2 * Copyright 2003 Eric Anholt
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
12 * The above copyright notice and this permission notice (including the next
13 * paragraph) shall be included in all copies or substantial portions of the
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * ERIC ANHOLT BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
20 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24 * Eric Anholt <anholt@FreeBSD.org>
26 * $FreeBSD: src/sys/dev/drm2/drm_irq.c,v 1.1 2012/05/22 11:07:44 kib Exp $
30 * Support code for handling setup/teardown of interrupt handlers and
31 * handing interrupt handlers off to the drivers.
34 #include <linux/export.h>
35 #include <linux/mutex.h>
36 #include <linux/time.h>
37 #include <linux/timer.h>
40 /* Access macro for slots in vblank timestamp ringbuffer. */
41 #define vblanktimestamp(dev, crtc, count) ( \
42 (dev)->_vblank_time[(crtc) * DRM_VBLANKTIME_RBSIZE + \
43 ((count) % DRM_VBLANKTIME_RBSIZE)])
45 /* Retry timestamp calculation up to 3 times to satisfy
46 * drm_timestamp_precision before giving up.
48 #define DRM_TIMESTAMP_MAXRETRIES 3
50 /* Threshold in nanoseconds for detection of redundant
51 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
53 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
55 int drm_irq_by_busid(struct drm_device *dev, void *data,
56 struct drm_file *file_priv)
58 struct drm_irq_busid *irq = data;
60 if ((irq->busnum >> 8) != dev->pci_domain ||
61 (irq->busnum & 0xff) != dev->pci_bus ||
62 irq->devnum != dev->pci_slot ||
63 irq->funcnum != dev->pci_func)
68 DRM_DEBUG("%d:%d:%d => IRQ %d\n",
69 irq->busnum, irq->devnum, irq->funcnum, irq->irq);
75 * Clear vblank timestamp buffer for a crtc.
77 static void clear_vblank_timestamps(struct drm_device *dev, int crtc)
79 memset(&dev->_vblank_time[crtc * DRM_VBLANKTIME_RBSIZE], 0,
80 DRM_VBLANKTIME_RBSIZE * sizeof(struct timeval));
87 return (x < 0 ? -x : x);
91 * Disable vblank irq's on crtc, make sure that last vblank count
92 * of hardware and corresponding consistent software vblank counter
93 * are preserved, even if there are any spurious vblank irq's after
96 static void vblank_disable_and_save(struct drm_device *dev, int crtc)
101 struct timeval tvblank;
103 /* Prevent vblank irq processing while disabling vblank irqs,
104 * so no updates of timestamps or count can happen after we've
105 * disabled. Needed to prevent races in case of delayed irq's.
107 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE);
109 dev->driver->disable_vblank(dev, crtc);
110 dev->vblank_enabled[crtc] = 0;
112 /* No further vblank irq's will be processed after
113 * this point. Get current hardware vblank count and
114 * vblank timestamp, repeat until they are consistent.
116 * FIXME: There is still a race condition here and in
117 * drm_update_vblank_count() which can cause off-by-one
118 * reinitialization of software vblank counter. If gpu
119 * vblank counter doesn't increment exactly at the leading
120 * edge of a vblank interval, then we can lose 1 count if
121 * we happen to execute between start of vblank and the
122 * delayed gpu counter increment.
125 dev->last_vblank[crtc] = dev->driver->get_vblank_counter(dev, crtc);
126 vblrc = drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0);
127 } while (dev->last_vblank[crtc] != dev->driver->get_vblank_counter(dev, crtc));
129 /* Compute time difference to stored timestamp of last vblank
130 * as updated by last invocation of drm_handle_vblank() in vblank irq.
132 vblcount = atomic_read(&dev->_vblank_count[crtc]);
133 diff_ns = timeval_to_ns(&tvblank) -
134 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
136 /* If there is at least 1 msec difference between the last stored
137 * timestamp and tvblank, then we are currently executing our
138 * disable inside a new vblank interval, the tvblank timestamp
139 * corresponds to this new vblank interval and the irq handler
140 * for this vblank didn't run yet and won't run due to our disable.
141 * Therefore we need to do the job of drm_handle_vblank() and
142 * increment the vblank counter by one to account for this vblank.
