mapping != NULL) &&
	146	(dev->dev_mapping != inode->i_mapping));
	147	if (dev->dev_mapping == NULL)
	148	dev->dev_mapping = inode->i_mapping;
	149	}
a2c0a97b JB	150	mutex_unlock(&dev->struct_mutex);
a2c0a97b JB	151
1da177e4 LT	152	return retcode;
	153	}
	154	EXPORT_SYMBOL(drm_open);
	155
d985c108 DA	156	/**
	157	* File \c open operation.
	158	*
	159	* \param inode device inode.
	160	* \param filp file pointer.
	161	*
	162	* Puts the dev->fops corresponding to the device minor number into
	163	* \p filp, call the \c open method, and restore the file operations.
	164	*/
	165	int drm_stub_open(struct inode inode, struct file filp)
	166	{
84b1fd10	167	struct drm_device *dev = NULL;
2c14f28b DA	168	struct drm_minor *minor;
2c14f28b DA	169	int minor_id = iminor(inode);
d985c108	170	int err = -ENODEV;
99ac48f5	171	const struct file_operations *old_fops;
d985c108 DA	172
	173	DRM_DEBUG("\n");
	174
70ffa16e JC	175	/* BKL pushdown: note that nothing else serializes idr_find() */
70ffa16e JC	176	lock_kernel();
2c14f28b DA	177	minor = idr_find(&drm_minors_idr, minor_id);
2c14f28b DA	178	if (!minor)
70ffa16e	179	goto out;
d985c108	180
2c14f28b	181	if (!(dev = minor->dev))
70ffa16e	182	goto out;
d985c108 DA	183
	184	old_fops = filp->f_op;
	185	filp->f_op = fops_get(&dev->driver->fops);
f41ced8f LP	186	if (filp->f_op == NULL) {
	187	filp->f_op = old_fops;
	188	goto out;
	189	}
d985c108 DA	190	if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
	191	fops_put(filp->f_op);
	192	filp->f_op = fops_get(old_fops);
	193	}
	194	fops_put(old_fops);
	195
70ffa16e JC	196	out:
70ffa16e JC	197	unlock_kernel();
d985c108 DA	198	return err;
	199	}
	200
	201	/**
	202	* Check whether DRI will run on this CPU.
	203	*
	204	* \return non-zero if the DRI will run on this CPU, or zero otherwise.
	205	*/
	206	static int drm_cpu_valid(void)
	207	{
	208	#if defined(__i386__)
	209	if (boot_cpu_data.x86 == 3)
	210	return 0; /* No cmpxchg on a 386 */
	211	#endif
	212	#if defined(__sparc__) && !defined(__sparc_v9__)
	213	return 0; /* No cmpxchg before v9 sparc. */
	214	#endif
	215	return 1;
	216	}
	217
	218	/**
	219	* Called whenever a process opens /dev/drm.
	220	*
	221	* \param inode device inode.
	222	* \param filp file pointer.
	223	* \param dev device.
	224	* \return zero on success or a negative number on failure.
	225	*
	226	* Creates and initializes a drm_file structure for the file private data in \p
	227	* filp and add it into the double linked list in \p dev.
