3 * File operations for DRM
5 * \author Rickard E. (Rik) Faith <faith@valinux.com>
6 * \author Daryll Strauss <daryll@valinux.com>
7 * \author Gareth Hughes <gareth@valinux.com>
11 * Created: Mon Jan 4 08:58:31 1999 by faith@valinux.com
13 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
14 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
15 * All Rights Reserved.
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18 * copy of this software and associated documentation files (the "Software"),
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22 * Software is furnished to do so, subject to the following conditions:
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
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38 #include <linux/poll.h>
39 #include <linux/slab.h>
40 #include <linux/module.h>
41 #include "drm_legacy.h"
42 #include "drm_internal.h"
44 /* from BKL pushdown */
45 DEFINE_MUTEX(drm_global_mutex);
48 * DOC: file operations
50 * Drivers must define the file operations structure that forms the DRM
51 * userspace API entry point, even though most of those operations are
52 * implemented in the DRM core. The mandatory functions are drm_open(),
53 * drm_read(), drm_ioctl() and drm_compat_ioctl if CONFIG_COMPAT is enabled.
54 * Drivers which implement private ioctls that require 32/64 bit compatibility
55 * support must provided their onw .compat_ioctl() handler that processes
56 * private ioctls and calls drm_compat_ioctl() for core ioctls.
58 * In addition drm_read() and drm_poll() provide support for DRM events. DRM
59 * events are a generic and extensible means to send asynchronous events to
60 * userspace through the file descriptor. They are used to send vblank event and
61 * page flip completions by the KMS API. But drivers can also use it for their
62 * own needs, e.g. to signal completion of rendering.
64 * The memory mapping implementation will vary depending on how the driver
65 * manages memory. Legacy drivers will use the deprecated drm_legacy_mmap()
66 * function, modern drivers should use one of the provided memory-manager
67 * specific implementations. For GEM-based drivers this is drm_gem_mmap().
69 * No other file operations are supported by the DRM userspace API. Overall the
70 * following is an example #file_operations structure::
72 * static const example_drm_fops = {
73 * .owner = THIS_MODULE,
75 * .release = drm_release,
76 * .unlocked_ioctl = drm_ioctl,
77 * #ifdef CONFIG_COMPAT
78 * .compat_ioctl = drm_compat_ioctl,
82 * .llseek = no_llseek,
83 * .mmap = drm_gem_mmap,
87 static int drm_open_helper(struct file *filp, struct drm_minor *minor);
89 static int drm_setup(struct drm_device * dev)
93 if (dev->driver->firstopen &&
94 !drm_core_check_feature(dev, DRIVER_MODESET)) {
95 ret = dev->driver->firstopen(dev);
100 ret = drm_legacy_dma_setup(dev);
110 * drm_open - open method for DRM file
111 * @inode: device inode
112 * @filp: file pointer.
114 * This function must be used by drivers as their .open() #file_operations
115 * method. It looks up the correct DRM device and instantiates all the per-file
120 * 0 on success or negative errno value on falure.
122 int drm_open(struct inode *inode, struct file *filp)
124 struct drm_device *dev;
125 struct drm_minor *minor;
129 minor = drm_minor_acquire(iminor(inode));
131 return PTR_ERR(minor);
134 if (!dev->open_count++)
137 /* share address_space across all char-devs of a single device */
138 filp->f_mapping = dev->anon_inode->i_mapping;
140 retcode = drm_open_helper(filp, minor);
144 retcode = drm_setup(dev);
152 drm_minor_release(minor);
155 EXPORT_SYMBOL(drm_open);
158 * Check whether DRI will run on this CPU.
160 * \return non-zero if the DRI will run on this CPU, or zero otherwise.
162 static int drm_cpu_valid(void)
164 #if defined(__sparc__) && !defined(__sparc_v9__)
165 return 0; /* No cmpxchg before v9 sparc. */
171 * Called whenever a process opens /dev/drm.
173 * \param filp file pointer.
174 * \param minor acquired minor-object.
175 * \return zero on success or a negative number on failure.
177 * Creates and initializes a drm_file structure for the file private data in \p
178 * filp and add it into the double linked list in \p dev.
