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"
43 #include "drm_crtc_internal.h"
45 /* from BKL pushdown */
46 DEFINE_MUTEX(drm_global_mutex
);
49 * DOC: file operations
51 * Drivers must define the file operations structure that forms the DRM
52 * userspace API entry point, even though most of those operations are
53 * implemented in the DRM core. The mandatory functions are drm_open(),
54 * drm_read(), drm_ioctl() and drm_compat_ioctl if CONFIG_COMPAT is enabled.
55 * Drivers which implement private ioctls that require 32/64 bit compatibility
56 * support must provided their onw .compat_ioctl() handler that processes
57 * private ioctls and calls drm_compat_ioctl() for core ioctls.
59 * In addition drm_read() and drm_poll() provide support for DRM events. DRM
60 * events are a generic and extensible means to send asynchronous events to
61 * userspace through the file descriptor. They are used to send vblank event and
62 * page flip completions by the KMS API. But drivers can also use it for their
63 * own needs, e.g. to signal completion of rendering.
65 * The memory mapping implementation will vary depending on how the driver
66 * manages memory. Legacy drivers will use the deprecated drm_legacy_mmap()
67 * function, modern drivers should use one of the provided memory-manager
68 * specific implementations. For GEM-based drivers this is drm_gem_mmap().
70 * No other file operations are supported by the DRM userspace API. Overall the
71 * following is an example #file_operations structure::
73 * static const example_drm_fops = {
74 * .owner = THIS_MODULE,
76 * .release = drm_release,
77 * .unlocked_ioctl = drm_ioctl,
78 * #ifdef CONFIG_COMPAT
79 * .compat_ioctl = drm_compat_ioctl,
83 * .llseek = no_llseek,
84 * .mmap = drm_gem_mmap,
88 static int drm_open_helper(struct file
*filp
, struct drm_minor
*minor
);
90 static int drm_setup(struct drm_device
* dev
)
94 if (dev
->driver
->firstopen
&&
95 drm_core_check_feature(dev
, DRIVER_LEGACY
)) {
96 ret
= dev
->driver
->firstopen(dev
);
101 ret
= drm_legacy_dma_setup(dev
);
111 * drm_open - open method for DRM file
112 * @inode: device inode
113 * @filp: file pointer.
115 * This function must be used by drivers as their .open() #file_operations
116 * method. It looks up the correct DRM device and instantiates all the per-file
121 * 0 on success or negative errno value on falure.
123 int drm_open(struct inode
*inode
, struct file
*filp
)
125 struct drm_device
*dev
;
126 struct drm_minor
*minor
;
130 minor
= drm_minor_acquire(iminor(inode
));
132 return PTR_ERR(minor
);
135 if (!dev
->open_count
++)
138 /* share address_space across all char-devs of a single device */
139 filp
->f_mapping
= dev
->anon_inode
->i_mapping
;
141 retcode
= drm_open_helper(filp
, minor
);
145 retcode
= drm_setup(dev
);
153 drm_minor_release(minor
);
156 EXPORT_SYMBOL(drm_open
);
159 * Check whether DRI will run on this CPU.
161 * \return non-zero if the DRI will run on this CPU, or zero otherwise.
163 static int drm_cpu_valid(void)
165 #if defined(__sparc__) && !defined(__sparc_v9__)
166 return 0; /* No cmpxchg before v9 sparc. */
172 * Called whenever a process opens /dev/drm.
174 * \param filp file pointer.
175 * \param minor acquired minor-object.
176 * \return zero on success or a negative number on failure.
178 * Creates and initializes a drm_file structure for the file private data in \p
179 * filp and add it into the double linked list in \p dev.
