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 MALLOC_DEFINE(DRM_MEM_VBLANK, "drm_vblank", "DRM VBLANK Handling Data");
42 /* Access macro for slots in vblank timestamp ringbuffer. */
43 #define vblanktimestamp(dev, crtc, count) ( \
44 (dev)->_vblank_time[(crtc) * DRM_VBLANKTIME_RBSIZE + \
45 ((count) % DRM_VBLANKTIME_RBSIZE)])
47 /* Retry timestamp calculation up to 3 times to satisfy
48 * drm_timestamp_precision before giving up.
50 #define DRM_TIMESTAMP_MAXRETRIES 3
52 /* Threshold in nanoseconds for detection of redundant
53 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
55 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
57 int drm_irq_by_busid(struct drm_device *dev, void *data,
58 struct drm_file *file_priv)
60 struct drm_irq_busid *irq = data;
62 if ((irq->busnum >> 8) != dev->pci_domain ||
63 (irq->busnum & 0xff) != dev->pci_bus ||
64 irq->devnum != dev->pci_slot ||
65 irq->funcnum != dev->pci_func)
70 DRM_DEBUG("%d:%d:%d => IRQ %d\n",
71 irq->busnum, irq->devnum, irq->funcnum, irq->irq);
77 * Clear vblank timestamp buffer for a crtc.
79 static void clear_vblank_timestamps(struct drm_device *dev, int crtc)
81 memset(&dev->_vblank_time[crtc * DRM_VBLANKTIME_RBSIZE], 0,
82 DRM_VBLANKTIME_RBSIZE * sizeof(struct timeval));
89 return (x < 0 ? -x : x);
93 * Disable vblank irq's on crtc, make sure that last vblank count
94 * of hardware and corresponding consistent software vblank counter
95 * are preserved, even if there are any spurious vblank irq's after
98 static void vblank_disable_and_save(struct drm_device *dev, int crtc)
103 struct timeval tvblank;
105 /* Prevent vblank irq processing while disabling vblank irqs,
106 * so no updates of timestamps or count can happen after we've
107 * disabled. Needed to prevent races in case of delayed irq's.
109 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE);
111 dev->driver->disable_vblank(dev, crtc);
112 dev->vblank_enabled[crtc] = 0;
114 /* No further vblank irq's will be processed after
115 * this point. Get current hardware vblank count and
116 * vblank timestamp, repeat until they are consistent.
118 * FIXME: There is still a race condition here and in
119 * drm_update_vblank_count() which can cause off-by-one
120 * reinitialization of software vblank counter. If gpu
121 * vblank counter doesn't increment exactly at the leading
122 * edge of a vblank interval, then we can lose 1 count if
123 * we happen to execute between start of vblank and the
124 * delayed gpu counter increment.
127 dev->last_vblank[crtc] = dev->driver->get_vblank_counter(dev, crtc);
128 vblrc = drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0);
129 } while (dev->last_vblank[crtc] != dev->driver->get_vblank_counter(dev, crtc));
131 /* Compute time difference to stored timestamp of last vblank
132 * as updated by last invocation of drm_handle_vblank() in vblank irq.
134 vblcount = atomic_read(&dev->_vblank_count[crtc]);
135 diff_ns = timeval_to_ns(&tvblank) -
136 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
138 /* If there is at least 1 msec difference between the last stored
139 * timestamp and tvblank, then we are currently executing our
140 * disable inside a new vblank interval, the tvblank timestamp
141 * corresponds to this new vblank interval and the irq handler
142 * for this vblank didn't run yet and won't run due to our disable.
143 * Therefore we need to do the job of drm_handle_vblank() and
144 * increment the vblank counter by one to account for this vblank.
