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)
203 setup_timer(&dev->vblank_disable_timer, vblank_disable_fn,
205 lockinit(&dev->vblank_time_lock, "drmvtl", 0, LK_CANRECURSE);
207 dev->num_crtcs = num_crtcs;
209 dev->vbl_queue = kmalloc(sizeof(wait_queue_head_t) * num_crtcs,
212 dev->_vblank_count = kmalloc(sizeof(atomic_t) * num_crtcs,
214 dev->vblank_refcount = kmalloc(sizeof(atomic_t) * num_crtcs,
216 dev->vblank_enabled = kmalloc(num_crtcs * sizeof(int),
217 M_DRM, M_WAITOK | M_ZERO);
218 dev->last_vblank = kmalloc(num_crtcs * sizeof(u32),
219 M_DRM, M_WAITOK | M_ZERO);
220 dev->last_vblank_wait = kmalloc(num_crtcs * sizeof(u32),
221 M_DRM, M_WAITOK | M_ZERO);
222 dev->vblank_inmodeset = kmalloc(num_crtcs * sizeof(int),
223 M_DRM, M_WAITOK | M_ZERO);
224 dev->_vblank_time = kmalloc(num_crtcs * DRM_VBLANKTIME_RBSIZE *
225 sizeof(struct timeval), M_DRM, M_WAITOK | M_ZERO);
226 DRM_INFO("Supports vblank timestamp caching Rev 1 (10.10.2010).\n");
228 /* Driver specific high-precision vblank timestamping supported? */
229 if (dev->driver->get_vblank_timestamp)
230 DRM_INFO("Driver supports precise vblank timestamp query.\n");
232 DRM_INFO("No driver support for vblank timestamp query.\n");
234 /* Zero per-crtc vblank stuff */
235 for (i = 0; i < num_crtcs; i++) {
236 init_waitqueue_head(&dev->vbl_queue[i]);
237 atomic_set(&dev->_vblank_count[i], 0);
238 atomic_set(&dev->vblank_refcount[i], 0);
241 dev->vblank_disable_allowed = 0;
244 EXPORT_SYMBOL(drm_vblank_init);
247 * Install IRQ handler.
249 * \param dev DRM device.
251 * Initializes the IRQ related data. Installs the handler, calling the driver
252 * \c irq_preinstall() and \c irq_postinstall() functions
253 * before and after the installation.
255 int drm_irq_install(struct drm_device *dev)
259 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
267 /* Driver must have been initialized */
268 if (!dev->dev_private) {
273 if (dev->irq_enabled) {
277 dev->irq_enabled = 1;
280 DRM_DEBUG("irq=%d\n", dev->irq);
282 /* Before installing handler */
283 if (dev->driver->irq_preinstall)
284 dev->driver->irq_preinstall(dev);
286 /* Install handler */
287 ret = bus_setup_intr(dev->dev, dev->irqr, INTR_MPSAFE,
288 dev->driver->irq_handler, dev, &dev->irqh, &dev->irq_lock);
292 dev->irq_enabled = 0;
297 /* After installing handler */
298 if (dev->driver->irq_postinstall)
299 ret = dev->driver->irq_postinstall(dev);
303 dev->irq_enabled = 0;
305 bus_teardown_intr(dev->dev, dev->irqr, dev->irqh);
310 EXPORT_SYMBOL(drm_irq_install);
313 * Uninstall the IRQ handler.
315 * \param dev DRM device.
317 * Calls the driver's \c irq_uninstall() function, and stops the irq.
319 int drm_irq_uninstall(struct drm_device *dev)
323 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
327 irq_enabled = dev->irq_enabled;
328 dev->irq_enabled = 0;
332 * Wake up any waiters so they don't hang.
334 if (dev->num_crtcs) {
335 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE);
336 for (i = 0; i < dev->num_crtcs; i++) {
337 DRM_WAKEUP(&dev->vbl_queue[i]);
338 dev->vblank_enabled[i] = 0;
339 dev->last_vblank[i] =
340 dev->driver->get_vblank_counter(dev, i);
342 lockmgr(&dev->vbl_lock, LK_RELEASE);
348 DRM_DEBUG("irq=%d\n", dev->irq);
350 if (dev->driver->irq_uninstall)
351 dev->driver->irq_uninstall(dev);
353 bus_teardown_intr(dev->dev, dev->irqr, dev->irqh);
357 EXPORT_SYMBOL(drm_irq_uninstall);
362 * \param inode device inode.
