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
20 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
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
31 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
32 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
33 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
34 * OTHER DEALINGS IN THE SOFTWARE.
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 there is no current master make this fd it, but do not create
233 * any master object for render clients */
234 mutex_lock(&dev->master_mutex);
235 if (drm_is_primary_client(priv) && !priv->minor->master) {
236 /* create a new master */
237 ret = drm_new_set_master(dev, priv);
240 } else if (drm_is_primary_client(priv)) {
241 /* get a reference to the master */
242 priv->master = drm_master_get(priv->minor->master);
244 mutex_unlock(&dev->master_mutex);
246 mutex_lock(&dev->filelist_mutex);
247 list_add(&priv->lhead, &dev->filelist);
248 mutex_unlock(&dev->filelist_mutex);
255 struct pci_dev *pci_dev;
256 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
258 dev->hose = pci_dev->sysdata;
259 pci_dev_put(pci_dev);
262 struct pci_bus *b = list_entry(pci_root_buses.next,
263 struct pci_bus, node);
265 dev->hose = b->sysdata;
273 mutex_unlock(&dev->master_mutex);
274 if (dev->driver->postclose)
275 dev->driver->postclose(dev, priv);
277 if (drm_core_check_feature(dev, DRIVER_PRIME))
278 drm_prime_destroy_file_private(&priv->prime);
279 if (drm_core_check_feature(dev, DRIVER_GEM))
280 drm_gem_release(dev, priv);
283 filp->private_data = NULL;
287 static void drm_events_release(struct drm_file *file_priv)
289 struct drm_device *dev = file_priv->minor->dev;
290 struct drm_pending_event *e, *et;
293 spin_lock_irqsave(&dev->event_lock, flags);
295 /* Unlink pending events */
296 list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
298 list_del(&e->pending_link);
302 /* Remove unconsumed events */
303 list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
308 spin_unlock_irqrestore(&dev->event_lock, flags);
312 * drm_legacy_dev_reinit
314 * Reinitializes a legacy/ums drm device in it's lastclose function.
316 static void drm_legacy_dev_reinit(struct drm_device *dev)
318 if (dev->irq_enabled)
319 drm_irq_uninstall(dev);
321 mutex_lock(&dev->struct_mutex);
323 drm_legacy_agp_clear(dev);
325 drm_legacy_sg_cleanup(dev);
326 drm_legacy_vma_flush(dev);
327 drm_legacy_dma_takedown(dev);
329 mutex_unlock(&dev->struct_mutex);
331 dev->sigdata.lock = NULL;
333 dev->context_flag = 0;
334 dev->last_context = 0;
337 DRM_DEBUG("lastclose completed\n");
341 * Take down the DRM device.
343 * \param dev DRM device structure.
345 * Frees every resource in \p dev.
349 void drm_lastclose(struct drm_device * dev)
353 if (dev->driver->lastclose)
354 dev->driver->lastclose(dev);
355 DRM_DEBUG("driver lastclose completed\n");
357 if (!drm_core_check_feature(dev, DRIVER_MODESET))
358 drm_legacy_dev_reinit(dev);
362 * drm_release - release method for DRM file
363 * @inode: device inode
364 * @filp: file pointer.
366 * This function must be used by drivers as their .release() #file_operations
367 * method. It frees any resources associated with the open file, and if this is
368 * the last open file for the DRM device also proceeds to call drm_lastclose().
372 * Always succeeds and returns 0.
374 int drm_release(struct inode *inode, struct file *filp)
376 struct drm_file *file_priv = filp->private_data;
377 struct drm_minor *minor = file_priv->minor;
378 struct drm_device *dev = minor->dev;
380 mutex_lock(&drm_global_mutex);
382 DRM_DEBUG("open_count = %d\n", dev->open_count);
384 mutex_lock(&dev->filelist_mutex);
385 list_del(&file_priv->lhead);
386 mutex_unlock(&dev->filelist_mutex);
388 mutex_lock(&dev->struct_mutex);
389 if (file_priv->magic)
390 idr_remove(&file_priv->master->magic_map, file_priv->magic);
391 mutex_unlock(&dev->struct_mutex);
393 if (dev->driver->preclose)
394 dev->driver->preclose(dev, file_priv);
396 /* ========================================================
397 * Begin inline drm_release
400 DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
401 task_pid_nr(current),
402 (long)old_encode_dev(file_priv->minor->kdev->devt),
405 if (!drm_core_check_feature(dev, DRIVER_MODESET))
406 drm_legacy_lock_release(dev, filp);
408 if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
409 drm_legacy_reclaim_buffers(dev, file_priv);
411 drm_events_release(file_priv);
413 if (drm_core_check_feature(dev, DRIVER_MODESET)) {
414 drm_fb_release(file_priv);
415 drm_property_destroy_user_blobs(dev, file_priv);
418 if (drm_core_check_feature(dev, DRIVER_GEM))
419 drm_gem_release(dev, file_priv);
421 drm_legacy_ctxbitmap_flush(dev, file_priv);
423 mutex_lock(&dev->master_mutex);
425 if (file_priv->is_master) {
426 struct drm_master *master = file_priv->master;
429 * Since the master is disappearing, so is the
430 * possibility to lock.