146 * Skip this step if there isn't any high precision timestamp
147 * available. In that case we can't account for this and just
150 if ((vblrc > 0) && (abs64(diff_ns) > 1000000)) {
151 atomic_inc(&dev->_vblank_count[crtc]);
154 /* Invalidate all timestamps while vblank irq's are off. */
155 clear_vblank_timestamps(dev, crtc);
157 lockmgr(&dev->vblank_time_lock, LK_RELEASE);
160 static void vblank_disable_fn(unsigned long arg)
162 struct drm_device *dev = (struct drm_device *)arg;
165 if (!dev->vblank_disable_allowed)
168 for (i = 0; i < dev->num_crtcs; i++) {
169 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE);
170 if (atomic_read(&dev->vblank_refcount[i]) == 0 &&
171 dev->vblank_enabled[i]) {
172 DRM_DEBUG("disabling vblank on crtc %d\n", i);
173 vblank_disable_and_save(dev, i);
175 lockmgr(&dev->vbl_lock, LK_RELEASE);
179 void drm_vblank_cleanup(struct drm_device *dev)
181 /* Bail if the driver didn't call drm_vblank_init() */
182 if (dev->num_crtcs == 0)
185 del_timer_sync(&dev->vblank_disable_timer);
187 vblank_disable_fn((unsigned long)dev);
189 drm_free(dev->_vblank_count, DRM_MEM_VBLANK);
190 drm_free(dev->vblank_refcount, DRM_MEM_VBLANK);
191 drm_free(dev->vblank_enabled, DRM_MEM_VBLANK);
192 drm_free(dev->last_vblank, DRM_MEM_VBLANK);
193 drm_free(dev->last_vblank_wait, DRM_MEM_VBLANK);
194 drm_free(dev->vblank_inmodeset, DRM_MEM_VBLANK);
195 drm_free(dev->_vblank_time, DRM_MEM_VBLANK);
199 EXPORT_SYMBOL(drm_vblank_cleanup);
201 int drm_vblank_init(struct drm_device *dev, int num_crtcs)
205 setup_timer(&dev->vblank_disable_timer, vblank_disable_fn,
207 lockinit(&dev->vblank_time_lock, "drmvtl", 0, LK_CANRECURSE);
209 dev->num_crtcs = num_crtcs;
211 dev->vbl_queue = kmalloc(sizeof(wait_queue_head_t) * num_crtcs,
212 DRM_MEM_VBLANK, M_WAITOK);
214 dev->_vblank_count = kmalloc(sizeof(atomic_t) * num_crtcs,
215 DRM_MEM_VBLANK, M_WAITOK);
216 dev->vblank_refcount = kmalloc(sizeof(atomic_t) * num_crtcs,
217 DRM_MEM_VBLANK, M_WAITOK);
218 dev->vblank_enabled = kmalloc(num_crtcs * sizeof(int),
219 DRM_MEM_VBLANK, M_WAITOK | M_ZERO);
220 dev->last_vblank = kmalloc(num_crtcs * sizeof(u32),
221 DRM_MEM_VBLANK, M_WAITOK | M_ZERO);
222 dev->last_vblank_wait = kmalloc(num_crtcs * sizeof(u32),
223 DRM_MEM_VBLANK, M_WAITOK | M_ZERO);
224 dev->vblank_inmodeset = kmalloc(num_crtcs * sizeof(int),
225 DRM_MEM_VBLANK, M_WAITOK | M_ZERO);
226 dev->_vblank_time = kmalloc(num_crtcs * DRM_VBLANKTIME_RBSIZE *
227 sizeof(struct timeval), DRM_MEM_VBLANK, M_WAITOK | M_ZERO);
228 DRM_INFO("Supports vblank timestamp caching Rev 1 (10.10.2010).\n");
230 /* Driver specific high-precision vblank timestamping supported? */
231 if (dev->driver->get_vblank_timestamp)
232 DRM_INFO("Driver supports precise vblank timestamp query.\n");
234 DRM_INFO("No driver support for vblank timestamp query.\n");
236 /* Zero per-crtc vblank stuff */
237 for (i = 0; i < num_crtcs; i++) {
238 init_waitqueue_head(&dev->vbl_queue[i]);
239 atomic_set(&dev->_vblank_count[i], 0);
240 atomic_set(&dev->vblank_refcount[i], 0);
243 dev->vblank_disable_allowed = 0;
246 EXPORT_SYMBOL(drm_vblank_init);
249 * Install IRQ handler.
251 * \param dev DRM device.
253 * Initializes the IRQ related data. Installs the handler, calling the driver
254 * \c irq_preinstall() and \c irq_postinstall() functions
255 * before and after the installation.
257 int drm_irq_install(struct drm_device *dev)
261 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
269 /* Driver must have been initialized */
270 if (!dev->dev_private) {
275 if (dev->irq_enabled) {
279 dev->irq_enabled = 1;
282 DRM_DEBUG("irq=%d\n", dev->irq);
284 /* Before installing handler */
285 if (dev->driver->irq_preinstall)
286 dev->driver->irq_preinstall(dev);
288 /* Install handler */
289 ret = bus_setup_intr(dev->dev, dev->irqr, INTR_MPSAFE,
290 dev->driver->irq_handler, dev, &dev->irqh, &dev->irq_lock);
294 dev->irq_enabled = 0;
299 /* After installing handler */
300 if (dev->driver->irq_postinstall)
301 ret = dev->driver->irq_postinstall(dev);
305 dev->irq_enabled = 0;
307 bus_teardown_intr(dev->dev, dev->irqr, dev->irqh);
312 EXPORT_SYMBOL(drm_irq_install);
315 * Uninstall the IRQ handler.
