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.
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
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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:
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
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
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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 * drm_new_set_master - Allocate a new master object and become master for the
172 * associated master realm.
174 * @dev: The associated device.
175 * @fpriv: File private identifying the client.
177 * This function must be called with dev::struct_mutex held.
178 * Returns negative error code on failure. Zero on success.
180 int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv)
182 struct drm_master *old_master;
185 lockdep_assert_held_once(&dev->master_mutex);
187 /* create a new master */
188 fpriv->minor->master = drm_master_create(fpriv->minor);
189 if (!fpriv->minor->master)
192 /* take another reference for the copy in the local file priv */
193 old_master = fpriv->master;
194 fpriv->master = drm_master_get(fpriv->minor->master);
196 if (dev->driver->master_create) {
197 ret = dev->driver->master_create(dev, fpriv->master);
201 if (dev->driver->master_set) {
202 ret = dev->driver->master_set(dev, fpriv, true);
207 fpriv->is_master = 1;
208 fpriv->allowed_master = 1;
209 fpriv->authenticated = 1;
211 drm_master_put(&old_master);
216 /* drop both references and restore old master on failure */
217 drm_master_put(&fpriv->minor->master);
218 drm_master_put(&fpriv->master);
219 fpriv->master = old_master;
225 * Called whenever a process opens /dev/drm.
227 * \param filp file pointer.
228 * \param minor acquired minor-object.
229 * \return zero on success or a negative number on failure.
231 * Creates and initializes a drm_file structure for the file private data in \p
232 * filp and add it into the double linked list in \p dev.
234 static int drm_open_helper(struct file *filp, struct drm_minor *minor)
236 struct drm_device *dev = minor->dev;
237 struct drm_file *priv;
240 if (filp->f_flags & O_EXCL)
241 return -EBUSY; /* No exclusive opens */
242 if (!drm_cpu_valid())
244 if (dev->switch_power_state != DRM_SWITCH_POWER_ON && dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
247 DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor->index);
249 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
253 filp->private_data = priv;
255 priv->uid = current_euid();
256 priv->pid = get_pid(task_pid(current));
259 /* for compatibility root is always authenticated */
260 priv->authenticated = capable(CAP_SYS_ADMIN);
261 priv->lock_count = 0;
263 INIT_LIST_HEAD(&priv->lhead);
264 INIT_LIST_HEAD(&priv->fbs);
265 mutex_init(&priv->fbs_lock);
266 INIT_LIST_HEAD(&priv->blobs);
267 INIT_LIST_HEAD(&priv->pending_event_list);
268 INIT_LIST_HEAD(&priv->event_list);
269 init_waitqueue_head(&priv->event_wait);
270 priv->event_space = 4096; /* set aside 4k for event buffer */
272 mutex_init(&priv->event_read_lock);
274 if (drm_core_check_feature(dev, DRIVER_GEM))
275 drm_gem_open(dev, priv);
277 if (drm_core_check_feature(dev, DRIVER_PRIME))
278 drm_prime_init_file_private(&priv->prime);
280 if (dev->driver->open) {
281 ret = dev->driver->open(dev, priv);
283 goto out_prime_destroy;
286 /* if there is no current master make this fd it, but do not create
287 * any master object for render clients */
288 mutex_lock(&dev->master_mutex);
289 if (drm_is_primary_client(priv) && !priv->minor->master) {
290 /* create a new master */
291 ret = drm_new_set_master(dev, priv);
294 } else if (drm_is_primary_client(priv)) {
295 /* get a reference to the master */
296 priv->master = drm_master_get(priv->minor->master);
298 mutex_unlock(&dev->master_mutex);
300 mutex_lock(&dev->struct_mutex);
301 list_add(&priv->lhead, &dev->filelist);
302 mutex_unlock(&dev->struct_mutex);
309 struct pci_dev *pci_dev;
310 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
312 dev->hose = pci_dev->sysdata;
313 pci_dev_put(pci_dev);
316 struct pci_bus *b = list_entry(pci_root_buses.next,
317 struct pci_bus, node);
319 dev->hose = b->sysdata;
327 mutex_unlock(&dev->master_mutex);
328 if (dev->driver->postclose)
329 dev->driver->postclose(dev, priv);
331 if (drm_core_check_feature(dev, DRIVER_PRIME))
332 drm_prime_destroy_file_private(&priv->prime);
333 if (drm_core_check_feature(dev, DRIVER_GEM))
334 drm_gem_release(dev, priv);
337 filp->private_data = NULL;
341 static void drm_master_release(struct drm_device *dev, struct file *filp)
343 struct drm_file *file_priv = filp->private_data;
345 if (drm_legacy_i_have_hw_lock(dev, file_priv)) {
346 DRM_DEBUG("File %p released, freeing lock for context %d\n",
347 filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
348 drm_legacy_lock_free(&file_priv->master->lock,
349 _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
353 static void drm_events_release(struct drm_file *file_priv)
355 struct drm_device *dev = file_priv->minor->dev;
356 struct drm_pending_event *e, *et;
359 spin_lock_irqsave(&dev->event_lock, flags);
361 /* Unlink pending events */
362 list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
364 list_del(&e->pending_link);
368 /* Remove unconsumed events */
369 list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
374 spin_unlock_irqrestore(&dev->event_lock, flags);
378 * drm_legacy_dev_reinit
380 * Reinitializes a legacy/ums drm device in it's lastclose function.
