5 * \author Rickard E. (Rik) Faith <faith@valinux.com>
6 * \author Gareth Hughes <gareth@valinux.com>
10 * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
12 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
13 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
14 * All Rights Reserved.
16 * Permission is hereby granted, free of charge, to any person obtaining a
17 * copy of this software and associated documentation files (the "Software"),
18 * to deal in the Software without restriction, including without limitation
19 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
20 * and/or sell copies of the Software, and to permit persons to whom the
21 * Software is furnished to do so, subject to the following conditions:
23 * The above copyright notice and this permission notice (including the next
24 * paragraph) shall be included in all copies or substantial portions of the
27 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
28 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
29 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
30 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
31 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
32 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
33 * OTHER DEALINGS IN THE SOFTWARE.
37 #include "drm_trace.h"
39 #include <linux/interrupt.h> /* For task queue support */
40 #include <linux/slab.h>
42 #include <linux/vgaarb.h>
43 #include <linux/export.h>
45 /* Access macro for slots in vblank timestamp ringbuffer. */
46 #define vblanktimestamp(dev, crtc, count) \
47 ((dev)->vblank[crtc].time[(count) % DRM_VBLANKTIME_RBSIZE])
49 /* Retry timestamp calculation up to 3 times to satisfy
50 * drm_timestamp_precision before giving up.
52 #define DRM_TIMESTAMP_MAXRETRIES 3
54 /* Threshold in nanoseconds for detection of redundant
55 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
57 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
60 * Clear vblank timestamp buffer for a crtc.
62 static void clear_vblank_timestamps(struct drm_device *dev, int crtc)
64 memset(dev->vblank[crtc].time, 0, sizeof(dev->vblank[crtc].time));
68 * Disable vblank irq's on crtc, make sure that last vblank count
69 * of hardware and corresponding consistent software vblank counter
70 * are preserved, even if there are any spurious vblank irq's after
73 static void vblank_disable_and_save(struct drm_device *dev, int crtc)
75 unsigned long irqflags;
79 struct timeval tvblank;
80 int count = DRM_TIMESTAMP_MAXRETRIES;
82 /* Prevent vblank irq processing while disabling vblank irqs,
83 * so no updates of timestamps or count can happen after we've
84 * disabled. Needed to prevent races in case of delayed irq's.
86 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
88 dev->driver->disable_vblank(dev, crtc);
89 dev->vblank[crtc].enabled = false;
91 /* No further vblank irq's will be processed after
92 * this point. Get current hardware vblank count and
93 * vblank timestamp, repeat until they are consistent.
95 * FIXME: There is still a race condition here and in
96 * drm_update_vblank_count() which can cause off-by-one
97 * reinitialization of software vblank counter. If gpu
98 * vblank counter doesn't increment exactly at the leading
99 * edge of a vblank interval, then we can lose 1 count if
100 * we happen to execute between start of vblank and the
101 * delayed gpu counter increment.
104 dev->vblank[crtc].last = dev->driver->get_vblank_counter(dev, crtc);
105 vblrc = drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0);
106 } while (dev->vblank[crtc].last != dev->driver->get_vblank_counter(dev, crtc) && (--count) && vblrc);
111 /* Compute time difference to stored timestamp of last vblank
112 * as updated by last invocation of drm_handle_vblank() in vblank irq.
114 vblcount = atomic_read(&dev->vblank[crtc].count);
115 diff_ns = timeval_to_ns(&tvblank) -
116 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
118 /* If there is at least 1 msec difference between the last stored
119 * timestamp and tvblank, then we are currently executing our
120 * disable inside a new vblank interval, the tvblank timestamp
121 * corresponds to this new vblank interval and the irq handler
122 * for this vblank didn't run yet and won't run due to our disable.
123 * Therefore we need to do the job of drm_handle_vblank() and
124 * increment the vblank counter by one to account for this vblank.