144 * Skip this step if there isn't any high precision timestamp
145 * available. In that case we can't account for this and just
148 if ((vblrc > 0) && (abs64(diff_ns) > 1000000)) {
149 atomic_inc(&dev->_vblank_count[crtc]);
152 /* Invalidate all timestamps while vblank irq's are off. */
153 clear_vblank_timestamps(dev, crtc);
155 lockmgr(&dev->vblank_time_lock, LK_RELEASE);
158 static void vblank_disable_fn(unsigned long arg)
160 struct drm_device *dev = (struct drm_device *)arg;
163 if (!dev->vblank_disable_allowed)
166 for (i = 0; i < dev->num_crtcs; i++) {
167 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE);
168 if (atomic_read(&dev->vblank_refcount[i]) == 0 &&
169 dev->vblank_enabled[i]) {
170 DRM_DEBUG("disabling vblank on crtc %d\n", i);
171 vblank_disable_and_save(dev, i);
173 lockmgr(&dev->vbl_lock, LK_RELEASE);
177 void drm_vblank_cleanup(struct drm_device *dev)
179 /* Bail if the driver didn't call drm_vblank_init() */
180 if (dev->num_crtcs == 0)
183 del_timer_sync(&dev->vblank_disable_timer);
185 vblank_disable_fn((unsigned long)dev);
187 drm_free(dev->_vblank_count, M_DRM);
188 drm_free(dev->vblank_refcount, M_DRM);
189 drm_free(dev->vblank_enabled, M_DRM);
190 drm_free(dev->last_vblank, M_DRM);
191 drm_free(dev->last_vblank_wait, M_DRM);
192 drm_free(dev->vblank_inmodeset, M_DRM);
193 drm_free(dev->_vblank_time, M_DRM);
197 EXPORT_SYMBOL(drm_vblank_cleanup);
199 int drm_vblank_init(struct drm_device *dev, int num_crtcs)
201 int i, ret = -ENOMEM;
203 setup_timer(&dev->vblank_disable_timer, vblank_disable_fn,
205 lockinit(&dev->vbl_lock, "drmvbl", 0, LK_CANRECURSE);
206 lockinit(&dev->vblank_time_lock, "drmvtl", 0, LK_CANRECURSE);
208 dev->num_crtcs = num_crtcs;
210 dev->vbl_queue = kmalloc(sizeof(wait_queue_head_t) * num_crtcs,
213 dev->_vblank_count = kmalloc(sizeof(atomic_t) * num_crtcs,
215 dev->vblank_refcount = kmalloc(sizeof(atomic_t) * num_crtcs,
217 dev->vblank_enabled = kmalloc(num_crtcs * sizeof(int),
218 M_DRM, M_WAITOK | M_ZERO);
219 dev->last_vblank = kmalloc(num_crtcs * sizeof(u32),
220 M_DRM, M_WAITOK | M_ZERO);
221 dev->last_vblank_wait = kmalloc(num_crtcs * sizeof(u32),
222 M_DRM, M_WAITOK | M_ZERO);
223 dev->vblank_inmodeset = kmalloc(num_crtcs * sizeof(int),
224 M_DRM, M_WAITOK | M_ZERO);
226 dev->_vblank_time = kmalloc(num_crtcs * DRM_VBLANKTIME_RBSIZE *
227 sizeof(struct timeval), M_DRM, M_WAITOK | M_ZERO);
228 if (!dev->_vblank_time)
231 DRM_INFO("Supports vblank timestamp caching Rev 1 (10.10.2010).\n");
233 /* Driver specific high-precision vblank timestamping supported? */
234 if (dev->driver->get_vblank_timestamp)
235 DRM_INFO("Driver supports precise vblank timestamp query.\n");
237 DRM_INFO("No driver support for vblank timestamp query.\n");
239 /* Zero per-crtc vblank stuff */
240 for (i = 0; i < num_crtcs; i++) {
241 init_waitqueue_head(&dev->vbl_queue[i]);
242 atomic_set(&dev->_vblank_count[i], 0);
243 atomic_set(&dev->vblank_refcount[i], 0);
246 dev->vblank_disable_allowed = 0;
250 drm_vblank_cleanup(dev);
253 EXPORT_SYMBOL(drm_vblank_init);
256 * Install IRQ handler.
258 * \param dev DRM device.
260 * Initializes the IRQ related data. Installs the handler, calling the driver
261 * \c irq_preinstall() and \c irq_postinstall() functions
262 * before and after the installation.
264 int drm_irq_install(struct drm_device *dev)
268 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
276 /* Driver must have been initialized */
277 if (!dev->dev_private) {
282 if (dev->irq_enabled) {
286 dev->irq_enabled = 1;
289 DRM_DEBUG("irq=%d\n", dev->irq);
291 /* Before installing handler */
292 if (dev->driver->irq_preinstall)
293 dev->driver->irq_preinstall(dev);
295 /* Install handler */
296 ret = bus_setup_intr(dev->dev, dev->irqr, INTR_MPSAFE,
297 dev->driver->irq_handler, dev, &dev->irqh, &dev->irq_lock);
301 dev->irq_enabled = 0;
306 /* After installing handler */
307 if (dev->driver->irq_postinstall)
308 ret = dev->driver->irq_postinstall(dev);
312 dev->irq_enabled = 0;
314 bus_teardown_intr(dev->dev, dev->irqr, dev->irqh);
319 EXPORT_SYMBOL(drm_irq_install);
322 * Uninstall the IRQ handler.
