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drm: use after free in drm_queue_vblank_event()
[~shefty/rdma-dev.git] / drivers / gpu / drm / drm_irq.c
1 /**
2  * \file drm_irq.c
3  * IRQ support
4  *
5  * \author Rickard E. (Rik) Faith <faith@valinux.com>
6  * \author Gareth Hughes <gareth@valinux.com>
7  */
8
9 /*
10  * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
11  *
12  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
13  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
14  * All Rights Reserved.
15  *
16  * Permission is hereby granted, free of charge, to any person obtaining a
17  * copy of this software and associated documentation files (the "Software"),
18  * to deal in the Software without restriction, including without limitation
19  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
20  * and/or sell copies of the Software, and to permit persons to whom the
21  * Software is furnished to do so, subject to the following conditions:
22  *
23  * The above copyright notice and this permission notice (including the next
24  * paragraph) shall be included in all copies or substantial portions of the
25  * Software.
26  *
27  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
28  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
29  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
30  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
31  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
32  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
33  * OTHER DEALINGS IN THE SOFTWARE.
34  */
35
36 #include "drmP.h"
37 #include "drm_trace.h"
38
39 #include <linux/interrupt.h>    /* For task queue support */
40 #include <linux/slab.h>
41
42 #include <linux/vgaarb.h>
43 /**
44  * Get interrupt from bus id.
45  *
46  * \param inode device inode.
47  * \param file_priv DRM file private.
48  * \param cmd command.
49  * \param arg user argument, pointing to a drm_irq_busid structure.
50  * \return zero on success or a negative number on failure.
51  *
52  * Finds the PCI device with the specified bus id and gets its IRQ number.
53  * This IOCTL is deprecated, and will now return EINVAL for any busid not equal
54  * to that of the device that this DRM instance attached to.
55  */
56 int drm_irq_by_busid(struct drm_device *dev, void *data,
57                      struct drm_file *file_priv)
58 {
59         struct drm_irq_busid *p = data;
60
61         if (drm_core_check_feature(dev, DRIVER_USE_PLATFORM_DEVICE))
62                 return -EINVAL;
63
64         if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
65                 return -EINVAL;
66
67         if ((p->busnum >> 8) != drm_get_pci_domain(dev) ||
68             (p->busnum & 0xff) != dev->pdev->bus->number ||
69             p->devnum != PCI_SLOT(dev->pdev->devfn) || p->funcnum != PCI_FUNC(dev->pdev->devfn))
70                 return -EINVAL;
71
72         p->irq = dev->pdev->irq;
73
74         DRM_DEBUG("%d:%d:%d => IRQ %d\n", p->busnum, p->devnum, p->funcnum,
75                   p->irq);
76
77         return 0;
78 }
79
80 static void vblank_disable_fn(unsigned long arg)
81 {
82         struct drm_device *dev = (struct drm_device *)arg;
83         unsigned long irqflags;
84         int i;
85
86         if (!dev->vblank_disable_allowed)
87                 return;
88
89         for (i = 0; i < dev->num_crtcs; i++) {
90                 spin_lock_irqsave(&dev->vbl_lock, irqflags);
91                 if (atomic_read(&dev->vblank_refcount[i]) == 0 &&
92                     dev->vblank_enabled[i]) {
93                         DRM_DEBUG("disabling vblank on crtc %d\n", i);
94                         dev->last_vblank[i] =
95                                 dev->driver->get_vblank_counter(dev, i);
