linux-core/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
  38 #include <linux/interrupt.h>    /* For task queue support */
  39
  40 /**
  41  * Get interrupt from bus id.
  42  *
  43  * \param inode device inode.
  44  * \param file_priv DRM file private.
  45  * \param cmd command.
  46  * \param arg user argument, pointing to a drm_irq_busid structure.
  47  * \return zero on success or a negative number on failure.
  48  *
  49  * Finds the PCI device with the specified bus id and gets its IRQ number.
  50  * This IOCTL is deprecated, and will now return EINVAL for any busid not equal
  51  * to that of the device that this DRM instance attached to.
  52  */
  53 int drm_irq_by_busid(struct drm_device *dev, void *data,
  54                      struct drm_file *file_priv)
  55 {
  56         struct drm_irq_busid *p = data;
  57
  58         if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
  59                 return -EINVAL;
  60
  61         if ((p->busnum >> 8) != drm_get_pci_domain(dev) ||
  62             (p->busnum & 0xff) != dev->pdev->bus->number ||
  63             p->devnum != PCI_SLOT(dev->pdev->devfn) || p->funcnum != PCI_FUNC(dev->pdev->devfn))
  64                 return -EINVAL;
  65
  66         p->irq = dev->pdev->irq;
  67
  68         DRM_DEBUG("%d:%d:%d => IRQ %d\n", p->busnum, p->devnum, p->funcnum,
  69                   p->irq);
  70
  71         return 0;
  72 }
  73
  74 static void vblank_disable_fn(unsigned long arg)
  75 {
  76         struct drm_device *dev = (struct drm_device *)arg;
  77         unsigned long irqflags;
  78         int i;
  79
  80         for (i = 0; i < dev->num_crtcs; i++) {
  81                 spin_lock_irqsave(&dev->vbl_lock, irqflags);
  82                 if (atomic_read(&dev->vblank_refcount[i]) == 0 &&
  83                     dev->vblank_enabled[i]) {
  84                         dev->driver->disable_vblank(dev, i);
  85                         dev->vblank_enabled[i] = 0;
  86                 }
  87                 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
  88         }
  89 }
  90
  91 static void drm_vblank_cleanup(struct drm_device *dev)
  92 {
  93         del_timer(&dev->vblank_disable_timer);
  94
  95         vblank_disable_fn((unsigned long)dev);
  96
  97         if (dev->vbl_queue)
  98             drm_free(dev->vbl_queue, sizeof(*dev->vbl_queue) * dev->num_crtcs,
  99                  DRM_MEM_DRIVER);
 100
 101         if (dev->vbl_sigs)
 102             drm_free(dev->vbl_sigs, sizeof(*dev->vbl_sigs) * dev->num_crtcs,
 103                  DRM_MEM_DRIVER);
 104
 105         if (dev->_vblank_count)
 106             drm_free(dev->_vblank_count, sizeof(*dev->_vblank_count) *
 107                  dev->num_crtcs, DRM_MEM_DRIVER);
 108
 109         if (dev->vblank_refcount)
 110             drm_free(dev->vblank_refcount, sizeof(*dev->vblank_refcount) *
 111                  dev->num_crtcs, DRM_MEM_DRIVER);
 112
 113         if (dev->vblank_enabled)
 114             drm_free(dev->vblank_enabled, sizeof(*dev->vblank_enabled) *
 115                  dev->num_crtcs, DRM_MEM_DRIVER);
 116
 117         if (dev->last_vblank)
 118             drm_free(dev->last_vblank, sizeof(*dev->last_vblank) * dev->num_crtcs,
 119                  DRM_MEM_DRIVER);
 120
 121         if (dev->vblank_premodeset)
 122             drm_free(dev->vblank_premodeset, sizeof(*dev->vblank_premodeset) *
 123                  dev->num_crtcs, DRM_MEM_DRIVER);
 124
 125         if (dev->vblank_offset)
 126             drm_free(dev->vblank_offset, sizeof(*dev->vblank_offset) * dev->num_crtcs,
 127                  DRM_MEM_DRIVER);
