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_vblank_crtc *vblank = (void *)arg;
144 struct drm_device *dev = vblank->dev;
145 unsigned long irqflags;
146 int crtc = vblank->crtc;
148 if (!dev->vblank_disable_allowed)
151 spin_lock_irqsave(&dev->vbl_lock, irqflags);
152 if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) {
153 DRM_DEBUG("disabling vblank on crtc %d\n", crtc);
154 vblank_disable_and_save(dev, crtc);
156 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
159 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 for (crtc = 0; crtc < dev->num_crtcs; crtc++) {
168 del_timer_sync(&dev->vblank[crtc].disable_timer);
169 vblank_disable_fn((unsigned long)&dev->vblank[crtc]);
176 EXPORT_SYMBOL(drm_vblank_cleanup);
178 int drm_vblank_init(struct drm_device *dev, int num_crtcs)
180 int i, ret = -ENOMEM;
182 spin_lock_init(&dev->vbl_lock);
183 spin_lock_init(&dev->vblank_time_lock);
185 dev->num_crtcs = num_crtcs;
187 dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
191 for (i = 0; i < num_crtcs; i++) {
192 dev->vblank[i].dev = dev;
193 dev->vblank[i].crtc = i;
194 init_waitqueue_head(&dev->vblank[i].queue);
195 setup_timer(&dev->vblank[i].disable_timer, vblank_disable_fn,
196 (unsigned long)&dev->vblank[i]);
199 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
201 /* Driver specific high-precision vblank timestamping supported? */
202 if (dev->driver->get_vblank_timestamp)
203 DRM_INFO("Driver supports precise vblank timestamp query.\n");
205 DRM_INFO("No driver support for vblank timestamp query.\n");
207 dev->vblank_disable_allowed = false;
212 drm_vblank_cleanup(dev);
215 EXPORT_SYMBOL(drm_vblank_init);
217 static void drm_irq_vgaarb_nokms(void *cookie, bool state)
219 struct drm_device *dev = cookie;
221 if (dev->driver->vgaarb_irq) {
222 dev->driver->vgaarb_irq(dev, state);
226 if (!dev->irq_enabled)
230 if (dev->driver->irq_uninstall)
231 dev->driver->irq_uninstall(dev);
233 if (dev->driver->irq_preinstall)
234 dev->driver->irq_preinstall(dev);
235 if (dev->driver->irq_postinstall)
236 dev->driver->irq_postinstall(dev);
241 * Install IRQ handler.
243 * \param dev DRM device.
245 * Initializes the IRQ related data. Installs the handler, calling the driver
246 * \c irq_preinstall() and \c irq_postinstall() functions
247 * before and after the installation.
249 int drm_irq_install(struct drm_device *dev, int irq)
252 unsigned long sh_flags = 0;
254 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
260 /* Driver must have been initialized */
261 if (!dev->dev_private)
264 if (dev->irq_enabled)
266 dev->irq_enabled = true;
268 DRM_DEBUG("irq=%d\n", irq);
270 /* Before installing handler */
271 if (dev->driver->irq_preinstall)
272 dev->driver->irq_preinstall(dev);
274 /* Install handler */
275 if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
276 sh_flags = IRQF_SHARED;
278 ret = request_irq(irq, dev->driver->irq_handler,
279 sh_flags, dev->driver->name, dev);
282 dev->irq_enabled = false;
286 if (!drm_core_check_feature(dev, DRIVER_MODESET))
287 vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
289 /* After installing handler */
290 if (dev->driver->irq_postinstall)
291 ret = dev->driver->irq_postinstall(dev);
294 dev->irq_enabled = false;
295 if (!drm_core_check_feature(dev, DRIVER_MODESET))
296 vga_client_register(dev->pdev, NULL, NULL, NULL);
304 EXPORT_SYMBOL(drm_irq_install);
307 * Uninstall the IRQ handler.
309 * \param dev DRM device.
311 * Calls the driver's \c irq_uninstall() function, and stops the irq.
313 int drm_irq_uninstall(struct drm_device *dev)
315 unsigned long irqflags;
319 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
322 irq_enabled = dev->irq_enabled;
323 dev->irq_enabled = false;
326 * Wake up any waiters so they don't hang.