317 * \param dev DRM device.
319 * Calls the driver's \c irq_uninstall() function, and stops the irq.
321 int drm_irq_uninstall(struct drm_device *dev)
325 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
329 irq_enabled = dev->irq_enabled;
330 dev->irq_enabled = 0;
334 * Wake up any waiters so they don't hang.
336 if (dev->num_crtcs) {
337 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE);
338 for (i = 0; i < dev->num_crtcs; i++) {
339 DRM_WAKEUP(&dev->vbl_queue[i]);
340 dev->vblank_enabled[i] = 0;
341 dev->last_vblank[i] =
342 dev->driver->get_vblank_counter(dev, i);
344 lockmgr(&dev->vbl_lock, LK_RELEASE);
350 DRM_DEBUG("irq=%d\n", dev->irq);
352 if (dev->driver->irq_uninstall)
353 dev->driver->irq_uninstall(dev);
355 bus_teardown_intr(dev->dev, dev->irqr, dev->irqh);
359 EXPORT_SYMBOL(drm_irq_uninstall);
364 * \param inode device inode.
365 * \param file_priv DRM file private.
366 * \param cmd command.
367 * \param arg user argument, pointing to a drm_control structure.
368 * \return zero on success or a negative number on failure.
370 * Calls irq_install() or irq_uninstall() according to \p arg.
372 int drm_control(struct drm_device *dev, void *data,
373 struct drm_file *file_priv)
375 struct drm_control *ctl = data;
377 /* if we haven't irq we fallback for compatibility reasons -
378 * this used to be a separate function in drm_dma.h
383 case DRM_INST_HANDLER:
384 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
386 if (drm_core_check_feature(dev, DRIVER_MODESET))
388 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
389 ctl->irq != dev->irq)
391 return drm_irq_install(dev);
392 case DRM_UNINST_HANDLER:
393 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
395 if (drm_core_check_feature(dev, DRIVER_MODESET))
397 return drm_irq_uninstall(dev);
404 drm_calc_timestamping_constants(struct drm_crtc *crtc)
406 int64_t linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
409 /* Dot clock in Hz: */
410 dotclock = (uint64_t) crtc->hwmode.clock * 1000;
412 /* Fields of interlaced scanout modes are only halve a frame duration.
413 * Double the dotclock to get halve the frame-/line-/pixelduration.
415 if (crtc->hwmode.flags & DRM_MODE_FLAG_INTERLACE)
418 /* Valid dotclock? */
420 /* Convert scanline length in pixels and video dot clock to
421 * line duration, frame duration and pixel duration in
424 pixeldur_ns = (int64_t)1000000000 / dotclock;
425 linedur_ns = ((uint64_t)crtc->hwmode.crtc_htotal *
426 1000000000) / dotclock;
427 framedur_ns = (int64_t)crtc->hwmode.crtc_vtotal * linedur_ns;
429 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
432 crtc->pixeldur_ns = pixeldur_ns;
433 crtc->linedur_ns = linedur_ns;
434 crtc->framedur_ns = framedur_ns;
436 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
437 crtc->base.id, crtc->hwmode.crtc_htotal,
438 crtc->hwmode.crtc_vtotal, crtc->hwmode.crtc_vdisplay);
439 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
440 crtc->base.id, (int) dotclock/1000, (int) framedur_ns,
441 (int) linedur_ns, (int) pixeldur_ns);
445 * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
446 * drivers. Implements calculation of exact vblank timestamps from
447 * given drm_display_mode timings and current video scanout position
448 * of a crtc. This can be called from within get_vblank_timestamp()
449 * implementation of a kms driver to implement the actual timestamping.
451 * Should return timestamps conforming to the OML_sync_control OpenML
452 * extension specification. The timestamp corresponds to the end of
453 * the vblank interval, aka start of scanout of topmost-leftmost display
454 * pixel in the following video frame.
456 * Requires support for optional dev->driver->get_scanout_position()
457 * in kms driver, plus a bit of setup code to provide a drm_display_mode
458 * that corresponds to the true scanout timing.
460 * The current implementation only handles standard video modes. It
461 * returns as no operation if a doublescan or interlaced video mode is
462 * active. Higher level code is expected to handle this.
465 * @crtc: Which crtc's vblank timestamp to retrieve.
466 * @max_error: Desired maximum allowable error in timestamps (nanosecs).
467 * On return contains true maximum error of timestamp.
468 * @vblank_time: Pointer to struct timeval which should receive the timestamp.