 128 }
 129
 130 int drm_vblank_init(struct drm_device *dev, int num_crtcs)
 131 {
 132         int i, ret = -ENOMEM;
 133
 134         setup_timer(&dev->vblank_disable_timer, vblank_disable_fn,
 135                     (unsigned long)dev);
 136         init_timer_deferrable(&dev->vblank_disable_timer);
 137         spin_lock_init(&dev->vbl_lock);
 138         atomic_set(&dev->vbl_signal_pending, 0);
 139         dev->num_crtcs = num_crtcs;
 140
 141         dev->vbl_queue = drm_alloc(sizeof(wait_queue_head_t) * num_crtcs,
 142                                    DRM_MEM_DRIVER);
 143         if (!dev->vbl_queue)
 144                 goto err;
 145
 146         dev->vbl_sigs = drm_alloc(sizeof(struct list_head) * num_crtcs,
 147                                   DRM_MEM_DRIVER);
 148         if (!dev->vbl_sigs)
 149                 goto err;
 150
 151         dev->_vblank_count = drm_alloc(sizeof(atomic_t) * num_crtcs,
 152                                       DRM_MEM_DRIVER);
 153         if (!dev->_vblank_count)
 154                 goto err;
 155
 156         dev->vblank_refcount = drm_alloc(sizeof(atomic_t) * num_crtcs,
 157                                          DRM_MEM_DRIVER);
 158         if (!dev->vblank_refcount)
 159                 goto err;
 160
 161         dev->vblank_enabled = drm_calloc(num_crtcs, sizeof(int),
 162                                          DRM_MEM_DRIVER);
 163         if (!dev->vblank_enabled)
 164                 goto err;
 165
 166         dev->last_vblank = drm_calloc(num_crtcs, sizeof(u32), DRM_MEM_DRIVER);
 167         if (!dev->last_vblank)
 168                 goto err;
 169
 170         dev->vblank_premodeset = drm_calloc(num_crtcs, sizeof(u32),
 171                                             DRM_MEM_DRIVER);
 172         if (!dev->vblank_premodeset)
 173                 goto err;
 174
 175         dev->vblank_offset = drm_calloc(num_crtcs, sizeof(u32), DRM_MEM_DRIVER);
 176         if (!dev->vblank_offset)
 177                 goto err;
 178
 179         /* Zero per-crtc vblank stuff */
 180         for (i = 0; i < num_crtcs; i++) {
 181                 init_waitqueue_head(&dev->vbl_queue[i]);
 182                 INIT_LIST_HEAD(&dev->vbl_sigs[i]);
 183                 atomic_set(&dev->_vblank_count[i], 0);
 184                 atomic_set(&dev->vblank_refcount[i], 0);
 185         }
 186
 187         return 0;
 188
 189 err:
 190         drm_vblank_cleanup(dev);
 191         return ret;
 192 }
 193 EXPORT_SYMBOL(drm_vblank_init);
 194
 195 int drm_wait_hotplug(struct drm_device *dev, void *data,
 196                     struct drm_file *file_priv)
 197 {
 198         union drm_wait_hotplug *hotplugwait = data;
 199         struct timeval now;
 200         int ret = 0;
 201         unsigned int flags;
 202
 203         if ((!dev->irq) || (!dev->irq_enabled))
 204                 return -EINVAL;
 205
 206         flags = hotplugwait->request.type;
 207
 208         if (flags & _DRM_HOTPLUG_SIGNAL) {
 209                 unsigned long irqflags;
 210                 struct list_head *hotplug_sigs = dev->hotplug_sigs;
 211                 struct drm_hotplug_sig *hotplug_sig;
 212
 213                 hotplug_sig = drm_calloc(1, sizeof(struct drm_hotplug_sig),
 214                                      DRM_MEM_DRIVER);
 215                 if (!hotplug_sig)
 216                         return -ENOMEM;
 217
 218                 atomic_inc(&dev->hotplug_signal_pending);
 219
 220                 hotplug_sig->info.si_signo = hotplugwait->request.signal;
 221                 hotplug_sig->task = current;