	228	*/
	229	static int drm_open_helper(struct inode inode, struct file filp,
84b1fd10	230	struct drm_device * dev)
d985c108	231	{
2c14f28b	232	int minor_id = iminor(inode);
84b1fd10	233	struct drm_file *priv;
d985c108 DA	234	int ret;
	235
	236	if (filp->f_flags & O_EXCL)
	237	return -EBUSY; /* No exclusive opens */
	238	if (!drm_cpu_valid())
	239	return -EINVAL;
	240
2c14f28b	241	DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id);
d985c108	242
9a298b2a	243	priv = kmalloc(sizeof(*priv), GFP_KERNEL);
d985c108 DA	244	if (!priv)
	245	return -ENOMEM;
	246
	247	memset(priv, 0, sizeof(*priv));
	248	filp->private_data = priv;
6c340eac	249	priv->filp = filp;
2df68b43	250	priv->uid = current_euid();
ba25f9dc	251	priv->pid = task_pid_nr(current);
2c14f28b	252	priv->minor = idr_find(&drm_minors_idr, minor_id);
d985c108 DA	253	priv->ioctl_count = 0;
	254	/* for compatibility root is always authenticated */
	255	priv->authenticated = capable(CAP_SYS_ADMIN);
	256	priv->lock_count = 0;
	257
bd1b331f	258	INIT_LIST_HEAD(&priv->lhead);
f453ba04	259	INIT_LIST_HEAD(&priv->fbs);
bd1b331f	260
673a394b EA	261	if (dev->driver->driver_features & DRIVER_GEM)
	262	drm_gem_open(dev, priv);
	263
d985c108 DA	264	if (dev->driver->open) {
	265	ret = dev->driver->open(dev, priv);
	266	if (ret < 0)
	267	goto out_free;
	268	}
	269
7c1c2871 DA	270
7c1c2871 DA	271	/* if there is no current master make this fd it */
30e2fb18	272	mutex_lock(&dev->struct_mutex);
7c1c2871 DA	273	if (!priv->minor->master) {
	274	/* create a new master */
	275	priv->minor->master = drm_master_create(priv->minor);
	276	if (!priv->minor->master) {
dba5ed0c	277	mutex_unlock(&dev->struct_mutex);
7c1c2871 DA	278	ret = -ENOMEM;
	279	goto out_free;
	280	}
	281
	282	priv->is_master = 1;
	283	/* take another reference for the copy in the local file priv */
	284	priv->master = drm_master_get(priv->minor->master);
	285
	286	priv->authenticated = 1;
	287
	288	mutex_unlock(&dev->struct_mutex);
	289	if (dev->driver->master_create) {
	290	ret = dev->driver->master_create(dev, priv->master);
	291	if (ret) {
	292	mutex_lock(&dev->struct_mutex);
	293	/* drop both references if this fails */
	294	drm_master_put(&priv->minor->master);
	295	drm_master_put(&priv->master);
	296	mutex_unlock(&dev->struct_mutex);
	297	goto out_free;
	298	}
	299	}
	300	} else {
	301	/* get a reference to the master */
	302	priv->master = drm_master_get(priv->minor->master);
	303	mutex_unlock(&dev->struct_mutex);
	304	}
bd1b331f	305
7c1c2871	306	mutex_lock(&dev->struct_mutex);
bd1b331f	307	list_add(&priv->lhead, &dev->filelist);
30e2fb18	308	mutex_unlock(&dev->struct_mutex);
d985c108 DA	309
	310	#ifdef __alpha__
	311	/*
	312	* Default the hose
	313	*/
	314	if (!dev->hose) {
	315	struct pci_dev *pci_dev;
	316	pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
	317	if (pci_dev) {
	318	dev->hose = pci_dev->sysdata;
	319	pci_dev_put(pci_dev);
	320	}
	321	if (!dev->hose) {
	322	struct pci_bus *b = pci_bus_b(pci_root_buses.next);
	323	if (b)
	324	dev->hose = b->sysdata;
	325	}
	326	}
	327	#endif
	328
	329	return 0;
	330	out_free:
9a298b2a	331	kfree(priv);
d985c108 DA	332	filp->private_data = NULL;
	333	return ret;
	334	}
	335
	336	/** No-op. */
	337	int drm_fasync(int fd, struct file *filp, int on)
	338	{
84b1fd10	339	struct drm_file *priv = filp->private_data;
2c14f28b	340	struct drm_device *dev = priv->minor->dev;
d985c108 DA	341
d985c108 DA	342	DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
2c14f28b	343	(long)old_encode_dev(priv->minor->device));
60aa4924	344	return fasync_helper(fd, filp, on, &dev->buf_async);
d985c108 DA	345	}
	346	EXPORT_SYMBOL(drm_fasync);
	347
7c1c2871 DA	348	/*
	349	* Reclaim locked buffers; note that this may be a bad idea if the current
	350	* context doesn't have the hw lock...