432 mutex_lock(&dev->struct_mutex);
433 if (master->lock.hw_lock) {
434 if (dev->sigdata.lock == master->lock.hw_lock)
435 dev->sigdata.lock = NULL;
436 master->lock.hw_lock = NULL;
437 master->lock.file_priv = NULL;
438 wake_up_interruptible_all(&master->lock.lock_queue);
440 mutex_unlock(&dev->struct_mutex);
442 if (file_priv->minor->master == file_priv->master) {
443 /* drop the reference held my the minor */
444 if (dev->driver->master_drop)
445 dev->driver->master_drop(dev, file_priv, true);
446 drm_master_put(&file_priv->minor->master);
450 /* drop the master reference held by the file priv */
451 if (file_priv->master)
452 drm_master_put(&file_priv->master);
453 file_priv->is_master = 0;
454 mutex_unlock(&dev->master_mutex);
456 if (dev->driver->postclose)
457 dev->driver->postclose(dev, file_priv);
460 if (drm_core_check_feature(dev, DRIVER_PRIME))
461 drm_prime_destroy_file_private(&file_priv->prime);
463 WARN_ON(!list_empty(&file_priv->event_list));
465 put_pid(file_priv->pid);
468 /* ========================================================
469 * End inline drm_release
472 if (!--dev->open_count) {
474 if (drm_device_is_unplugged(dev))
477 mutex_unlock(&drm_global_mutex);
479 drm_minor_release(minor);
483 EXPORT_SYMBOL(drm_release);
486 * drm_read - read method for DRM file
487 * @filp: file pointer
488 * @buffer: userspace destination pointer for the read
489 * @count: count in bytes to read
490 * @offset: offset to read
492 * This function must be used by drivers as their .read() #file_operations
493 * method iff they use DRM events for asynchronous signalling to userspace.
494 * Since events are used by the KMS API for vblank and page flip completion this
495 * means all modern display drivers must use it.
497 * @offset is ignore, DRM events are read like a pipe. Therefore drivers also
498 * must set the .llseek() #file_operation to no_llseek(). Polling support is
499 * provided by drm_poll().
501 * This function will only ever read a full event. Therefore userspace must
502 * supply a big enough buffer to fit any event to ensure forward progress. Since
503 * the maximum event space is currently 4K it's recommended to just use that for
508 * Number of bytes read (always aligned to full events, and can be 0) or a
509 * negative error code on failure.
511 ssize_t drm_read(struct file *filp, char __user *buffer,
512 size_t count, loff_t *offset)
514 struct drm_file *file_priv = filp->private_data;
515 struct drm_device *dev = file_priv->minor->dev;
518 if (!access_ok(VERIFY_WRITE, buffer, count))
521 ret = mutex_lock_interruptible(&file_priv->event_read_lock);
526 struct drm_pending_event *e = NULL;
528 spin_lock_irq(&dev->event_lock);
529 if (!list_empty(&file_priv->event_list)) {
530 e = list_first_entry(&file_priv->event_list,
531 struct drm_pending_event, link);
532 file_priv->event_space += e->event->length;
535 spin_unlock_irq(&dev->event_lock);
541 if (filp->f_flags & O_NONBLOCK) {
546 mutex_unlock(&file_priv->event_read_lock);
547 ret = wait_event_interruptible(file_priv->event_wait,
548 !list_empty(&file_priv->event_list));
550 ret = mutex_lock_interruptible(&file_priv->event_read_lock);
554 unsigned length = e->event->length;
556 if (length > count - ret) {
558 spin_lock_irq(&dev->event_lock);
559 file_priv->event_space -= length;
560 list_add(&e->link, &file_priv->event_list);
561 spin_unlock_irq(&dev->event_lock);
565 if (copy_to_user(buffer + ret, e->event, length)) {
575 mutex_unlock(&file_priv->event_read_lock);
579 EXPORT_SYMBOL(drm_read);
582 * drm_poll - poll method for DRM file
583 * @filp: file pointer
584 * @wait: poll waiter table
586 * This function must be used by drivers as their .read() #file_operations
587 * method iff they use DRM events for asynchronous signalling to userspace.
588 * Since events are used by the KMS API for vblank and page flip completion this
589 * means all modern display drivers must use it.
591 * See also drm_read().
595 * Mask of POLL flags indicating the current status of the file.