 222                 hotplug_sig->counter =
 223                         hotplugwait->reply.counter =
 224                                         dev->mode_config.hotplug_counter;
 225
 226                 spin_lock_irqsave(&dev->hotplug_lock, irqflags);
 227
 228                 list_add_tail(&hotplug_sig->head, hotplug_sigs);
 229
 230                 spin_unlock_irqrestore(&dev->hotplug_lock, irqflags);
 231         } else {
 232                 int cur_hotplug = dev->mode_config.hotplug_counter;
 233
 234                 DRM_WAIT_ON(ret, dev->hotplug_queue, 3 * DRM_HZ,
 235                                 dev->mode_config.hotplug_counter > cur_hotplug);
 236
 237                 do_gettimeofday(&now);
 238
 239                 hotplugwait->reply.tval_sec = now.tv_sec;
 240                 hotplugwait->reply.tval_usec = now.tv_usec;
 241                 hotplugwait->reply.counter = dev->mode_config.hotplug_counter;
 242         }
 243
 244         return ret;
 245 }
 246
 247 static void drm_hotplug_cleanup(struct drm_device *dev)
 248 {
 249         if (dev->hotplug_sigs)
 250             drm_free(dev->hotplug_sigs, sizeof(*dev->hotplug_sigs),
 251                  DRM_MEM_DRIVER);
 252 }
 253 EXPORT_SYMBOL(drm_hotplug_cleanup);
 254
 255 int drm_hotplug_init(struct drm_device *dev)
 256 {
 257         spin_lock_init(&dev->hotplug_lock);
 258         atomic_set(&dev->hotplug_signal_pending, 0);
 259
 260         dev->hotplug_sigs = drm_alloc(sizeof(struct list_head), DRM_MEM_DRIVER);
 261         if (!dev->hotplug_sigs)
 262                 return -ENOMEM;
 263
 264         INIT_LIST_HEAD(dev->hotplug_sigs);
 265         init_waitqueue_head(&dev->hotplug_queue);
 266
 267         return 0;
 268 }
 269 EXPORT_SYMBOL(drm_hotplug_init);
 270
 271 /**
 272  * Install IRQ handler.
 273  *
 274  * \param dev DRM device.
 275  *
 276  * Initializes the IRQ related data. Installs the handler, calling the driver
 277  * \c drm_driver_irq_preinstall() and \c drm_driver_irq_postinstall() functions
 278  * before and after the installation.
 279  */
 280 int drm_irq_install(struct drm_device * dev)
 281 {
 282         int ret = 0;
 283         unsigned long sh_flags = 0;
 284
 285         if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
 286                 return -EINVAL;
 287
 288         if (dev->pdev->irq == 0)
 289                 return -EINVAL;
 290
 291         mutex_lock(&dev->struct_mutex);
 292
 293         /* Driver must have been initialized */
 294         if (!dev->dev_private) {
 295                 mutex_unlock(&dev->struct_mutex);
 296                 return -EINVAL;
 297         }
 298
 299         if (dev->irq_enabled) {
 300                 mutex_unlock(&dev->struct_mutex);
 301                 return 0;
 302         }
 303         dev->irq_enabled = 1;
 304         mutex_unlock(&dev->struct_mutex);
 305
 306         DRM_DEBUG("irq=%d\n", dev->pdev->irq);
 307
 308         /* Before installing handler */
 309         dev->driver->irq_preinstall(dev);
 310
 311         /* Install handler */
 312         if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
 313                 sh_flags = IRQF_SHARED;
 314
 315         ret = request_irq(dev->pdev->irq, dev->driver->irq_handler,
 316                           sh_flags, dev->devname, dev);
 317         if (ret < 0) {
 318                 mutex_lock(&dev->struct_mutex);
 319                 dev->irq_enabled = 0;
 320                 mutex_unlock(&dev->struct_mutex);
 321                 return ret;
 322         }
 323         /* Expose the device irq to device drivers that want to export it for
 324          * whatever reason.