	351	*/
	352	static void drm_reclaim_locked_buffers(struct drm_device dev, struct file f)
	353	{
	354	struct drm_file *file_priv = f->private_data;
	355
	356	if (drm_i_have_hw_lock(dev, file_priv)) {
	357	dev->driver->reclaim_buffers_locked(dev, file_priv);
	358	} else {
	359	unsigned long _end = jiffies + 3 * DRM_HZ;
	360	int locked = 0;
	361
	362	drm_idlelock_take(&file_priv->master->lock);
	363
	364	/*
	365	* Wait for a while.
	366	*/
	367	do {
	368	spin_lock_bh(&file_priv->master->lock.spinlock);
	369	locked = file_priv->master->lock.idle_has_lock;
	370	spin_unlock_bh(&file_priv->master->lock.spinlock);
	371	if (locked)
	372	break;
	373	schedule();
	374	} while (!time_after_eq(jiffies, _end));
	375
	376	if (!locked) {
	377	DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n"
	378	"\tdriver to use reclaim_buffers_idlelocked() instead.\n"
	379	"\tI will go on reclaiming the buffers anyway.\n");
	380	}
	381
	382	dev->driver->reclaim_buffers_locked(dev, file_priv);
	383	drm_idlelock_release(&file_priv->master->lock);
	384	}
	385	}
	386
	387	static void drm_master_release(struct drm_device dev, struct file filp)
	388	{
	389	struct drm_file *file_priv = filp->private_data;
	390
	391	if (dev->driver->reclaim_buffers_locked &&
	392	file_priv->master->lock.hw_lock)
	393	drm_reclaim_locked_buffers(dev, filp);
	394
	395	if (dev->driver->reclaim_buffers_idlelocked &&
	396	file_priv->master->lock.hw_lock) {
	397	drm_idlelock_take(&file_priv->master->lock);
	398	dev->driver->reclaim_buffers_idlelocked(dev, file_priv);
	399	drm_idlelock_release(&file_priv->master->lock);
	400	}
	401
	402
	403	if (drm_i_have_hw_lock(dev, file_priv)) {
	404	DRM_DEBUG("File %p released, freeing lock for context %d\n",
	405	filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
	406	drm_lock_free(&file_priv->master->lock,
	407	_DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
	408	}
	409
	410	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) &&
	411	!dev->driver->reclaim_buffers_locked) {
412	dev->driver->reclaim_buffers(dev, file_priv);
413	}
414	}
415
1da177e4 LT	416	/**
	417	* Release file.
	418	*
	419	* \param inode device inode
6c340eac	420	* \param file_priv DRM file private.
1da177e4 LT	421	* \return zero on success or a negative number on failure.
	422	*
	423	* If the hardware lock is held then free it, and take it again for the kernel
	424	* context since it's necessary to reclaim buffers. Unlink the file private
	425	* data from its list and free it. Decreases the open count and if it reaches
22eae947	426	* zero calls drm_lastclose().
1da177e4	427	*/
b5e89ed5	428	int drm_release(struct inode inode, struct file filp)
1da177e4	429	{
6c340eac	430	struct drm_file *file_priv = filp->private_data;
2c14f28b	431	struct drm_device *dev = file_priv->minor->dev;
1da177e4 LT	432	int retcode = 0;
	433
	434	lock_kernel();
1da177e4	435
b5e89ed5	436	DRM_DEBUG("open_count = %d\n", dev->open_count);
1da177e4	437
22eae947	438	if (dev->driver->preclose)
6c340eac	439	dev->driver->preclose(dev, file_priv);
1da177e4 LT	440
	441	/* ========================================================
	442	* Begin inline drm_release
	443	*/
	444
b5e89ed5	445	DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
ba25f9dc	446	task_pid_nr(current),
2c14f28b	447	(long)old_encode_dev(file_priv->minor->device),
b5e89ed5 DA	448	dev->open_count);