324 * \param dev DRM device.
326 * Calls the driver's \c irq_uninstall() function, and stops the irq.
328 int drm_irq_uninstall(struct drm_device *dev)
332 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
336 irq_enabled = dev->irq_enabled;
337 dev->irq_enabled = 0;
341 * Wake up any waiters so they don't hang.
343 if (dev->num_crtcs) {
344 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE);
345 for (i = 0; i < dev->num_crtcs; i++) {
346 DRM_WAKEUP(&dev->vbl_queue[i]);
347 dev->vblank_enabled[i] = 0;
348 dev->last_vblank[i] =
349 dev->driver->get_vblank_counter(dev, i);
351 lockmgr(&dev->vbl_lock, LK_RELEASE);
357 DRM_DEBUG("irq=%d\n", dev->irq);
359 if (dev->driver->irq_uninstall)
360 dev->driver->irq_uninstall(dev);
362 bus_teardown_intr(dev->dev, dev->irqr, dev->irqh);
366 EXPORT_SYMBOL(drm_irq_uninstall);
371 * \param inode device inode.
372 * \param file_priv DRM file private.
373 * \param cmd command.
374 * \param arg user argument, pointing to a drm_control structure.
375 * \return zero on success or a negative number on failure.
377 * Calls irq_install() or irq_uninstall() according to \p arg.
379 int drm_control(struct drm_device *dev, void *data,
380 struct drm_file *file_priv)
382 struct drm_control *ctl = data;
384 /* if we haven't irq we fallback for compatibility reasons -
385 * this used to be a separate function in drm_dma.h
390 case DRM_INST_HANDLER:
391 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
393 if (drm_core_check_feature(dev, DRIVER_MODESET))
395 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
396 ctl->irq != dev->irq)
398 return drm_irq_install(dev);
399 case DRM_UNINST_HANDLER:
400 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
402 if (drm_core_check_feature(dev, DRIVER_MODESET))
404 return drm_irq_uninstall(dev);
411 drm_calc_timestamping_constants(struct drm_crtc *crtc)
413 int64_t linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
416 /* Dot clock in Hz: */
417 dotclock = (uint64_t) crtc->hwmode.clock * 1000;
419 /* Fields of interlaced scanout modes are only halve a frame duration.
420 * Double the dotclock to get halve the frame-/line-/pixelduration.
422 if (crtc->hwmode.flags & DRM_MODE_FLAG_INTERLACE)
425 /* Valid dotclock? */
427 /* Convert scanline length in pixels and video dot clock to
428 * line duration, frame duration and pixel duration in
431 pixeldur_ns = (int64_t)1000000000 / dotclock;
432 linedur_ns = ((uint64_t)crtc->hwmode.crtc_htotal *
433 1000000000) / dotclock;
434 framedur_ns = (int64_t)crtc->hwmode.crtc_vtotal * linedur_ns;
436 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
439 crtc->pixeldur_ns = pixeldur_ns;
440 crtc->linedur_ns = linedur_ns;
441 crtc->framedur_ns = framedur_ns;
443 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
444 crtc->base.id, crtc->hwmode.crtc_htotal,
445 crtc->hwmode.crtc_vtotal, crtc->hwmode.crtc_vdisplay);
446 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
447 crtc->base.id, (int) dotclock/1000, (int) framedur_ns,
448 (int) linedur_ns, (int) pixeldur_ns);
452 * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
453 * drivers. Implements calculation of exact vblank timestamps from
454 * given drm_display_mode timings and current video scanout position
455 * of a crtc. This can be called from within get_vblank_timestamp()
456 * implementation of a kms driver to implement the actual timestamping.
458 * Should return timestamps conforming to the OML_sync_control OpenML
459 * extension specification. The timestamp corresponds to the end of
460 * the vblank interval, aka start of scanout of topmost-leftmost display
461 * pixel in the following video frame.
463 * Requires support for optional dev->driver->get_scanout_position()
464 * in kms driver, plus a bit of setup code to provide a drm_display_mode
465 * that corresponds to the true scanout timing.
467 * The current implementation only handles standard video modes. It
468 * returns as no operation if a doublescan or interlaced video mode is
469 * active. Higher level code is expected to handle this.