 325          */
 326         dev->irq = dev->pdev->irq;
 327
 328         /* After installing handler */
 329         ret = dev->driver->irq_postinstall(dev);
 330         if (ret < 0) {
 331                 mutex_lock(&dev->struct_mutex);
 332                 dev->irq_enabled = 0;
 333                 mutex_unlock(&dev->struct_mutex);
 334         }
 335
 336         return ret;
 337 }
 338 EXPORT_SYMBOL(drm_irq_install);
 339
 340 /**
 341  * Uninstall the IRQ handler.
 342  *
 343  * \param dev DRM device.
 344  *
 345  * Calls the driver's \c drm_driver_irq_uninstall() function, and stops the irq.
 346  */
 347 int drm_irq_uninstall(struct drm_device * dev)
 348 {
 349         int irq_enabled;
 350
 351         if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
 352                 return -EINVAL;
 353
 354         mutex_lock(&dev->struct_mutex);
 355         irq_enabled = dev->irq_enabled;
 356         dev->irq_enabled = 0;
 357         mutex_unlock(&dev->struct_mutex);
 358
 359         if (!irq_enabled)
 360                 return -EINVAL;
 361
 362         DRM_DEBUG("irq=%d\n", dev->pdev->irq);
 363
 364         dev->driver->irq_uninstall(dev);
 365
 366         free_irq(dev->pdev->irq, dev);
 367
 368         drm_vblank_cleanup(dev);
 369
 370         drm_hotplug_cleanup(dev);
 371
 372         dev->locked_tasklet_func = NULL;
 373
 374         return 0;
 375 }
 376 EXPORT_SYMBOL(drm_irq_uninstall);
 377
 378 /**
 379  * IRQ control ioctl.
 380  *
 381  * \param inode device inode.
 382  * \param file_priv DRM file private.
 383  * \param cmd command.
 384  * \param arg user argument, pointing to a drm_control structure.
 385  * \return zero on success or a negative number on failure.
 386  *
 387  * Calls irq_install() or irq_uninstall() according to \p arg.
 388  */
 389 int drm_control(struct drm_device *dev, void *data,
 390                 struct drm_file *file_priv)
 391 {
 392         struct drm_control *ctl = data;
 393
 394         /* if we haven't irq we fallback for compatibility reasons - this used to be a separate function in drm_dma.h */
 395
 396
 397         switch (ctl->func) {
 398         case DRM_INST_HANDLER:
 399                 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
 400                         return 0;
 401                 if (drm_core_check_feature(dev, DRIVER_MODESET))
 402                         return 0;
 403                 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
 404                     ctl->irq != dev->pdev->irq)
 405                         return -EINVAL;
 406                 return drm_irq_install(dev);
 407         case DRM_UNINST_HANDLER:
 408                 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
 409                         return 0;
 410                 if (drm_core_check_feature(dev, DRIVER_MODESET))
 411                         return 0;
 412                 return drm_irq_uninstall(dev);
 413         default:
 414                 return -EINVAL;
 415         }
 416 }
 417
 418 /**
 419  * drm_vblank_count - retrieve "cooked" vblank counter value
 420  * @dev: DRM device
 421  * @crtc: which counter to retrieve
 422  *
 423  * Fetches the "cooked" vblank count value that represents the number of
 424  * vblank events since the system was booted, including lost events due to
 425  * modesetting activity.
 426  */
 427 u32 drm_vblank_count(struct drm_device *dev, int crtc)
 428 {
 429         return atomic_read(&dev->_vblank_count[crtc]) +
 430                 dev->vblank_offset[crtc];
 431 }
 432 EXPORT_SYMBOL(drm_vblank_count);
 433
 434 /**
 435  * drm_update_vblank_count - update the master vblank counter
 436  * @dev: DRM device
 437  * @crtc: counter to update
 438  *
 439  * Call back into the driver to update the appropriate vblank counter
 440  * (specified by @crtc).  Deal with wraparound, if it occurred, and
 441  * update the last read value so we can deal with wraparound on the next
 442  * call if necessary.
 443  */
 444 void drm_update_vblank_count(struct drm_device *dev, int crtc)
 445 {
 446         unsigned long irqflags;
 447         u32 cur_vblank, diff;
 448
 449         /*
 450          * Interrupts were disabled prior to this call, so deal with counter
 451          * wrap if needed.