328 if (dev->num_crtcs) {
329 spin_lock_irqsave(&dev->vbl_lock, irqflags);
330 for (i = 0; i < dev->num_crtcs; i++) {
331 wake_up(&dev->vblank[i].queue);
332 dev->vblank[i].enabled = false;
333 dev->vblank[i].last =
334 dev->driver->get_vblank_counter(dev, i);
336 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
342 DRM_DEBUG("irq=%d\n", dev->irq);
344 if (!drm_core_check_feature(dev, DRIVER_MODESET))
345 vga_client_register(dev->pdev, NULL, NULL, NULL);
347 if (dev->driver->irq_uninstall)
348 dev->driver->irq_uninstall(dev);
350 free_irq(dev->irq, dev);
354 EXPORT_SYMBOL(drm_irq_uninstall);
359 * \param inode device inode.
360 * \param file_priv DRM file private.
361 * \param cmd command.
362 * \param arg user argument, pointing to a drm_control structure.
363 * \return zero on success or a negative number on failure.
365 * Calls irq_install() or irq_uninstall() according to \p arg.
367 int drm_control(struct drm_device *dev, void *data,
368 struct drm_file *file_priv)
370 struct drm_control *ctl = data;
373 /* if we haven't irq we fallback for compatibility reasons -
374 * this used to be a separate function in drm_dma.h
377 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
379 if (drm_core_check_feature(dev, DRIVER_MODESET))
381 /* UMS was only ever support on pci devices. */
382 if (WARN_ON(!dev->pdev))
386 case DRM_INST_HANDLER:
387 irq = dev->pdev->irq;
389 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
392 mutex_lock(&dev->struct_mutex);
393 ret = drm_irq_install(dev, irq);
394 mutex_unlock(&dev->struct_mutex);
397 case DRM_UNINST_HANDLER:
398 mutex_lock(&dev->struct_mutex);
399 ret = drm_irq_uninstall(dev);
400 mutex_unlock(&dev->struct_mutex);
409 * drm_calc_timestamping_constants - Calculate vblank timestamp constants
411 * @crtc drm_crtc whose timestamp constants should be updated.
412 * @mode display mode containing the scanout timings
414 * Calculate and store various constants which are later
415 * needed by vblank and swap-completion timestamping, e.g,
416 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
417 * derived from crtc's true scanout timing, so they take
418 * things like panel scaling or other adjustments into account.
420 void drm_calc_timestamping_constants(struct drm_crtc *crtc,
421 const struct drm_display_mode *mode)
423 int linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
424 int dotclock = mode->crtc_clock;
426 /* Valid dotclock? */
428 int frame_size = mode->crtc_htotal * mode->crtc_vtotal;
431 * Convert scanline length in pixels and video
432 * dot clock to line duration, frame duration
433 * and pixel duration in nanoseconds:
435 pixeldur_ns = 1000000 / dotclock;
436 linedur_ns = div_u64((u64) mode->crtc_htotal * 1000000, dotclock);
437 framedur_ns = div_u64((u64) frame_size * 1000000, dotclock);
440 * Fields of interlaced scanout modes are only half a frame duration.
442 if (mode->flags & DRM_MODE_FLAG_INTERLACE)
445 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
448 crtc->pixeldur_ns = pixeldur_ns;
449 crtc->linedur_ns = linedur_ns;
450 crtc->framedur_ns = framedur_ns;
452 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
453 crtc->base.id, mode->crtc_htotal,
454 mode->crtc_vtotal, mode->crtc_vdisplay);
455 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
456 crtc->base.id, dotclock, framedur_ns,
457 linedur_ns, pixeldur_ns);
459 EXPORT_SYMBOL(drm_calc_timestamping_constants);
462 * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
463 * drivers. Implements calculation of exact vblank timestamps from
464 * given drm_display_mode timings and current video scanout position
465 * of a crtc. This can be called from within get_vblank_timestamp()
466 * implementation of a kms driver to implement the actual timestamping.
468 * Should return timestamps conforming to the OML_sync_control OpenML
469 * extension specification. The timestamp corresponds to the end of
470 * the vblank interval, aka start of scanout of topmost-leftmost display
471 * pixel in the following video frame.
473 * Requires support for optional dev->driver->get_scanout_position()
474 * in kms driver, plus a bit of setup code to provide a drm_display_mode
475 * that corresponds to the true scanout timing.
