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