 452          * NOTE!  It's possible we lost a full dev->max_vblank_count events
 453          * here if the register is small or we had vblank interrupts off for
 454          * a long time.
 455          */
 456         cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
 457         spin_lock_irqsave(&dev->vbl_lock, irqflags);
 458         if (cur_vblank < dev->last_vblank[crtc]) {
 459                 diff = dev->max_vblank_count -
 460                         dev->last_vblank[crtc];
 461                 diff += cur_vblank;
 462         } else {
 463                 diff = cur_vblank - dev->last_vblank[crtc];
 464         }
 465         dev->last_vblank[crtc] = cur_vblank;
 466         spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
 467
 468         atomic_add(diff, &dev->_vblank_count[crtc]);
 469 }
 470 EXPORT_SYMBOL(drm_update_vblank_count);
 471
 472 /**
 473  * drm_vblank_get - get a reference count on vblank events
 474  * @dev: DRM device
 475  * @crtc: which CRTC to own
 476  *
 477  * Acquire a reference count on vblank events to avoid having them disabled
 478  * while in use.  Note callers will probably want to update the master counter
 479  * using drm_update_vblank_count() above before calling this routine so that
 480  * wakeups occur on the right vblank event.
 481  *
 482  * RETURNS
 483  * Zero on success, nonzero on failure.
 484  */
 485 int drm_vblank_get(struct drm_device *dev, int crtc)
 486 {
 487         unsigned long irqflags;
 488         int ret = 0;
 489
 490         spin_lock_irqsave(&dev->vbl_lock, irqflags);
 491         /* Going from 0->1 means we have to enable interrupts again */
 492         if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1 &&
 493             !dev->vblank_enabled[crtc]) {
 494                 ret = dev->driver->enable_vblank(dev, crtc);
 495                 if (ret)
 496                         atomic_dec(&dev->vblank_refcount[crtc]);
 497                 else
 498                         dev->vblank_enabled[crtc] = 1;
 499         }
 500         spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
 501
 502         return ret;
 503 }
 504 EXPORT_SYMBOL(drm_vblank_get);
 505
 506 /**
 507  * drm_vblank_put - give up ownership of vblank events
 508  * @dev: DRM device
 509  * @crtc: which counter to give up
 510  *
 511  * Release ownership of a given vblank counter, turning off interrupts
 512  * if possible.
 513  */
 514 void drm_vblank_put(struct drm_device *dev, int crtc)
 515 {
 516         /* Last user schedules interrupt disable */
 517         if (atomic_dec_and_test(&dev->vblank_refcount[crtc]))
 518             mod_timer(&dev->vblank_disable_timer, jiffies + 5*DRM_HZ);
 519 }
 520 EXPORT_SYMBOL(drm_vblank_put);
 521
 522 /**
 523  * drm_modeset_ctl - handle vblank event counter changes across mode switch
 524  * @DRM_IOCTL_ARGS: standard ioctl arguments
 525  *
 526  * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
 527  * ioctls around modesetting so that any lost vblank events are accounted for.
 528  */
 529 int drm_modeset_ctl(struct drm_device *dev, void *data,
 530                     struct drm_file *file_priv)
 531 {
 532         struct drm_modeset_ctl *modeset = data;
 533         int crtc, ret = 0;
 534         u32 new;
 535
 536         crtc = modeset->crtc;
 537         if (crtc >= dev->num_crtcs) {
 538                 ret = -EINVAL;
 539                 goto out;
 540         }
 541
 542         switch (modeset->cmd) {
 543         case _DRM_PRE_MODESET:
 544                 dev->vblank_premodeset[crtc] =
 545                         dev->driver->get_vblank_counter(dev, crtc);
 546                 break;
 547         case _DRM_POST_MODESET:
 548                 new = dev->driver->get_vblank_counter(dev, crtc);
 549                 dev->vblank_offset[crtc] = dev->vblank_premodeset[crtc] - new;
 550                 break;
 551         default:
 552                 ret = -EINVAL;
 553                 break;
 554         }
 555
 556 out:
 557         return ret;
 558 }
 559
 560 /**
 561  * Wait for VBLANK.