597 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
599 struct drm_file *file_priv = filp->private_data;
600 unsigned int mask = 0;
602 poll_wait(filp, &file_priv->event_wait, wait);
604 if (!list_empty(&file_priv->event_list))
605 mask |= POLLIN | POLLRDNORM;
609 EXPORT_SYMBOL(drm_poll);
612 * drm_event_reserve_init_locked - init a DRM event and reserve space for it
614 * @file_priv: DRM file private data
615 * @p: tracking structure for the pending event
616 * @e: actual event data to deliver to userspace
618 * This function prepares the passed in event for eventual delivery. If the event
619 * doesn't get delivered (because the IOCTL fails later on, before queuing up
620 * anything) then the even must be cancelled and freed using
621 * drm_event_cancel_free(). Successfully initialized events should be sent out
622 * using drm_send_event() or drm_send_event_locked() to signal completion of the
623 * asynchronous event to userspace.
625 * If callers embedded @p into a larger structure it must be allocated with
626 * kmalloc and @p must be the first member element.
628 * This is the locked version of drm_event_reserve_init() for callers which
629 * already hold dev->event_lock.
633 * 0 on success or a negative error code on failure.
635 int drm_event_reserve_init_locked(struct drm_device *dev,
636 struct drm_file *file_priv,
637 struct drm_pending_event *p,
640 if (file_priv->event_space < e->length)
643 file_priv->event_space -= e->length;
646 list_add(&p->pending_link, &file_priv->pending_event_list);
647 p->file_priv = file_priv;
651 EXPORT_SYMBOL(drm_event_reserve_init_locked);
654 * drm_event_reserve_init - init a DRM event and reserve space for it
656 * @file_priv: DRM file private data
657 * @p: tracking structure for the pending event
658 * @e: actual event data to deliver to userspace
660 * This function prepares the passed in event for eventual delivery. If the event
661 * doesn't get delivered (because the IOCTL fails later on, before queuing up
662 * anything) then the even must be cancelled and freed using
663 * drm_event_cancel_free(). Successfully initialized events should be sent out
664 * using drm_send_event() or drm_send_event_locked() to signal completion of the
665 * asynchronous event to userspace.
667 * If callers embedded @p into a larger structure it must be allocated with
668 * kmalloc and @p must be the first member element.
670 * Callers which already hold dev->event_lock should use
671 * drm_event_reserve_init() instead.
675 * 0 on success or a negative error code on failure.
677 int drm_event_reserve_init(struct drm_device *dev,
678 struct drm_file *file_priv,
679 struct drm_pending_event *p,
685 spin_lock_irqsave(&dev->event_lock, flags);
686 ret = drm_event_reserve_init_locked(dev, file_priv, p, e);
687 spin_unlock_irqrestore(&dev->event_lock, flags);
691 EXPORT_SYMBOL(drm_event_reserve_init);
694 * drm_event_cancel_free - free a DRM event and release it's space
696 * @p: tracking structure for the pending event
698 * This function frees the event @p initialized with drm_event_reserve_init()
699 * and releases any allocated space.
701 void drm_event_cancel_free(struct drm_device *dev,
702 struct drm_pending_event *p)
705 spin_lock_irqsave(&dev->event_lock, flags);
707 p->file_priv->event_space += p->event->length;
708 list_del(&p->pending_link);
710 spin_unlock_irqrestore(&dev->event_lock, flags);
713 EXPORT_SYMBOL(drm_event_cancel_free);
716 * drm_send_event_locked - send DRM event to file descriptor
718 * @e: DRM event to deliver
720 * This function sends the event @e, initialized with drm_event_reserve_init(),
721 * to its associated userspace DRM file. Callers must already hold
722 * dev->event_lock, see drm_send_event() for the unlocked version.
724 * Note that the core will take care of unlinking and disarming events when the
725 * corresponding DRM file is closed. Drivers need not worry about whether the
726 * DRM file for this event still exists and can call this function upon
727 * completion of the asynchronous work unconditionally.
729 void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
731 assert_spin_locked(&dev->event_lock);
734 /* ->completion might disappear as soon as it signalled. */
735 complete_all(e->completion);
736 e->completion = NULL;
740 fence_signal(e->fence);
749 list_del(&e->pending_link);
750 list_add_tail(&e->link,
751 &e->file_priv->event_list);
752 wake_up_interruptible(&e->file_priv->event_wait);
754 EXPORT_SYMBOL(drm_send_event_locked);
757 * drm_send_event - send DRM event to file descriptor
759 * @e: DRM event to deliver
761 * This function sends the event @e, initialized with drm_event_reserve_init(),
762 * to its associated userspace DRM file. This function acquires dev->event_lock,
763 * see drm_send_event_locked() for callers which already hold this lock.
765 * Note that the core will take care of unlinking and disarming events when the
766 * corresponding DRM file is closed. Drivers need not worry about whether the
767 * DRM file for this event still exists and can call this function upon
768 * completion of the asynchronous work unconditionally.
770 void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
772 unsigned long irqflags;
774 spin_lock_irqsave(&dev->event_lock, irqflags);
775 drm_send_event_locked(dev, e);
776 spin_unlock_irqrestore(&dev->event_lock, irqflags);
778 EXPORT_SYMBOL(drm_send_event);