126 * Skip this step if there isn't any high precision timestamp
127 * available. In that case we can't account for this and just
130 if ((vblrc > 0) && (abs64(diff_ns) > 1000000)) {
131 atomic_inc(&dev->vblank[crtc].count);
132 smp_mb__after_atomic_inc();
135 /* Invalidate all timestamps while vblank irq's are off. */
136 clear_vblank_timestamps(dev, crtc);
138 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
141 static void vblank_disable_fn(unsigned long arg)
143 struct drm_device *dev = (struct drm_device *)arg;
144 unsigned long irqflags;
147 if (!dev->vblank_disable_allowed)
150 for (i = 0; i < dev->num_crtcs; i++) {
151 spin_lock_irqsave(&dev->vbl_lock, irqflags);
152 if (atomic_read(&dev->vblank[i].refcount) == 0 &&
153 dev->vblank[i].enabled) {
154 DRM_DEBUG("disabling vblank on crtc %d\n", i);
155 vblank_disable_and_save(dev, i);
157 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
161 void drm_vblank_cleanup(struct drm_device *dev)
163 /* Bail if the driver didn't call drm_vblank_init() */
164 if (dev->num_crtcs == 0)
167 del_timer_sync(&dev->vblank_disable_timer);
169 vblank_disable_fn((unsigned long)dev);
175 EXPORT_SYMBOL(drm_vblank_cleanup);
177 int drm_vblank_init(struct drm_device *dev, int num_crtcs)
179 int i, ret = -ENOMEM;
181 setup_timer(&dev->vblank_disable_timer, vblank_disable_fn,
183 spin_lock_init(&dev->vbl_lock);
184 spin_lock_init(&dev->vblank_time_lock);
186 dev->num_crtcs = num_crtcs;
188 dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
192 for (i = 0; i < num_crtcs; i++)
193 init_waitqueue_head(&dev->vblank[i].queue);
195 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
197 /* Driver specific high-precision vblank timestamping supported? */
198 if (dev->driver->get_vblank_timestamp)
199 DRM_INFO("Driver supports precise vblank timestamp query.\n");
201 DRM_INFO("No driver support for vblank timestamp query.\n");
203 dev->vblank_disable_allowed = false;
208 drm_vblank_cleanup(dev);
211 EXPORT_SYMBOL(drm_vblank_init);
213 static void drm_irq_vgaarb_nokms(void *cookie, bool state)
215 struct drm_device *dev = cookie;
217 if (dev->driver->vgaarb_irq) {
218 dev->driver->vgaarb_irq(dev, state);
222 if (!dev->irq_enabled)
226 if (dev->driver->irq_uninstall)
227 dev->driver->irq_uninstall(dev);
229 if (dev->driver->irq_preinstall)
230 dev->driver->irq_preinstall(dev);
231 if (dev->driver->irq_postinstall)
232 dev->driver->irq_postinstall(dev);
237 * Install IRQ handler.
239 * \param dev DRM device.
241 * Initializes the IRQ related data. Installs the handler, calling the driver
242 * \c irq_preinstall() and \c irq_postinstall() functions
243 * before and after the installation.
245 int drm_irq_install(struct drm_device *dev, int irq)
248 unsigned long sh_flags = 0;
251 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
257 /* Driver must have been initialized */
258 if (!dev->dev_private)
261 if (dev->irq_enabled)
263 dev->irq_enabled = true;
265 DRM_DEBUG("irq=%d\n", irq);
267 /* Before installing handler */
268 if (dev->driver->irq_preinstall)
269 dev->driver->irq_preinstall(dev);
271 /* Install handler */
272 if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
273 sh_flags = IRQF_SHARED;
276 irqname = dev->devname;
278 irqname = dev->driver->name;
280 ret = request_irq(irq, dev->driver->irq_handler,
281 sh_flags, irqname, dev);
284 dev->irq_enabled = false;
288 if (!drm_core_check_feature(dev, DRIVER_MODESET))
289 vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
291 /* After installing handler */
292 if (dev->driver->irq_postinstall)
293 ret = dev->driver->irq_postinstall(dev);
296 dev->irq_enabled = false;
297 if (!drm_core_check_feature(dev, DRIVER_MODESET))
298 vga_client_register(dev->pdev, NULL, NULL, NULL);
306 EXPORT_SYMBOL(drm_irq_install);
309 * Uninstall the IRQ handler.
311 * \param dev DRM device.
313 * Calls the driver's \c irq_uninstall() function, and stops the irq.
315 int drm_irq_uninstall(struct drm_device *dev)
317 unsigned long irqflags;
321 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
324 irq_enabled = dev->irq_enabled;
325 dev->irq_enabled = false;
328 * Wake up any waiters so they don't hang.
330 if (dev->num_crtcs) {
331 spin_lock_irqsave(&dev->vbl_lock, irqflags);
332 for (i = 0; i < dev->num_crtcs; i++) {
333 wake_up(&dev->vblank[i].queue);
334 dev->vblank[i].enabled = false;
335 dev->vblank[i].last =
336 dev->driver->get_vblank_counter(dev, i);
338 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
344 DRM_DEBUG("irq=%d\n", dev->irq);
346 if (!drm_core_check_feature(dev, DRIVER_MODESET))
347 vga_client_register(dev->pdev, NULL, NULL, NULL);
349 if (dev->driver->irq_uninstall)
350 dev->driver->irq_uninstall(dev);
352 free_irq(dev->irq, dev);
356 EXPORT_SYMBOL(drm_irq_uninstall);
361 * \param inode device inode.
