Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 909 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
new file mode 100644
index 000000000..a8b4d918e
--- /dev/null
+++ b/drivers/gpu/drm/drm_file.c
@@ -0,0 +1,909 @@
+/*
+ * \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 <linux/anon_inodes.h>
+#include <linux/dma-fence.h>
+#include <linux/file.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+
+#include <drm/drm_client.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_file.h>
+#include <drm/drm_print.h>
+
+#include "drm_crtc_internal.h"
+#include "drm_internal.h"
+#include "drm_legacy.h"
+
+/* from BKL pushdown */
+DEFINE_MUTEX(drm_global_mutex);
+
+bool drm_dev_needs_global_mutex(struct drm_device *dev)
+{
+	/*
+	 * Legacy drivers rely on all kinds of BKL locking semantics, don't
+	 * bother. They also still need BKL locking for their ioctls, so better
+	 * safe than sorry.
+	 */
+	if (drm_core_check_feature(dev, DRIVER_LEGACY))
+		return true;
+
+	/*
+	 * The deprecated ->load callback must be called after the driver is
+	 * already registered. This means such drivers rely on the BKL to make
+	 * sure an open can't proceed until the driver is actually fully set up.
+	 * Similar hilarity holds for the unload callback.
+	 */
+	if (dev->driver->load || dev->driver->unload)
+		return true;
+
+	/*
+	 * Drivers with the lastclose callback assume that it's synchronized
+	 * against concurrent opens, which again needs the BKL. The proper fix
+	 * is to use the drm_client infrastructure with proper locking for each
+	 * client.
+	 */
+	if (dev->driver->lastclose)
+		return true;
+
+	return false;
+}
+
+/**
+ * DOC: file operations
+ *
+ * Drivers must define the file operations structure that forms the DRM
+ * userspace API entry point, even though most of those operations are
+ * implemented in the DRM core. The resulting &struct file_operations must be
+ * stored in the &drm_driver.fops field. The mandatory functions are drm_open(),
+ * drm_read(), drm_ioctl() and drm_compat_ioctl() if CONFIG_COMPAT is enabled
+ * Note that drm_compat_ioctl will be NULL if CONFIG_COMPAT=n, so there's no
+ * need to sprinkle #ifdef into the code. Drivers which implement private ioctls
+ * that require 32/64 bit compatibility support must provide their own
+ * &file_operations.compat_ioctl handler that processes private ioctls and calls
+ * drm_compat_ioctl() for core ioctls.
+ *
+ * In addition drm_read() and drm_poll() provide support for DRM events. DRM
+ * events are a generic and extensible means to send asynchronous events to
+ * userspace through the file descriptor. They are used to send vblank event and
+ * page flip completions by the KMS API. But drivers can also use it for their
+ * own needs, e.g. to signal completion of rendering.
+ *
+ * For the driver-side event interface see drm_event_reserve_init() and
+ * drm_send_event() as the main starting points.
+ *
+ * The memory mapping implementation will vary depending on how the driver
+ * manages memory. Legacy drivers will use the deprecated drm_legacy_mmap()
+ * function, modern drivers should use one of the provided memory-manager
+ * specific implementations. For GEM-based drivers this is drm_gem_mmap().
+ *
+ * No other file operations are supported by the DRM userspace API. Overall the
+ * following is an example &file_operations structure::
+ *
+ *     static const example_drm_fops = {
+ *             .owner = THIS_MODULE,
+ *             .open = drm_open,
+ *             .release = drm_release,
+ *             .unlocked_ioctl = drm_ioctl,
+ *             .compat_ioctl = drm_compat_ioctl, // NULL if CONFIG_COMPAT=n
+ *             .poll = drm_poll,
+ *             .read = drm_read,
+ *             .llseek = no_llseek,
+ *             .mmap = drm_gem_mmap,
+ *     };
+ *
+ * For plain GEM based drivers there is the DEFINE_DRM_GEM_FOPS() macro, and for
+ * DMA based drivers there is the DEFINE_DRM_GEM_DMA_FOPS() macro to make this
+ * simpler.
+ *
+ * The driver's &file_operations must be stored in &drm_driver.fops.