382 static void drm_legacy_dev_reinit(struct drm_device *dev)
384 if (dev->irq_enabled)
385 drm_irq_uninstall(dev);
387 mutex_lock(&dev->struct_mutex);
389 drm_legacy_agp_clear(dev);
391 drm_legacy_sg_cleanup(dev);
392 drm_legacy_vma_flush(dev);
393 drm_legacy_dma_takedown(dev);
395 mutex_unlock(&dev->struct_mutex);
397 dev->sigdata.lock = NULL;
399 dev->context_flag = 0;
400 dev->last_context = 0;
403 DRM_DEBUG("lastclose completed\n");
407 * Take down the DRM device.
409 * \param dev DRM device structure.
411 * Frees every resource in \p dev.
415 void drm_lastclose(struct drm_device * dev)
419 if (dev->driver->lastclose)
420 dev->driver->lastclose(dev);
421 DRM_DEBUG("driver lastclose completed\n");
423 if (!drm_core_check_feature(dev, DRIVER_MODESET))
424 drm_legacy_dev_reinit(dev);
428 * drm_release - release method for DRM file
429 * @inode: device inode
430 * @filp: file pointer.
432 * This function must be used by drivers as their .release() #file_operations
433 * method. It frees any resources associated with the open file, and if this is
434 * the last open file for the DRM device also proceeds to call drm_lastclose().
438 * Always succeeds and returns 0.
440 int drm_release(struct inode *inode, struct file *filp)
442 struct drm_file *file_priv = filp->private_data;
443 struct drm_minor *minor = file_priv->minor;
444 struct drm_device *dev = minor->dev;
446 mutex_lock(&drm_global_mutex);
448 DRM_DEBUG("open_count = %d\n", dev->open_count);
450 mutex_lock(&dev->struct_mutex);
451 list_del(&file_priv->lhead);
452 if (file_priv->magic)
453 idr_remove(&file_priv->master->magic_map, file_priv->magic);
454 mutex_unlock(&dev->struct_mutex);
456 if (dev->driver->preclose)
457 dev->driver->preclose(dev, file_priv);
459 /* ========================================================
460 * Begin inline drm_release
463 DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
464 task_pid_nr(current),
465 (long)old_encode_dev(file_priv->minor->kdev->devt),
468 /* if the master has gone away we can't do anything with the lock */
469 if (file_priv->minor->master)
470 drm_master_release(dev, filp);
472 if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
473 drm_legacy_reclaim_buffers(dev, file_priv);
475 drm_events_release(file_priv);
477 if (drm_core_check_feature(dev, DRIVER_MODESET)) {
478 drm_fb_release(file_priv);
479 drm_property_destroy_user_blobs(dev, file_priv);
482 if (drm_core_check_feature(dev, DRIVER_GEM))
483 drm_gem_release(dev, file_priv);
485 drm_legacy_ctxbitmap_flush(dev, file_priv);
487 mutex_lock(&dev->master_mutex);
489 if (file_priv->is_master) {
490 struct drm_master *master = file_priv->master;
493 * Since the master is disappearing, so is the
494 * possibility to lock.