362 * \param file_priv DRM file private.
363 * \param cmd command.
364 * \param arg user argument, pointing to a drm_control structure.
365 * \return zero on success or a negative number on failure.
367 * Calls irq_install() or irq_uninstall() according to \p arg.
369 int drm_control(struct drm_device *dev, void *data,
370 struct drm_file *file_priv)
372 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
379 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
381 if (drm_core_check_feature(dev, DRIVER_MODESET))
383 /* UMS was only ever support on pci devices. */
384 if (WARN_ON(!dev->pdev))
388 case DRM_INST_HANDLER:
389 irq = dev->pdev->irq;
391 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
394 mutex_lock(&dev->struct_mutex);
395 ret = drm_irq_install(dev, irq);
396 mutex_unlock(&dev->struct_mutex);
399 case DRM_UNINST_HANDLER:
400 mutex_lock(&dev->struct_mutex);
401 ret = drm_irq_uninstall(dev);
402 mutex_unlock(&dev->struct_mutex);
411 * drm_calc_timestamping_constants - Calculate vblank timestamp constants
413 * @crtc drm_crtc whose timestamp constants should be updated.
414 * @mode display mode containing the scanout timings
416 * Calculate and store various constants which are later
417 * needed by vblank and swap-completion timestamping, e.g,
418 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
419 * derived from crtc's true scanout timing, so they take
420 * things like panel scaling or other adjustments into account.
422 void drm_calc_timestamping_constants(struct drm_crtc *crtc,
423 const struct drm_display_mode *mode)
425 int linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
426 int dotclock = mode->crtc_clock;
428 /* Valid dotclock? */
430 int frame_size = mode->crtc_htotal * mode->crtc_vtotal;
433 * Convert scanline length in pixels and video
434 * dot clock to line duration, frame duration
435 * and pixel duration in nanoseconds:
437 pixeldur_ns = 1000000 / dotclock;
438 linedur_ns = div_u64((u64) mode->crtc_htotal * 1000000, dotclock);
439 framedur_ns = div_u64((u64) frame_size * 1000000, dotclock);
442 * Fields of interlaced scanout modes are only half a frame duration.
444 if (mode->flags & DRM_MODE_FLAG_INTERLACE)
447 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
450 crtc->pixeldur_ns = pixeldur_ns;
451 crtc->linedur_ns = linedur_ns;
452 crtc->framedur_ns = framedur_ns;
454 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
455 crtc->base.id, mode->crtc_htotal,
456 mode->crtc_vtotal, mode->crtc_vdisplay);
457 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
458 crtc->base.id, dotclock, framedur_ns,
459 linedur_ns, pixeldur_ns);
461 EXPORT_SYMBOL(drm_calc_timestamping_constants);
464 * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
465 * drivers. Implements calculation of exact vblank timestamps from
466 * given drm_display_mode timings and current video scanout position
467 * of a crtc. This can be called from within get_vblank_timestamp()
468 * implementation of a kms driver to implement the actual timestamping.
470 * Should return timestamps conforming to the OML_sync_control OpenML
471 * extension specification. The timestamp corresponds to the end of
472 * the vblank interval, aka start of scanout of topmost-leftmost display
473 * pixel in the following video frame.
475 * Requires support for optional dev->driver->get_scanout_position()
476 * in kms driver, plus a bit of setup code to provide a drm_display_mode
477 * that corresponds to the true scanout timing.
479 * The current implementation only handles standard video modes. It
480 * returns as no operation if a doublescan or interlaced video mode is
481 * active. Higher level code is expected to handle this.
484 * @crtc: Which crtc's vblank timestamp to retrieve.
485 * @max_error: Desired maximum allowable error in timestamps (nanosecs).
486 * On return contains true maximum error of timestamp.
487 * @vblank_time: Pointer to struct timeval which should receive the timestamp.
488 * @flags: Flags to pass to driver:
490 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
491 * @refcrtc: drm_crtc* of crtc which defines scanout timing.
492 * @mode: mode which defines the scanout timings
494 * Returns negative value on error, failure or if not supported in current
497 * -EINVAL - Invalid crtc.
