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 * 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
->event_list
);
268 init_waitqueue_head(&priv
->event_wait
);
269 priv
->event_space
= 4096; /* set aside 4k for event buffer */
271 mutex_init(&priv
->event_read_lock
);
273 if (drm_core_check_feature(dev
, DRIVER_GEM
))
274 drm_gem_open(dev
, priv
);
276 if (drm_core_check_feature(dev
, DRIVER_PRIME
))
277 drm_prime_init_file_private(&priv
->prime
);
279 if (dev
->driver
->open
) {
280 ret
= dev
->driver
->open(dev
, priv
);
282 goto out_prime_destroy
;
285 /* if there is no current master make this fd it, but do not create
286 * any master object for render clients */
287 mutex_lock(&dev
->master_mutex
);
288 if (drm_is_primary_client(priv
) && !priv
->minor
->master
) {
289 /* create a new master */
290 ret
= drm_new_set_master(dev
, priv
);
293 } else if (drm_is_primary_client(priv
)) {
294 /* get a reference to the master */
295 priv
->master
= drm_master_get(priv
->minor
->master
);
297 mutex_unlock(&dev
->master_mutex
);
299 mutex_lock(&dev
->struct_mutex
);
300 list_add(&priv
->lhead
, &dev
->filelist
);
301 mutex_unlock(&dev
->struct_mutex
);
308 struct pci_dev
*pci_dev
;
309 pci_dev
= pci_get_class(PCI_CLASS_DISPLAY_VGA
<< 8, NULL
);
311 dev
->hose
= pci_dev
->sysdata
;
312 pci_dev_put(pci_dev
);
315 struct pci_bus
*b
= list_entry(pci_root_buses
.next
,
316 struct pci_bus
, node
);
318 dev
->hose
= b
->sysdata
;
326 mutex_unlock(&dev
->master_mutex
);
327 if (dev
->driver
->postclose
)
328 dev
->driver
->postclose(dev
, priv
);
330 if (drm_core_check_feature(dev
, DRIVER_PRIME
))
331 drm_prime_destroy_file_private(&priv
->prime
);
332 if (drm_core_check_feature(dev
, DRIVER_GEM
))
333 drm_gem_release(dev
, priv
);
336 filp
->private_data
= NULL
;
340 static void drm_master_release(struct drm_device
*dev
, struct file
*filp
)
342 struct drm_file
*file_priv
= filp
->private_data
;
344 if (drm_legacy_i_have_hw_lock(dev
, file_priv
)) {
345 DRM_DEBUG("File %p released, freeing lock for context %d\n",
346 filp
, _DRM_LOCKING_CONTEXT(file_priv
->master
->lock
.hw_lock
->lock
));
347 drm_legacy_lock_free(&file_priv
->master
->lock
,
348 _DRM_LOCKING_CONTEXT(file_priv
->master
->lock
.hw_lock
->lock
));
352 static void drm_events_release(struct drm_file
*file_priv
)
354 struct drm_device
*dev
= file_priv
->minor
->dev
;
355 struct drm_pending_event
*e
, *et
;
356 struct drm_pending_vblank_event
*v
, *vt
;
359 spin_lock_irqsave(&dev
->event_lock
, flags
);
361 /* Remove pending flips */
362 list_for_each_entry_safe(v
, vt
, &dev
->vblank_event_list
, base
.link
)
363 if (v
->base
.file_priv
== file_priv
) {
364 list_del(&v
->base
.link
);
365 drm_vblank_put(dev
, v
->pipe
);
366 v
->base
.destroy(&v
->base
);
369 /* Remove unconsumed events */
370 list_for_each_entry_safe(e
, et
, &file_priv
->event_list
, link
) {
375 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
379 * drm_legacy_dev_reinit
381 * Reinitializes a legacy/ums drm device in it's lastclose function.
383 static void drm_legacy_dev_reinit(struct drm_device
*dev
)
385 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
388 dev
->sigdata
.lock
= NULL
;
390 dev
->context_flag
= 0;
391 dev
->last_context
= 0;
396 * Take down the DRM device.
398 * \param dev DRM device structure.
400 * Frees every resource in \p dev.