+ *
+ * For driver-private IOCTL handling see the more detailed discussion in
+ * :ref:`IOCTL support in the userland interfaces chapter<drm_driver_ioctl>`.
+ */
+
+/**
+ * drm_file_alloc - allocate file context
+ * @minor: minor to allocate on
+ *
+ * This allocates a new DRM file context. It is not linked into any context and
+ * can be used by the caller freely. Note that the context keeps a pointer to
+ * @minor, so it must be freed before @minor is.
+ *
+ * RETURNS:
+ * Pointer to newly allocated context, ERR_PTR on failure.
+ */
+struct drm_file *drm_file_alloc(struct drm_minor *minor)
+{
+	struct drm_device *dev = minor->dev;
+	struct drm_file *file;
+	int ret;
+
+	file = kzalloc(sizeof(*file), GFP_KERNEL);
+	if (!file)
+		return ERR_PTR(-ENOMEM);
+
+	file->pid = get_pid(task_pid(current));
+	file->minor = minor;
+
+	/* for compatibility root is always authenticated */
+	file->authenticated = capable(CAP_SYS_ADMIN);
+
+	INIT_LIST_HEAD(&file->lhead);
+	INIT_LIST_HEAD(&file->fbs);
+	mutex_init(&file->fbs_lock);
+	INIT_LIST_HEAD(&file->blobs);
+	INIT_LIST_HEAD(&file->pending_event_list);
+	INIT_LIST_HEAD(&file->event_list);
+	init_waitqueue_head(&file->event_wait);
+	file->event_space = 4096; /* set aside 4k for event buffer */
+
+	spin_lock_init(&file->master_lookup_lock);
+	mutex_init(&file->event_read_lock);
+
+	if (drm_core_check_feature(dev, DRIVER_GEM))
+		drm_gem_open(dev, file);
+
+	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
+		drm_syncobj_open(file);
+
+	drm_prime_init_file_private(&file->prime);
+
+	if (dev->driver->open) {
+		ret = dev->driver->open(dev, file);
+		if (ret < 0)
+			goto out_prime_destroy;
+	}
+
+	return file;
+
+out_prime_destroy:
+	drm_prime_destroy_file_private(&file->prime);
+	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
+		drm_syncobj_release(file);
+	if (drm_core_check_feature(dev, DRIVER_GEM))
+		drm_gem_release(dev, file);
+	put_pid(file->pid);
+	kfree(file);
+
+	return ERR_PTR(ret);
+}
+
+static void drm_events_release(struct drm_file *file_priv)
+{
+	struct drm_device *dev = file_priv->minor->dev;
+	struct drm_pending_event *e, *et;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->event_lock, flags);
+
+	/* Unlink pending events */
+	list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
+				 pending_link) {
+		list_del(&e->pending_link);
+		e->file_priv = NULL;
+	}
+
+	/* Remove unconsumed events */
+	list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
+		list_del(&e->link);
+		kfree(e);
+	}
+
+	spin_unlock_irqrestore(&dev->event_lock, flags);
+}
+
+/**
+ * drm_file_free - free file context
+ * @file: context to free, or NULL
+ *
+ * This destroys and deallocates a DRM file context previously allocated via
+ * drm_file_alloc(). The caller must make sure to unlink it from any contexts
+ * before calling this.
+ *
+ * If NULL is passed, this is a no-op.