96                         dev->driver->disable_vblank(dev, i);
97                         dev->vblank_enabled[i] = 0;
98                 }
99                 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
100         }
101 }
102
103 void drm_vblank_cleanup(struct drm_device *dev)
104 {
105         /* Bail if the driver didn't call drm_vblank_init() */
106         if (dev->num_crtcs == 0)
107                 return;
108
109         del_timer(&dev->vblank_disable_timer);
110
111         vblank_disable_fn((unsigned long)dev);
112
113         kfree(dev->vbl_queue);
114         kfree(dev->_vblank_count);
115         kfree(dev->vblank_refcount);
116         kfree(dev->vblank_enabled);
117         kfree(dev->last_vblank);
118         kfree(dev->last_vblank_wait);
119         kfree(dev->vblank_inmodeset);
120
121         dev->num_crtcs = 0;
122 }
123 EXPORT_SYMBOL(drm_vblank_cleanup);
124
125 int drm_vblank_init(struct drm_device *dev, int num_crtcs)
126 {
127         int i, ret = -ENOMEM;
128
129         setup_timer(&dev->vblank_disable_timer, vblank_disable_fn,
130                     (unsigned long)dev);
131         spin_lock_init(&dev->vbl_lock);
132         dev->num_crtcs = num_crtcs;
133
134         dev->vbl_queue = kmalloc(sizeof(wait_queue_head_t) * num_crtcs,
135                                  GFP_KERNEL);
136         if (!dev->vbl_queue)
137                 goto err;
138
139         dev->_vblank_count = kmalloc(sizeof(atomic_t) * num_crtcs, GFP_KERNEL);
140         if (!dev->_vblank_count)
141                 goto err;
142
143         dev->vblank_refcount = kmalloc(sizeof(atomic_t) * num_crtcs,
144                                        GFP_KERNEL);
145         if (!dev->vblank_refcount)
146                 goto err;
147
148         dev->vblank_enabled = kcalloc(num_crtcs, sizeof(int), GFP_KERNEL);
149         if (!dev->vblank_enabled)
150                 goto err;
151
152         dev->last_vblank = kcalloc(num_crtcs, sizeof(u32), GFP_KERNEL);
153         if (!dev->last_vblank)
154                 goto err;
155
156         dev->last_vblank_wait = kcalloc(num_crtcs, sizeof(u32), GFP_KERNEL);
157         if (!dev->last_vblank_wait)
158                 goto err;
159
160         dev->vblank_inmodeset = kcalloc(num_crtcs, sizeof(int), GFP_KERNEL);
161         if (!dev->vblank_inmodeset)
162                 goto err;
163
164         /* Zero per-crtc vblank stuff */
165         for (i = 0; i < num_crtcs; i++) {
166                 init_waitqueue_head(&dev->vbl_queue[i]);
167                 atomic_set(&dev->_vblank_count[i], 0);
168                 atomic_set(&dev->vblank_refcount[i], 0);
169         }
170
171         dev->vblank_disable_allowed = 0;
172         return 0;
173
174 err:
175         drm_vblank_cleanup(dev);
176         return ret;
177 }
178 EXPORT_SYMBOL(drm_vblank_init);
179
180 static void drm_irq_vgaarb_nokms(void *cookie, bool state)
181 {
182         struct drm_device *dev = cookie;
183
184         if (dev->driver->vgaarb_irq) {
185                 dev->driver->vgaarb_irq(dev, state);
186                 return;
187         }
188
189         if (!dev->irq_enabled)
190                 return;
191
192         if (state)
193                 dev->driver->irq_uninstall(dev);
194         else {
195                 dev->driver->irq_preinstall(dev);
196                 dev->driver->irq_postinstall(dev);
197         }
198 }
199
200 /**
201  * Install IRQ handler.
202  *
203  * \param dev DRM device.
204  *
205  * Initializes the IRQ related data. Installs the handler, calling the driver
206  * \c drm_driver_irq_preinstall() and \c drm_driver_irq_postinstall() functions
207  * before and after the installation.