477 * The current implementation only handles standard video modes. It
478 * returns as no operation if a doublescan or interlaced video mode is
479 * active. Higher level code is expected to handle this.
482 * @crtc: Which crtc's vblank timestamp to retrieve.
483 * @max_error: Desired maximum allowable error in timestamps (nanosecs).
484 * On return contains true maximum error of timestamp.
485 * @vblank_time: Pointer to struct timeval which should receive the timestamp.
486 * @flags: Flags to pass to driver:
488 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
489 * @refcrtc: drm_crtc* of crtc which defines scanout timing.
490 * @mode: mode which defines the scanout timings
492 * Returns negative value on error, failure or if not supported in current
495 * -EINVAL - Invalid crtc.
496 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
497 * -ENOTSUPP - Function not supported in current display mode.
498 * -EIO - Failed, e.g., due to failed scanout position query.
500 * Returns or'ed positive status flags on success:
502 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
503 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
506 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
508 struct timeval *vblank_time,
510 const struct drm_crtc *refcrtc,
511 const struct drm_display_mode *mode)
513 ktime_t stime, etime, mono_time_offset;
514 struct timeval tv_etime;
517 int framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
520 if (crtc < 0 || crtc >= dev->num_crtcs) {
521 DRM_ERROR("Invalid crtc %d\n", crtc);
525 /* Scanout position query not supported? Should not happen. */
526 if (!dev->driver->get_scanout_position) {
527 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
531 /* Durations of frames, lines, pixels in nanoseconds. */
532 framedur_ns = refcrtc->framedur_ns;
533 linedur_ns = refcrtc->linedur_ns;
534 pixeldur_ns = refcrtc->pixeldur_ns;
536 /* If mode timing undefined, just return as no-op:
537 * Happens during initial modesetting of a crtc.
539 if (framedur_ns == 0) {
540 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc);
544 /* Get current scanout position with system timestamp.
545 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
546 * if single query takes longer than max_error nanoseconds.
548 * This guarantees a tight bound on maximum error if
549 * code gets preempted or delayed for some reason.
551 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
553 * Get vertical and horizontal scanout position vpos, hpos,
554 * and bounding timestamps stime, etime, pre/post query.
556 vbl_status = dev->driver->get_scanout_position(dev, crtc, flags, &vpos,
557 &hpos, &stime, &etime);
560 * Get correction for CLOCK_MONOTONIC -> CLOCK_REALTIME if
561 * CLOCK_REALTIME is requested.
563 if (!drm_timestamp_monotonic)
564 mono_time_offset = ktime_get_monotonic_offset();
566 /* Return as no-op if scanout query unsupported or failed. */
567 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
568 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
573 /* Compute uncertainty in timestamp of scanout position query. */
574 duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
576 /* Accept result with < max_error nsecs timing uncertainty. */
577 if (duration_ns <= *max_error)
581 /* Noisy system timing? */
582 if (i == DRM_TIMESTAMP_MAXRETRIES) {
583 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
584 crtc, duration_ns/1000, *max_error/1000, i);
587 /* Return upper bound of timestamp precision error. */
588 *max_error = duration_ns;
590 /* Check if in vblank area:
591 * vpos is >=0 in video scanout area, but negative
592 * within vblank area, counting down the number of lines until
595 invbl = vbl_status & DRM_SCANOUTPOS_INVBL;
597 /* Convert scanout position into elapsed time at raw_time query
598 * since start of scanout at first display scanline. delta_ns
599 * can be negative if start of scanout hasn't happened yet.
601 delta_ns = vpos * linedur_ns + hpos * pixeldur_ns;
603 if (!drm_timestamp_monotonic)
604 etime = ktime_sub(etime, mono_time_offset);
606 /* save this only for debugging purposes */
607 tv_etime = ktime_to_timeval(etime);
608 /* Subtract time delta from raw timestamp to get final
609 * vblank_time timestamp for end of vblank.
