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
 589         e = kzalloc(sizeof *e, GFP_KERNEL);
 590         if (e == NULL)
 591                 return -ENOMEM;
 592
 593         e->pipe = pipe;
 594         e->base.pid = current->pid;
 595         e->event.base.type = DRM_EVENT_VBLANK;
 596         e->event.base.length = sizeof e->event;
 597         e->event.user_data = vblwait->request.signal;
 598         e->base.event = &e->event.base;
 599         e->base.file_priv = file_priv;
 600         e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
 601
 602         do_gettimeofday(&now);
 603         spin_lock_irqsave(&dev->event_lock, flags);
 604
 605         if (file_priv->event_space < sizeof e->event) {
 606                 spin_unlock_irqrestore(&dev->event_lock, flags);
 607                 kfree(e);
 608                 return -ENOMEM;
 609         }
 610
 611         file_priv->event_space -= sizeof e->event;
 612         seq = drm_vblank_count(dev, pipe);
 613         if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
 614             (seq - vblwait->request.sequence) <= (1 << 23)) {
 615                 vblwait->request.sequence = seq + 1;
 616                 vblwait->reply.sequence = vblwait->request.sequence;
 617         }
 618
 619         DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
 620                   vblwait->request.sequence, seq, pipe);
 621
 622         trace_drm_vblank_event_queued(current->pid, pipe,
 623                                       vblwait->request.sequence);
 624
 625         e->event.sequence = vblwait->request.sequence;
 626         if ((seq - vblwait->request.sequence) <= (1 << 23)) {
 627                 e->event.tv_sec = now.tv_sec;
 628                 e->event.tv_usec = now.tv_usec;
 629                 drm_vblank_put(dev, e->pipe);
 630                 list_add_tail(&e->base.link, &e->base.file_priv->event_list);
 631                 wake_up_interruptible(&e->base.file_priv->event_wait);
 632                 trace_drm_vblank_event_delivered(current->pid, pipe,
 633                                                  vblwait->request.sequence);
 634         } else {
 635                 list_add_tail(&e->base.link, &dev->vblank_event_list);
 636         }
 637
 638         spin_unlock_irqrestore(&dev->event_lock, flags);
 639
 640         return 0;
 641 }
 642
 643 /**
 644  * Wait for VBLANK.
 645  *
 646  * \param inode device inode.
 647  * \param file_priv DRM file private.
 648  * \param cmd command.
 649  * \param data user argument, pointing to a drm_wait_vblank structure.
 650  * \return zero on success or a negative number on failure.
 651  *
 652  * This function enables the vblank interrupt on the pipe requested, then
 653  * sleeps waiting for the requested sequence number to occur, and drops
 654  * the vblank interrupt refcount afterwards. (vblank irq disable follows that
 655  * after a timeout with no further vblank waits scheduled).
 656  */
 657 int drm_wait_vblank(struct drm_device *dev, void *data,
 658                     struct drm_file *file_priv)
 659 {
 660         union drm_wait_vblank *vblwait = data;
 661         int ret = 0;
 662         unsigned int flags, seq, crtc;
 663
 664         if ((!drm_dev_to_irq(dev)) || (!dev->irq_enabled))
 665                 return -EINVAL;
 666
 667         if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
 668                 return -EINVAL;
 669
 670         if (vblwait->request.type &
 671             ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK)) {
 672                 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
 673                           vblwait->request.type,
 674                           (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK));
 675                 return -EINVAL;
 676         }
 677
 678         flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
 679         crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
 680
 681         if (crtc >= dev->num_crtcs)
 682                 return -EINVAL;
 683
 684         ret = drm_vblank_get(dev, crtc);
 685         if (ret) {
 686                 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
 687                 return ret;
 688         }
 689         seq = drm_vblank_count(dev, crtc);
 690
 691         switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
 692         case _DRM_VBLANK_RELATIVE:
 693                 vblwait->request.sequence += seq;
 694                 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
 695         case _DRM_VBLANK_ABSOLUTE:
 696                 break;
 697         default:
 698                 ret = -EINVAL;
 699                 goto done;
 700         }
 701
 702         if (flags & _DRM_VBLANK_EVENT)
 703                 return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
 704
 705         if ((flags & _DRM_VBLANK_NEXTONMISS) &&
 706             (seq - vblwait->request.sequence) <= (1<<23)) {
 707                 vblwait->request.sequence = seq + 1;
 708         }
 709
 710         DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
 711                   vblwait->request.sequence, crtc);
 712         dev->last_vblank_wait[crtc] = vblwait->request.sequence;
 713         DRM_WAIT_ON(ret, dev->vbl_queue[crtc], 3 * DRM_HZ,
 714                     (((drm_vblank_count(dev, crtc) -
 715                        vblwait->request.sequence) <= (1 << 23)) ||
 716                      !dev->irq_enabled));
 717
 718         if (ret != -EINTR) {
 719                 struct timeval now;
 720
 721                 do_gettimeofday(&now);
 722
 723                 vblwait->reply.tval_sec = now.tv_sec;
 724                 vblwait->reply.tval_usec = now.tv_usec;
 725                 vblwait->reply.sequence = drm_vblank_count(dev, crtc);
 726                 DRM_DEBUG("returning %d to client\n",
 727                           vblwait->reply.sequence);
 728         } else {
 729                 DRM_DEBUG("vblank wait interrupted by signal\n");
 730         }
 731
 732 done:
 733         drm_vblank_put(dev, crtc);
 734         return ret;
 735 }
 736
 737 void drm_handle_vblank_events(struct drm_device *dev, int crtc)
 738 {
 739         struct drm_pending_vblank_event *e, *t;
 740         struct timeval now;
 741         unsigned long flags;
 742         unsigned int seq;
 743
 744         do_gettimeofday(&now);
 745         seq = drm_vblank_count(dev, crtc);
 746
 747         spin_lock_irqsave(&dev->event_lock, flags);
 748
 749         list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
 750                 if (e->pipe != crtc)
 751                         continue;
 752                 if ((seq - e->event.sequence) > (1<<23))
 753                         continue;
 754
 755                 DRM_DEBUG("vblank event on %d, current %d\n",
 756                           e->event.sequence, seq);
 757
 758                 e->event.sequence = seq;
 759                 e->event.tv_sec = now.tv_sec;
 760                 e->event.tv_usec = now.tv_usec;
 761                 drm_vblank_put(dev, e->pipe);
 762                 list_move_tail(&e->base.link, &e->base.file_priv->event_list);
 763                 wake_up_interruptible(&e->base.file_priv->event_wait);
 764                 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
 765                                                  e->event.sequence);
 766         }
 767
 768         spin_unlock_irqrestore(&dev->event_lock, flags);
 769
 770         trace_drm_vblank_event(crtc, seq);
 771 }
 772
 773 /**
 774  * drm_handle_vblank - handle a vblank event
 775  * @dev: DRM device
 776  * @crtc: where this event occurred
 777  *
 778  * Drivers should call this routine in their vblank interrupt handlers to
 779  * update the vblank counter and send any signals that may be pending.
 780  */
 781 void drm_handle_vblank(struct drm_device *dev, int crtc)
 782 {
 783         if (!dev->num_crtcs)
 784                 return;
 785
 786         atomic_inc(&dev->_vblank_count[crtc]);
 787         DRM_WAKEUP(&dev->vbl_queue[crtc]);
 788         drm_handle_vblank_events(dev, crtc);
 789 }
 790 EXPORT_SYMBOL(drm_handle_vblank);