498 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
499 * -ENOTSUPP - Function not supported in current display mode.
500 * -EIO - Failed, e.g., due to failed scanout position query.
502 * Returns or'ed positive status flags on success:
504 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
505 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
508 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
510 struct timeval *vblank_time,
512 const struct drm_crtc *refcrtc,
513 const struct drm_display_mode *mode)
515 ktime_t stime, etime, mono_time_offset;
516 struct timeval tv_etime;
519 int framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
522 if (crtc < 0 || crtc >= dev->num_crtcs) {
523 DRM_ERROR("Invalid crtc %d\n", crtc);
527 /* Scanout position query not supported? Should not happen. */
528 if (!dev->driver->get_scanout_position) {
529 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
533 /* Durations of frames, lines, pixels in nanoseconds. */
534 framedur_ns = refcrtc->framedur_ns;
535 linedur_ns = refcrtc->linedur_ns;
536 pixeldur_ns = refcrtc->pixeldur_ns;
538 /* If mode timing undefined, just return as no-op:
539 * Happens during initial modesetting of a crtc.
541 if (framedur_ns == 0) {
542 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc);
546 /* Get current scanout position with system timestamp.
547 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
548 * if single query takes longer than max_error nanoseconds.
550 * This guarantees a tight bound on maximum error if
551 * code gets preempted or delayed for some reason.
553 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
555 * Get vertical and horizontal scanout position vpos, hpos,
556 * and bounding timestamps stime, etime, pre/post query.
558 vbl_status = dev->driver->get_scanout_position(dev, crtc, flags, &vpos,
559 &hpos, &stime, &etime);
562 * Get correction for CLOCK_MONOTONIC -> CLOCK_REALTIME if
563 * CLOCK_REALTIME is requested.
565 if (!drm_timestamp_monotonic)
566 mono_time_offset = ktime_get_monotonic_offset();
568 /* Return as no-op if scanout query unsupported or failed. */
569 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
570 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
575 /* Compute uncertainty in timestamp of scanout position query. */
576 duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
578 /* Accept result with < max_error nsecs timing uncertainty. */
579 if (duration_ns <= *max_error)
583 /* Noisy system timing? */
584 if (i == DRM_TIMESTAMP_MAXRETRIES) {
585 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
586 crtc, duration_ns/1000, *max_error/1000, i);
589 /* Return upper bound of timestamp precision error. */
590 *max_error = duration_ns;
592 /* Check if in vblank area:
593 * vpos is >=0 in video scanout area, but negative
594 * within vblank area, counting down the number of lines until
597 invbl = vbl_status & DRM_SCANOUTPOS_INVBL;
599 /* Convert scanout position into elapsed time at raw_time query
600 * since start of scanout at first display scanline. delta_ns
601 * can be negative if start of scanout hasn't happened yet.
603 delta_ns = vpos * linedur_ns + hpos * pixeldur_ns;
605 if (!drm_timestamp_monotonic)
606 etime = ktime_sub(etime, mono_time_offset);
608 /* save this only for debugging purposes */
609 tv_etime = ktime_to_timeval(etime);
610 /* Subtract time delta from raw timestamp to get final
611 * vblank_time timestamp for end of vblank.
614 etime = ktime_add_ns(etime, -delta_ns);
616 etime = ktime_sub_ns(etime, delta_ns);
617 *vblank_time = ktime_to_timeval(etime);
619 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
620 crtc, (int)vbl_status, hpos, vpos,
621 (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
622 (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
623 duration_ns/1000, i);
625 vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
627 vbl_status |= DRM_VBLANKTIME_INVBL;
631 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
633 static struct timeval get_drm_timestamp(void)
638 if (!drm_timestamp_monotonic)
639 now = ktime_sub(now, ktime_get_monotonic_offset());
641 return ktime_to_timeval(now);
645 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
649 * @crtc: which crtc's vblank timestamp to retrieve
650 * @tvblank: Pointer to target struct timeval which should receive the timestamp
651 * @flags: Flags to pass to driver:
653 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
655 * Fetches the system timestamp corresponding to the time of the most recent
656 * vblank interval on specified crtc. May call into kms-driver to
657 * compute the timestamp with a high-precision GPU specific method.
659 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
660 * call, i.e., it isn't very precisely locked to the true vblank.
662 * Returns non-zero if timestamp is considered to be very precise.