181 static int drm_open_helper(struct file
*filp
, struct drm_minor
*minor
)
183 struct drm_device
*dev
= minor
->dev
;
184 struct drm_file
*priv
;
187 if (filp
->f_flags
& O_EXCL
)
188 return -EBUSY
; /* No exclusive opens */
189 if (!drm_cpu_valid())
191 if (dev
->switch_power_state
!= DRM_SWITCH_POWER_ON
&& dev
->switch_power_state
!= DRM_SWITCH_POWER_DYNAMIC_OFF
)
194 DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current
), minor
->index
);
196 priv
= kzalloc(sizeof(*priv
), GFP_KERNEL
);
200 filp
->private_data
= priv
;
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_LEGACY
))
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 if (dev
->driver
->preclose
)
380 dev
->driver
->preclose(dev
, file_priv
);
382 /* ========================================================
383 * Begin inline drm_release
386 DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n",
387 task_pid_nr(current
),
388 (long)old_encode_dev(file_priv
->minor
->kdev
->devt
),
391 if (drm_core_check_feature(dev
, DRIVER_LEGACY
))
392 drm_legacy_lock_release(dev
, filp
);
394 if (drm_core_check_feature(dev
, DRIVER_HAVE_DMA
))
395 drm_legacy_reclaim_buffers(dev
, file_priv
);
397 drm_events_release(file_priv
);
399 if (drm_core_check_feature(dev
, DRIVER_MODESET
)) {
400 drm_fb_release(file_priv
);
401 drm_property_destroy_user_blobs(dev
, file_priv
);
404 if (drm_core_check_feature(dev
, DRIVER_GEM
))
405 drm_gem_release(dev
, file_priv
);
407 drm_legacy_ctxbitmap_flush(dev
, file_priv
);
409 if (drm_is_primary_client(file_priv
))
410 drm_master_release(file_priv
);
412 if (dev
->driver
->postclose
)
413 dev
->driver
->postclose(dev
, file_priv
);
415 if (drm_core_check_feature(dev
, DRIVER_PRIME
))
416 drm_prime_destroy_file_private(&file_priv
->prime
);
418 WARN_ON(!list_empty(&file_priv
->event_list
));
420 put_pid(file_priv
->pid
);
423 /* ========================================================
424 * End inline drm_release
427 if (!--dev
->open_count
) {
429 if (drm_device_is_unplugged(dev
))
432 mutex_unlock(&drm_global_mutex
);
434 drm_minor_release(minor
);
438 EXPORT_SYMBOL(drm_release
);
441 * drm_read - read method for DRM file
442 * @filp: file pointer
443 * @buffer: userspace destination pointer for the read
444 * @count: count in bytes to read
445 * @offset: offset to read
447 * This function must be used by drivers as their .read() #file_operations
448 * method iff they use DRM events for asynchronous signalling to userspace.
449 * Since events are used by the KMS API for vblank and page flip completion this
450 * means all modern display drivers must use it.
452 * @offset is ignore, DRM events are read like a pipe. Therefore drivers also
453 * must set the .llseek() #file_operation to no_llseek(). Polling support is
454 * provided by drm_poll().
456 * This function will only ever read a full event. Therefore userspace must
457 * supply a big enough buffer to fit any event to ensure forward progress. Since
458 * the maximum event space is currently 4K it's recommended to just use that for
463 * Number of bytes read (always aligned to full events, and can be 0) or a
464 * negative error code on failure.
466 ssize_t
drm_read(struct file
*filp
, char __user
*buffer
,
467 size_t count
, loff_t
*offset
)
469 struct drm_file
*file_priv
= filp
->private_data
;
470 struct drm_device
*dev
= file_priv
->minor
->dev
;
473 if (!access_ok(VERIFY_WRITE
, buffer
, count
))
476 ret
= mutex_lock_interruptible(&file_priv
->event_read_lock
);
481 struct drm_pending_event
*e
= NULL
;
483 spin_lock_irq(&dev
->event_lock
);
484 if (!list_empty(&file_priv
->event_list
)) {
485 e
= list_first_entry(&file_priv
->event_list
,
486 struct drm_pending_event
, link
);
487 file_priv
->event_space
+= e
->event
->length
;
490 spin_unlock_irq(&dev
->event_lock
);
496 if (filp
->f_flags
& O_NONBLOCK
) {
501 mutex_unlock(&file_priv
->event_read_lock
);
502 ret
= wait_event_interruptible(file_priv
->event_wait
,
503 !list_empty(&file_priv
->event_list
));
505 ret
= mutex_lock_interruptible(&file_priv
->event_read_lock
);
509 unsigned length
= e
->event
->length
;
511 if (length
> count
- ret
) {
513 spin_lock_irq(&dev
->event_lock
);
514 file_priv
->event_space
-= length
;
515 list_add(&e
->link
, &file_priv
->event_list
);
516 spin_unlock_irq(&dev
->event_lock
);
520 if (copy_to_user(buffer
+ ret
, e
->event
, length
)) {
530 mutex_unlock(&file_priv
->event_read_lock
);
534 EXPORT_SYMBOL(drm_read
);
537 * drm_poll - poll method for DRM file
538 * @filp: file pointer
539 * @wait: poll waiter table
541 * This function must be used by drivers as their .read() #file_operations
542 * method iff they use DRM events for asynchronous signalling to userspace.
543 * Since events are used by the KMS API for vblank and page flip completion this
544 * means all modern display drivers must use it.
546 * See also drm_read().
550 * Mask of POLL flags indicating the current status of the file.
552 unsigned int drm_poll(struct file
*filp
, struct poll_table_struct
*wait
)
554 struct drm_file
*file_priv
= filp
->private_data
;
555 unsigned int mask
= 0;
557 poll_wait(filp
, &file_priv
->event_wait
, wait
);
559 if (!list_empty(&file_priv
->event_list
))
560 mask
|= POLLIN
| POLLRDNORM
;
564 EXPORT_SYMBOL(drm_poll
);
567 * drm_event_reserve_init_locked - init a DRM event and reserve space for it
569 * @file_priv: DRM file private data
570 * @p: tracking structure for the pending event
571 * @e: actual event data to deliver to userspace
573 * This function prepares the passed in event for eventual delivery. If the event
574 * doesn't get delivered (because the IOCTL fails later on, before queuing up
575 * anything) then the even must be cancelled and freed using
576 * drm_event_cancel_free(). Successfully initialized events should be sent out
577 * using drm_send_event() or drm_send_event_locked() to signal completion of the
578 * asynchronous event to userspace.