472 * @crtc: Which crtc's vblank timestamp to retrieve.
473 * @max_error: Desired maximum allowable error in timestamps (nanosecs).
474 * On return contains true maximum error of timestamp.
475 * @vblank_time: Pointer to struct timeval which should receive the timestamp.
476 * @flags: Flags to pass to driver:
478 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
479 * @refcrtc: drm_crtc* of crtc which defines scanout timing.
481 * Returns negative value on error, failure or if not supported in current
484 * -EINVAL - Invalid crtc.
485 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
486 * -ENOTSUPP - Function not supported in current display mode.
487 * -EIO - Failed, e.g., due to failed scanout position query.
489 * Returns or'ed positive status flags on success:
491 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
492 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
496 drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
497 int *max_error, struct timeval *vblank_time, unsigned flags,
498 struct drm_crtc *refcrtc)
500 struct timeval stime, raw_time;
501 struct drm_display_mode *mode;
502 int vbl_status, vtotal, vdisplay;
504 int64_t framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
507 if (crtc < 0 || crtc >= dev->num_crtcs) {
508 DRM_ERROR("Invalid crtc %d\n", crtc);
512 /* Scanout position query not supported? Should not happen. */
513 if (!dev->driver->get_scanout_position) {
514 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
518 mode = &refcrtc->hwmode;
519 vtotal = mode->crtc_vtotal;
520 vdisplay = mode->crtc_vdisplay;
522 /* Durations of frames, lines, pixels in nanoseconds. */
523 framedur_ns = refcrtc->framedur_ns;
524 linedur_ns = refcrtc->linedur_ns;
525 pixeldur_ns = refcrtc->pixeldur_ns;
527 /* If mode timing undefined, just return as no-op:
528 * Happens during initial modesetting of a crtc.
530 if (vtotal <= 0 || vdisplay <= 0 || framedur_ns == 0) {
531 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc);
535 /* Get current scanout position with system timestamp.
536 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
537 * if single query takes longer than max_error nanoseconds.
539 * This guarantees a tight bound on maximum error if
540 * code gets preempted or delayed for some reason.
542 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
543 /* Disable preemption to make it very likely to
544 * succeed in the first iteration.
548 /* Get system timestamp before query. */
549 getmicrouptime(&stime);
551 /* Get vertical and horizontal scanout pos. vpos, hpos. */
552 vbl_status = dev->driver->get_scanout_position(dev, crtc, &vpos, &hpos);
554 /* Get system timestamp after query. */
555 getmicrouptime(&raw_time);
559 /* Return as no-op if scanout query unsupported or failed. */
560 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
561 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
566 duration_ns = timeval_to_ns(&raw_time) - timeval_to_ns(&stime);
568 /* Accept result with < max_error nsecs timing uncertainty. */
569 if (duration_ns <= (int64_t) *max_error)
573 /* Noisy system timing? */
574 if (i == DRM_TIMESTAMP_MAXRETRIES) {
575 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
576 crtc, (int) duration_ns/1000, *max_error/1000, i);
579 /* Return upper bound of timestamp precision error. */
580 *max_error = (int) duration_ns;
582 /* Check if in vblank area:
583 * vpos is >=0 in video scanout area, but negative
584 * within vblank area, counting down the number of lines until
587 invbl = vbl_status & DRM_SCANOUTPOS_INVBL;
589 /* Convert scanout position into elapsed time at raw_time query
590 * since start of scanout at first display scanline. delta_ns
591 * can be negative if start of scanout hasn't happened yet.
593 delta_ns = (int64_t)vpos * linedur_ns + (int64_t)hpos * pixeldur_ns;
595 /* Is vpos outside nominal vblank area, but less than
596 * 1/100 of a frame height away from start of vblank?
597 * If so, assume this isn't a massively delayed vblank
598 * interrupt, but a vblank interrupt that fired a few
599 * microseconds before true start of vblank. Compensate
600 * by adding a full frame duration to the final timestamp.
601 * Happens, e.g., on ATI R500, R600.
603 * We only do this if DRM_CALLED_FROM_VBLIRQ.
605 if ((flags & DRM_CALLED_FROM_VBLIRQ) && !invbl &&
606 ((vdisplay - vpos) < vtotal / 100)) {
607 delta_ns = delta_ns - framedur_ns;
609 /* Signal this correction as "applied". */
613 /* Subtract time delta from raw timestamp to get final
614 * vblank_time timestamp for end of vblank.