363 * \param file_priv DRM file private.
364 * \param cmd command.
365 * \param arg user argument, pointing to a drm_control structure.
366 * \return zero on success or a negative number on failure.
368 * Calls irq_install() or irq_uninstall() according to \p arg.
370 int drm_control(struct drm_device *dev, void *data,
371 struct drm_file *file_priv)
373 struct drm_control *ctl = data;
375 /* if we haven't irq we fallback for compatibility reasons -
376 * this used to be a separate function in drm_dma.h
381 case DRM_INST_HANDLER:
382 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
384 if (drm_core_check_feature(dev, DRIVER_MODESET))
386 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
387 ctl->irq != dev->irq)
389 return drm_irq_install(dev);
390 case DRM_UNINST_HANDLER:
391 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
393 if (drm_core_check_feature(dev, DRIVER_MODESET))
395 return drm_irq_uninstall(dev);
402 drm_calc_timestamping_constants(struct drm_crtc *crtc)
404 int64_t linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
407 /* Dot clock in Hz: */
408 dotclock = (uint64_t) crtc->hwmode.clock * 1000;
410 /* Fields of interlaced scanout modes are only halve a frame duration.
411 * Double the dotclock to get halve the frame-/line-/pixelduration.
413 if (crtc->hwmode.flags & DRM_MODE_FLAG_INTERLACE)
416 /* Valid dotclock? */
418 /* Convert scanline length in pixels and video dot clock to
419 * line duration, frame duration and pixel duration in
422 pixeldur_ns = (int64_t)1000000000 / dotclock;
423 linedur_ns = ((uint64_t)crtc->hwmode.crtc_htotal *
424 1000000000) / dotclock;
425 framedur_ns = (int64_t)crtc->hwmode.crtc_vtotal * linedur_ns;
427 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
430 crtc->pixeldur_ns = pixeldur_ns;
431 crtc->linedur_ns = linedur_ns;
432 crtc->framedur_ns = framedur_ns;
434 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
435 crtc->base.id, crtc->hwmode.crtc_htotal,
436 crtc->hwmode.crtc_vtotal, crtc->hwmode.crtc_vdisplay);
437 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
438 crtc->base.id, (int) dotclock/1000, (int) framedur_ns,
439 (int) linedur_ns, (int) pixeldur_ns);
443 * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
444 * drivers. Implements calculation of exact vblank timestamps from
445 * given drm_display_mode timings and current video scanout position
446 * of a crtc. This can be called from within get_vblank_timestamp()
447 * implementation of a kms driver to implement the actual timestamping.
449 * Should return timestamps conforming to the OML_sync_control OpenML
450 * extension specification. The timestamp corresponds to the end of
451 * the vblank interval, aka start of scanout of topmost-leftmost display
452 * pixel in the following video frame.
454 * Requires support for optional dev->driver->get_scanout_position()
455 * in kms driver, plus a bit of setup code to provide a drm_display_mode
456 * that corresponds to the true scanout timing.
458 * The current implementation only handles standard video modes. It
459 * returns as no operation if a doublescan or interlaced video mode is
460 * active. Higher level code is expected to handle this.
463 * @crtc: Which crtc's vblank timestamp to retrieve.
464 * @max_error: Desired maximum allowable error in timestamps (nanosecs).
465 * On return contains true maximum error of timestamp.
466 * @vblank_time: Pointer to struct timeval which should receive the timestamp.
467 * @flags: Flags to pass to driver:
469 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
470 * @refcrtc: drm_crtc* of crtc which defines scanout timing.
472 * Returns negative value on error, failure or if not supported in current
475 * -EINVAL - Invalid crtc.
476 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
477 * -ENOTSUPP - Function not supported in current display mode.
478 * -EIO - Failed, e.g., due to failed scanout position query.