+ */
+void drm_file_free(struct drm_file *file)
+{
+	struct drm_device *dev;
+
+	if (!file)
+		return;
+
+	dev = file->minor->dev;
+
+	DRM_DEBUG("comm=\"%s\", pid=%d, dev=0x%lx, open_count=%d\n",
+		  current->comm, task_pid_nr(current),
+		  (long)old_encode_dev(file->minor->kdev->devt),
+		  atomic_read(&dev->open_count));
+
+#ifdef CONFIG_DRM_LEGACY
+	if (drm_core_check_feature(dev, DRIVER_LEGACY) &&
+	    dev->driver->preclose)
+		dev->driver->preclose(dev, file);
+#endif
+
+	if (drm_core_check_feature(dev, DRIVER_LEGACY))
+		drm_legacy_lock_release(dev, file->filp);
+
+	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
+		drm_legacy_reclaim_buffers(dev, file);
+
+	drm_events_release(file);
+
+	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+		drm_fb_release(file);
+		drm_property_destroy_user_blobs(dev, file);
+	}
+
+	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
+		drm_syncobj_release(file);
+
+	if (drm_core_check_feature(dev, DRIVER_GEM))
+		drm_gem_release(dev, file);
+
+	drm_legacy_ctxbitmap_flush(dev, file);
+
+	if (drm_is_primary_client(file))
+		drm_master_release(file);
+
+	if (dev->driver->postclose)
+		dev->driver->postclose(dev, file);
+
+	drm_prime_destroy_file_private(&file->prime);
+
+	WARN_ON(!list_empty(&file->event_list));
+
+	put_pid(file->pid);
+	kfree(file);
+}
+
+static void drm_close_helper(struct file *filp)
+{
+	struct drm_file *file_priv = filp->private_data;
+	struct drm_device *dev = file_priv->minor->dev;
+
+	mutex_lock(&dev->filelist_mutex);
+	list_del(&file_priv->lhead);
+	mutex_unlock(&dev->filelist_mutex);
+
+	drm_file_free(file_priv);
+}
+
+/*
+ * 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(__sparc__) && !defined(__sparc_v9__)
+	return 0;		/* No cmpxchg before v9 sparc. */
+#endif
+	return 1;
+}
+
+/*
+ * Called whenever a process opens a drm node
+ *
+ * \param filp file pointer.
+ * \param minor acquired minor-object.
+ * \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 file *filp, struct drm_minor *minor)
+{
+	struct drm_device *dev = minor->dev;
+	struct drm_file *priv;
+	int ret;
+
+	if (filp->f_flags & O_EXCL)
+		return -EBUSY;	/* No exclusive opens */
+	if (!drm_cpu_valid())
+		return -EINVAL;
+	if (dev->switch_power_state != DRM_SWITCH_POWER_ON &&
+	    dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
+		return -EINVAL;
+
+	DRM_DEBUG("comm=\"%s\", pid=%d, minor=%d\n", current->comm,
+		  task_pid_nr(current), minor->index);
+
+	priv = drm_file_alloc(minor);
+	if (IS_ERR(priv))
+		return PTR_ERR(priv);
+
+	if (drm_is_primary_client(priv)) {
+		ret = drm_master_open(priv);
+		if (ret) {
+			drm_file_free(priv);
+			return ret;
+		}
+	}
+
+	filp->private_data = priv;
+	filp->f_mode |= FMODE_UNSIGNED_OFFSET;
+	priv->filp = filp;
+
+	mutex_lock(&dev->filelist_mutex);
+	list_add(&priv->lhead, &dev->filelist);
+	mutex_unlock(&dev->filelist_mutex);
+
+#ifdef CONFIG_DRM_LEGACY
+#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 = list_entry(pci_root_buses.next,
+				struct pci_bus, node);
+			if (b)
+				dev->hose = b->sysdata;
+		}
+	}
+#endif
+#endif
+
+	return 0;
+}
+
+/**
+ * drm_open - open method for DRM file
+ * @inode: device inode
+ * @filp: file pointer.
+ *
+ * This function must be used by drivers as their &file_operations.open method.
+ * It looks up the correct DRM device and instantiates all the per-file
+ * resources for it. It also calls the &drm_driver.open driver callback.
+ *
+ * RETURNS:
+ *
+ * 0 on success or negative errno value on failure.