616 *vblank_time = ns_to_timeval(timeval_to_ns(&raw_time) - delta_ns);
618 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %jd.%jd -> %jd.%jd [e %d us, %d rep]\n",
619 crtc, (int)vbl_status, hpos, vpos, (uintmax_t)raw_time.tv_sec,
620 (uintmax_t)raw_time.tv_usec, (uintmax_t)vblank_time->tv_sec,
621 (uintmax_t)vblank_time->tv_usec, (int)duration_ns/1000, i);
623 vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
625 vbl_status |= DRM_VBLANKTIME_INVBL;
630 static struct timeval get_drm_timestamp(void)
634 getmicrouptime(&now);
640 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
644 * @crtc: which crtc's vblank timestamp to retrieve
645 * @tvblank: Pointer to target struct timeval which should receive the timestamp
646 * @flags: Flags to pass to driver:
648 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
650 * Fetches the system timestamp corresponding to the time of the most recent
651 * vblank interval on specified crtc. May call into kms-driver to
652 * compute the timestamp with a high-precision GPU specific method.
654 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
655 * call, i.e., it isn't very precisely locked to the true vblank.
657 * Returns non-zero if timestamp is considered to be very precise.
659 u32 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
660 struct timeval *tvblank, unsigned flags)
664 /* Define requested maximum error on timestamps (nanoseconds). */
665 int max_error = (int) drm_timestamp_precision * 1000;
667 /* Query driver if possible and precision timestamping enabled. */
668 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
669 ret = dev->driver->get_vblank_timestamp(dev, crtc, &max_error,
675 /* GPU high precision timestamp query unsupported or failed.
676 * Return gettimeofday timestamp as best estimate.
684 * drm_vblank_count - retrieve "cooked" vblank counter value
686 * @crtc: which counter to retrieve
688 * Fetches the "cooked" vblank count value that represents the number of
689 * vblank events since the system was booted, including lost events due to
690 * modesetting activity.
692 u32 drm_vblank_count(struct drm_device *dev, int crtc)
694 return atomic_read(&dev->_vblank_count[crtc]);
698 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
699 * and the system timestamp corresponding to that vblank counter value.
702 * @crtc: which counter to retrieve
703 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
705 * Fetches the "cooked" vblank count value that represents the number of
706 * vblank events since the system was booted, including lost events due to
707 * modesetting activity. Returns corresponding system timestamp of the time
708 * of the vblank interval that corresponds to the current value vblank counter
711 u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
712 struct timeval *vblanktime)
716 /* Read timestamp from slot of _vblank_time ringbuffer
717 * that corresponds to current vblank count. Retry if
718 * count has incremented during readout. This works like
722 cur_vblank = atomic_read(&dev->_vblank_count[crtc]);
723 *vblanktime = vblanktimestamp(dev, crtc, cur_vblank);
725 } while (cur_vblank != atomic_read(&dev->_vblank_count[crtc]));
730 static void send_vblank_event(struct drm_device *dev,
731 struct drm_pending_vblank_event *e,
732 unsigned long seq, struct timeval *now)
734 KKASSERT(mutex_is_locked(&dev->event_lock));
735 e->event.sequence = seq;
736 e->event.tv_sec = now->tv_sec;
737 e->event.tv_usec = now->tv_usec;
739 list_add_tail(&e->base.link,
740 &e->base.file_priv->event_list);
741 drm_event_wakeup(&e->base);
743 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
749 * drm_send_vblank_event - helper to send vblank event after pageflip
751 * @crtc: CRTC in question
752 * @e: the event to send
754 * Updates sequence # and timestamp on event, and sends it to userspace.
755 * Caller must hold event lock.
757 void drm_send_vblank_event(struct drm_device *dev, int crtc,
758 struct drm_pending_vblank_event *e)
763 seq = drm_vblank_count_and_time(dev, crtc, &now);
767 now = get_drm_timestamp();
770 send_vblank_event(dev, e, seq, &now);
772 EXPORT_SYMBOL(drm_send_vblank_event);
775 * drm_update_vblank_count - update the master vblank counter
777 * @crtc: counter to update
779 * Call back into the driver to update the appropriate vblank counter
780 * (specified by @crtc). Deal with wraparound, if it occurred, and
781 * update the last read value so we can deal with wraparound on the next
784 * Only necessary when going from off->on, to account for frames we
785 * didn't get an interrupt for.
787 * Note: caller must hold dev->vbl_lock since this reads & writes
788 * device vblank fields.
790 static void drm_update_vblank_count(struct drm_device *dev, int crtc)
792 u32 cur_vblank, diff, tslot, rc;
793 struct timeval t_vblank;
796 * Interrupts were disabled prior to this call, so deal with counter
798 * NOTE! It's possible we lost a full dev->max_vblank_count events
799 * here if the register is small or we had vblank interrupts off for
802 * We repeat the hardware vblank counter & timestamp query until
803 * we get consistent results. This to prevent races between gpu
804 * updating its hardware counter while we are retrieving the
805 * corresponding vblank timestamp.