469 * @flags: Flags to pass to driver:
471 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
472 * @refcrtc: drm_crtc* of crtc which defines scanout timing.
474 * Returns negative value on error, failure or if not supported in current
477 * -EINVAL - Invalid crtc.
478 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
479 * -ENOTSUPP - Function not supported in current display mode.
480 * -EIO - Failed, e.g., due to failed scanout position query.
482 * Returns or'ed positive status flags on success:
484 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
485 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
489 drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
490 int *max_error, struct timeval *vblank_time, unsigned flags,
491 struct drm_crtc *refcrtc)
493 struct timeval stime, raw_time;
494 struct drm_display_mode *mode;
495 int vbl_status, vtotal, vdisplay;
497 int64_t framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
500 if (crtc < 0 || crtc >= dev->num_crtcs) {
501 DRM_ERROR("Invalid crtc %d\n", crtc);
505 /* Scanout position query not supported? Should not happen. */
506 if (!dev->driver->get_scanout_position) {
507 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
511 mode = &refcrtc->hwmode;
512 vtotal = mode->crtc_vtotal;
513 vdisplay = mode->crtc_vdisplay;
515 /* Durations of frames, lines, pixels in nanoseconds. */
516 framedur_ns = refcrtc->framedur_ns;
517 linedur_ns = refcrtc->linedur_ns;
518 pixeldur_ns = refcrtc->pixeldur_ns;
520 /* If mode timing undefined, just return as no-op:
521 * Happens during initial modesetting of a crtc.
523 if (vtotal <= 0 || vdisplay <= 0 || framedur_ns == 0) {
524 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc);
528 /* Get current scanout position with system timestamp.
529 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
530 * if single query takes longer than max_error nanoseconds.
532 * This guarantees a tight bound on maximum error if
533 * code gets preempted or delayed for some reason.
535 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
536 /* Disable preemption to make it very likely to
537 * succeed in the first iteration.
541 /* Get system timestamp before query. */
542 getmicrouptime(&stime);
544 /* Get vertical and horizontal scanout pos. vpos, hpos. */
545 vbl_status = dev->driver->get_scanout_position(dev, crtc, &vpos, &hpos);
547 /* Get system timestamp after query. */
548 getmicrouptime(&raw_time);
552 /* Return as no-op if scanout query unsupported or failed. */
553 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
554 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
559 duration_ns = timeval_to_ns(&raw_time) - timeval_to_ns(&stime);
561 /* Accept result with < max_error nsecs timing uncertainty. */
562 if (duration_ns <= (int64_t) *max_error)
566 /* Noisy system timing? */
567 if (i == DRM_TIMESTAMP_MAXRETRIES) {
568 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
569 crtc, (int) duration_ns/1000, *max_error/1000, i);
572 /* Return upper bound of timestamp precision error. */
573 *max_error = (int) duration_ns;
575 /* Check if in vblank area:
576 * vpos is >=0 in video scanout area, but negative
577 * within vblank area, counting down the number of lines until
580 invbl = vbl_status & DRM_SCANOUTPOS_INVBL;
582 /* Convert scanout position into elapsed time at raw_time query
583 * since start of scanout at first display scanline. delta_ns
584 * can be negative if start of scanout hasn't happened yet.
586 delta_ns = (int64_t)vpos * linedur_ns + (int64_t)hpos * pixeldur_ns;
588 /* Is vpos outside nominal vblank area, but less than
589 * 1/100 of a frame height away from start of vblank?
590 * If so, assume this isn't a massively delayed vblank
591 * interrupt, but a vblank interrupt that fired a few
592 * microseconds before true start of vblank. Compensate
593 * by adding a full frame duration to the final timestamp.
594 * Happens, e.g., on ATI R500, R600.
596 * We only do this if DRM_CALLED_FROM_VBLIRQ.
598 if ((flags & DRM_CALLED_FROM_VBLIRQ) && !invbl &&
599 ((vdisplay - vpos) < vtotal / 100)) {
600 delta_ns = delta_ns - framedur_ns;
602 /* Signal this correction as "applied". */
606 /* Subtract time delta from raw timestamp to get final
607 * vblank_time timestamp for end of vblank.