208  */
209 int drm_irq_install(struct drm_device *dev)
210 {
211         int ret = 0;
212         unsigned long sh_flags = 0;
213         char *irqname;
214
215         if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
216                 return -EINVAL;
217
218         if (drm_dev_to_irq(dev) == 0)
219                 return -EINVAL;
220
221         mutex_lock(&dev->struct_mutex);
222
223         /* Driver must have been initialized */
224         if (!dev->dev_private) {
225                 mutex_unlock(&dev->struct_mutex);
226                 return -EINVAL;
227         }
228
229         if (dev->irq_enabled) {
230                 mutex_unlock(&dev->struct_mutex);
231                 return -EBUSY;
232         }
233         dev->irq_enabled = 1;
234         mutex_unlock(&dev->struct_mutex);
235
236         DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev));
237
238         /* Before installing handler */
239         dev->driver->irq_preinstall(dev);
240
241         /* Install handler */
242         if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
243                 sh_flags = IRQF_SHARED;
244
245         if (dev->devname)
246                 irqname = dev->devname;
247         else
248                 irqname = dev->driver->name;
249
250         ret = request_irq(drm_dev_to_irq(dev), dev->driver->irq_handler,
251                           sh_flags, irqname, dev);
252
253         if (ret < 0) {
254                 mutex_lock(&dev->struct_mutex);
255                 dev->irq_enabled = 0;
256                 mutex_unlock(&dev->struct_mutex);
257                 return ret;
258         }
259
260         if (!drm_core_check_feature(dev, DRIVER_MODESET))
261                 vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
262
263         /* After installing handler */
264         ret = dev->driver->irq_postinstall(dev);
265         if (ret < 0) {
266                 mutex_lock(&dev->struct_mutex);
267                 dev->irq_enabled = 0;
268                 mutex_unlock(&dev->struct_mutex);
269         }
270
271         return ret;
272 }
273 EXPORT_SYMBOL(drm_irq_install);
274
275 /**
276  * Uninstall the IRQ handler.
277  *
278  * \param dev DRM device.
279  *
280  * Calls the driver's \c drm_driver_irq_uninstall() function, and stops the irq.
281  */
282 int drm_irq_uninstall(struct drm_device * dev)
283 {
284         unsigned long irqflags;
285         int irq_enabled, i;
286
287         if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
288                 return -EINVAL;
289
290         mutex_lock(&dev->struct_mutex);
291         irq_enabled = dev->irq_enabled;
292         dev->irq_enabled = 0;
293         mutex_unlock(&dev->struct_mutex);
294
295         /*
296          * Wake up any waiters so they don't hang.
297          */
298         spin_lock_irqsave(&dev->vbl_lock, irqflags);
299         for (i = 0; i < dev->num_crtcs; i++) {
300                 DRM_WAKEUP(&dev->vbl_queue[i]);
301                 dev->vblank_enabled[i] = 0;
302                 dev->last_vblank[i] = dev->driver->get_vblank_counter(dev, i);
303         }
304         spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
305
306         if (!irq_enabled)
307                 return -EINVAL;
308
309         DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev));
310
311         if (!drm_core_check_feature(dev, DRIVER_MODESET))
312                 vga_client_register(dev->pdev, NULL, NULL, NULL);
313
314         dev->driver->irq_uninstall(dev);
315
316         free_irq(drm_dev_to_irq(dev), dev);
317
318         return 0;
319 }
320 EXPORT_SYMBOL(drm_irq_uninstall);
321
322 /**
323  * IRQ control ioctl.
324  *
325  * \param inode device inode.
326  * \param file_priv DRM file private.
327  * \param cmd command.
328  * \param arg user argument, pointing to a drm_control structure.
329  * \return zero on success or a negative number on failure.
330  *
331  * Calls irq_install() or irq_uninstall() according to \p arg.