612 etime = ktime_add_ns(etime, -delta_ns);
614 etime = ktime_sub_ns(etime, delta_ns);
615 *vblank_time = ktime_to_timeval(etime);
617 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
618 crtc, (int)vbl_status, hpos, vpos,
619 (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
620 (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
621 duration_ns/1000, i);
623 vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
625 vbl_status |= DRM_VBLANKTIME_INVBL;
629 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
631 static struct timeval get_drm_timestamp(void)
636 if (!drm_timestamp_monotonic)
637 now = ktime_sub(now, ktime_get_monotonic_offset());
639 return ktime_to_timeval(now);
643 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
647 * @crtc: which crtc's vblank timestamp to retrieve
648 * @tvblank: Pointer to target struct timeval which should receive the timestamp
649 * @flags: Flags to pass to driver:
651 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
653 * Fetches the system timestamp corresponding to the time of the most recent
654 * vblank interval on specified crtc. May call into kms-driver to
655 * compute the timestamp with a high-precision GPU specific method.
657 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
658 * call, i.e., it isn't very precisely locked to the true vblank.
660 * Returns non-zero if timestamp is considered to be very precise.
662 u32 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
663 struct timeval *tvblank, unsigned flags)
667 /* Define requested maximum error on timestamps (nanoseconds). */
668 int max_error = (int) drm_timestamp_precision * 1000;
670 /* Query driver if possible and precision timestamping enabled. */
671 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
672 ret = dev->driver->get_vblank_timestamp(dev, crtc, &max_error,
678 /* GPU high precision timestamp query unsupported or failed.
679 * Return current monotonic/gettimeofday timestamp as best estimate.
681 *tvblank = get_drm_timestamp();
685 EXPORT_SYMBOL(drm_get_last_vbltimestamp);
688 * drm_vblank_count - retrieve "cooked" vblank counter value
690 * @crtc: which counter to retrieve
692 * Fetches the "cooked" vblank count value that represents the number of
693 * vblank events since the system was booted, including lost events due to
694 * modesetting activity.
696 u32 drm_vblank_count(struct drm_device *dev, int crtc)
698 return atomic_read(&dev->vblank[crtc].count);
700 EXPORT_SYMBOL(drm_vblank_count);
703 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
704 * and the system timestamp corresponding to that vblank counter value.
707 * @crtc: which counter to retrieve
708 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
710 * Fetches the "cooked" vblank count value that represents the number of
711 * vblank events since the system was booted, including lost events due to
712 * modesetting activity. Returns corresponding system timestamp of the time
713 * of the vblank interval that corresponds to the current value vblank counter
716 u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
717 struct timeval *vblanktime)
721 /* Read timestamp from slot of _vblank_time ringbuffer
722 * that corresponds to current vblank count. Retry if
723 * count has incremented during readout. This works like
727 cur_vblank = atomic_read(&dev->vblank[crtc].count);
728 *vblanktime = vblanktimestamp(dev, crtc, cur_vblank);
730 } while (cur_vblank != atomic_read(&dev->vblank[crtc].count));
734 EXPORT_SYMBOL(drm_vblank_count_and_time);
736 static void send_vblank_event(struct drm_device *dev,
737 struct drm_pending_vblank_event *e,
738 unsigned long seq, struct timeval *now)
740 WARN_ON_SMP(!spin_is_locked(&dev->event_lock));
741 e->event.sequence = seq;
742 e->event.tv_sec = now->tv_sec;
743 e->event.tv_usec = now->tv_usec;
745 list_add_tail(&e->base.link,
746 &e->base.file_priv->event_list);
747 wake_up_interruptible(&e->base.file_priv->event_wait);
748 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
753 * drm_send_vblank_event - helper to send vblank event after pageflip
755 * @crtc: CRTC in question
756 * @e: the event to send
758 * Updates sequence # and timestamp on event, and sends it to userspace.
759 * Caller must hold event lock.
761 void drm_send_vblank_event(struct drm_device *dev, int crtc,
762 struct drm_pending_vblank_event *e)
767 seq = drm_vblank_count_and_time(dev, crtc, &now);
771 now = get_drm_timestamp();
774 send_vblank_event(dev, e, seq, &now);
776 EXPORT_SYMBOL(drm_send_vblank_event);
779 * drm_update_vblank_count - update the master vblank counter
781 * @crtc: counter to update
783 * Call back into the driver to update the appropriate vblank counter
784 * (specified by @crtc). Deal with wraparound, if it occurred, and
785 * update the last read value so we can deal with wraparound on the next
788 * Only necessary when going from off->on, to account for frames we
789 * didn't get an interrupt for.
791 * Note: caller must hold dev->vbl_lock since this reads & writes
792 * device vblank fields.