609 *vblank_time = ns_to_timeval(timeval_to_ns(&raw_time) - delta_ns);
611 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %jd.%jd -> %jd.%jd [e %d us, %d rep]\n",
612 crtc, (int)vbl_status, hpos, vpos, (uintmax_t)raw_time.tv_sec,
613 (uintmax_t)raw_time.tv_usec, (uintmax_t)vblank_time->tv_sec,
614 (uintmax_t)vblank_time->tv_usec, (int)duration_ns/1000, i);
616 vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
618 vbl_status |= DRM_VBLANKTIME_INVBL;
623 static struct timeval get_drm_timestamp(void)
627 getmicrouptime(&now);
633 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
637 * @crtc: which crtc's vblank timestamp to retrieve
638 * @tvblank: Pointer to target struct timeval which should receive the timestamp
639 * @flags: Flags to pass to driver:
641 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
643 * Fetches the system timestamp corresponding to the time of the most recent
644 * vblank interval on specified crtc. May call into kms-driver to
645 * compute the timestamp with a high-precision GPU specific method.
647 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
648 * call, i.e., it isn't very precisely locked to the true vblank.
650 * Returns non-zero if timestamp is considered to be very precise.
652 u32 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
653 struct timeval *tvblank, unsigned flags)
657 /* Define requested maximum error on timestamps (nanoseconds). */
658 int max_error = (int) drm_timestamp_precision * 1000;
660 /* Query driver if possible and precision timestamping enabled. */
661 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
662 ret = dev->driver->get_vblank_timestamp(dev, crtc, &max_error,
668 /* GPU high precision timestamp query unsupported or failed.
669 * Return gettimeofday timestamp as best estimate.
677 * drm_vblank_count - retrieve "cooked" vblank counter value
679 * @crtc: which counter to retrieve
681 * Fetches the "cooked" vblank count value that represents the number of
682 * vblank events since the system was booted, including lost events due to
683 * modesetting activity.
685 u32 drm_vblank_count(struct drm_device *dev, int crtc)
687 return atomic_read(&dev->_vblank_count[crtc]);
691 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
692 * and the system timestamp corresponding to that vblank counter value.
695 * @crtc: which counter to retrieve
696 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
698 * Fetches the "cooked" vblank count value that represents the number of
699 * vblank events since the system was booted, including lost events due to
700 * modesetting activity. Returns corresponding system timestamp of the time
701 * of the vblank interval that corresponds to the current value vblank counter
704 u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
705 struct timeval *vblanktime)
709 /* Read timestamp from slot of _vblank_time ringbuffer
710 * that corresponds to current vblank count. Retry if
711 * count has incremented during readout. This works like
715 cur_vblank = atomic_read(&dev->_vblank_count[crtc]);
716 *vblanktime = vblanktimestamp(dev, crtc, cur_vblank);
718 } while (cur_vblank != atomic_read(&dev->_vblank_count[crtc]));
723 static void send_vblank_event(struct drm_device *dev,
724 struct drm_pending_vblank_event *e,
725 unsigned long seq, struct timeval *now)
727 KKASSERT(mutex_is_locked(&dev->event_lock));
728 e->event.sequence = seq;
729 e->event.tv_sec = now->tv_sec;
730 e->event.tv_usec = now->tv_usec;
732 list_add_tail(&e->base.link,
733 &e->base.file_priv->event_list);
734 wakeup(&e->base.file_priv->event_list);
736 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
742 * drm_send_vblank_event - helper to send vblank event after pageflip
744 * @crtc: CRTC in question
745 * @e: the event to send
747 * Updates sequence # and timestamp on event, and sends it to userspace.
748 * Caller must hold event lock.
750 void drm_send_vblank_event(struct drm_device *dev, int crtc,
751 struct drm_pending_vblank_event *e)
756 seq = drm_vblank_count_and_time(dev, crtc, &now);
760 now = get_drm_timestamp();
763 send_vblank_event(dev, e, seq, &now);
765 EXPORT_SYMBOL(drm_send_vblank_event);
768 * drm_update_vblank_count - update the master vblank counter
770 * @crtc: counter to update
772 * Call back into the driver to update the appropriate vblank counter
773 * (specified by @crtc). Deal with wraparound, if it occurred, and
774 * update the last read value so we can deal with wraparound on the next
777 * Only necessary when going from off->on, to account for frames we
778 * didn't get an interrupt for.
780 * Note: caller must hold dev->vbl_lock since this reads & writes
781 * device vblank fields.
783 static void drm_update_vblank_count(struct drm_device *dev, int crtc)
785 u32 cur_vblank, diff, tslot, rc;
786 struct timeval t_vblank;
789 * Interrupts were disabled prior to this call, so deal with counter
791 * NOTE! It's possible we lost a full dev->max_vblank_count events
792 * here if the register is small or we had vblank interrupts off for
795 * We repeat the hardware vblank counter & timestamp query until
796 * we get consistent results. This to prevent races between gpu
797 * updating its hardware counter while we are retrieving the
798 * corresponding vblank timestamp.