b5e89ed5 DA	449
7c1c2871 DA	450	/* if the master has gone away we can't do anything with the lock */
	451	if (file_priv->minor->master)
	452	drm_master_release(dev, filp);
1da177e4	453
673a394b EA	454	if (dev->driver->driver_features & DRIVER_GEM)
	455	drm_gem_release(dev, file_priv);
	456
ea39f835 KH	457	if (dev->driver->driver_features & DRIVER_MODESET)
	458	drm_fb_release(file_priv);
	459
30e2fb18	460	mutex_lock(&dev->ctxlist_mutex);
bd1b331f	461	if (!list_empty(&dev->ctxlist)) {
55910517	462	struct drm_ctx_list pos, n;
1da177e4	463
bd1b331f	464	list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
6c340eac	465	if (pos->tag == file_priv &&
b5e89ed5	466	pos->handle != DRM_KERNEL_CONTEXT) {
1da177e4	467	if (dev->driver->context_dtor)
b5e89ed5 DA	468	dev->driver->context_dtor(dev,
b5e89ed5 DA	469	pos->handle);
1da177e4	470
b5e89ed5	471	drm_ctxbitmap_free(dev, pos->handle);
1da177e4	472
b5e89ed5	473	list_del(&pos->head);
9a298b2a	474	kfree(pos);
1da177e4 LT	475	--dev->ctx_count;
	476	}
	477	}
	478	}
30e2fb18	479	mutex_unlock(&dev->ctxlist_mutex);
1da177e4	480
30e2fb18	481	mutex_lock(&dev->struct_mutex);
7c1c2871 DA	482
7c1c2871 DA	483	if (file_priv->is_master) {
fda714c2	484	struct drm_master *master = file_priv->master;
84b1fd10	485	struct drm_file *temp;
7c1c2871 DA	486	list_for_each_entry(temp, &dev->filelist, lhead) {
	487	if ((temp->master == file_priv->master) &&
	488	(temp != file_priv))
	489	temp->authenticated = 0;
	490	}
bd1b331f	491
fda714c2 TH	492	/**
	493	* Since the master is disappearing, so is the
	494	* possibility to lock.
	495	*/
	496
	497	if (master->lock.hw_lock) {
	498	if (dev->sigdata.lock == master->lock.hw_lock)
	499	dev->sigdata.lock = NULL;
	500	master->lock.hw_lock = NULL;
	501	master->lock.file_priv = NULL;
	502	wake_up_interruptible_all(&master->lock.lock_queue);
	503	}
	504
7c1c2871 DA	505	if (file_priv->minor->master == file_priv->master) {
	506	/* drop the reference held my the minor */
	507	drm_master_put(&file_priv->minor->master);
	508	}
1da177e4	509	}
7c1c2871 DA	510
	511	/* drop the reference held my the file priv */
	512	drm_master_put(&file_priv->master);
	513	file_priv->is_master = 0;
6c340eac	514	list_del(&file_priv->lhead);
30e2fb18	515	mutex_unlock(&dev->struct_mutex);
b5e89ed5	516
22eae947	517	if (dev->driver->postclose)
6c340eac	518	dev->driver->postclose(dev, file_priv);
9a298b2a	519	kfree(file_priv);
1da177e4 LT	520
	521	/* ========================================================
	522	* End inline drm_release
	523	*/
	524
b5e89ed5 DA	525	atomic_inc(&dev->counts[_DRM_STAT_CLOSES]);
	526	spin_lock(&dev->count_lock);
	527	if (!--dev->open_count) {
7c1c2871 DA	528	if (atomic_read(&dev->ioctl_count)) {
	529	DRM_ERROR("Device busy: %d\n",
	530	atomic_read(&dev->ioctl_count));
b5e89ed5	531	spin_unlock(&dev->count_lock);
1da177e4 LT	532	unlock_kernel();
	533	return -EBUSY;
	534	}
b5e89ed5	535	spin_unlock(&dev->count_lock);
1da177e4	536	unlock_kernel();
22eae947	537	return drm_lastclose(dev);
1da177e4	538	}
b5e89ed5	539	spin_unlock(&dev->count_lock);
1da177e4 LT	540
	541	unlock_kernel();
	542
	543	return retcode;
	544	}
	545	EXPORT_SYMBOL(drm_release);
	546
1da177e4 LT	547	/** No-op. */
	548	unsigned int drm_poll(struct file filp, struct poll_table_struct wait)
	549	{
	550	return 0;
	551	}
b5e89ed5	552	EXPORT_SYMBOL(drm_poll);