664 u32 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
665 struct timeval *tvblank, unsigned flags)
669 /* Define requested maximum error on timestamps (nanoseconds). */
670 int max_error = (int) drm_timestamp_precision * 1000;
672 /* Query driver if possible and precision timestamping enabled. */
673 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
674 ret = dev->driver->get_vblank_timestamp(dev, crtc, &max_error,
680 /* GPU high precision timestamp query unsupported or failed.
681 * Return current monotonic/gettimeofday timestamp as best estimate.
683 *tvblank = get_drm_timestamp();
687 EXPORT_SYMBOL(drm_get_last_vbltimestamp);
690 * drm_vblank_count - retrieve "cooked" vblank counter value
692 * @crtc: which counter to retrieve
694 * Fetches the "cooked" vblank count value that represents the number of
695 * vblank events since the system was booted, including lost events due to
696 * modesetting activity.
698 u32 drm_vblank_count(struct drm_device *dev, int crtc)
700 return atomic_read(&dev->vblank[crtc].count);
702 EXPORT_SYMBOL(drm_vblank_count);
705 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
706 * and the system timestamp corresponding to that vblank counter value.
709 * @crtc: which counter to retrieve
710 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
712 * Fetches the "cooked" vblank count value that represents the number of
713 * vblank events since the system was booted, including lost events due to
714 * modesetting activity. Returns corresponding system timestamp of the time
715 * of the vblank interval that corresponds to the current value vblank counter
718 u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
719 struct timeval *vblanktime)
723 /* Read timestamp from slot of _vblank_time ringbuffer
724 * that corresponds to current vblank count. Retry if
725 * count has incremented during readout. This works like
729 cur_vblank = atomic_read(&dev->vblank[crtc].count);
730 *vblanktime = vblanktimestamp(dev, crtc, cur_vblank);
732 } while (cur_vblank != atomic_read(&dev->vblank[crtc].count));
736 EXPORT_SYMBOL(drm_vblank_count_and_time);
738 static void send_vblank_event(struct drm_device *dev,
739 struct drm_pending_vblank_event *e,
740 unsigned long seq, struct timeval *now)
742 WARN_ON_SMP(!spin_is_locked(&dev->event_lock));
743 e->event.sequence = seq;
744 e->event.tv_sec = now->tv_sec;
745 e->event.tv_usec = now->tv_usec;
747 list_add_tail(&e->base.link,
748 &e->base.file_priv->event_list);
749 wake_up_interruptible(&e->base.file_priv->event_wait);
750 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
755 * drm_send_vblank_event - helper to send vblank event after pageflip
757 * @crtc: CRTC in question
758 * @e: the event to send
760 * Updates sequence # and timestamp on event, and sends it to userspace.
761 * Caller must hold event lock.
763 void drm_send_vblank_event(struct drm_device *dev, int crtc,
764 struct drm_pending_vblank_event *e)
769 seq = drm_vblank_count_and_time(dev, crtc, &now);
773 now = get_drm_timestamp();
776 send_vblank_event(dev, e, seq, &now);
778 EXPORT_SYMBOL(drm_send_vblank_event);
781 * drm_update_vblank_count - update the master vblank counter
783 * @crtc: counter to update
785 * Call back into the driver to update the appropriate vblank counter
786 * (specified by @crtc). Deal with wraparound, if it occurred, and
787 * update the last read value so we can deal with wraparound on the next
790 * Only necessary when going from off->on, to account for frames we
791 * didn't get an interrupt for.
793 * Note: caller must hold dev->vbl_lock since this reads & writes
794 * device vblank fields.
796 static void drm_update_vblank_count(struct drm_device *dev, int crtc)
798 u32 cur_vblank, diff, tslot, rc;
799 struct timeval t_vblank;
802 * Interrupts were disabled prior to this call, so deal with counter
804 * NOTE! It's possible we lost a full dev->max_vblank_count events
805 * here if the register is small or we had vblank interrupts off for
808 * We repeat the hardware vblank counter & timestamp query until
809 * we get consistent results. This to prevent races between gpu
810 * updating its hardware counter while we are retrieving the
811 * corresponding vblank timestamp.
814 cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
815 rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0);
816 } while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc));
818 /* Deal with counter wrap */
819 diff = cur_vblank - dev->vblank[crtc].last;
820 if (cur_vblank < dev->vblank[crtc].last) {
821 diff += dev->max_vblank_count;
823 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
824 crtc, dev->vblank[crtc].last, cur_vblank, diff);
827 DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
830 /* Reinitialize corresponding vblank timestamp if high-precision query
831 * available. Skip this step if query unsupported or failed. Will
832 * reinitialize delayed at next vblank interrupt in that case.