801 cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
802 rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0);
803 } while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc));
805 /* Deal with counter wrap */
806 diff = cur_vblank - dev->last_vblank[crtc];
807 if (cur_vblank < dev->last_vblank[crtc]) {
808 diff += dev->max_vblank_count;
810 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
811 crtc, dev->last_vblank[crtc], cur_vblank, diff);
814 DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
817 /* Reinitialize corresponding vblank timestamp if high-precision query
818 * available. Skip this step if query unsupported or failed. Will
819 * reinitialize delayed at next vblank interrupt in that case.
822 tslot = atomic_read(&dev->_vblank_count[crtc]) + diff;
823 vblanktimestamp(dev, crtc, tslot) = t_vblank;
826 atomic_add(diff, &dev->_vblank_count[crtc]);
830 * drm_vblank_get - get a reference count on vblank events
832 * @crtc: which CRTC to own
834 * Acquire a reference count on vblank events to avoid having them disabled
838 * Zero on success, nonzero on failure.
840 int drm_vblank_get(struct drm_device *dev, int crtc)
844 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE);
845 /* Going from 0->1 means we have to enable interrupts again */
846 if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1) {
847 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE);
848 if (!dev->vblank_enabled[crtc]) {
849 /* Enable vblank irqs under vblank_time_lock protection.
850 * All vblank count & timestamp updates are held off
851 * until we are done reinitializing master counter and
852 * timestamps. Filtercode in drm_handle_vblank() will
853 * prevent double-accounting of same vblank interval.
855 ret = -dev->driver->enable_vblank(dev, crtc);
856 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n",
859 atomic_dec(&dev->vblank_refcount[crtc]);
861 dev->vblank_enabled[crtc] = 1;
862 drm_update_vblank_count(dev, crtc);
865 lockmgr(&dev->vblank_time_lock, LK_RELEASE);
867 if (!dev->vblank_enabled[crtc]) {
868 atomic_dec(&dev->vblank_refcount[crtc]);
872 lockmgr(&dev->vbl_lock, LK_RELEASE);
878 * drm_vblank_put - give up ownership of vblank events
880 * @crtc: which counter to give up
882 * Release ownership of a given vblank counter, turning off interrupts
883 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
885 void drm_vblank_put(struct drm_device *dev, int crtc)
887 BUG_ON(atomic_read(&dev->vblank_refcount[crtc]) == 0);
889 /* Last user schedules interrupt disable */
890 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE);
891 if (atomic_dec_and_test(&dev->vblank_refcount[crtc]) &&
892 (drm_vblank_offdelay > 0)) {
893 mod_timer(&dev->vblank_disable_timer,
894 jiffies + ((drm_vblank_offdelay * DRM_HZ)/1000));
896 lockmgr(&dev->vblank_time_lock, LK_RELEASE);
898 EXPORT_SYMBOL(drm_vblank_put);
900 void drm_vblank_off(struct drm_device *dev, int crtc)
902 struct drm_pending_vblank_event *e, *t;
906 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE);
907 vblank_disable_and_save(dev, crtc);
908 lockmgr(&dev->event_lock, LK_EXCLUSIVE);
909 wakeup(&dev->_vblank_count[crtc]);
911 /* Send any queued vblank events, lest the natives grow disquiet */
912 seq = drm_vblank_count_and_time(dev, crtc, &now);
913 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
916 DRM_DEBUG("Sending premature vblank event on disable: \
917 wanted %d, current %d\n",
918 e->event.sequence, seq);
919 list_del(&e->base.link);
920 drm_vblank_put(dev, e->pipe);
921 send_vblank_event(dev, e, seq, &now);
924 lockmgr(&dev->event_lock, LK_RELEASE);
925 lockmgr(&dev->vbl_lock, LK_RELEASE);
929 * drm_vblank_pre_modeset - account for vblanks across mode sets
931 * @crtc: CRTC in question
932 * @post: post or pre mode set?
934 * Account for vblank events across mode setting events, which will likely
935 * reset the hardware frame counter.
937 void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
939 /* vblank is not initialized (IRQ not installed ?) */
943 * To avoid all the problems that might happen if interrupts
944 * were enabled/disabled around or between these calls, we just
945 * have the kernel take a reference on the CRTC (just once though
946 * to avoid corrupting the count if multiple, mismatch calls occur),
947 * so that interrupts remain enabled in the interim.