+ */
+int drm_open(struct inode *inode, struct file *filp)
+{
+	struct drm_device *dev;
+	struct drm_minor *minor;
+	int retcode;
+	int need_setup = 0;
+
+	minor = drm_minor_acquire(iminor(inode));
+	if (IS_ERR(minor))
+		return PTR_ERR(minor);
+
+	dev = minor->dev;
+	if (drm_dev_needs_global_mutex(dev))
+		mutex_lock(&drm_global_mutex);
+
+	if (!atomic_fetch_inc(&dev->open_count))
+		need_setup = 1;
+
+	/* share address_space across all char-devs of a single device */
+	filp->f_mapping = dev->anon_inode->i_mapping;
+
+	retcode = drm_open_helper(filp, minor);
+	if (retcode)
+		goto err_undo;
+	if (need_setup) {
+		retcode = drm_legacy_setup(dev);
+		if (retcode) {
+			drm_close_helper(filp);
+			goto err_undo;
+		}
+	}
+
+	if (drm_dev_needs_global_mutex(dev))
+		mutex_unlock(&drm_global_mutex);
+
+	return 0;
+
+err_undo:
+	atomic_dec(&dev->open_count);
+	if (drm_dev_needs_global_mutex(dev))
+		mutex_unlock(&drm_global_mutex);
+	drm_minor_release(minor);
+	return retcode;
+}
+EXPORT_SYMBOL(drm_open);
+
+void drm_lastclose(struct drm_device * dev)
+{
+	DRM_DEBUG("\n");
+
+	if (dev->driver->lastclose)
+		dev->driver->lastclose(dev);
+	DRM_DEBUG("driver lastclose completed\n");
+
+	if (drm_core_check_feature(dev, DRIVER_LEGACY))
+		drm_legacy_dev_reinit(dev);
+
+	drm_client_dev_restore(dev);
+}
+
+/**
+ * drm_release - release method for DRM file
+ * @inode: device inode
+ * @filp: file pointer.
+ *
+ * This function must be used by drivers as their &file_operations.release
+ * method. It frees any resources associated with the open file, and calls the
+ * &drm_driver.postclose driver callback. If this is the last open file for the
+ * DRM device also proceeds to call the &drm_driver.lastclose driver callback.
+ *
+ * RETURNS:
+ *
+ * Always succeeds and returns 0.
+ */
+int drm_release(struct inode *inode, struct file *filp)
+{
+	struct drm_file *file_priv = filp->private_data;
+	struct drm_minor *minor = file_priv->minor;
+	struct drm_device *dev = minor->dev;
+
+	if (drm_dev_needs_global_mutex(dev))
+		mutex_lock(&drm_global_mutex);
+
+	DRM_DEBUG("open_count = %d\n", atomic_read(&dev->open_count));
+
+	drm_close_helper(filp);
+
+	if (atomic_dec_and_test(&dev->open_count))
+		drm_lastclose(dev);
+
+	if (drm_dev_needs_global_mutex(dev))
+		mutex_unlock(&drm_global_mutex);
+
+	drm_minor_release(minor);
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_release);
+
+/**
+ * drm_release_noglobal - release method for DRM file
+ * @inode: device inode
+ * @filp: file pointer.
+ *
+ * This function may be used by drivers as their &file_operations.release
+ * method. It frees any resources associated with the open file prior to taking
+ * the drm_global_mutex, which then calls the &drm_driver.postclose driver
+ * callback. If this is the last open file for the DRM device also proceeds to
+ * call the &drm_driver.lastclose driver callback.
+ *
+ * RETURNS:
+ *
+ * Always succeeds and returns 0.
+ */
+int drm_release_noglobal(struct inode *inode, struct file *filp)
+{
+	struct drm_file *file_priv = filp->private_data;
+	struct drm_minor *minor = file_priv->minor;
+	struct drm_device *dev = minor->dev;
+
+	drm_close_helper(filp);
+
+	if (atomic_dec_and_mutex_lock(&dev->open_count, &drm_global_mutex)) {
+		drm_lastclose(dev);
+		mutex_unlock(&drm_global_mutex);
+	}
+
+	drm_minor_release(minor);
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_release_noglobal);
+
+/**
+ * drm_read - read method for DRM file
+ * @filp: file pointer
+ * @buffer: userspace destination pointer for the read
+ * @count: count in bytes to read
+ * @offset: offset to read
+ *
+ * This function must be used by drivers as their &file_operations.read
+ * method if they use DRM events for asynchronous signalling to userspace.
+ * Since events are used by the KMS API for vblank and page flip completion this
+ * means all modern display drivers must use it.