404 int drm_lastclose(struct drm_device
* dev
)
408 if (dev
->driver
->lastclose
)
409 dev
->driver
->lastclose(dev
);
410 DRM_DEBUG("driver lastclose completed\n");
412 if (dev
->irq_enabled
&& !drm_core_check_feature(dev
, DRIVER_MODESET
))
413 drm_irq_uninstall(dev
);
415 mutex_lock(&dev
->struct_mutex
);
419 drm_legacy_sg_cleanup(dev
);
420 drm_legacy_vma_flush(dev
);
421 drm_legacy_dma_takedown(dev
);
423 mutex_unlock(&dev
->struct_mutex
);
425 drm_legacy_dev_reinit(dev
);
427 DRM_DEBUG("lastclose completed\n");
432 * drm_release - release method for DRM file
433 * @inode: device inode
434 * @filp: file pointer.
436 * This function must be used by drivers as their .release() #file_operations
437 * method. It frees any resources associated with the open file, and if this is
438 * the last open file for the DRM device also proceeds to call drm_lastclose().
442 * Always succeeds and returns 0.
444 int drm_release(struct inode
*inode
, struct file
*filp
)
446 struct drm_file
*file_priv
= filp
->private_data
;
447 struct drm_minor
*minor
= file_priv
->minor
;
448 struct drm_device
*dev
= minor
->dev
;
451 mutex_lock(&drm_global_mutex
);
453 DRM_DEBUG("open_count = %d\n", dev
->open_count
);
455 mutex_lock(&dev
->struct_mutex
);
456 list_del(&file_priv
->lhead
);
457 if (file_priv
->magic
)
458 idr_remove(&file_priv
->master
->magic_map
, file_priv
->magic
);
459 mutex_unlock(&dev
->struct_mutex
);
461 if (dev
->driver
->preclose
)
462 dev
->driver
->preclose(dev
, file_priv
);
464 /* ========================================================
465 * Begin inline drm_release
468 DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
469 task_pid_nr(current
),
470 (long)old_encode_dev(file_priv
->minor
->kdev
->devt
),
473 /* if the master has gone away we can't do anything with the lock */
474 if (file_priv
->minor
->master
)
475 drm_master_release(dev
, filp
);
477 if (drm_core_check_feature(dev
, DRIVER_HAVE_DMA
))
478 drm_legacy_reclaim_buffers(dev
, file_priv
);
480 drm_events_release(file_priv
);
482 if (drm_core_check_feature(dev
, DRIVER_MODESET
)) {
483 drm_fb_release(file_priv
);
484 drm_property_destroy_user_blobs(dev
, file_priv
);
487 if (drm_core_check_feature(dev
, DRIVER_GEM
))
488 drm_gem_release(dev
, file_priv
);
490 drm_legacy_ctxbitmap_flush(dev
, file_priv
);
492 mutex_lock(&dev
->master_mutex
);
494 if (file_priv
->is_master
) {
495 struct drm_master
*master
= file_priv
->master
;
498 * Since the master is disappearing, so is the
499 * possibility to lock.
501 mutex_lock(&dev
->struct_mutex
);
502 if (master
->lock
.hw_lock
) {
503 if (dev
->sigdata
.lock
== master
->lock
.hw_lock
)
504 dev
->sigdata
.lock
= NULL
;
505 master
->lock
.hw_lock
= NULL
;
506 master
->lock
.file_priv
= NULL
;
507 wake_up_interruptible_all(&master
->lock
.lock_queue
);
509 mutex_unlock(&dev
->struct_mutex
);
511 if (file_priv
->minor
->master
== file_priv
->master
) {
512 /* drop the reference held my the minor */
513 if (dev
->driver
->master_drop
)
514 dev
->driver
->master_drop(dev
, file_priv
, true);
515 drm_master_put(&file_priv
->minor
->master
);
519 /* drop the master reference held by the file priv */
520 if (file_priv
->master
)
521 drm_master_put(&file_priv
->master
);
522 file_priv
->is_master
= 0;
523 mutex_unlock(&dev
->master_mutex
);
525 if (dev
->driver
->postclose
)
526 dev
->driver
->postclose(dev
, file_priv
);
529 if (drm_core_check_feature(dev
, DRIVER_PRIME
))
530 drm_prime_destroy_file_private(&file_priv
->prime
);
532 WARN_ON(!list_empty(&file_priv
->event_list
));
534 put_pid(file_priv
->pid
);
537 /* ========================================================
538 * End inline drm_release
541 if (!--dev
->open_count
) {
542 retcode
= drm_lastclose(dev
);
543 if (drm_device_is_unplugged(dev
))
546 mutex_unlock(&drm_global_mutex
);
548 drm_minor_release(minor
);
552 EXPORT_SYMBOL(drm_release
);
555 * drm_read - read method for DRM file
556 * @filp: file pointer
557 * @buffer: userspace destination pointer for the read
558 * @count: count in bytes to read
559 * @offset: offset to read
561 * This function must be used by drivers as their .read() #file_operations
562 * method iff they use DRM events for asynchronous signalling to userspace.