835 tslot = atomic_read(&dev->vblank[crtc].count) + diff;
836 vblanktimestamp(dev, crtc, tslot) = t_vblank;
839 smp_mb__before_atomic_inc();
840 atomic_add(diff, &dev->vblank[crtc].count);
841 smp_mb__after_atomic_inc();
845 * drm_vblank_get - get a reference count on vblank events
847 * @crtc: which CRTC to own
849 * Acquire a reference count on vblank events to avoid having them disabled
853 * Zero on success, nonzero on failure.
855 int drm_vblank_get(struct drm_device *dev, int crtc)
857 unsigned long irqflags, irqflags2;
860 spin_lock_irqsave(&dev->vbl_lock, irqflags);
861 /* Going from 0->1 means we have to enable interrupts again */
862 if (atomic_add_return(1, &dev->vblank[crtc].refcount) == 1) {
863 spin_lock_irqsave(&dev->vblank_time_lock, irqflags2);
864 if (!dev->vblank[crtc].enabled) {
865 /* Enable vblank irqs under vblank_time_lock protection.
866 * All vblank count & timestamp updates are held off
867 * until we are done reinitializing master counter and
868 * timestamps. Filtercode in drm_handle_vblank() will
869 * prevent double-accounting of same vblank interval.
871 ret = dev->driver->enable_vblank(dev, crtc);
872 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n",
875 atomic_dec(&dev->vblank[crtc].refcount);
877 dev->vblank[crtc].enabled = true;
878 drm_update_vblank_count(dev, crtc);
881 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags2);
883 if (!dev->vblank[crtc].enabled) {
884 atomic_dec(&dev->vblank[crtc].refcount);
888 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
892 EXPORT_SYMBOL(drm_vblank_get);
895 * drm_vblank_put - give up ownership of vblank events
897 * @crtc: which counter to give up
899 * Release ownership of a given vblank counter, turning off interrupts
900 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
902 void drm_vblank_put(struct drm_device *dev, int crtc)
904 BUG_ON(atomic_read(&dev->vblank[crtc].refcount) == 0);
906 /* Last user schedules interrupt disable */
907 if (atomic_dec_and_test(&dev->vblank[crtc].refcount) &&
908 (drm_vblank_offdelay > 0))
909 mod_timer(&dev->vblank_disable_timer,
910 jiffies + ((drm_vblank_offdelay * HZ)/1000));
912 EXPORT_SYMBOL(drm_vblank_put);
915 * drm_vblank_off - disable vblank events on a CRTC
917 * @crtc: CRTC in question
919 * Caller must hold event lock.
921 void drm_vblank_off(struct drm_device *dev, int crtc)
923 struct drm_pending_vblank_event *e, *t;
925 unsigned long irqflags;
928 spin_lock_irqsave(&dev->vbl_lock, irqflags);
929 vblank_disable_and_save(dev, crtc);
930 wake_up(&dev->vblank[crtc].queue);
932 /* Send any queued vblank events, lest the natives grow disquiet */
933 seq = drm_vblank_count_and_time(dev, crtc, &now);
935 spin_lock(&dev->event_lock);
936 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
939 DRM_DEBUG("Sending premature vblank event on disable: \
940 wanted %d, current %d\n",
941 e->event.sequence, seq);
942 list_del(&e->base.link);
943 drm_vblank_put(dev, e->pipe);
944 send_vblank_event(dev, e, seq, &now);
946 spin_unlock(&dev->event_lock);
948 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
950 EXPORT_SYMBOL(drm_vblank_off);
953 * drm_vblank_pre_modeset - account for vblanks across mode sets
955 * @crtc: CRTC in question
957 * Account for vblank events across mode setting events, which will likely
958 * reset the hardware frame counter.
960 void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
962 /* vblank is not initialized (IRQ not installed ?), or has been freed */
966 * To avoid all the problems that might happen if interrupts
967 * were enabled/disabled around or between these calls, we just
968 * have the kernel take a reference on the CRTC (just once though
969 * to avoid corrupting the count if multiple, mismatch calls occur),
970 * so that interrupts remain enabled in the interim.