+ *
+ * @offset is ignored, DRM events are read like a pipe. Polling support is
+ * provided by drm_poll().
+ *
+ * This function will only ever read a full event. Therefore userspace must
+ * supply a big enough buffer to fit any event to ensure forward progress. Since
+ * the maximum event space is currently 4K it's recommended to just use that for
+ * safety.
+ *
+ * RETURNS:
+ *
+ * Number of bytes read (always aligned to full events, and can be 0) or a
+ * negative error code on failure.
+ */
+ssize_t drm_read(struct file *filp, char __user *buffer,
+		 size_t count, loff_t *offset)
+{
+	struct drm_file *file_priv = filp->private_data;
+	struct drm_device *dev = file_priv->minor->dev;
+	ssize_t ret;
+
+	ret = mutex_lock_interruptible(&file_priv->event_read_lock);
+	if (ret)
+		return ret;
+
+	for (;;) {
+		struct drm_pending_event *e = NULL;
+
+		spin_lock_irq(&dev->event_lock);
+		if (!list_empty(&file_priv->event_list)) {
+			e = list_first_entry(&file_priv->event_list,
+					struct drm_pending_event, link);
+			file_priv->event_space += e->event->length;
+			list_del(&e->link);
+		}
+		spin_unlock_irq(&dev->event_lock);
+
+		if (e == NULL) {
+			if (ret)
+				break;
+
+			if (filp->f_flags & O_NONBLOCK) {
+				ret = -EAGAIN;
+				break;
+			}
+
+			mutex_unlock(&file_priv->event_read_lock);
+			ret = wait_event_interruptible(file_priv->event_wait,
+						       !list_empty(&file_priv->event_list));
+			if (ret >= 0)
+				ret = mutex_lock_interruptible(&file_priv->event_read_lock);
+			if (ret)
+				return ret;
+		} else {
+			unsigned length = e->event->length;
+
+			if (length > count - ret) {
+put_back_event:
+				spin_lock_irq(&dev->event_lock);
+				file_priv->event_space -= length;
+				list_add(&e->link, &file_priv->event_list);
+				spin_unlock_irq(&dev->event_lock);
+				wake_up_interruptible_poll(&file_priv->event_wait,
+					EPOLLIN | EPOLLRDNORM);
+				break;
+			}
+
+			if (copy_to_user(buffer + ret, e->event, length)) {
+				if (ret == 0)
+					ret = -EFAULT;
+				goto put_back_event;
+			}
+
+			ret += length;
+			kfree(e);
+		}
+	}
+	mutex_unlock(&file_priv->event_read_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_read);
+
+/**
+ * drm_poll - poll method for DRM file
+ * @filp: file pointer
+ * @wait: poll waiter table
+ *
+ * This function must be used by drivers as their &file_operations.read method
+ * if they use DRM events for asynchronous signalling to userspace.  Since
+ * events are used by the KMS API for vblank and page flip completion this means
+ * all modern display drivers must use it.
+ *
+ * See also drm_read().
+ *
+ * RETURNS:
+ *
+ * Mask of POLL flags indicating the current status of the file.
+ */
+__poll_t drm_poll(struct file *filp, struct poll_table_struct *wait)
+{
+	struct drm_file *file_priv = filp->private_data;
+	__poll_t mask = 0;
+
+	poll_wait(filp, &file_priv->event_wait, wait);
+
+	if (!list_empty(&file_priv->event_list))
+		mask |= EPOLLIN | EPOLLRDNORM;
+
+	return mask;
+}
+EXPORT_SYMBOL(drm_poll);
+
+/**
+ * drm_event_reserve_init_locked - init a DRM event and reserve space for it
+ * @dev: DRM device
+ * @file_priv: DRM file private data
+ * @p: tracking structure for the pending event
+ * @e: actual event data to deliver to userspace
+ *
+ * This function prepares the passed in event for eventual delivery. If the event
+ * doesn't get delivered (because the IOCTL fails later on, before queuing up
+ * anything) then the even must be cancelled and freed using
+ * drm_event_cancel_free(). Successfully initialized events should be sent out
+ * using drm_send_event() or drm_send_event_locked() to signal completion of the
+ * asynchronous event to userspace.