496 mutex_lock(&dev->struct_mutex);
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);
504 mutex_unlock(&dev->struct_mutex);
506 if (file_priv->minor->master == file_priv->master) {
507 /* drop the reference held my the minor */
508 if (dev->driver->master_drop)
509 dev->driver->master_drop(dev, file_priv, true);
510 drm_master_put(&file_priv->minor->master);
514 /* drop the master reference held by the file priv */
515 if (file_priv->master)
516 drm_master_put(&file_priv->master);
517 file_priv->is_master = 0;
518 mutex_unlock(&dev->master_mutex);
520 if (dev->driver->postclose)
521 dev->driver->postclose(dev, file_priv);
524 if (drm_core_check_feature(dev, DRIVER_PRIME))
525 drm_prime_destroy_file_private(&file_priv->prime);
527 WARN_ON(!list_empty(&file_priv->event_list));
529 put_pid(file_priv->pid);
532 /* ========================================================
533 * End inline drm_release
536 if (!--dev->open_count) {
538 if (drm_device_is_unplugged(dev))
541 mutex_unlock(&drm_global_mutex);
543 drm_minor_release(minor);
547 EXPORT_SYMBOL(drm_release);
550 * drm_read - read method for DRM file
551 * @filp: file pointer
552 * @buffer: userspace destination pointer for the read
553 * @count: count in bytes to read
554 * @offset: offset to read
556 * This function must be used by drivers as their .read() #file_operations
557 * method iff they use DRM events for asynchronous signalling to userspace.
558 * Since events are used by the KMS API for vblank and page flip completion this
559 * means all modern display drivers must use it.
561 * @offset is ignore, DRM events are read like a pipe. Therefore drivers also
562 * must set the .llseek() #file_operation to no_llseek(). Polling support is
563 * provided by drm_poll().
565 * This function will only ever read a full event. Therefore userspace must
566 * supply a big enough buffer to fit any event to ensure forward progress. Since
567 * the maximum event space is currently 4K it's recommended to just use that for
572 * Number of bytes read (always aligned to full events, and can be 0) or a
573 * negative error code on failure.
575 ssize_t drm_read(struct file *filp, char __user *buffer,
576 size_t count, loff_t *offset)
578 struct drm_file *file_priv = filp->private_data;
579 struct drm_device *dev = file_priv->minor->dev;
582 if (!access_ok(VERIFY_WRITE, buffer, count))
585 ret = mutex_lock_interruptible(&file_priv->event_read_lock);
590 struct drm_pending_event *e = NULL;
592 spin_lock_irq(&dev->event_lock);
593 if (!list_empty(&file_priv->event_list)) {
594 e = list_first_entry(&file_priv->event_list,
595 struct drm_pending_event, link);
596 file_priv->event_space += e->event->length;
599 spin_unlock_irq(&dev->event_lock);
605 if (filp->f_flags & O_NONBLOCK) {
610 mutex_unlock(&file_priv->event_read_lock);
611 ret = wait_event_interruptible(file_priv->event_wait,
612 !list_empty(&file_priv->event_list));
614 ret = mutex_lock_interruptible(&file_priv->event_read_lock);
618 unsigned length = e->event->length;
620 if (length > count - ret) {
622 spin_lock_irq(&dev->event_lock);
623 file_priv->event_space -= length;
624 list_add(&e->link, &file_priv->event_list);
625 spin_unlock_irq(&dev->event_lock);
629 if (copy_to_user(buffer + ret, e->event, length)) {
639 mutex_unlock(&file_priv->event_read_lock);
643 EXPORT_SYMBOL(drm_read);
646 * drm_poll - poll method for DRM file
647 * @filp: file pointer
648 * @wait: poll waiter table
650 * This function must be used by drivers as their .read() #file_operations
651 * method iff they use DRM events for asynchronous signalling to userspace.
652 * Since events are used by the KMS API for vblank and page flip completion this
653 * means all modern display drivers must use it.
655 * See also drm_read().
659 * Mask of POLL flags indicating the current status of the file.
661 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
663 struct drm_file *file_priv = filp->private_data;
664 unsigned int mask = 0;
666 poll_wait(filp, &file_priv->event_wait, wait);
668 if (!list_empty(&file_priv->event_list))
669 mask |= POLLIN | POLLRDNORM;
673 EXPORT_SYMBOL(drm_poll);
676 * drm_event_reserve_init_locked - init a DRM event and reserve space for it
678 * @file_priv: DRM file private data
679 * @p: tracking structure for the pending event
680 * @e: actual event data to deliver to userspace
682 * This function prepares the passed in event for eventual delivery. If the event
683 * doesn't get delivered (because the IOCTL fails later on, before queuing up
684 * anything) then the even must be cancelled and freed using
685 * drm_event_cancel_free(). Successfully initialized events should be sent out
686 * using drm_send_event() or drm_send_event_locked() to signal completion of the
687 * asynchronous event to userspace.