180 static int drm_open_helper(struct file *filp, struct drm_minor *minor)
182 struct drm_device *dev = minor->dev;
183 struct drm_file *priv;
186 if (filp->f_flags & O_EXCL)
187 return -EBUSY; /* No exclusive opens */
188 if (!drm_cpu_valid())
190 if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
193 DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor->index);
195 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
199 filp->private_data = priv;
201 priv->uid = current_euid();
202 priv->pid = get_pid(task_pid(current));
205 /* for compatibility root is always authenticated */
206 priv->authenticated = capable(CAP_SYS_ADMIN);
207 priv->lock_count = 0;
209 INIT_LIST_HEAD(&priv->lhead);
210 INIT_LIST_HEAD(&priv->fbs);
211 mutex_init(&priv->fbs_lock);
212 INIT_LIST_HEAD(&priv->blobs);
213 INIT_LIST_HEAD(&priv->pending_event_list);
214 INIT_LIST_HEAD(&priv->event_list);
215 init_waitqueue_head(&priv->event_wait);
216 priv->event_space = 4096; /* set aside 4k for event buffer */
218 mutex_init(&priv->event_read_lock);
220 if (drm_core_check_feature(dev, DRIVER_GEM))
221 drm_gem_open(dev, priv);
223 if (drm_core_check_feature(dev, DRIVER_PRIME))
224 drm_prime_init_file_private(&priv->prime);
226 if (dev->driver->open) {
227 ret = dev->driver->open(dev, priv);
229 goto out_prime_destroy;
232 if (drm_is_primary_client(priv)) {
233 ret = drm_master_open(priv);
238 mutex_lock(&dev->filelist_mutex);
239 list_add(&priv->lhead, &dev->filelist);
240 mutex_unlock(&dev->filelist_mutex);
247 struct pci_dev *pci_dev;
248 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
250 dev->hose = pci_dev->sysdata;
251 pci_dev_put(pci_dev);
254 struct pci_bus *b = list_entry(pci_root_buses.next,
255 struct pci_bus, node);
257 dev->hose = b->sysdata;
265 if (dev->driver->postclose)
266 dev->driver->postclose(dev, priv);
268 if (drm_core_check_feature(dev, DRIVER_PRIME))
269 drm_prime_destroy_file_private(&priv->prime);
270 if (drm_core_check_feature(dev, DRIVER_GEM))
271 drm_gem_release(dev, priv);
274 filp->private_data = NULL;
278 static void drm_events_release(struct drm_file *file_priv)
280 struct drm_device *dev = file_priv->minor->dev;
281 struct drm_pending_event *e, *et;
284 spin_lock_irqsave(&dev->event_lock, flags);
286 /* Unlink pending events */
287 list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
289 list_del(&e->pending_link);
293 /* Remove unconsumed events */
294 list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
299 spin_unlock_irqrestore(&dev->event_lock, flags);
303 * drm_legacy_dev_reinit
305 * Reinitializes a legacy/ums drm device in it's lastclose function.
307 static void drm_legacy_dev_reinit(struct drm_device *dev)
309 if (dev->irq_enabled)
310 drm_irq_uninstall(dev);
312 mutex_lock(&dev->struct_mutex);
314 drm_legacy_agp_clear(dev);
316 drm_legacy_sg_cleanup(dev);
317 drm_legacy_vma_flush(dev);
318 drm_legacy_dma_takedown(dev);
320 mutex_unlock(&dev->struct_mutex);
322 dev->sigdata.lock = NULL;
324 dev->context_flag = 0;
325 dev->last_context = 0;
328 DRM_DEBUG("lastclose completed\n");
332 * Take down the DRM device.
334 * \param dev DRM device structure.
336 * Frees every resource in \p dev.
340 void drm_lastclose(struct drm_device * dev)
344 if (dev->driver->lastclose)
345 dev->driver->lastclose(dev);
346 DRM_DEBUG("driver lastclose completed\n");
348 if (!drm_core_check_feature(dev, DRIVER_MODESET))
349 drm_legacy_dev_reinit(dev);
353 * drm_release - release method for DRM file
354 * @inode: device inode
355 * @filp: file pointer.
357 * This function must be used by drivers as their .release() #file_operations
358 * method. It frees any resources associated with the open file, and if this is
359 * the last open file for the DRM device also proceeds to call drm_lastclose().
363 * Always succeeds and returns 0.
