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- /*
- * \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 <drm/drmP.h>
- #include <linux/poll.h>
- #include <linux/slab.h>
- #include <linux/module.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 mandatory functions are drm_open(),
- * drm_read(), drm_ioctl() and drm_compat_ioctl if CONFIG_COMPAT is enabled.
- * Drivers which implement private ioctls that require 32/64 bit compatibility
- * support must provided their onw .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.
- *
- * 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,
- * #ifdef CONFIG_COMPAT
- * .compat_ioctl = drm_compat_ioctl,
- * #endif
- * .poll = drm_poll,
- * .read = drm_read,
- * .llseek = no_llseek,
- * .mmap = drm_gem_mmap,
- * };
- */
- static int drm_open_helper(struct file *filp, struct drm_minor *minor);
- 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 .open() #file_operations
- * method. It looks up the correct DRM device and instantiates all the per-file
- * resources for it.
- *
- * 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)
- 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 = kzalloc(sizeof(*priv), GFP_KERNEL);
- if (!priv)
- return -ENOMEM;
- filp->private_data = priv;
- filp->f_mode |= FMODE_UNSIGNED_OFFSET;
- priv->filp = filp;
- priv->pid = get_pid(task_pid(current));
- priv->minor = minor;
- /* 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);
- mutex_init(&priv->fbs_lock);
- INIT_LIST_HEAD(&priv->blobs);
- INIT_LIST_HEAD(&priv->pending_event_list);
- INIT_LIST_HEAD(&priv->event_list);
- init_waitqueue_head(&priv->event_wait);
- priv->event_space = 4096; /* set aside 4k for event buffer */
- mutex_init(&priv->event_read_lock);
- if (drm_core_check_feature(dev, DRIVER_GEM))
- drm_gem_open(dev, priv);
- if (drm_core_check_feature(dev, DRIVER_PRIME))
- drm_prime_init_file_private(&priv->prime);
- if (dev->driver->open) {
- ret = dev->driver->open(dev, priv);
- if (ret < 0)
- goto out_prime_destroy;
- }
- if (drm_is_primary_client(priv)) {
- ret = drm_master_open(priv);
- if (ret)
- goto out_close;
- }
- 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;
- out_close:
- if (dev->driver->postclose)
- dev->driver->postclose(dev, priv);
- out_prime_destroy:
- if (drm_core_check_feature(dev, DRIVER_PRIME))
- drm_prime_destroy_file_private(&priv->prime);
- if (drm_core_check_feature(dev, DRIVER_GEM))
- drm_gem_release(dev, priv);
- put_pid(priv->pid);
- kfree(priv);
- filp->private_data = NULL;
- return 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_legacy_dev_reinit
- *
- * Reinitializes a legacy/ums drm device in it's lastclose function.
- */
- static void drm_legacy_dev_reinit(struct drm_device *dev)
- {
- if (dev->irq_enabled)
- drm_irq_uninstall(dev);
- mutex_lock(&dev->struct_mutex);
- drm_legacy_agp_clear(dev);
- drm_legacy_sg_cleanup(dev);
- drm_legacy_vma_flush(dev);
- drm_legacy_dma_takedown(dev);
- mutex_unlock(&dev->struct_mutex);
- dev->sigdata.lock = NULL;
- dev->context_flag = 0;
- dev->last_context = 0;
- dev->if_version = 0;
- DRM_DEBUG("lastclose completed\n");
- }
- /*
- * Take down the DRM device.
- *
- * \param dev DRM device structure.
- *
- * Frees every resource in \p dev.
- *
- * \sa drm_device
- */
- 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_release - release method for DRM file
- * @inode: device inode
- * @filp: file pointer.
- *
- * This function must be used by drivers as their .release() #file_operations
- * method. It frees any resources associated with the open file, and if this is
- * the last open file for the DRM device also proceeds to call drm_lastclose().
- *
- * 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);
- mutex_lock(&dev->filelist_mutex);
- list_del(&file_priv->lhead);
- mutex_unlock(&dev->filelist_mutex);
- 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->kdev->devt),
- dev->open_count);
- if (drm_core_check_feature(dev, DRIVER_LEGACY))
- drm_legacy_lock_release(dev, filp);
- if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
- drm_legacy_reclaim_buffers(dev, file_priv);
- drm_events_release(file_priv);
- if (drm_core_check_feature(dev, DRIVER_MODESET)) {
- drm_fb_release(file_priv);
- drm_property_destroy_user_blobs(dev, file_priv);
- }
- if (drm_core_check_feature(dev, DRIVER_GEM))
- drm_gem_release(dev, file_priv);
- drm_legacy_ctxbitmap_flush(dev, file_priv);
- if (drm_is_primary_client(file_priv))
- drm_master_release(file_priv);
- if (dev->driver->postclose)
- dev->driver->postclose(dev, file_priv);
- if (drm_core_check_feature(dev, DRIVER_PRIME))
- drm_prime_destroy_file_private(&file_priv->prime);
- WARN_ON(!list_empty(&file_priv->event_list));
- put_pid(file_priv->pid);
- kfree(file_priv);
- /* ========================================================
- * End inline drm_release
- */
- if (!--dev->open_count) {
- drm_lastclose(dev);
- if (drm_device_is_unplugged(dev))
- drm_put_dev(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 .read() #file_operations
- * 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 ignore, DRM events are read like a pipe. Therefore drivers also
- * must set the .llseek() #file_operation 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(VERIFY_WRITE, 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);
- 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 .read() #file_operations
- * 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.
- */
- unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
- {
- struct drm_file *file_priv = filp->private_data;
- unsigned int mask = 0;
- poll_wait(filp, &file_priv->event_wait, wait);
- if (!list_empty(&file_priv->event_list))
- mask |= POLLIN | POLLRDNORM;
- 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 dev->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 dev->event_lock should use
- * drm_event_reserve_init() 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 it's 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.
- */
- 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);
- 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
- * dev->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) {
- fence_signal(e->fence);
- 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 dev->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);
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