+ *
+ * If callers embedded @p into a larger structure it must be allocated with
+ * kmalloc and @p must be the first member element.
+ *
+ * This is the locked version of drm_event_reserve_init() for callers which
+ * already hold &drm_device.event_lock.
+ *
+ * RETURNS:
+ *
+ * 0 on success or a negative error code on failure.
+ */
+int drm_event_reserve_init_locked(struct drm_device *dev,
+				  struct drm_file *file_priv,
+				  struct drm_pending_event *p,
+				  struct drm_event *e)
+{
+	if (file_priv->event_space < e->length)
+		return -ENOMEM;
+
+	file_priv->event_space -= e->length;
+
+	p->event = e;
+	list_add(&p->pending_link, &file_priv->pending_event_list);
+	p->file_priv = file_priv;
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_event_reserve_init_locked);
+
+/**
+ * drm_event_reserve_init - init a DRM event and reserve space for it
+ * @dev: DRM device
+ * @file_priv: DRM file private data
+ * @p: tracking structure for the pending event
+ * @e: actual event data to deliver to userspace
+ *
+ * This function prepares the passed in event for eventual delivery. If the event
+ * doesn't get delivered (because the IOCTL fails later on, before queuing up
+ * anything) then the even must be cancelled and freed using
+ * drm_event_cancel_free(). Successfully initialized events should be sent out
+ * using drm_send_event() or drm_send_event_locked() to signal completion of the
+ * asynchronous event to userspace.
+ *
+ * If callers embedded @p into a larger structure it must be allocated with
+ * kmalloc and @p must be the first member element.
+ *
+ * Callers which already hold &drm_device.event_lock should use
+ * drm_event_reserve_init_locked() instead.
+ *
+ * RETURNS:
+ *
+ * 0 on success or a negative error code on failure.
+ */
+int drm_event_reserve_init(struct drm_device *dev,
+			   struct drm_file *file_priv,
+			   struct drm_pending_event *p,
+			   struct drm_event *e)
+{
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&dev->event_lock, flags);
+	ret = drm_event_reserve_init_locked(dev, file_priv, p, e);
+	spin_unlock_irqrestore(&dev->event_lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_event_reserve_init);
+
+/**
+ * drm_event_cancel_free - free a DRM event and release its space
+ * @dev: DRM device
+ * @p: tracking structure for the pending event
+ *
+ * This function frees the event @p initialized with drm_event_reserve_init()
+ * and releases any allocated space. It is used to cancel an event when the
+ * nonblocking operation could not be submitted and needed to be aborted.
+ */
+void drm_event_cancel_free(struct drm_device *dev,
+			   struct drm_pending_event *p)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->event_lock, flags);
+	if (p->file_priv) {
+		p->file_priv->event_space += p->event->length;
+		list_del(&p->pending_link);
+	}
+	spin_unlock_irqrestore(&dev->event_lock, flags);
+
+	if (p->fence)
+		dma_fence_put(p->fence);
+
+	kfree(p);
+}
+EXPORT_SYMBOL(drm_event_cancel_free);
+
+static void drm_send_event_helper(struct drm_device *dev,
+			   struct drm_pending_event *e, ktime_t timestamp)
+{
+	assert_spin_locked(&dev->event_lock);
+
+	if (e->completion) {
+		complete_all(e->completion);
+		e->completion_release(e->completion);
+		e->completion = NULL;
+	}
+
+	if (e->fence) {
+		if (timestamp)
+			dma_fence_signal_timestamp(e->fence, timestamp);
+		else
+			dma_fence_signal(e->fence);
+		dma_fence_put(e->fence);
+	}
+
+	if (!e->file_priv) {
+		kfree(e);
+		return;
+	}
+
+	list_del(&e->pending_link);
+	list_add_tail(&e->link,
+		      &e->file_priv->event_list);
+	wake_up_interruptible_poll(&e->file_priv->event_wait,
+		EPOLLIN | EPOLLRDNORM);
+}
+
+/**
+ * drm_send_event_timestamp_locked - send DRM event to file descriptor
+ * @dev: DRM device
+ * @e: DRM event to deliver
+ * @timestamp: timestamp to set for the fence event in kernel's CLOCK_MONOTONIC
+ * time domain
+ *
+ * This function sends the event @e, initialized with drm_event_reserve_init(),
+ * to its associated userspace DRM file. Callers must already hold
+ * &drm_device.event_lock.