480 * Returns or'ed positive status flags on success:
482 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
483 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
487 drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
488 int *max_error, struct timeval *vblank_time, unsigned flags,
489 struct drm_crtc *refcrtc)
491 struct timeval stime, raw_time;
492 struct drm_display_mode *mode;
493 int vbl_status, vtotal, vdisplay;
495 int64_t framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
498 if (crtc < 0 || crtc >= dev->num_crtcs) {
499 DRM_ERROR("Invalid crtc %d\n", crtc);
503 /* Scanout position query not supported? Should not happen. */
504 if (!dev->driver->get_scanout_position) {
505 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
509 mode = &refcrtc->hwmode;
510 vtotal = mode->crtc_vtotal;
511 vdisplay = mode->crtc_vdisplay;
513 /* Durations of frames, lines, pixels in nanoseconds. */
514 framedur_ns = refcrtc->framedur_ns;
515 linedur_ns = refcrtc->linedur_ns;
516 pixeldur_ns = refcrtc->pixeldur_ns;
518 /* If mode timing undefined, just return as no-op:
519 * Happens during initial modesetting of a crtc.
521 if (vtotal <= 0 || vdisplay <= 0 || framedur_ns == 0) {
522 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc);
526 /* Get current scanout position with system timestamp.
527 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
528 * if single query takes longer than max_error nanoseconds.
530 * This guarantees a tight bound on maximum error if
531 * code gets preempted or delayed for some reason.
533 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
534 /* Disable preemption to make it very likely to
535 * succeed in the first iteration.
539 /* Get system timestamp before query. */
540 getmicrouptime(&stime);
542 /* Get vertical and horizontal scanout pos. vpos, hpos. */
543 vbl_status = dev->driver->get_scanout_position(dev, crtc, &vpos, &hpos);
545 /* Get system timestamp after query. */
546 getmicrouptime(&raw_time);
550 /* Return as no-op if scanout query unsupported or failed. */
551 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
552 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
557 duration_ns = timeval_to_ns(&raw_time) - timeval_to_ns(&stime);
559 /* Accept result with < max_error nsecs timing uncertainty. */
560 if (duration_ns <= (int64_t) *max_error)
564 /* Noisy system timing? */
565 if (i == DRM_TIMESTAMP_MAXRETRIES) {
566 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
567 crtc, (int) duration_ns/1000, *max_error/1000, i);
570 /* Return upper bound of timestamp precision error. */
571 *max_error = (int) duration_ns;
573 /* Check if in vblank area:
574 * vpos is >=0 in video scanout area, but negative
575 * within vblank area, counting down the number of lines until
578 invbl = vbl_status & DRM_SCANOUTPOS_INVBL;
580 /* Convert scanout position into elapsed time at raw_time query
581 * since start of scanout at first display scanline. delta_ns
582 * can be negative if start of scanout hasn't happened yet.
584 delta_ns = (int64_t)vpos * linedur_ns + (int64_t)hpos * pixeldur_ns;
586 /* Is vpos outside nominal vblank area, but less than
587 * 1/100 of a frame height away from start of vblank?
588 * If so, assume this isn't a massively delayed vblank
589 * interrupt, but a vblank interrupt that fired a few
590 * microseconds before true start of vblank. Compensate
591 * by adding a full frame duration to the final timestamp.
592 * Happens, e.g., on ATI R500, R600.
594 * We only do this if DRM_CALLED_FROM_VBLIRQ.
596 if ((flags & DRM_CALLED_FROM_VBLIRQ) && !invbl &&
597 ((vdisplay - vpos) < vtotal / 100)) {
598 delta_ns = delta_ns - framedur_ns;
600 /* Signal this correction as "applied". */
604 /* Subtract time delta from raw timestamp to get final
605 * vblank_time timestamp for end of vblank.
607 *vblank_time = ns_to_timeval(timeval_to_ns(&raw_time) - delta_ns);
609 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %jd.%jd -> %jd.%jd [e %d us, %d rep]\n",
610 crtc, (int)vbl_status, hpos, vpos, (uintmax_t)raw_time.tv_sec,
611 (uintmax_t)raw_time.tv_usec, (uintmax_t)vblank_time->tv_sec,
612 (uintmax_t)vblank_time->tv_usec, (int)duration_ns/1000, i);
614 vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
616 vbl_status |= DRM_VBLANKTIME_INVBL;
621 static struct timeval get_drm_timestamp(void)
625 getmicrouptime(&now);
631 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
635 * @crtc: which crtc's vblank timestamp to retrieve
636 * @tvblank: Pointer to target struct timeval which should receive the timestamp
637 * @flags: Flags to pass to driver:
639 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
641 * Fetches the system timestamp corresponding to the time of the most recent
642 * vblank interval on specified crtc. May call into kms-driver to
643 * compute the timestamp with a high-precision GPU specific method.
645 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
646 * call, i.e., it isn't very precisely locked to the true vblank.