808 cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
809 rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0);
810 } while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc));
812 /* Deal with counter wrap */
813 diff = cur_vblank - dev->last_vblank[crtc];
814 if (cur_vblank < dev->last_vblank[crtc]) {
815 diff += dev->max_vblank_count;
817 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
818 crtc, dev->last_vblank[crtc], cur_vblank, diff);
821 DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
824 /* Reinitialize corresponding vblank timestamp if high-precision query
825 * available. Skip this step if query unsupported or failed. Will
826 * reinitialize delayed at next vblank interrupt in that case.
829 tslot = atomic_read(&dev->_vblank_count[crtc]) + diff;
830 vblanktimestamp(dev, crtc, tslot) = t_vblank;
833 atomic_add(diff, &dev->_vblank_count[crtc]);
837 * drm_vblank_get - get a reference count on vblank events
839 * @crtc: which CRTC to own
841 * Acquire a reference count on vblank events to avoid having them disabled
845 * Zero on success, nonzero on failure.
847 int drm_vblank_get(struct drm_device *dev, int crtc)
851 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE);
852 /* Going from 0->1 means we have to enable interrupts again */
853 if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1) {
854 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE);
855 if (!dev->vblank_enabled[crtc]) {
856 /* Enable vblank irqs under vblank_time_lock protection.
857 * All vblank count & timestamp updates are held off
858 * until we are done reinitializing master counter and
859 * timestamps. Filtercode in drm_handle_vblank() will
860 * prevent double-accounting of same vblank interval.
862 ret = -dev->driver->enable_vblank(dev, crtc);
863 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n",
866 atomic_dec(&dev->vblank_refcount[crtc]);
868 dev->vblank_enabled[crtc] = 1;
869 drm_update_vblank_count(dev, crtc);
872 lockmgr(&dev->vblank_time_lock, LK_RELEASE);
874 if (!dev->vblank_enabled[crtc]) {
875 atomic_dec(&dev->vblank_refcount[crtc]);
879 lockmgr(&dev->vbl_lock, LK_RELEASE);
885 * drm_vblank_put - give up ownership of vblank events
887 * @crtc: which counter to give up
889 * Release ownership of a given vblank counter, turning off interrupts
890 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
892 void drm_vblank_put(struct drm_device *dev, int crtc)
894 BUG_ON(atomic_read(&dev->vblank_refcount[crtc]) == 0);
896 /* Last user schedules interrupt disable */
897 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE);
898 if (atomic_dec_and_test(&dev->vblank_refcount[crtc]) &&
899 (drm_vblank_offdelay > 0)) {
900 mod_timer(&dev->vblank_disable_timer,
901 jiffies + ((drm_vblank_offdelay * DRM_HZ)/1000));
903 lockmgr(&dev->vblank_time_lock, LK_RELEASE);
905 EXPORT_SYMBOL(drm_vblank_put);
907 void drm_vblank_off(struct drm_device *dev, int crtc)
909 struct drm_pending_vblank_event *e, *t;
913 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE);
914 vblank_disable_and_save(dev, crtc);
915 lockmgr(&dev->event_lock, LK_EXCLUSIVE);
916 wakeup(&dev->_vblank_count[crtc]);
918 /* Send any queued vblank events, lest the natives grow disquiet */
919 seq = drm_vblank_count_and_time(dev, crtc, &now);
920 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
923 DRM_DEBUG("Sending premature vblank event on disable: \
924 wanted %d, current %d\n",
925 e->event.sequence, seq);
926 list_del(&e->base.link);
927 drm_vblank_put(dev, e->pipe);
928 send_vblank_event(dev, e, seq, &now);
931 lockmgr(&dev->event_lock, LK_RELEASE);
932 lockmgr(&dev->vbl_lock, LK_RELEASE);
936 * drm_vblank_pre_modeset - account for vblanks across mode sets
938 * @crtc: CRTC in question
939 * @post: post or pre mode set?
941 * Account for vblank events across mode setting events, which will likely
942 * reset the hardware frame counter.
944 void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
946 /* vblank is not initialized (IRQ not installed ?) */
950 * To avoid all the problems that might happen if interrupts
951 * were enabled/disabled around or between these calls, we just
952 * have the kernel take a reference on the CRTC (just once though
953 * to avoid corrupting the count if multiple, mismatch calls occur),
954 * so that interrupts remain enabled in the interim.