332  */
333 int drm_control(struct drm_device *dev, void *data,
334                 struct drm_file *file_priv)
335 {
336         struct drm_control *ctl = data;
337
338         /* if we haven't irq we fallback for compatibility reasons - this used to be a separate function in drm_dma.h */
339
340
341         switch (ctl->func) {
342         case DRM_INST_HANDLER:
343                 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
344                         return 0;
345                 if (drm_core_check_feature(dev, DRIVER_MODESET))
346                         return 0;
347                 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
348                     ctl->irq != drm_dev_to_irq(dev))
349                         return -EINVAL;
350                 return drm_irq_install(dev);
351         case DRM_UNINST_HANDLER:
352                 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
353                         return 0;
354                 if (drm_core_check_feature(dev, DRIVER_MODESET))
355                         return 0;
356                 return drm_irq_uninstall(dev);
357         default:
358                 return -EINVAL;
359         }
360 }
361
362 /**
363  * drm_vblank_count - retrieve "cooked" vblank counter value
364  * @dev: DRM device
365  * @crtc: which counter to retrieve
366  *
367  * Fetches the "cooked" vblank count value that represents the number of
368  * vblank events since the system was booted, including lost events due to
369  * modesetting activity.
370  */
371 u32 drm_vblank_count(struct drm_device *dev, int crtc)
372 {
373         return atomic_read(&dev->_vblank_count[crtc]);
374 }
375 EXPORT_SYMBOL(drm_vblank_count);
376
377 /**
378  * drm_update_vblank_count - update the master vblank counter
379  * @dev: DRM device
380  * @crtc: counter to update
381  *
382  * Call back into the driver to update the appropriate vblank counter
383  * (specified by @crtc).  Deal with wraparound, if it occurred, and
384  * update the last read value so we can deal with wraparound on the next
385  * call if necessary.
386  *
387  * Only necessary when going from off->on, to account for frames we
388  * didn't get an interrupt for.
389  *
390  * Note: caller must hold dev->vbl_lock since this reads & writes
391  * device vblank fields.
392  */
393 static void drm_update_vblank_count(struct drm_device *dev, int crtc)
394 {
395         u32 cur_vblank, diff;
396
397         /*
398          * Interrupts were disabled prior to this call, so deal with counter
399          * wrap if needed.
400          * NOTE!  It's possible we lost a full dev->max_vblank_count events
401          * here if the register is small or we had vblank interrupts off for
402          * a long time.
403          */
404         cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
405         diff = cur_vblank - dev->last_vblank[crtc];
406         if (cur_vblank < dev->last_vblank[crtc]) {
407                 diff += dev->max_vblank_count;
408
409                 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
410                           crtc, dev->last_vblank[crtc], cur_vblank, diff);
411         }
412
413         DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
414                   crtc, diff);
415
416         atomic_add(diff, &dev->_vblank_count[crtc]);
417 }
418
419 /**
420  * drm_vblank_get - get a reference count on vblank events
421  * @dev: DRM device
422  * @crtc: which CRTC to own
423  *
424  * Acquire a reference count on vblank events to avoid having them disabled
425  * while in use.
426  *
427  * RETURNS
428  * Zero on success, nonzero on failure.
429  */
430 int drm_vblank_get(struct drm_device *dev, int crtc)
431 {
432         unsigned long irqflags;
433         int ret = 0;
434
435         spin_lock_irqsave(&dev->vbl_lock, irqflags);
436         /* Going from 0->1 means we have to enable interrupts again */
437         if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1) {
438                 if (!dev->vblank_enabled[crtc]) {
439                         ret = dev->driver->enable_vblank(dev, crtc);
440                         DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n", crtc, ret);
441                         if (ret)
442                                 atomic_dec(&dev->vblank_refcount[crtc]);
443                         else {
444                                 dev->vblank_enabled[crtc] = 1;
445                                 drm_update_vblank_count(dev, crtc);
446                         }
447                 }
448         } else {
449                 if (!dev->vblank_enabled[crtc]) {
450                         atomic_dec(&dev->vblank_refcount[crtc]);
451                         ret = -EINVAL;
452                 }
453         }
454         spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
455
456         return ret;
457 }
458 EXPORT_SYMBOL(drm_vblank_get);
459
460 /**
461  * drm_vblank_put - give up ownership of vblank events
462  * @dev: DRM device
463  * @crtc: which counter to give up
464  *
465  * Release ownership of a given vblank counter, turning off interrupts
466  * if possible.