648 * Returns non-zero if timestamp is considered to be very precise.
650 u32 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
651 struct timeval *tvblank, unsigned flags)
655 /* Define requested maximum error on timestamps (nanoseconds). */
656 int max_error = (int) drm_timestamp_precision * 1000;
658 /* Query driver if possible and precision timestamping enabled. */
659 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
660 ret = dev->driver->get_vblank_timestamp(dev, crtc, &max_error,
666 /* GPU high precision timestamp query unsupported or failed.
667 * Return gettimeofday timestamp as best estimate.
675 * drm_vblank_count - retrieve "cooked" vblank counter value
677 * @crtc: which counter to retrieve
679 * Fetches the "cooked" vblank count value that represents the number of
680 * vblank events since the system was booted, including lost events due to
681 * modesetting activity.
683 u32 drm_vblank_count(struct drm_device *dev, int crtc)
685 return atomic_read(&dev->_vblank_count[crtc]);
689 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
690 * and the system timestamp corresponding to that vblank counter value.
693 * @crtc: which counter to retrieve
694 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
696 * Fetches the "cooked" vblank count value that represents the number of
697 * vblank events since the system was booted, including lost events due to
698 * modesetting activity. Returns corresponding system timestamp of the time
699 * of the vblank interval that corresponds to the current value vblank counter
702 u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
703 struct timeval *vblanktime)
707 /* Read timestamp from slot of _vblank_time ringbuffer
708 * that corresponds to current vblank count. Retry if
709 * count has incremented during readout. This works like
713 cur_vblank = atomic_read(&dev->_vblank_count[crtc]);
714 *vblanktime = vblanktimestamp(dev, crtc, cur_vblank);
716 } while (cur_vblank != atomic_read(&dev->_vblank_count[crtc]));
721 static void send_vblank_event(struct drm_device *dev,
722 struct drm_pending_vblank_event *e,
723 unsigned long seq, struct timeval *now)
725 KKASSERT(mutex_is_locked(&dev->event_lock));
726 e->event.sequence = seq;
727 e->event.tv_sec = now->tv_sec;
728 e->event.tv_usec = now->tv_usec;
730 list_add_tail(&e->base.link,
731 &e->base.file_priv->event_list);
732 drm_event_wakeup(&e->base);
734 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
740 * drm_send_vblank_event - helper to send vblank event after pageflip
742 * @crtc: CRTC in question
743 * @e: the event to send
745 * Updates sequence # and timestamp on event, and sends it to userspace.
746 * Caller must hold event lock.
748 void drm_send_vblank_event(struct drm_device *dev, int crtc,
749 struct drm_pending_vblank_event *e)
754 seq = drm_vblank_count_and_time(dev, crtc, &now);
758 now = get_drm_timestamp();
761 send_vblank_event(dev, e, seq, &now);
763 EXPORT_SYMBOL(drm_send_vblank_event);
766 * drm_update_vblank_count - update the master vblank counter
768 * @crtc: counter to update
770 * Call back into the driver to update the appropriate vblank counter
771 * (specified by @crtc). Deal with wraparound, if it occurred, and
772 * update the last read value so we can deal with wraparound on the next
775 * Only necessary when going from off->on, to account for frames we
776 * didn't get an interrupt for.
778 * Note: caller must hold dev->vbl_lock since this reads & writes
779 * device vblank fields.
781 static void drm_update_vblank_count(struct drm_device *dev, int crtc)
783 u32 cur_vblank, diff, tslot, rc;
784 struct timeval t_vblank;
787 * Interrupts were disabled prior to this call, so deal with counter
789 * NOTE! It's possible we lost a full dev->max_vblank_count events
790 * here if the register is small or we had vblank interrupts off for
793 * We repeat the hardware vblank counter & timestamp query until
794 * we get consistent results. This to prevent races between gpu
795 * updating its hardware counter while we are retrieving the
796 * corresponding vblank timestamp.
799 cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
800 rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0);
801 } while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc));
803 /* Deal with counter wrap */
804 diff = cur_vblank - dev->last_vblank[crtc];
805 if (cur_vblank < dev->last_vblank[crtc]) {
806 diff += dev->max_vblank_count;
808 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
809 crtc, dev->last_vblank[crtc], cur_vblank, diff);
812 DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
815 /* Reinitialize corresponding vblank timestamp if high-precision query
816 * available. Skip this step if query unsupported or failed. Will
817 * reinitialize delayed at next vblank interrupt in that case.