580 * If callers embedded @p into a larger structure it must be allocated with
581 * kmalloc and @p must be the first member element.
583 * This is the locked version of drm_event_reserve_init() for callers which
584 * already hold dev->event_lock.
588 * 0 on success or a negative error code on failure.
590 int drm_event_reserve_init_locked(struct drm_device
*dev
,
591 struct drm_file
*file_priv
,
592 struct drm_pending_event
*p
,
595 if (file_priv
->event_space
< e
->length
)
598 file_priv
->event_space
-= e
->length
;
601 list_add(&p
->pending_link
, &file_priv
->pending_event_list
);
602 p
->file_priv
= file_priv
;
606 EXPORT_SYMBOL(drm_event_reserve_init_locked
);
609 * drm_event_reserve_init - init a DRM event and reserve space for it
611 * @file_priv: DRM file private data
612 * @p: tracking structure for the pending event
613 * @e: actual event data to deliver to userspace
615 * This function prepares the passed in event for eventual delivery. If the event
616 * doesn't get delivered (because the IOCTL fails later on, before queuing up
617 * anything) then the even must be cancelled and freed using
618 * drm_event_cancel_free(). Successfully initialized events should be sent out
619 * using drm_send_event() or drm_send_event_locked() to signal completion of the
620 * asynchronous event to userspace.
622 * If callers embedded @p into a larger structure it must be allocated with
623 * kmalloc and @p must be the first member element.
625 * Callers which already hold dev->event_lock should use
626 * drm_event_reserve_init() instead.
630 * 0 on success or a negative error code on failure.
632 int drm_event_reserve_init(struct drm_device
*dev
,
633 struct drm_file
*file_priv
,
634 struct drm_pending_event
*p
,
640 spin_lock_irqsave(&dev
->event_lock
, flags
);
641 ret
= drm_event_reserve_init_locked(dev
, file_priv
, p
, e
);
642 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
646 EXPORT_SYMBOL(drm_event_reserve_init
);
649 * drm_event_cancel_free - free a DRM event and release it's space
651 * @p: tracking structure for the pending event
653 * This function frees the event @p initialized with drm_event_reserve_init()
654 * and releases any allocated space.
656 void drm_event_cancel_free(struct drm_device
*dev
,
657 struct drm_pending_event
*p
)
660 spin_lock_irqsave(&dev
->event_lock
, flags
);
662 p
->file_priv
->event_space
+= p
->event
->length
;
663 list_del(&p
->pending_link
);
665 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
668 EXPORT_SYMBOL(drm_event_cancel_free
);
671 * drm_send_event_locked - send DRM event to file descriptor
673 * @e: DRM event to deliver
675 * This function sends the event @e, initialized with drm_event_reserve_init(),
676 * to its associated userspace DRM file. Callers must already hold
677 * dev->event_lock, see drm_send_event() for the unlocked version.
679 * Note that the core will take care of unlinking and disarming events when the
680 * corresponding DRM file is closed. Drivers need not worry about whether the
681 * DRM file for this event still exists and can call this function upon
682 * completion of the asynchronous work unconditionally.
684 void drm_send_event_locked(struct drm_device
*dev
, struct drm_pending_event
*e
)
686 assert_spin_locked(&dev
->event_lock
);
689 /* ->completion might disappear as soon as it signalled. */
690 complete_all(e
->completion
);
691 e
->completion
= NULL
;
695 fence_signal(e
->fence
);
704 list_del(&e
->pending_link
);
705 list_add_tail(&e
->link
,
706 &e
->file_priv
->event_list
);
707 wake_up_interruptible(&e
->file_priv
->event_wait
);
709 EXPORT_SYMBOL(drm_send_event_locked
);
712 * drm_send_event - send DRM event to file descriptor
714 * @e: DRM event to deliver
716 * This function sends the event @e, initialized with drm_event_reserve_init(),
717 * to its associated userspace DRM file. This function acquires dev->event_lock,
718 * see drm_send_event_locked() for callers which already hold this lock.
720 * Note that the core will take care of unlinking and disarming events when the
721 * corresponding DRM file is closed. Drivers need not worry about whether the
722 * DRM file for this event still exists and can call this function upon
723 * completion of the asynchronous work unconditionally.
725 void drm_send_event(struct drm_device
*dev
, struct drm_pending_event
*e
)
727 unsigned long irqflags
;
729 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
730 drm_send_event_locked(dev
, e
);
731 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
733 EXPORT_SYMBOL(drm_send_event
);