949 if (!dev->vblank_inmodeset[crtc]) {
950 dev->vblank_inmodeset[crtc] = 0x1;
951 if (drm_vblank_get(dev, crtc) == 0)
952 dev->vblank_inmodeset[crtc] |= 0x2;
956 void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
959 if (dev->vblank_inmodeset[crtc]) {
960 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE);
961 dev->vblank_disable_allowed = 1;
962 lockmgr(&dev->vbl_lock, LK_RELEASE);
964 if (dev->vblank_inmodeset[crtc] & 0x2)
965 drm_vblank_put(dev, crtc);
967 dev->vblank_inmodeset[crtc] = 0;
972 * drm_modeset_ctl - handle vblank event counter changes across mode switch
973 * @DRM_IOCTL_ARGS: standard ioctl arguments
975 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
976 * ioctls around modesetting so that any lost vblank events are accounted for.
978 * Generally the counter will reset across mode sets. If interrupts are
979 * enabled around this call, we don't have to do anything since the counter
980 * will have already been incremented.
982 int drm_modeset_ctl(struct drm_device *dev, void *data,
983 struct drm_file *file_priv)
985 struct drm_modeset_ctl *modeset = data;
989 /* If drm_vblank_init() hasn't been called yet, just no-op */
993 crtc = modeset->crtc;
994 if (crtc >= dev->num_crtcs) {
999 switch (modeset->cmd) {
1000 case _DRM_PRE_MODESET:
1001 drm_vblank_pre_modeset(dev, crtc);
1003 case _DRM_POST_MODESET:
1004 drm_vblank_post_modeset(dev, crtc);
1016 drm_vblank_event_destroy(struct drm_pending_event *e)
1019 drm_free(e, DRM_MEM_VBLANK);
1022 static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
1023 union drm_wait_vblank *vblwait,
1024 struct drm_file *file_priv)
1026 struct drm_pending_vblank_event *e;
1031 e = kmalloc(sizeof *e, DRM_MEM_VBLANK, M_WAITOK | M_ZERO);
1034 e->base.pid = curproc->p_pid;
1035 e->event.base.type = DRM_EVENT_VBLANK;
1036 e->event.base.length = sizeof e->event;
1037 e->event.user_data = vblwait->request.signal;
1038 e->base.event = &e->event.base;
1039 e->base.file_priv = file_priv;
1040 e->base.destroy = drm_vblank_event_destroy;
1042 lockmgr(&dev->event_lock, LK_EXCLUSIVE);
1044 if (file_priv->event_space < sizeof e->event) {
1049 file_priv->event_space -= sizeof e->event;
1050 seq = drm_vblank_count_and_time(dev, pipe, &now);
1052 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1053 (seq - vblwait->request.sequence) <= (1 << 23)) {
1054 vblwait->request.sequence = seq + 1;
1055 vblwait->reply.sequence = vblwait->request.sequence;
1058 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1059 vblwait->request.sequence, seq, pipe);
1061 e->event.sequence = vblwait->request.sequence;
1062 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1063 drm_vblank_put(dev, pipe);
1064 send_vblank_event(dev, e, seq, &now);
1065 vblwait->reply.sequence = seq;
1067 /* drm_handle_vblank_events will call drm_vblank_put */
1068 list_add_tail(&e->base.link, &dev->vblank_event_list);
1069 vblwait->reply.sequence = vblwait->request.sequence;
1072 lockmgr(&dev->event_lock, LK_RELEASE);
1077 lockmgr(&dev->event_lock, LK_RELEASE);
1078 drm_free(e, DRM_MEM_VBLANK);
1079 drm_vblank_put(dev, pipe);
1086 * \param inode device inode.
1087 * \param file_priv DRM file private.
1088 * \param cmd command.
1089 * \param data user argument, pointing to a drm_wait_vblank structure.
1090 * \return zero on success or a negative number on failure.
1092 * This function enables the vblank interrupt on the pipe requested, then
1093 * sleeps waiting for the requested sequence number to occur, and drops
1094 * the vblank interrupt refcount afterwards. (vblank irq disable follows that
1095 * after a timeout with no further vblank waits scheduled).