563 * Since events are used by the KMS API for vblank and page flip completion this
564 * means all modern display drivers must use it.
566 * @offset is ignore, DRM events are read like a pipe. Therefore drivers also
567 * must set the .llseek() #file_operation to no_llseek(). Polling support is
568 * provided by drm_poll().
570 * This function will only ever read a full event. Therefore userspace must
571 * supply a big enough buffer to fit any event to ensure forward progress. Since
572 * the maximum event space is currently 4K it's recommended to just use that for
577 * Number of bytes read (always aligned to full events, and can be 0) or a
578 * negative error code on failure.
580 ssize_t
drm_read(struct file
*filp
, char __user
*buffer
,
581 size_t count
, loff_t
*offset
)
583 struct drm_file
*file_priv
= filp
->private_data
;
584 struct drm_device
*dev
= file_priv
->minor
->dev
;
587 if (!access_ok(VERIFY_WRITE
, buffer
, count
))
590 ret
= mutex_lock_interruptible(&file_priv
->event_read_lock
);
595 struct drm_pending_event
*e
= NULL
;
597 spin_lock_irq(&dev
->event_lock
);
598 if (!list_empty(&file_priv
->event_list
)) {
599 e
= list_first_entry(&file_priv
->event_list
,
600 struct drm_pending_event
, link
);
601 file_priv
->event_space
+= e
->event
->length
;
604 spin_unlock_irq(&dev
->event_lock
);
610 if (filp
->f_flags
& O_NONBLOCK
) {
615 mutex_unlock(&file_priv
->event_read_lock
);
616 ret
= wait_event_interruptible(file_priv
->event_wait
,
617 !list_empty(&file_priv
->event_list
));
619 ret
= mutex_lock_interruptible(&file_priv
->event_read_lock
);
623 unsigned length
= e
->event
->length
;
625 if (length
> count
- ret
) {
627 spin_lock_irq(&dev
->event_lock
);
628 file_priv
->event_space
-= length
;
629 list_add(&e
->link
, &file_priv
->event_list
);
630 spin_unlock_irq(&dev
->event_lock
);
634 if (copy_to_user(buffer
+ ret
, e
->event
, length
)) {
644 mutex_unlock(&file_priv
->event_read_lock
);
648 EXPORT_SYMBOL(drm_read
);
651 * drm_poll - poll method for DRM file
652 * @filp: file pointer
653 * @wait: poll waiter table
655 * This function must be used by drivers as their .read() #file_operations
656 * method iff they use DRM events for asynchronous signalling to userspace.
657 * Since events are used by the KMS API for vblank and page flip completion this
658 * means all modern display drivers must use it.
660 * See also drm_read().
664 * Mask of POLL flags indicating the current status of the file.
666 unsigned int drm_poll(struct file
*filp
, struct poll_table_struct
*wait
)
668 struct drm_file
*file_priv
= filp
->private_data
;
669 unsigned int mask
= 0;
671 poll_wait(filp
, &file_priv
->event_wait
, wait
);
673 if (!list_empty(&file_priv
->event_list
))
674 mask
|= POLLIN
| POLLRDNORM
;
678 EXPORT_SYMBOL(drm_poll
);
681 * drm_event_reserve_init_locked - init a DRM event and reserve space for it
683 * @file_priv: DRM file private data
684 * @p: tracking structure for the pending event
685 * @e: actual event data to deliver to userspace
687 * This function prepares the passed in event for eventual delivery. If the event
688 * doesn't get delivered (because the IOCTL fails later on, before queuing up
689 * anything) then the even must be cancelled and freed using
690 * drm_event_cancel_free(). Successfully initialized events should be sent out
691 * using drm_send_event() or drm_send_event_locked() to signal completion of the
692 * asynchronous event to userspace.