 562  *
 563  * \param inode device inode.
 564  * \param file_priv DRM file private.
 565  * \param cmd command.
 566  * \param data user argument, pointing to a drm_wait_vblank structure.
 567  * \return zero on success or a negative number on failure.
 568  *
 569  * Verifies the IRQ is installed.
 570  *
 571  * If a signal is requested checks if this task has already scheduled the same signal
 572  * for the same vblank sequence number - nothing to be done in
 573  * that case. If the number of tasks waiting for the interrupt exceeds 100 the
 574  * function fails. Otherwise adds a new entry to drm_device::vbl_sigs for this
 575  * task.
 576  *
 577  * If a signal is not requested, then calls vblank_wait().
 578  */
 579 int drm_wait_vblank(struct drm_device *dev, void *data,
 580                     struct drm_file *file_priv)
 581 {
 582         union drm_wait_vblank *vblwait = data;
 583         struct timeval now;
 584         int ret = 0;
 585         unsigned int flags, seq, crtc;
 586
 587         if ((!dev->pdev->irq) || (!dev->irq_enabled))
 588                 return -EINVAL;
 589
 590         if (vblwait->request.type &
 591             ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK)) {
 592                 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
 593                           vblwait->request.type,
 594                           (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK));
 595                 return -EINVAL;
 596         }
 597
 598         flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
 599         crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
 600
 601         if (crtc >= dev->num_crtcs)
 602                 return -EINVAL;
 603
 604         drm_update_vblank_count(dev, crtc);
 605         seq = drm_vblank_count(dev, crtc);
 606
 607         switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
 608         case _DRM_VBLANK_RELATIVE:
 609                 vblwait->request.sequence += seq;
 610                 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
 611         case _DRM_VBLANK_ABSOLUTE:
 612                 break;
 613         default:
 614                 return -EINVAL;
 615         }
 616
 617         if ((flags & _DRM_VBLANK_NEXTONMISS) &&
 618             (seq - vblwait->request.sequence) <= (1<<23)) {
 619                 vblwait->request.sequence = seq + 1;
 620         }
 621
 622         if (flags & _DRM_VBLANK_SIGNAL) {
 623                 unsigned long irqflags;
 624                 struct list_head *vbl_sigs = &dev->vbl_sigs[crtc];
 625                 struct drm_vbl_sig *vbl_sig, *tmp;
 626
 627                 spin_lock_irqsave(&dev->vbl_lock, irqflags);
 628
 629                 /* Check if this task has already scheduled the same signal
 630                  * for the same vblank sequence number; nothing to be done in
 631                  * that case
 632                  */
 633                 list_for_each_entry_safe(vbl_sig, tmp, vbl_sigs, head) {
 634                         if (vbl_sig->sequence == vblwait->request.sequence
 635                             && vbl_sig->info.si_signo ==
 636                             vblwait->request.signal
 637                             && vbl_sig->task == current) {
 638                                 spin_unlock_irqrestore(&dev->vbl_lock,
 639                                                        irqflags);
 640                                 vblwait->reply.sequence = seq;
 641                                 goto done;
 642                         }
 643                 }
 644
 645                 if (atomic_read(&dev->vbl_signal_pending) >= 100) {
 646                         spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
 647                         return -EBUSY;
 648                 }
 649
 650                 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
 651
 652                 vbl_sig = drm_calloc(1, sizeof(struct drm_vbl_sig),
 653                                      DRM_MEM_DRIVER);
 654                 if (!vbl_sig)
 655                         return -ENOMEM;
 656
 657                 ret = drm_vblank_get(dev, crtc);
 658                 if (ret) {
 659                         drm_free(vbl_sig, sizeof(struct drm_vbl_sig),
 660                                  DRM_MEM_DRIVER);
 661                         return ret;
 662                 }
 663
 664                 atomic_inc(&dev->vbl_signal_pending);
 665
 666                 vbl_sig->sequence = vblwait->request.sequence;
 667                 vbl_sig->info.si_signo = vblwait->request.signal;
 668                 vbl_sig->task = current;
 669
 670                 spin_lock_irqsave(&dev->vbl_lock, irqflags);
 671
 672                 list_add_tail(&vbl_sig->head, vbl_sigs);
 673
 674                 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
 675
 676                 vblwait->reply.sequence = seq;
 677         } else {
 678                 unsigned long cur_vblank;
 679
 680                 ret = drm_vblank_get(dev, crtc);
 681                 if (ret)
 682                         return ret;
 683                 DRM_WAIT_ON(ret, dev->vbl_queue[crtc], 3 * DRM_HZ,
 684                             (((cur_vblank = drm_vblank_count(dev, crtc))
 685                               - vblwait->request.sequence) <= (1 << 23)));
 686                 drm_vblank_put(dev, crtc);
 687                 do_gettimeofday(&now);
 688
 689                 vblwait->reply.tval_sec = now.tv_sec;
 690                 vblwait->reply.tval_usec = now.tv_usec;
 691                 vblwait->reply.sequence = cur_vblank;
 692         }
 693
 694       done:
 695         return ret;
 696 }
 697
 698 /**
 699  * Send the VBLANK signals.