1097 int drm_wait_vblank(struct drm_device *dev, void *data,
1098 struct drm_file *file_priv)
1100 union drm_wait_vblank *vblwait = data;
1102 unsigned int flags, seq, crtc, high_crtc;
1104 if (/*(!drm_dev_to_irq(dev)) || */(!dev->irq_enabled))
1107 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1110 if (vblwait->request.type &
1111 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1112 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1113 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1114 vblwait->request.type,
1115 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1116 _DRM_VBLANK_HIGH_CRTC_MASK));
1120 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1121 high_crtc = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1123 crtc = high_crtc >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1125 crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1126 if (crtc >= dev->num_crtcs)
1129 ret = drm_vblank_get(dev, crtc);
1131 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1134 seq = drm_vblank_count(dev, crtc);
1136 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1137 case _DRM_VBLANK_RELATIVE:
1138 vblwait->request.sequence += seq;
1139 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1140 case _DRM_VBLANK_ABSOLUTE:
1147 if (flags & _DRM_VBLANK_EVENT) {
1148 /* must hold on to the vblank ref until the event fires
1149 * drm_vblank_put will be called asynchronously
1151 return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
1154 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1155 (seq - vblwait->request.sequence) <= (1<<23)) {
1156 vblwait->request.sequence = seq + 1;
1159 dev->last_vblank_wait[crtc] = vblwait->request.sequence;
1160 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE);
1161 while (((drm_vblank_count(dev, crtc) - vblwait->request.sequence) >
1162 (1 << 23)) && dev->irq_enabled) {
1164 * The wakeups from the drm_irq_uninstall() and
1165 * drm_vblank_off() may be lost there since vbl_lock
1166 * is not held. Then, the timeout will wake us; the 3
1167 * seconds delay should not be a problem for
1168 * application when crtc is disabled or irq
1169 * uninstalled anyway.
1171 ret = lksleep(&dev->_vblank_count[crtc], &dev->vblank_time_lock,
1172 PCATCH, "drmvbl", 3 * hz);
1176 lockmgr(&dev->vblank_time_lock, LK_RELEASE);
1181 reply_seq = drm_vblank_count_and_time(dev, crtc, &now);
1182 vblwait->reply.sequence = reply_seq;
1183 vblwait->reply.tval_sec = now.tv_sec;
1184 vblwait->reply.tval_usec = now.tv_usec;
1188 drm_vblank_put(dev, crtc);
1192 void drm_handle_vblank_events(struct drm_device *dev, int crtc)
1194 struct drm_pending_vblank_event *e, *t;
1198 seq = drm_vblank_count_and_time(dev, crtc, &now);
1200 lockmgr(&dev->event_lock, LK_EXCLUSIVE);
1202 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1203 if (e->pipe != crtc)
1205 if ((seq - e->event.sequence) > (1<<23))
1208 DRM_DEBUG("vblank event on %d, current %d\n",
1209 e->event.sequence, seq);
1211 list_del(&e->base.link);
1212 drm_vblank_put(dev, e->pipe);
1213 send_vblank_event(dev, e, seq, &now);
1216 lockmgr(&dev->event_lock, LK_RELEASE);
1220 * drm_handle_vblank - handle a vblank event
1222 * @crtc: where this event occurred
1224 * Drivers should call this routine in their vblank interrupt handlers to
1225 * update the vblank counter and send any signals that may be pending.
1227 bool drm_handle_vblank(struct drm_device *dev, int crtc)
1231 struct timeval tvblank;
1233 if (!dev->num_crtcs)
1236 /* Need timestamp lock to prevent concurrent execution with
1237 * vblank enable/disable, as this would cause inconsistent
1238 * or corrupted timestamps and vblank counts.
1240 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE);
1242 /* Vblank irq handling disabled. Nothing to do. */
1243 if (!dev->vblank_enabled[crtc]) {
1244 lockmgr(&dev->vblank_time_lock, LK_RELEASE);
1248 /* Fetch corresponding timestamp for this vblank interval from
1249 * driver and store it in proper slot of timestamp ringbuffer.
1252 /* Get current timestamp and count. */
1253 vblcount = atomic_read(&dev->_vblank_count[crtc]);
1254 drm_get_last_vbltimestamp(dev, crtc, &tvblank, DRM_CALLED_FROM_VBLIRQ);
1256 /* Compute time difference to timestamp of last vblank */
1257 diff_ns = timeval_to_ns(&tvblank) -
1258 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
1260 /* Update vblank timestamp and count if at least
1261 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1262 * difference between last stored timestamp and current
1263 * timestamp. A smaller difference means basically
1264 * identical timestamps. Happens if this vblank has
1265 * been already processed and this is a redundant call,
1266 * e.g., due to spurious vblank interrupts. We need to
1267 * ignore those for accounting.
1269 if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) {
1270 /* Store new timestamp in ringbuffer. */
1271 vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
1273 /* Increment cooked vblank count. This also atomically commits
1274 * the timestamp computed above.
1276 atomic_inc(&dev->_vblank_count[crtc]);
1278 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1279 crtc, (int) diff_ns);
1282 wakeup(&dev->_vblank_count[crtc]);
1283 drm_handle_vblank_events(dev, crtc);
1285 lockmgr(&dev->vblank_time_lock, LK_RELEASE);