467  */
468 void drm_vblank_put(struct drm_device *dev, int crtc)
469 {
470         BUG_ON (atomic_read (&dev->vblank_refcount[crtc]) == 0);
471
472         /* Last user schedules interrupt disable */
473         if (atomic_dec_and_test(&dev->vblank_refcount[crtc]))
474                 mod_timer(&dev->vblank_disable_timer, jiffies + 5*DRM_HZ);
475 }
476 EXPORT_SYMBOL(drm_vblank_put);
477
478 void drm_vblank_off(struct drm_device *dev, int crtc)
479 {
480         unsigned long irqflags;
481
482         spin_lock_irqsave(&dev->vbl_lock, irqflags);
483         dev->driver->disable_vblank(dev, crtc);
484         DRM_WAKEUP(&dev->vbl_queue[crtc]);
485         dev->vblank_enabled[crtc] = 0;
486         dev->last_vblank[crtc] = dev->driver->get_vblank_counter(dev, crtc);
487         spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
488 }
489 EXPORT_SYMBOL(drm_vblank_off);
490
491 /**
492  * drm_vblank_pre_modeset - account for vblanks across mode sets
493  * @dev: DRM device
494  * @crtc: CRTC in question
495  * @post: post or pre mode set?
496  *
497  * Account for vblank events across mode setting events, which will likely
498  * reset the hardware frame counter.
499  */
500 void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
501 {
502         /* vblank is not initialized (IRQ not installed ?) */
503         if (!dev->num_crtcs)
504                 return;
505         /*
506          * To avoid all the problems that might happen if interrupts
507          * were enabled/disabled around or between these calls, we just
508          * have the kernel take a reference on the CRTC (just once though
509          * to avoid corrupting the count if multiple, mismatch calls occur),
510          * so that interrupts remain enabled in the interim.
511          */
512         if (!dev->vblank_inmodeset[crtc]) {
513                 dev->vblank_inmodeset[crtc] = 0x1;
514                 if (drm_vblank_get(dev, crtc) == 0)
515                         dev->vblank_inmodeset[crtc] |= 0x2;
516         }
517 }
518 EXPORT_SYMBOL(drm_vblank_pre_modeset);
519
520 void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
521 {
522         unsigned long irqflags;
523
524         if (dev->vblank_inmodeset[crtc]) {
525                 spin_lock_irqsave(&dev->vbl_lock, irqflags);
526                 dev->vblank_disable_allowed = 1;
527                 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
528
529                 if (dev->vblank_inmodeset[crtc] & 0x2)
530                         drm_vblank_put(dev, crtc);
531
532                 dev->vblank_inmodeset[crtc] = 0;
533         }
534 }
535 EXPORT_SYMBOL(drm_vblank_post_modeset);
536
537 /**
538  * drm_modeset_ctl - handle vblank event counter changes across mode switch
539  * @DRM_IOCTL_ARGS: standard ioctl arguments
540  *
541  * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
542  * ioctls around modesetting so that any lost vblank events are accounted for.
543  *
544  * Generally the counter will reset across mode sets.  If interrupts are
545  * enabled around this call, we don't have to do anything since the counter
546  * will have already been incremented.