956 if (!dev->vblank_inmodeset[crtc]) {
957 dev->vblank_inmodeset[crtc] = 0x1;
958 if (drm_vblank_get(dev, crtc) == 0)
959 dev->vblank_inmodeset[crtc] |= 0x2;
963 void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
966 if (dev->vblank_inmodeset[crtc]) {
967 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE);
968 dev->vblank_disable_allowed = 1;
969 lockmgr(&dev->vbl_lock, LK_RELEASE);
971 if (dev->vblank_inmodeset[crtc] & 0x2)
972 drm_vblank_put(dev, crtc);
974 dev->vblank_inmodeset[crtc] = 0;
979 * drm_modeset_ctl - handle vblank event counter changes across mode switch
980 * @DRM_IOCTL_ARGS: standard ioctl arguments
982 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
983 * ioctls around modesetting so that any lost vblank events are accounted for.
985 * Generally the counter will reset across mode sets. If interrupts are
986 * enabled around this call, we don't have to do anything since the counter
987 * will have already been incremented.
989 int drm_modeset_ctl(struct drm_device *dev, void *data,
990 struct drm_file *file_priv)
992 struct drm_modeset_ctl *modeset = data;
996 /* If drm_vblank_init() hasn't been called yet, just no-op */
1000 crtc = modeset->crtc;
1001 if (crtc >= dev->num_crtcs) {
1006 switch (modeset->cmd) {
1007 case _DRM_PRE_MODESET:
1008 drm_vblank_pre_modeset(dev, crtc);
1010 case _DRM_POST_MODESET:
1011 drm_vblank_post_modeset(dev, crtc);
1023 drm_vblank_event_destroy(struct drm_pending_event *e)
1029 static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
1030 union drm_wait_vblank *vblwait,
1031 struct drm_file *file_priv)
1033 struct drm_pending_vblank_event *e;
1038 e = kmalloc(sizeof *e, M_DRM, M_WAITOK | M_ZERO);
1041 e->base.pid = curproc->p_pid;
1042 e->event.base.type = DRM_EVENT_VBLANK;
1043 e->event.base.length = sizeof e->event;
1044 e->event.user_data = vblwait->request.signal;
1045 e->base.event = &e->event.base;
1046 e->base.file_priv = file_priv;
1047 e->base.destroy = drm_vblank_event_destroy;
1049 lockmgr(&dev->event_lock, LK_EXCLUSIVE);
1051 if (file_priv->event_space < sizeof e->event) {
1056 file_priv->event_space -= sizeof e->event;
1057 seq = drm_vblank_count_and_time(dev, pipe, &now);
1059 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1060 (seq - vblwait->request.sequence) <= (1 << 23)) {
1061 vblwait->request.sequence = seq + 1;
1062 vblwait->reply.sequence = vblwait->request.sequence;
1065 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1066 vblwait->request.sequence, seq, pipe);
1068 e->event.sequence = vblwait->request.sequence;
1069 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1070 drm_vblank_put(dev, pipe);
1071 send_vblank_event(dev, e, seq, &now);
1072 vblwait->reply.sequence = seq;
1074 /* drm_handle_vblank_events will call drm_vblank_put */
1075 list_add_tail(&e->base.link, &dev->vblank_event_list);
1076 vblwait->reply.sequence = vblwait->request.sequence;
1079 lockmgr(&dev->event_lock, LK_RELEASE);
1084 lockmgr(&dev->event_lock, LK_RELEASE);
1086 drm_vblank_put(dev, pipe);
1093 * \param inode device inode.
1094 * \param file_priv DRM file private.
1095 * \param cmd command.
1096 * \param data user argument, pointing to a drm_wait_vblank structure.
1097 * \return zero on success or a negative number on failure.
1099 * This function enables the vblank interrupt on the pipe requested, then
1100 * sleeps waiting for the requested sequence number to occur, and drops
1101 * the vblank interrupt refcount afterwards. (vblank irq disable follows that
1102 * after a timeout with no further vblank waits scheduled).