365 int drm_release(struct inode *inode, struct file *filp)
367 struct drm_file *file_priv = filp->private_data;
368 struct drm_minor *minor = file_priv->minor;
369 struct drm_device *dev = minor->dev;
371 mutex_lock(&drm_global_mutex);
373 DRM_DEBUG("open_count = %d\n", dev->open_count);
375 mutex_lock(&dev->filelist_mutex);
376 list_del(&file_priv->lhead);
377 mutex_unlock(&dev->filelist_mutex);
379 mutex_lock(&dev->struct_mutex);
380 if (file_priv->magic)
381 idr_remove(&file_priv->master->magic_map, file_priv->magic);
382 mutex_unlock(&dev->struct_mutex);
384 if (dev->driver->preclose)
385 dev->driver->preclose(dev, file_priv);
387 /* ========================================================
388 * Begin inline drm_release
391 DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
392 task_pid_nr(current),
393 (long)old_encode_dev(file_priv->minor->kdev->devt),
396 if (!drm_core_check_feature(dev, DRIVER_MODESET))
397 drm_legacy_lock_release(dev, filp);
399 if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
400 drm_legacy_reclaim_buffers(dev, file_priv);
402 drm_events_release(file_priv);
404 if (drm_core_check_feature(dev, DRIVER_MODESET)) {
405 drm_fb_release(file_priv);
406 drm_property_destroy_user_blobs(dev, file_priv);
409 if (drm_core_check_feature(dev, DRIVER_GEM))
410 drm_gem_release(dev, file_priv);
412 drm_legacy_ctxbitmap_flush(dev, file_priv);
414 if (drm_is_primary_client(file_priv))
415 drm_master_release(file_priv);
417 if (dev->driver->postclose)
418 dev->driver->postclose(dev, file_priv);
420 if (drm_core_check_feature(dev, DRIVER_PRIME))
421 drm_prime_destroy_file_private(&file_priv->prime);
423 WARN_ON(!list_empty(&file_priv->event_list));
425 put_pid(file_priv->pid);
428 /* ========================================================
429 * End inline drm_release
432 if (!--dev->open_count) {
434 if (drm_device_is_unplugged(dev))
437 mutex_unlock(&drm_global_mutex);
439 drm_minor_release(minor);
443 EXPORT_SYMBOL(drm_release);
446 * drm_read - read method for DRM file
447 * @filp: file pointer
448 * @buffer: userspace destination pointer for the read
449 * @count: count in bytes to read
450 * @offset: offset to read
452 * This function must be used by drivers as their .read() #file_operations
453 * method iff they use DRM events for asynchronous signalling to userspace.
454 * Since events are used by the KMS API for vblank and page flip completion this
455 * means all modern display drivers must use it.
457 * @offset is ignore, DRM events are read like a pipe. Therefore drivers also
458 * must set the .llseek() #file_operation to no_llseek(). Polling support is
459 * provided by drm_poll().
461 * This function will only ever read a full event. Therefore userspace must
462 * supply a big enough buffer to fit any event to ensure forward progress. Since
463 * the maximum event space is currently 4K it's recommended to just use that for
468 * Number of bytes read (always aligned to full events, and can be 0) or a
469 * negative error code on failure.
471 ssize_t drm_read(struct file *filp, char __user *buffer,
472 size_t count, loff_t *offset)
474 struct drm_file *file_priv = filp->private_data;
475 struct drm_device *dev = file_priv->minor->dev;
478 if (!access_ok(VERIFY_WRITE, buffer, count))
481 ret = mutex_lock_interruptible(&file_priv->event_read_lock);
486 struct drm_pending_event *e = NULL;
488 spin_lock_irq(&dev->event_lock);
489 if (!list_empty(&file_priv->event_list)) {
490 e = list_first_entry(&file_priv->event_list,
491 struct drm_pending_event, link);
492 file_priv->event_space += e->event->length;
495 spin_unlock_irq(&dev->event_lock);
501 if (filp->f_flags & O_NONBLOCK) {
506 mutex_unlock(&file_priv->event_read_lock);
507 ret = wait_event_interruptible(file_priv->event_wait,
508 !list_empty(&file_priv->event_list));
510 ret = mutex_lock_interruptible(&file_priv->event_read_lock);
514 unsigned length = e->event->length;
516 if (length > count - ret) {
518 spin_lock_irq(&dev->event_lock);
519 file_priv->event_space -= length;
520 list_add(&e->link, &file_priv->event_list);
521 spin_unlock_irq(&dev->event_lock);
525 if (copy_to_user(buffer + ret, e->event, length)) {
535 mutex_unlock(&file_priv->event_read_lock);
539 EXPORT_SYMBOL(drm_read);
542 * drm_poll - poll method for DRM file
543 * @filp: file pointer
544 * @wait: poll waiter table
546 * This function must be used by drivers as their .read() #file_operations
547 * method iff they use DRM events for asynchronous signalling to userspace.
548 * Since events are used by the KMS API for vblank and page flip completion this
549 * means all modern display drivers must use it.
551 * See also drm_read().
555 * Mask of POLL flags indicating the current status of the file.
557 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
559 struct drm_file *file_priv = filp->private_data;
560 unsigned int mask = 0;
562 poll_wait(filp, &file_priv->event_wait, wait);
564 if (!list_empty(&file_priv->event_list))
565 mask |= POLLIN | POLLRDNORM;
569 EXPORT_SYMBOL(drm_poll);
572 * drm_event_reserve_init_locked - init a DRM event and reserve space for it
574 * @file_priv: DRM file private data
575 * @p: tracking structure for the pending event
576 * @e: actual event data to deliver to userspace
578 * This function prepares the passed in event for eventual delivery. If the event
579 * doesn't get delivered (because the IOCTL fails later on, before queuing up
580 * anything) then the even must be cancelled and freed using
581 * drm_event_cancel_free(). Successfully initialized events should be sent out
582 * using drm_send_event() or drm_send_event_locked() to signal completion of the
583 * asynchronous event to userspace.