547  */
548 int drm_modeset_ctl(struct drm_device *dev, void *data,
549                     struct drm_file *file_priv)
550 {
551         struct drm_modeset_ctl *modeset = data;
552         int crtc, ret = 0;
553
554         /* If drm_vblank_init() hasn't been called yet, just no-op */
555         if (!dev->num_crtcs)
556                 goto out;
557
558         crtc = modeset->crtc;
559         if (crtc >= dev->num_crtcs) {
560                 ret = -EINVAL;
561                 goto out;
562         }
563
564         switch (modeset->cmd) {
565         case _DRM_PRE_MODESET:
566                 drm_vblank_pre_modeset(dev, crtc);
567                 break;
568         case _DRM_POST_MODESET:
569                 drm_vblank_post_modeset(dev, crtc);
570                 break;
571         default:
572                 ret = -EINVAL;
573                 break;
574         }
575
576 out:
577         return ret;
578 }
579
580 static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
581                                   union drm_wait_vblank *vblwait,
582                                   struct drm_file *file_priv)
583 {
584         struct drm_pending_vblank_event *e;
585         struct timeval now;
586         unsigned long flags;
587         unsigned int seq;
588         int ret;
589
590         e = kzalloc(sizeof *e, GFP_KERNEL);
591         if (e == NULL) {
592                 ret = -ENOMEM;
593                 goto err_put;
594         }
595
596         e->pipe = pipe;
597         e->base.pid = current->pid;
598         e->event.base.type = DRM_EVENT_VBLANK;
599         e->event.base.length = sizeof e->event;
600         e->event.user_data = vblwait->request.signal;
601         e->base.event = &e->event.base;
602         e->base.file_priv = file_priv;
603         e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
604
605         do_gettimeofday(&now);
606         spin_lock_irqsave(&dev->event_lock, flags);
607
608         if (file_priv->event_space < sizeof e->event) {
609                 ret = -EBUSY;
610                 goto err_unlock;
611         }
612
613         file_priv->event_space -= sizeof e->event;
614         seq = drm_vblank_count(dev, pipe);
615         if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
616             (seq - vblwait->request.sequence) <= (1 << 23)) {
617                 vblwait->request.sequence = seq + 1;
618                 vblwait->reply.sequence = vblwait->request.sequence;
619         }
620
621         DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
622                   vblwait->request.sequence, seq, pipe);
623
624         trace_drm_vblank_event_queued(current->pid, pipe,
625                                       vblwait->request.sequence);
626
627         e->event.sequence = vblwait->request.sequence;
628         if ((seq - vblwait->request.sequence) <= (1 << 23)) {
629                 e->event.tv_sec = now.tv_sec;
630                 e->event.tv_usec = now.tv_usec;
631                 drm_vblank_put(dev, pipe);
632                 list_add_tail(&e->base.link, &e->base.file_priv->event_list);
633                 wake_up_interruptible(&e->base.file_priv->event_wait);
634                 trace_drm_vblank_event_delivered(current->pid, pipe,
635                                                  vblwait->request.sequence);
636         } else {
637                 list_add_tail(&e->base.link, &dev->vblank_event_list);
638         }
639
640         spin_unlock_irqrestore(&dev->event_lock, flags);
641
642         return 0;
643
644 err_unlock:
645         spin_unlock_irqrestore(&dev->event_lock, flags);
646         kfree(e);
647 err_put:
648         drm_vblank_put(dev, pipe);
649         return ret;
650 }
651
652 /**
653  * Wait for VBLANK.
654  *
655  * \param inode device inode.
656  * \param file_priv DRM file private.
657  * \param cmd command.
658  * \param data user argument, pointing to a drm_wait_vblank structure.
659  * \return zero on success or a negative number on failure.
660  *
661  * This function enables the vblank interrupt on the pipe requested, then
662  * sleeps waiting for the requested sequence number to occur, and drops
663  * the vblank interrupt refcount afterwards. (vblank irq disable follows that
664  * after a timeout with no further vblank waits scheduled).