689 * If callers embedded @p into a larger structure it must be allocated with
690 * kmalloc and @p must be the first member element.
692 * This is the locked version of drm_event_reserve_init() for callers which
693 * already hold dev->event_lock.
697 * 0 on success or a negative error code on failure.
699 int drm_event_reserve_init_locked(struct drm_device *dev,
700 struct drm_file *file_priv,
701 struct drm_pending_event *p,
704 if (file_priv->event_space < e->length)
707 file_priv->event_space -= e->length;
710 list_add(&p->pending_link, &file_priv->pending_event_list);
711 p->file_priv = file_priv;
713 /* we *could* pass this in as arg, but everyone uses kfree: */
714 p->destroy = (void (*) (struct drm_pending_event *)) kfree;
718 EXPORT_SYMBOL(drm_event_reserve_init_locked);
721 * drm_event_reserve_init - init a DRM event and reserve space for it
723 * @file_priv: DRM file private data
724 * @p: tracking structure for the pending event
725 * @e: actual event data to deliver to userspace
727 * This function prepares the passed in event for eventual delivery. If the event
728 * doesn't get delivered (because the IOCTL fails later on, before queuing up
729 * anything) then the even must be cancelled and freed using
730 * drm_event_cancel_free(). Successfully initialized events should be sent out
731 * using drm_send_event() or drm_send_event_locked() to signal completion of the
732 * asynchronous event to userspace.
734 * If callers embedded @p into a larger structure it must be allocated with
735 * kmalloc and @p must be the first member element.
737 * Callers which already hold dev->event_lock should use
738 * drm_event_reserve_init() instead.
742 * 0 on success or a negative error code on failure.
744 int drm_event_reserve_init(struct drm_device *dev,
745 struct drm_file *file_priv,
746 struct drm_pending_event *p,
752 spin_lock_irqsave(&dev->event_lock, flags);
753 ret = drm_event_reserve_init_locked(dev, file_priv, p, e);
754 spin_unlock_irqrestore(&dev->event_lock, flags);
758 EXPORT_SYMBOL(drm_event_reserve_init);
761 * drm_event_cancel_free - free a DRM event and release it's space
763 * @p: tracking structure for the pending event
765 * This function frees the event @p initialized with drm_event_reserve_init()
766 * and releases any allocated space.
768 void drm_event_cancel_free(struct drm_device *dev,
769 struct drm_pending_event *p)
772 spin_lock_irqsave(&dev->event_lock, flags);
774 p->file_priv->event_space += p->event->length;
775 list_del(&p->pending_link);
777 spin_unlock_irqrestore(&dev->event_lock, flags);
780 EXPORT_SYMBOL(drm_event_cancel_free);
783 * drm_send_event_locked - send DRM event to file descriptor
785 * @e: DRM event to deliver
787 * This function sends the event @e, initialized with drm_event_reserve_init(),
788 * to its associated userspace DRM file. Callers must already hold
789 * dev->event_lock, see drm_send_event() for the unlocked version.
791 * Note that the core will take care of unlinking and disarming events when the
792 * corresponding DRM file is closed. Drivers need not worry about whether the
793 * DRM file for this event still exists and can call this function upon
794 * completion of the asynchronous work unconditionally.
796 void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
798 assert_spin_locked(&dev->event_lock);
805 list_del(&e->pending_link);
806 list_add_tail(&e->link,
807 &e->file_priv->event_list);
808 wake_up_interruptible(&e->file_priv->event_wait);
810 EXPORT_SYMBOL(drm_send_event_locked);
813 * drm_send_event - send DRM event to file descriptor
815 * @e: DRM event to deliver
817 * This function sends the event @e, initialized with drm_event_reserve_init(),
818 * to its associated userspace DRM file. This function acquires dev->event_lock,
819 * see drm_send_event_locked() for callers which already hold this lock.
821 * Note that the core will take care of unlinking and disarming events when the
822 * corresponding DRM file is closed. Drivers need not worry about whether the
823 * DRM file for this event still exists and can call this function upon
824 * completion of the asynchronous work unconditionally.
826 void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
828 unsigned long irqflags;
830 spin_lock_irqsave(&dev->event_lock, irqflags);
831 drm_send_event_locked(dev, e);
832 spin_unlock_irqrestore(&dev->event_lock, irqflags);
834 EXPORT_SYMBOL(drm_send_event);