820 tslot = atomic_read(&dev->_vblank_count[crtc]) + diff;
821 vblanktimestamp(dev, crtc, tslot) = t_vblank;
824 atomic_add(diff, &dev->_vblank_count[crtc]);
828 * drm_vblank_get - get a reference count on vblank events
830 * @crtc: which CRTC to own
832 * Acquire a reference count on vblank events to avoid having them disabled
836 * Zero on success, nonzero on failure.
838 int drm_vblank_get(struct drm_device *dev, int crtc)
842 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE);
843 /* Going from 0->1 means we have to enable interrupts again */
844 if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1) {
845 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE);
846 if (!dev->vblank_enabled[crtc]) {
847 /* Enable vblank irqs under vblank_time_lock protection.
848 * All vblank count & timestamp updates are held off
849 * until we are done reinitializing master counter and
850 * timestamps. Filtercode in drm_handle_vblank() will
851 * prevent double-accounting of same vblank interval.
853 ret = -dev->driver->enable_vblank(dev, crtc);
854 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n",
857 atomic_dec(&dev->vblank_refcount[crtc]);
859 dev->vblank_enabled[crtc] = 1;
860 drm_update_vblank_count(dev, crtc);
863 lockmgr(&dev->vblank_time_lock, LK_RELEASE);
865 if (!dev->vblank_enabled[crtc]) {
866 atomic_dec(&dev->vblank_refcount[crtc]);
870 lockmgr(&dev->vbl_lock, LK_RELEASE);
876 * drm_vblank_put - give up ownership of vblank events
878 * @crtc: which counter to give up
880 * Release ownership of a given vblank counter, turning off interrupts
881 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
883 void drm_vblank_put(struct drm_device *dev, int crtc)
885 BUG_ON(atomic_read(&dev->vblank_refcount[crtc]) == 0);
887 /* Last user schedules interrupt disable */
888 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE);
889 if (atomic_dec_and_test(&dev->vblank_refcount[crtc]) &&
890 (drm_vblank_offdelay > 0)) {
891 mod_timer(&dev->vblank_disable_timer,
892 jiffies + ((drm_vblank_offdelay * DRM_HZ)/1000));
894 lockmgr(&dev->vblank_time_lock, LK_RELEASE);
896 EXPORT_SYMBOL(drm_vblank_put);
898 void drm_vblank_off(struct drm_device *dev, int crtc)
900 struct drm_pending_vblank_event *e, *t;
904 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE);
905 vblank_disable_and_save(dev, crtc);
906 lockmgr(&dev->event_lock, LK_EXCLUSIVE);
907 wakeup(&dev->_vblank_count[crtc]);
909 /* Send any queued vblank events, lest the natives grow disquiet */
910 seq = drm_vblank_count_and_time(dev, crtc, &now);
911 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
914 DRM_DEBUG("Sending premature vblank event on disable: \
915 wanted %d, current %d\n",
916 e->event.sequence, seq);
917 list_del(&e->base.link);
918 drm_vblank_put(dev, e->pipe);
919 send_vblank_event(dev, e, seq, &now);
922 lockmgr(&dev->event_lock, LK_RELEASE);
923 lockmgr(&dev->vbl_lock, LK_RELEASE);
927 * drm_vblank_pre_modeset - account for vblanks across mode sets
929 * @crtc: CRTC in question
930 * @post: post or pre mode set?
932 * Account for vblank events across mode setting events, which will likely
933 * reset the hardware frame counter.
935 void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
937 /* vblank is not initialized (IRQ not installed ?) */
941 * To avoid all the problems that might happen if interrupts
942 * were enabled/disabled around or between these calls, we just
943 * have the kernel take a reference on the CRTC (just once though
944 * to avoid corrupting the count if multiple, mismatch calls occur),
945 * so that interrupts remain enabled in the interim.
947 if (!dev->vblank_inmodeset[crtc]) {
948 dev->vblank_inmodeset[crtc] = 0x1;
949 if (drm_vblank_get(dev, crtc) == 0)
950 dev->vblank_inmodeset[crtc] |= 0x2;
954 void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
957 if (dev->vblank_inmodeset[crtc]) {
958 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE);
959 dev->vblank_disable_allowed = 1;
960 lockmgr(&dev->vbl_lock, LK_RELEASE);
962 if (dev->vblank_inmodeset[crtc] & 0x2)
963 drm_vblank_put(dev, crtc);
965 dev->vblank_inmodeset[crtc] = 0;
970 * drm_modeset_ctl - handle vblank event counter changes across mode switch
971 * @DRM_IOCTL_ARGS: standard ioctl arguments
973 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
974 * ioctls around modesetting so that any lost vblank events are accounted for.