 700  *
 701  * \param dev DRM device.
 702  * \param crtc CRTC where the vblank event occurred
 703  *
 704  * Sends a signal for each task in drm_device::vbl_sigs and empties the list.
 705  *
 706  * If a signal is not requested, then calls vblank_wait().
 707  */
 708 static void drm_vbl_send_signals(struct drm_device * dev, int crtc)
 709 {
 710         struct drm_vbl_sig *vbl_sig, *tmp;
 711         struct list_head *vbl_sigs;
 712         unsigned int vbl_seq;
 713         unsigned long flags;
 714
 715         spin_lock_irqsave(&dev->vbl_lock, flags);
 716
 717         vbl_sigs = &dev->vbl_sigs[crtc];
 718         vbl_seq = drm_vblank_count(dev, crtc);
 719
 720         list_for_each_entry_safe(vbl_sig, tmp, vbl_sigs, head) {
 721             if ((vbl_seq - vbl_sig->sequence) <= (1 << 23)) {
 722                 vbl_sig->info.si_code = vbl_seq;
 723                 send_sig_info(vbl_sig->info.si_signo,
 724                               &vbl_sig->info, vbl_sig->task);
 725
 726                 list_del(&vbl_sig->head);
 727
 728                 drm_free(vbl_sig, sizeof(*vbl_sig),
 729                          DRM_MEM_DRIVER);
 730                 atomic_dec(&dev->vbl_signal_pending);
 731                 drm_vblank_put(dev, crtc);
 732             }
 733         }
 734
 735         spin_unlock_irqrestore(&dev->vbl_lock, flags);
 736 }
 737
 738 /**
 739  * drm_handle_vblank - handle a vblank event
 740  * @dev: DRM device
 741  * @crtc: where this event occurred
 742  *
 743  * Drivers should call this routine in their vblank interrupt handlers to
 744  * update the vblank counter and send any signals that may be pending.
 745  */
 746 void drm_handle_vblank(struct drm_device *dev, int crtc)
 747 {
 748         drm_update_vblank_count(dev, crtc);
 749         DRM_WAKEUP(&dev->vbl_queue[crtc]);
 750         drm_vbl_send_signals(dev, crtc);
 751 }
 752 EXPORT_SYMBOL(drm_handle_vblank);
 753
 754 /**
 755  * Send the HOTPLUG signals.
 756  *
 757  * \param dev DRM device.
 758  *
 759  * Sends a signal for each task in drm_device::hotplug_sigs and empties the list.