1104 int drm_wait_vblank(struct drm_device *dev, void *data,
1105 struct drm_file *file_priv)
1107 union drm_wait_vblank *vblwait = data;
1109 unsigned int flags, seq, crtc, high_crtc;
1111 if (/*(!drm_dev_to_irq(dev)) || */(!dev->irq_enabled))
1114 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1117 if (vblwait->request.type &
1118 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1119 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1120 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1121 vblwait->request.type,
1122 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1123 _DRM_VBLANK_HIGH_CRTC_MASK));
1127 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1128 high_crtc = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1130 crtc = high_crtc >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1132 crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1133 if (crtc >= dev->num_crtcs)
1136 ret = drm_vblank_get(dev, crtc);
1138 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1141 seq = drm_vblank_count(dev, crtc);
1143 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1144 case _DRM_VBLANK_RELATIVE:
1145 vblwait->request.sequence += seq;
1146 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1147 case _DRM_VBLANK_ABSOLUTE:
1154 if (flags & _DRM_VBLANK_EVENT) {
1155 /* must hold on to the vblank ref until the event fires
1156 * drm_vblank_put will be called asynchronously
1158 return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
1161 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1162 (seq - vblwait->request.sequence) <= (1<<23)) {
1163 vblwait->request.sequence = seq + 1;
1166 dev->last_vblank_wait[crtc] = vblwait->request.sequence;
1167 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE);
1168 while (((drm_vblank_count(dev, crtc) - vblwait->request.sequence) >
1169 (1 << 23)) && dev->irq_enabled) {
1171 * The wakeups from the drm_irq_uninstall() and
1172 * drm_vblank_off() may be lost there since vbl_lock
1173 * is not held. Then, the timeout will wake us; the 3
1174 * seconds delay should not be a problem for
1175 * application when crtc is disabled or irq
1176 * uninstalled anyway.
1178 ret = lksleep(&dev->_vblank_count[crtc], &dev->vblank_time_lock,
1179 PCATCH, "drmvbl", 3 * hz);
1183 lockmgr(&dev->vblank_time_lock, LK_RELEASE);
1188 reply_seq = drm_vblank_count_and_time(dev, crtc, &now);
1189 vblwait->reply.sequence = reply_seq;
1190 vblwait->reply.tval_sec = now.tv_sec;
1191 vblwait->reply.tval_usec = now.tv_usec;
1195 drm_vblank_put(dev, crtc);
1199 void drm_handle_vblank_events(struct drm_device *dev, int crtc)
1201 struct drm_pending_vblank_event *e, *t;
1205 seq = drm_vblank_count_and_time(dev, crtc, &now);
1207 lockmgr(&dev->event_lock, LK_EXCLUSIVE);
1209 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1210 if (e->pipe != crtc)
1212 if ((seq - e->event.sequence) > (1<<23))
1215 DRM_DEBUG("vblank event on %d, current %d\n",
1216 e->event.sequence, seq);
1218 list_del(&e->base.link);
1219 drm_vblank_put(dev, e->pipe);
1220 send_vblank_event(dev, e, seq, &now);
1223 lockmgr(&dev->event_lock, LK_RELEASE);
1227 * drm_handle_vblank - handle a vblank event
1229 * @crtc: where this event occurred
1231 * Drivers should call this routine in their vblank interrupt handlers to
1232 * update the vblank counter and send any signals that may be pending.
1234 bool drm_handle_vblank(struct drm_device *dev, int crtc)
1238 struct timeval tvblank;
1240 if (!dev->num_crtcs)
1243 /* Need timestamp lock to prevent concurrent execution with
1244 * vblank enable/disable, as this would cause inconsistent
1245 * or corrupted timestamps and vblank counts.
1247 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE);
1249 /* Vblank irq handling disabled. Nothing to do. */
1250 if (!dev->vblank_enabled[crtc]) {
1251 lockmgr(&dev->vblank_time_lock, LK_RELEASE);
1255 /* Fetch corresponding timestamp for this vblank interval from
1256 * driver and store it in proper slot of timestamp ringbuffer.
1259 /* Get current timestamp and count. */
1260 vblcount = atomic_read(&dev->_vblank_count[crtc]);
1261 drm_get_last_vbltimestamp(dev, crtc, &tvblank, DRM_CALLED_FROM_VBLIRQ);
1263 /* Compute time difference to timestamp of last vblank */
1264 diff_ns = timeval_to_ns(&tvblank) -
1265 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
1267 /* Update vblank timestamp and count if at least
1268 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1269 * difference between last stored timestamp and current
1270 * timestamp. A smaller difference means basically
1271 * identical timestamps. Happens if this vblank has
1272 * been already processed and this is a redundant call,
1273 * e.g., due to spurious vblank interrupts. We need to
1274 * ignore those for accounting.
1276 if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) {
1277 /* Store new timestamp in ringbuffer. */
1278 vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
1280 /* Increment cooked vblank count. This also atomically commits
1281 * the timestamp computed above.
1283 atomic_inc(&dev->_vblank_count[crtc]);
1285 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1286 crtc, (int) diff_ns);
1289 wakeup(&dev->_vblank_count[crtc]);
1290 drm_handle_vblank_events(dev, crtc);
1292 lockmgr(&dev->vblank_time_lock, LK_RELEASE);