976 * Generally the counter will reset across mode sets. If interrupts are
977 * enabled around this call, we don't have to do anything since the counter
978 * will have already been incremented.
980 int drm_modeset_ctl(struct drm_device *dev, void *data,
981 struct drm_file *file_priv)
983 struct drm_modeset_ctl *modeset = data;
987 /* If drm_vblank_init() hasn't been called yet, just no-op */
991 crtc = modeset->crtc;
992 if (crtc >= dev->num_crtcs) {
997 switch (modeset->cmd) {
998 case _DRM_PRE_MODESET:
999 drm_vblank_pre_modeset(dev, crtc);
1001 case _DRM_POST_MODESET:
1002 drm_vblank_post_modeset(dev, crtc);
1014 drm_vblank_event_destroy(struct drm_pending_event *e)
1020 static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
1021 union drm_wait_vblank *vblwait,
1022 struct drm_file *file_priv)
1024 struct drm_pending_vblank_event *e;
1029 e = kmalloc(sizeof *e, M_DRM, M_WAITOK | M_ZERO);
1032 e->base.pid = curproc->p_pid;
1033 e->event.base.type = DRM_EVENT_VBLANK;
1034 e->event.base.length = sizeof e->event;
1035 e->event.user_data = vblwait->request.signal;
1036 e->base.event = &e->event.base;
1037 e->base.file_priv = file_priv;
1038 e->base.destroy = drm_vblank_event_destroy;
1040 lockmgr(&dev->event_lock, LK_EXCLUSIVE);
1042 if (file_priv->event_space < sizeof e->event) {
1047 file_priv->event_space -= sizeof e->event;
1048 seq = drm_vblank_count_and_time(dev, pipe, &now);
1050 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1051 (seq - vblwait->request.sequence) <= (1 << 23)) {
1052 vblwait->request.sequence = seq + 1;
1053 vblwait->reply.sequence = vblwait->request.sequence;
1056 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1057 vblwait->request.sequence, seq, pipe);
1059 e->event.sequence = vblwait->request.sequence;
1060 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1061 drm_vblank_put(dev, pipe);
1062 send_vblank_event(dev, e, seq, &now);
1063 vblwait->reply.sequence = seq;
1065 /* drm_handle_vblank_events will call drm_vblank_put */
1066 list_add_tail(&e->base.link, &dev->vblank_event_list);
1067 vblwait->reply.sequence = vblwait->request.sequence;
1070 lockmgr(&dev->event_lock, LK_RELEASE);
1075 lockmgr(&dev->event_lock, LK_RELEASE);
1077 drm_vblank_put(dev, pipe);
1084 * \param inode device inode.
1085 * \param file_priv DRM file private.
1086 * \param cmd command.
1087 * \param data user argument, pointing to a drm_wait_vblank structure.
1088 * \return zero on success or a negative number on failure.
1090 * This function enables the vblank interrupt on the pipe requested, then
1091 * sleeps waiting for the requested sequence number to occur, and drops
1092 * the vblank interrupt refcount afterwards. (vblank irq disable follows that
1093 * after a timeout with no further vblank waits scheduled).