694 * If callers embedded @p into a larger structure it must be allocated with
695 * kmalloc and @p must be the first member element.
697 * This is the locked version of drm_event_reserve_init() for callers which
698 * already hold dev->event_lock.
702 * 0 on success or a negative error code on failure.
704 int drm_event_reserve_init_locked(struct drm_device
*dev
,
705 struct drm_file
*file_priv
,
706 struct drm_pending_event
*p
,
709 if (file_priv
->event_space
< e
->length
)
712 file_priv
->event_space
-= e
->length
;
715 p
->file_priv
= file_priv
;
717 /* we *could* pass this in as arg, but everyone uses kfree: */
718 p
->destroy
= (void (*) (struct drm_pending_event
*)) kfree
;
722 EXPORT_SYMBOL(drm_event_reserve_init_locked
);
725 * drm_event_reserve_init - init a DRM event and reserve space for it
727 * @file_priv: DRM file private data
728 * @p: tracking structure for the pending event
729 * @e: actual event data to deliver to userspace
731 * This function prepares the passed in event for eventual delivery. If the event
732 * doesn't get delivered (because the IOCTL fails later on, before queuing up
733 * anything) then the even must be cancelled and freed using
734 * drm_event_cancel_free(). Successfully initialized events should be sent out
735 * using drm_send_event() or drm_send_event_locked() to signal completion of the
736 * asynchronous event to userspace.
738 * If callers embedded @p into a larger structure it must be allocated with
739 * kmalloc and @p must be the first member element.
741 * Callers which already hold dev->event_lock should use
742 * drm_event_reserve_init() instead.
746 * 0 on success or a negative error code on failure.
748 int drm_event_reserve_init(struct drm_device
*dev
,
749 struct drm_file
*file_priv
,
750 struct drm_pending_event
*p
,
756 spin_lock_irqsave(&dev
->event_lock
, flags
);
757 ret
= drm_event_reserve_init_locked(dev
, file_priv
, p
, e
);
758 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
762 EXPORT_SYMBOL(drm_event_reserve_init
);
765 * drm_event_cancel_free - free a DRM event and release it's space
767 * @p: tracking structure for the pending event
769 * This function frees the event @p initialized with drm_event_reserve_init()
770 * and releases any allocated space.
772 void drm_event_cancel_free(struct drm_device
*dev
,
773 struct drm_pending_event
*p
)
776 spin_lock_irqsave(&dev
->event_lock
, flags
);
777 p
->file_priv
->event_space
+= p
->event
->length
;
778 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
781 EXPORT_SYMBOL(drm_event_cancel_free
);
784 * drm_send_event_locked - send DRM event to file descriptor
786 * @e: DRM event to deliver
788 * This function sends the event @e, initialized with drm_event_reserve_init(),
789 * to its associated userspace DRM file. Callers must already hold
790 * dev->event_lock, see drm_send_event() for the unlocked version.
792 void drm_send_event_locked(struct drm_device
*dev
, struct drm_pending_event
*e
)
794 assert_spin_locked(&dev
->event_lock
);
796 list_add_tail(&e
->link
,
797 &e
->file_priv
->event_list
);
798 wake_up_interruptible(&e
->file_priv
->event_wait
);
800 EXPORT_SYMBOL(drm_send_event_locked
);
803 * drm_send_event - send DRM event to file descriptor
805 * @e: DRM event to deliver
807 * This function sends the event @e, initialized with drm_event_reserve_init(),
808 * to its associated userspace DRM file. This function acquires dev->event_lock,
809 * see drm_send_event_locked() for callers which already hold this lock.
811 void drm_send_event(struct drm_device
*dev
, struct drm_pending_event
*e
)
813 unsigned long irqflags
;
815 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
816 drm_send_event_locked(dev
, e
);
817 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
819 EXPORT_SYMBOL(drm_send_event
);