665  */
666 int drm_wait_vblank(struct drm_device *dev, void *data,
667                     struct drm_file *file_priv)
668 {
669         union drm_wait_vblank *vblwait = data;
670         int ret = 0;
671         unsigned int flags, seq, crtc;
672
673         if ((!drm_dev_to_irq(dev)) || (!dev->irq_enabled))
674                 return -EINVAL;
675
676         if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
677                 return -EINVAL;
678
679         if (vblwait->request.type &
680             ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK)) {
681                 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
682                           vblwait->request.type,
683                           (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK));
684                 return -EINVAL;
685         }
686
687         flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
688         crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
689
690         if (crtc >= dev->num_crtcs)
691                 return -EINVAL;
692
693         ret = drm_vblank_get(dev, crtc);
694         if (ret) {
695                 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
696                 return ret;
697         }
698         seq = drm_vblank_count(dev, crtc);
699
700         switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
701         case _DRM_VBLANK_RELATIVE:
702                 vblwait->request.sequence += seq;
703                 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
704         case _DRM_VBLANK_ABSOLUTE:
705                 break;
706         default:
707                 ret = -EINVAL;
708                 goto done;
709         }
710
711         if (flags & _DRM_VBLANK_EVENT)
712                 return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
713
714         if ((flags & _DRM_VBLANK_NEXTONMISS) &&
715             (seq - vblwait->request.sequence) <= (1<<23)) {
716                 vblwait->request.sequence = seq + 1;
717         }
718
719         DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
720                   vblwait->request.sequence, crtc);
721         dev->last_vblank_wait[crtc] = vblwait->request.sequence;
722         DRM_WAIT_ON(ret, dev->vbl_queue[crtc], 3 * DRM_HZ,
723                     (((drm_vblank_count(dev, crtc) -
724                        vblwait->request.sequence) <= (1 << 23)) ||
725                      !dev->irq_enabled));
726
727         if (ret != -EINTR) {
728                 struct timeval now;
729
730                 do_gettimeofday(&now);
731
732                 vblwait->reply.tval_sec = now.tv_sec;
733                 vblwait->reply.tval_usec = now.tv_usec;
734                 vblwait->reply.sequence = drm_vblank_count(dev, crtc);
735                 DRM_DEBUG("returning %d to client\n",
736                           vblwait->reply.sequence);
737         } else {
738                 DRM_DEBUG("vblank wait interrupted by signal\n");
739         }
740
741 done:
742         drm_vblank_put(dev, crtc);
743         return ret;
744 }
745
746 void drm_handle_vblank_events(struct drm_device *dev, int crtc)
747 {
748         struct drm_pending_vblank_event *e, *t;
749         struct timeval now;
750         unsigned long flags;
751         unsigned int seq;
752
753         do_gettimeofday(&now);
754         seq = drm_vblank_count(dev, crtc);
755
756         spin_lock_irqsave(&dev->event_lock, flags);
757
758         list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
759                 if (e->pipe != crtc)
760                         continue;
761                 if ((seq - e->event.sequence) > (1<<23))
762                         continue;
763
764                 DRM_DEBUG("vblank event on %d, current %d\n",
765                           e->event.sequence, seq);
766
767                 e->event.sequence = seq;
768                 e->event.tv_sec = now.tv_sec;
769                 e->event.tv_usec = now.tv_usec;
770                 drm_vblank_put(dev, e->pipe);
771                 list_move_tail(&e->base.link, &e->base.file_priv->event_list);
772                 wake_up_interruptible(&e->base.file_priv->event_wait);
773                 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
774                                                  e->event.sequence);
775         }
776
777         spin_unlock_irqrestore(&dev->event_lock, flags);
778
779         trace_drm_vblank_event(crtc, seq);
780 }
781
782 /**
783  * drm_handle_vblank - handle a vblank event
784  * @dev: DRM device
785  * @crtc: where this event occurred
786  *
787  * Drivers should call this routine in their vblank interrupt handlers to
788  * update the vblank counter and send any signals that may be pending.
789  */
790 void drm_handle_vblank(struct drm_device *dev, int crtc)
791 {
792         if (!dev->num_crtcs)
793                 return;
794
795         atomic_inc(&dev->_vblank_count[crtc]);
796         DRM_WAKEUP(&dev->vbl_queue[crtc]);
797         drm_handle_vblank_events(dev, crtc);
798 }
799 EXPORT_SYMBOL(drm_handle_vblank);