972 if (!dev->vblank[crtc].inmodeset) {
973 dev->vblank[crtc].inmodeset = 0x1;
974 if (drm_vblank_get(dev, crtc) == 0)
975 dev->vblank[crtc].inmodeset |= 0x2;
978 EXPORT_SYMBOL(drm_vblank_pre_modeset);
980 void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
982 unsigned long irqflags;
984 /* vblank is not initialized (IRQ not installed ?), or has been freed */
988 if (dev->vblank[crtc].inmodeset) {
989 spin_lock_irqsave(&dev->vbl_lock, irqflags);
990 dev->vblank_disable_allowed = true;
991 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
993 if (dev->vblank[crtc].inmodeset & 0x2)
994 drm_vblank_put(dev, crtc);
996 dev->vblank[crtc].inmodeset = 0;
999 EXPORT_SYMBOL(drm_vblank_post_modeset);
1002 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1003 * @DRM_IOCTL_ARGS: standard ioctl arguments
1005 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1006 * ioctls around modesetting so that any lost vblank events are accounted for.
1008 * Generally the counter will reset across mode sets. If interrupts are
1009 * enabled around this call, we don't have to do anything since the counter
1010 * will have already been incremented.
1012 int drm_modeset_ctl(struct drm_device *dev, void *data,
1013 struct drm_file *file_priv)
1015 struct drm_modeset_ctl *modeset = data;
1018 /* If drm_vblank_init() hasn't been called yet, just no-op */
1019 if (!dev->num_crtcs)
1022 /* KMS drivers handle this internally */
1023 if (drm_core_check_feature(dev, DRIVER_MODESET))
1026 crtc = modeset->crtc;
1027 if (crtc >= dev->num_crtcs)
1030 switch (modeset->cmd) {
1031 case _DRM_PRE_MODESET:
1032 drm_vblank_pre_modeset(dev, crtc);
1034 case _DRM_POST_MODESET:
1035 drm_vblank_post_modeset(dev, crtc);
1044 static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
1045 union drm_wait_vblank *vblwait,
1046 struct drm_file *file_priv)
1048 struct drm_pending_vblank_event *e;
1050 unsigned long flags;
1054 e = kzalloc(sizeof *e, GFP_KERNEL);
1061 e->base.pid = current->pid;
1062 e->event.base.type = DRM_EVENT_VBLANK;
1063 e->event.base.length = sizeof e->event;
1064 e->event.user_data = vblwait->request.signal;
1065 e->base.event = &e->event.base;
1066 e->base.file_priv = file_priv;
1067 e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
1069 spin_lock_irqsave(&dev->event_lock, flags);
1071 if (file_priv->event_space < sizeof e->event) {
1076 file_priv->event_space -= sizeof e->event;
1077 seq = drm_vblank_count_and_time(dev, pipe, &now);
1079 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1080 (seq - vblwait->request.sequence) <= (1 << 23)) {
1081 vblwait->request.sequence = seq + 1;
1082 vblwait->reply.sequence = vblwait->request.sequence;
1085 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1086 vblwait->request.sequence, seq, pipe);
1088 trace_drm_vblank_event_queued(current->pid, pipe,
1089 vblwait->request.sequence);
1091 e->event.sequence = vblwait->request.sequence;
1092 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1093 drm_vblank_put(dev, pipe);
1094 send_vblank_event(dev, e, seq, &now);
1095 vblwait->reply.sequence = seq;
1097 /* drm_handle_vblank_events will call drm_vblank_put */
1098 list_add_tail(&e->base.link, &dev->vblank_event_list);
1099 vblwait->reply.sequence = vblwait->request.sequence;
1102 spin_unlock_irqrestore(&dev->event_lock, flags);
1107 spin_unlock_irqrestore(&dev->event_lock, flags);
1110 drm_vblank_put(dev, pipe);
1117 * \param inode device inode.
1118 * \param file_priv DRM file private.
1119 * \param cmd command.
1120 * \param data user argument, pointing to a drm_wait_vblank structure.
1121 * \return zero on success or a negative number on failure.
1123 * This function enables the vblank interrupt on the pipe requested, then
1124 * sleeps waiting for the requested sequence number to occur, and drops
1125 * the vblank interrupt refcount afterwards. (vblank irq disable follows that
1126 * after a timeout with no further vblank waits scheduled).