 760  */
 761 static void drm_hotplug_send_signals(struct drm_device * dev)
 762 {
 763         struct drm_hotplug_sig *hotplug_sig, *tmp;
 764         struct list_head *hotplug_sigs;
 765         unsigned long flags;
 766
 767         spin_lock_irqsave(&dev->hotplug_lock, flags);
 768
 769         hotplug_sigs = dev->hotplug_sigs;
 770
 771         list_for_each_entry_safe(hotplug_sig, tmp, hotplug_sigs, head) {
 772             hotplug_sig->info.si_code = hotplug_sig->counter;
 773
 774             send_sig_info(hotplug_sig->info.si_signo,
 775                               &hotplug_sig->info, hotplug_sig->task);
 776
 777             list_del(&hotplug_sig->head);
 778
 779             drm_free(hotplug_sig, sizeof(*hotplug_sig),
 780                          DRM_MEM_DRIVER);
 781             atomic_dec(&dev->hotplug_signal_pending);
 782         }
 783
 784         spin_unlock_irqrestore(&dev->hotplug_lock, flags);
 785 }
 786
 787 /**
 788  * drm_handle_hotplug - handle a hotplug event
 789  * @dev: DRM device
 790  * @crtc: where this event occurred
 791  *
 792  * Drivers should call this routine in their hotplug interrupt handlers.
 793  */
 794 void drm_handle_hotplug(struct drm_device *dev)
 795 {
 796         DRM_WAKEUP(&dev->hotplug_queue);
 797         drm_hotplug_send_signals(dev);
 798 }
 799 EXPORT_SYMBOL(drm_handle_hotplug);
 800
 801 /**
 802  * Tasklet wrapper function.
 803  *
 804  * \param data DRM device in disguise.
 805  *
 806  * Attempts to grab the HW lock and calls the driver callback on success. On
 807  * failure, leave the lock marked as contended so the callback can be called
 808  * from drm_unlock().
 809  */
 810 static void drm_locked_tasklet_func(unsigned long data)
 811 {
 812         struct drm_device *dev = (struct drm_device *)data;
 813         unsigned long irqflags;
 814
 815         spin_lock_irqsave(&dev->tasklet_lock, irqflags);
 816
 817         if (!dev->locked_tasklet_func ||
 818             !drm_lock_take(&dev->primary->master->lock,
 819                            DRM_KERNEL_CONTEXT)) {
 820                 spin_unlock_irqrestore(&dev->tasklet_lock, irqflags);
 821                 return;
 822         }
 823
 824         dev->primary->master->lock.lock_time = jiffies;
 825         atomic_inc(&dev->counts[_DRM_STAT_LOCKS]);
 826
 827         dev->locked_tasklet_func(dev);
 828
 829         drm_lock_free(&dev->primary->master->lock,
 830                       DRM_KERNEL_CONTEXT);
 831
 832         dev->locked_tasklet_func = NULL;
 833
 834         spin_unlock_irqrestore(&dev->tasklet_lock, irqflags);
 835 }
 836
 837 /**
 838  * Schedule a tasklet to call back a driver hook with the HW lock held.
 839  *
 840  * \param dev DRM device.
 841  * \param func Driver callback.
 842  *
 843  * This is intended for triggering actions that require the HW lock from an
 844  * interrupt handler. The lock will be grabbed ASAP after the interrupt handler
 845  * completes. Note that the callback may be called from interrupt or process
 846  * context, it must not make any assumptions about this. Also, the HW lock will
 847  * be held with the kernel context or any client context.
 848  */
 849 void drm_locked_tasklet(struct drm_device *dev, void (*func)(struct drm_device *))
 850 {
 851         unsigned long irqflags;
 852         static DECLARE_TASKLET(drm_tasklet, drm_locked_tasklet_func, 0);
 853
 854         if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ) ||
 855             test_bit(TASKLET_STATE_SCHED, &drm_tasklet.state))
 856                 return;
 857
 858         spin_lock_irqsave(&dev->tasklet_lock, irqflags);
 859
 860         if (dev->locked_tasklet_func) {
 861                 spin_unlock_irqrestore(&dev->tasklet_lock, irqflags);
 862                 return;
 863         }
 864
 865         dev->locked_tasklet_func = func;
 866
 867         spin_unlock_irqrestore(&dev->tasklet_lock, irqflags);
 868
 869         drm_tasklet.data = (unsigned long)dev;
 870
 871         tasklet_hi_schedule(&drm_tasklet);
 872 }
 873 EXPORT_SYMBOL(drm_locked_tasklet);