Staging
v0.7.0
v0.7.0
drm_file.c
/*
* \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/poll.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <drm/drm_client.h>
#include <drm/drm_file.h>
#include <drm/drmP.h>
#include "drm_legacy.h"
#include "drm_internal.h"
#include "drm_crtc_internal.h"
/* from BKL pushdown */
DEFINE_MUTEX(drm_global_mutex);
/**
* 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(), and
* for drivers which use the CMA GEM helpers it's drm_gem_cma_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
* CMA based drivers there is the DEFINE_DRM_GEM_CMA_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>`.
*/
static int drm_open_helper(struct file *filp, struct drm_minor *minor);
/**
* 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 */
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);
if (drm_core_check_feature(dev, DRIVER_PRIME))
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:
if (drm_core_check_feature(dev, DRIVER_PRIME))
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.
*
* RETURNS:
* 0 on success, or error code on failure.
*/
void drm_file_free(struct drm_file *file)
{
struct drm_device *dev;
if (!file)
return;
dev = file->minor->dev;
DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
task_pid_nr(current),
(long)old_encode_dev(file->minor->kdev->devt),
dev->open_count);
if (drm_core_check_feature(dev, DRIVER_LEGACY) &&
dev->driver->preclose)
dev->driver->preclose(dev, file);
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);
if (drm_core_check_feature(dev, DRIVER_PRIME))
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);
}
static int drm_setup(struct drm_device * dev)
{
int ret;
if (dev->driver->firstopen &&
drm_core_check_feature(dev, DRIVER_LEGACY)) {
ret = dev->driver->firstopen(dev);
if (ret != 0)
return ret;
}
ret = drm_legacy_dma_setup(dev);
if (ret < 0)
return ret;
DRM_DEBUG("\n");
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 falure.
*/
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 (!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_setup(dev);
if (retcode) {
drm_close_helper(filp);
goto err_undo;
}
}
return 0;
err_undo:
dev->open_count--;
drm_minor_release(minor);
return retcode;
}
EXPORT_SYMBOL(drm_open);
/*
* 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 /dev/drm.
*
* \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("pid = %d, minor = %d\n", 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 __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
return 0;
}
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;
mutex_lock(&drm_global_mutex);
DRM_DEBUG("open_count = %d\n", dev->open_count);
drm_close_helper(filp);
if (!--dev->open_count)
drm_lastclose(dev);
mutex_unlock(&drm_global_mutex);
drm_minor_release(minor);
return 0;
}
EXPORT_SYMBOL(drm_release);
/**
* 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 iff 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. Therefore drivers also
* must set the &file_operation.llseek to no_llseek(). 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;
if (!access_ok(buffer, count))
return -EFAULT;
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(&file_priv->event_wait);
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
* iff 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);
/**
* 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)
{
assert_spin_locked(&dev->event_lock);
if (e->completion) {
complete_all(e->completion);
e->completion_release(e->completion);
e->completion = NULL;
}
if (e->fence) {
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(&e->file_priv->event_wait);
}
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_locked(dev, e);
spin_unlock_irqrestore(&dev->event_lock, irqflags);
}
EXPORT_SYMBOL(drm_send_event);