+ *
+ * Note that the core will take care of unlinking and disarming events when the
+ * corresponding DRM file is closed. Drivers need not worry about whether the
+ * DRM file for this event still exists and can call this function upon
+ * completion of the asynchronous work unconditionally.
+ */
+void drm_send_event_timestamp_locked(struct drm_device *dev,
+				     struct drm_pending_event *e, ktime_t timestamp)
+{
+	drm_send_event_helper(dev, e, timestamp);
+}
+EXPORT_SYMBOL(drm_send_event_timestamp_locked);
+
+/**
+ * drm_send_event_locked - send DRM event to file descriptor
+ * @dev: DRM device
+ * @e: DRM event to deliver
+ *
+ * This function sends the event @e, initialized with drm_event_reserve_init(),
+ * to its associated userspace DRM file. Callers must already hold
+ * &drm_device.event_lock, see drm_send_event() for the unlocked version.
+ *
+ * Note that the core will take care of unlinking and disarming events when the
+ * corresponding DRM file is closed. Drivers need not worry about whether the
+ * DRM file for this event still exists and can call this function upon
+ * completion of the asynchronous work unconditionally.
+ */
+void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
+{
+	drm_send_event_helper(dev, e, 0);
+}
+EXPORT_SYMBOL(drm_send_event_locked);
+
+/**
+ * drm_send_event - send DRM event to file descriptor
+ * @dev: DRM device
+ * @e: DRM event to deliver
+ *
+ * This function sends the event @e, initialized with drm_event_reserve_init(),
+ * to its associated userspace DRM file. This function acquires
+ * &drm_device.event_lock, see drm_send_event_locked() for callers which already
+ * hold this lock.
+ *
+ * Note that the core will take care of unlinking and disarming events when the
+ * corresponding DRM file is closed. Drivers need not worry about whether the
+ * DRM file for this event still exists and can call this function upon
+ * completion of the asynchronous work unconditionally.
+ */
+void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
+{
+	unsigned long irqflags;
+
+	spin_lock_irqsave(&dev->event_lock, irqflags);
+	drm_send_event_helper(dev, e, 0);
+	spin_unlock_irqrestore(&dev->event_lock, irqflags);
+}
+EXPORT_SYMBOL(drm_send_event);
+
+/**
+ * mock_drm_getfile - Create a new struct file for the drm device
+ * @minor: drm minor to wrap (e.g. #drm_device.primary)
+ * @flags: file creation mode (O_RDWR etc)
+ *
+ * This create a new struct file that wraps a DRM file context around a
+ * DRM minor. This mimicks userspace opening e.g. /dev/dri/card0, but without
+ * invoking userspace. The struct file may be operated on using its f_op
+ * (the drm_device.driver.fops) to mimick userspace operations, or be supplied
+ * to userspace facing functions as an internal/anonymous client.
+ *
+ * RETURNS:
+ * Pointer to newly created struct file, ERR_PTR on failure.
+ */
+struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags)
+{
+	struct drm_device *dev = minor->dev;
+	struct drm_file *priv;
+	struct file *file;
+
+	priv = drm_file_alloc(minor);
+	if (IS_ERR(priv))
+		return ERR_CAST(priv);
+
+	file = anon_inode_getfile("drm", dev->driver->fops, priv, flags);
+	if (IS_ERR(file)) {
+		drm_file_free(priv);
+		return file;
+	}
+
+	/* Everyone shares a single global address space */
+	file->f_mapping = dev->anon_inode->i_mapping;
+
+	drm_dev_get(dev);
+	priv->filp = file;
+
+	return file;
+}
+EXPORT_SYMBOL_FOR_TESTS_ONLY(mock_drm_getfile);