1128 int drm_wait_vblank(struct drm_device *dev, void *data,
1129 struct drm_file *file_priv)
1131 union drm_wait_vblank *vblwait = data;
1133 unsigned int flags, seq, crtc, high_crtc;
1135 if (!dev->irq_enabled)
1138 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1141 if (vblwait->request.type &
1142 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1143 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1144 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1145 vblwait->request.type,
1146 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1147 _DRM_VBLANK_HIGH_CRTC_MASK));
1151 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1152 high_crtc = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1154 crtc = high_crtc >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1156 crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1157 if (crtc >= dev->num_crtcs)
1160 ret = drm_vblank_get(dev, crtc);
1162 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1165 seq = drm_vblank_count(dev, crtc);
1167 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1168 case _DRM_VBLANK_RELATIVE:
1169 vblwait->request.sequence += seq;
1170 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1171 case _DRM_VBLANK_ABSOLUTE:
1178 if (flags & _DRM_VBLANK_EVENT) {
1179 /* must hold on to the vblank ref until the event fires
1180 * drm_vblank_put will be called asynchronously
1182 return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
1185 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1186 (seq - vblwait->request.sequence) <= (1<<23)) {
1187 vblwait->request.sequence = seq + 1;
1190 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1191 vblwait->request.sequence, crtc);
1192 dev->vblank[crtc].last_wait = vblwait->request.sequence;
1193 DRM_WAIT_ON(ret, dev->vblank[crtc].queue, 3 * HZ,
1194 (((drm_vblank_count(dev, crtc) -
1195 vblwait->request.sequence) <= (1 << 23)) ||
1196 !dev->irq_enabled));
1198 if (ret != -EINTR) {
1201 vblwait->reply.sequence = drm_vblank_count_and_time(dev, crtc, &now);
1202 vblwait->reply.tval_sec = now.tv_sec;
1203 vblwait->reply.tval_usec = now.tv_usec;
1205 DRM_DEBUG("returning %d to client\n",
1206 vblwait->reply.sequence);
1208 DRM_DEBUG("vblank wait interrupted by signal\n");
1212 drm_vblank_put(dev, crtc);
1216 static void drm_handle_vblank_events(struct drm_device *dev, int crtc)
1218 struct drm_pending_vblank_event *e, *t;
1220 unsigned long flags;
1223 seq = drm_vblank_count_and_time(dev, crtc, &now);
1225 spin_lock_irqsave(&dev->event_lock, flags);
1227 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1228 if (e->pipe != crtc)
1230 if ((seq - e->event.sequence) > (1<<23))
1233 DRM_DEBUG("vblank event on %d, current %d\n",
1234 e->event.sequence, seq);
1236 list_del(&e->base.link);
1237 drm_vblank_put(dev, e->pipe);
1238 send_vblank_event(dev, e, seq, &now);
1241 spin_unlock_irqrestore(&dev->event_lock, flags);
1243 trace_drm_vblank_event(crtc, seq);
1247 * drm_handle_vblank - handle a vblank event
1249 * @crtc: where this event occurred
1251 * Drivers should call this routine in their vblank interrupt handlers to
1252 * update the vblank counter and send any signals that may be pending.
1254 bool drm_handle_vblank(struct drm_device *dev, int crtc)
1258 struct timeval tvblank;
1259 unsigned long irqflags;
1261 if (!dev->num_crtcs)
1264 /* Need timestamp lock to prevent concurrent execution with
1265 * vblank enable/disable, as this would cause inconsistent
1266 * or corrupted timestamps and vblank counts.
1268 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
1270 /* Vblank irq handling disabled. Nothing to do. */
1271 if (!dev->vblank[crtc].enabled) {
1272 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
1276 /* Fetch corresponding timestamp for this vblank interval from
1277 * driver and store it in proper slot of timestamp ringbuffer.
1280 /* Get current timestamp and count. */
1281 vblcount = atomic_read(&dev->vblank[crtc].count);
1282 drm_get_last_vbltimestamp(dev, crtc, &tvblank, DRM_CALLED_FROM_VBLIRQ);
1284 /* Compute time difference to timestamp of last vblank */
1285 diff_ns = timeval_to_ns(&tvblank) -
1286 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
1288 /* Update vblank timestamp and count if at least
1289 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1290 * difference between last stored timestamp and current
1291 * timestamp. A smaller difference means basically
1292 * identical timestamps. Happens if this vblank has
1293 * been already processed and this is a redundant call,
1294 * e.g., due to spurious vblank interrupts. We need to
1295 * ignore those for accounting.
1297 if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) {
1298 /* Store new timestamp in ringbuffer. */
1299 vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
1301 /* Increment cooked vblank count. This also atomically commits
1302 * the timestamp computed above.
1304 smp_mb__before_atomic_inc();
1305 atomic_inc(&dev->vblank[crtc].count);
1306 smp_mb__after_atomic_inc();
1308 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1309 crtc, (int) diff_ns);
1312 wake_up(&dev->vblank[crtc].queue);
1313 drm_handle_vblank_events(dev, crtc);
1315 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
1318 EXPORT_SYMBOL(drm_handle_vblank);