585 * If callers embedded @p into a larger structure it must be allocated with
586 * kmalloc and @p must be the first member element.
588 * This is the locked version of drm_event_reserve_init() for callers which
589 * already hold dev->event_lock.
593 * 0 on success or a negative error code on failure.
595 int drm_event_reserve_init_locked(struct drm_device *dev,
596 struct drm_file *file_priv,
597 struct drm_pending_event *p,
600 if (file_priv->event_space < e->length)
603 file_priv->event_space -= e->length;
606 list_add(&p->pending_link, &file_priv->pending_event_list);
607 p->file_priv = file_priv;
611 EXPORT_SYMBOL(drm_event_reserve_init_locked);
614 * drm_event_reserve_init - init a DRM event and reserve space for it
616 * @file_priv: DRM file private data
617 * @p: tracking structure for the pending event
618 * @e: actual event data to deliver to userspace
620 * This function prepares the passed in event for eventual delivery. If the event
621 * doesn't get delivered (because the IOCTL fails later on, before queuing up
622 * anything) then the even must be cancelled and freed using
623 * drm_event_cancel_free(). Successfully initialized events should be sent out
624 * using drm_send_event() or drm_send_event_locked() to signal completion of the
625 * asynchronous event to userspace.
627 * If callers embedded @p into a larger structure it must be allocated with
628 * kmalloc and @p must be the first member element.
630 * Callers which already hold dev->event_lock should use
631 * drm_event_reserve_init() instead.
635 * 0 on success or a negative error code on failure.
637 int drm_event_reserve_init(struct drm_device *dev,
638 struct drm_file *file_priv,
639 struct drm_pending_event *p,
645 spin_lock_irqsave(&dev->event_lock, flags);
646 ret = drm_event_reserve_init_locked(dev, file_priv, p, e);
647 spin_unlock_irqrestore(&dev->event_lock, flags);
651 EXPORT_SYMBOL(drm_event_reserve_init);
654 * drm_event_cancel_free - free a DRM event and release it's space
656 * @p: tracking structure for the pending event
658 * This function frees the event @p initialized with drm_event_reserve_init()
659 * and releases any allocated space.
661 void drm_event_cancel_free(struct drm_device *dev,
662 struct drm_pending_event *p)
665 spin_lock_irqsave(&dev->event_lock, flags);
667 p->file_priv->event_space += p->event->length;
668 list_del(&p->pending_link);
670 spin_unlock_irqrestore(&dev->event_lock, flags);
673 EXPORT_SYMBOL(drm_event_cancel_free);
676 * drm_send_event_locked - send DRM event to file descriptor
678 * @e: DRM event to deliver
680 * This function sends the event @e, initialized with drm_event_reserve_init(),
681 * to its associated userspace DRM file. Callers must already hold
682 * dev->event_lock, see drm_send_event() for the unlocked version.
684 * Note that the core will take care of unlinking and disarming events when the
685 * corresponding DRM file is closed. Drivers need not worry about whether the
686 * DRM file for this event still exists and can call this function upon
687 * completion of the asynchronous work unconditionally.
689 void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
691 assert_spin_locked(&dev->event_lock);
694 /* ->completion might disappear as soon as it signalled. */
695 complete_all(e->completion);
696 e->completion = NULL;
700 fence_signal(e->fence);
709 list_del(&e->pending_link);
710 list_add_tail(&e->link,
711 &e->file_priv->event_list);
712 wake_up_interruptible(&e->file_priv->event_wait);
714 EXPORT_SYMBOL(drm_send_event_locked);
717 * drm_send_event - send DRM event to file descriptor
719 * @e: DRM event to deliver
721 * This function sends the event @e, initialized with drm_event_reserve_init(),
722 * to its associated userspace DRM file. This function acquires dev->event_lock,
723 * see drm_send_event_locked() for callers which already hold this lock.
725 * Note that the core will take care of unlinking and disarming events when the
726 * corresponding DRM file is closed. Drivers need not worry about whether the
727 * DRM file for this event still exists and can call this function upon
728 * completion of the asynchronous work unconditionally.
730 void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
732 unsigned long irqflags;
734 spin_lock_irqsave(&dev->event_lock, irqflags);
735 drm_send_event_locked(dev, e);
736 spin_unlock_irqrestore(&dev->event_lock, irqflags);
738 EXPORT_SYMBOL(drm_send_event);