1095 int drm_wait_vblank(struct drm_device *dev, void *data,
1096 struct drm_file *file_priv)
1098 union drm_wait_vblank *vblwait = data;
1100 unsigned int flags, seq, crtc, high_crtc;
1102 if (/*(!drm_dev_to_irq(dev)) || */(!dev->irq_enabled))
1105 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1108 if (vblwait->request.type &
1109 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1110 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1111 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1112 vblwait->request.type,
1113 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1114 _DRM_VBLANK_HIGH_CRTC_MASK));
1118 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1119 high_crtc = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1121 crtc = high_crtc >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1123 crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1124 if (crtc >= dev->num_crtcs)
1127 ret = drm_vblank_get(dev, crtc);
1129 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1132 seq = drm_vblank_count(dev, crtc);
1134 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1135 case _DRM_VBLANK_RELATIVE:
1136 vblwait->request.sequence += seq;
1137 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1138 case _DRM_VBLANK_ABSOLUTE:
1145 if (flags & _DRM_VBLANK_EVENT) {
1146 /* must hold on to the vblank ref until the event fires
1147 * drm_vblank_put will be called asynchronously
1149 return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
1152 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1153 (seq - vblwait->request.sequence) <= (1<<23)) {
1154 vblwait->request.sequence = seq + 1;
1157 dev->last_vblank_wait[crtc] = vblwait->request.sequence;
1158 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE);
1159 while (((drm_vblank_count(dev, crtc) - vblwait->request.sequence) >
1160 (1 << 23)) && dev->irq_enabled) {
1162 * The wakeups from the drm_irq_uninstall() and
1163 * drm_vblank_off() may be lost there since vbl_lock
1164 * is not held. Then, the timeout will wake us; the 3
1165 * seconds delay should not be a problem for
1166 * application when crtc is disabled or irq
1167 * uninstalled anyway.
1169 ret = lksleep(&dev->_vblank_count[crtc], &dev->vblank_time_lock,
1170 PCATCH, "drmvbl", 3 * hz);
1174 lockmgr(&dev->vblank_time_lock, LK_RELEASE);
1179 reply_seq = drm_vblank_count_and_time(dev, crtc, &now);
1180 vblwait->reply.sequence = reply_seq;
1181 vblwait->reply.tval_sec = now.tv_sec;
1182 vblwait->reply.tval_usec = now.tv_usec;
1186 drm_vblank_put(dev, crtc);
1190 void drm_handle_vblank_events(struct drm_device *dev, int crtc)
1192 struct drm_pending_vblank_event *e, *t;
1196 seq = drm_vblank_count_and_time(dev, crtc, &now);
1198 lockmgr(&dev->event_lock, LK_EXCLUSIVE);
1200 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1201 if (e->pipe != crtc)
1203 if ((seq - e->event.sequence) > (1<<23))
1206 DRM_DEBUG("vblank event on %d, current %d\n",
1207 e->event.sequence, seq);
1209 list_del(&e->base.link);
1210 drm_vblank_put(dev, e->pipe);
1211 send_vblank_event(dev, e, seq, &now);
1214 lockmgr(&dev->event_lock, LK_RELEASE);
1218 * drm_handle_vblank - handle a vblank event
1220 * @crtc: where this event occurred
1222 * Drivers should call this routine in their vblank interrupt handlers to
1223 * update the vblank counter and send any signals that may be pending.
1225 bool drm_handle_vblank(struct drm_device *dev, int crtc)
1229 struct timeval tvblank;
1231 if (!dev->num_crtcs)
1234 /* Need timestamp lock to prevent concurrent execution with
1235 * vblank enable/disable, as this would cause inconsistent
1236 * or corrupted timestamps and vblank counts.
1238 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE);
1240 /* Vblank irq handling disabled. Nothing to do. */
1241 if (!dev->vblank_enabled[crtc]) {
1242 lockmgr(&dev->vblank_time_lock, LK_RELEASE);
1246 /* Fetch corresponding timestamp for this vblank interval from
1247 * driver and store it in proper slot of timestamp ringbuffer.
1250 /* Get current timestamp and count. */
1251 vblcount = atomic_read(&dev->_vblank_count[crtc]);
1252 drm_get_last_vbltimestamp(dev, crtc, &tvblank, DRM_CALLED_FROM_VBLIRQ);
1254 /* Compute time difference to timestamp of last vblank */
1255 diff_ns = timeval_to_ns(&tvblank) -
1256 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
1258 /* Update vblank timestamp and count if at least
1259 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1260 * difference between last stored timestamp and current
1261 * timestamp. A smaller difference means basically
1262 * identical timestamps. Happens if this vblank has
1263 * been already processed and this is a redundant call,
1264 * e.g., due to spurious vblank interrupts. We need to
1265 * ignore those for accounting.
1267 if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) {
1268 /* Store new timestamp in ringbuffer. */
1269 vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
1271 /* Increment cooked vblank count. This also atomically commits
1272 * the timestamp computed above.
1274 atomic_inc(&dev->_vblank_count[crtc]);
1276 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1277 crtc, (int) diff_ns);
1280 wakeup(&dev->_vblank_count[crtc]);
1281 drm_handle_vblank_events(dev, crtc);
1283 lockmgr(&dev->vblank_time_lock, LK_RELEASE);