794 static void drm_update_vblank_count(struct drm_device *dev, int crtc)
796 u32 cur_vblank, diff, tslot, rc;
797 struct timeval t_vblank;
800 * Interrupts were disabled prior to this call, so deal with counter
802 * NOTE! It's possible we lost a full dev->max_vblank_count events
803 * here if the register is small or we had vblank interrupts off for
806 * We repeat the hardware vblank counter & timestamp query until
807 * we get consistent results. This to prevent races between gpu
808 * updating its hardware counter while we are retrieving the
809 * corresponding vblank timestamp.
812 cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
813 rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0);
814 } while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc));
816 /* Deal with counter wrap */
817 diff = cur_vblank - dev->vblank[crtc].last;
818 if (cur_vblank < dev->vblank[crtc].last) {
819 diff += dev->max_vblank_count;
821 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
822 crtc, dev->vblank[crtc].last, cur_vblank, diff);
825 DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
828 /* Reinitialize corresponding vblank timestamp if high-precision query
829 * available. Skip this step if query unsupported or failed. Will
830 * reinitialize delayed at next vblank interrupt in that case.
833 tslot = atomic_read(&dev->vblank[crtc].count) + diff;
834 vblanktimestamp(dev, crtc, tslot) = t_vblank;
837 smp_mb__before_atomic_inc();
838 atomic_add(diff, &dev->vblank[crtc].count);
839 smp_mb__after_atomic_inc();
843 * drm_vblank_enable - enable the vblank interrupt on a CRTC
845 * @crtc: CRTC in question
847 static int drm_vblank_enable(struct drm_device *dev, int crtc)
851 assert_spin_locked(&dev->vbl_lock);
853 spin_lock(&dev->vblank_time_lock);
855 if (!dev->vblank[crtc].enabled) {
856 /* Enable vblank irqs under vblank_time_lock protection.
857 * All vblank count & timestamp updates are held off
858 * until we are done reinitializing master counter and
859 * timestamps. Filtercode in drm_handle_vblank() will
860 * prevent double-accounting of same vblank interval.
862 ret = dev->driver->enable_vblank(dev, crtc);
863 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n", crtc, ret);
865 atomic_dec(&dev->vblank[crtc].refcount);
867 dev->vblank[crtc].enabled = true;
868 drm_update_vblank_count(dev, crtc);
872 spin_unlock(&dev->vblank_time_lock);
878 * drm_vblank_get - get a reference count on vblank events
880 * @crtc: which CRTC to own
882 * Acquire a reference count on vblank events to avoid having them disabled
886 * Zero on success, nonzero on failure.
888 int drm_vblank_get(struct drm_device *dev, int crtc)
890 unsigned long irqflags;
893 spin_lock_irqsave(&dev->vbl_lock, irqflags);
894 /* Going from 0->1 means we have to enable interrupts again */
895 if (atomic_add_return(1, &dev->vblank[crtc].refcount) == 1) {
896 ret = drm_vblank_enable(dev, crtc);
898 if (!dev->vblank[crtc].enabled) {
899 atomic_dec(&dev->vblank[crtc].refcount);
903 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
907 EXPORT_SYMBOL(drm_vblank_get);
910 * drm_vblank_put - give up ownership of vblank events
912 * @crtc: which counter to give up
914 * Release ownership of a given vblank counter, turning off interrupts
915 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
917 void drm_vblank_put(struct drm_device *dev, int crtc)
919 BUG_ON(atomic_read(&dev->vblank[crtc].refcount) == 0);
921 /* Last user schedules interrupt disable */
922 if (atomic_dec_and_test(&dev->vblank[crtc].refcount) &&
923 (drm_vblank_offdelay > 0))
924 mod_timer(&dev->vblank[crtc].disable_timer,
925 jiffies + ((drm_vblank_offdelay * HZ)/1000));
927 EXPORT_SYMBOL(drm_vblank_put);
930 * drm_vblank_off - disable vblank events on a CRTC
932 * @crtc: CRTC in question
934 void drm_vblank_off(struct drm_device *dev, int crtc)
936 struct drm_pending_vblank_event *e, *t;
938 unsigned long irqflags;
941 spin_lock_irqsave(&dev->vbl_lock, irqflags);
942 vblank_disable_and_save(dev, crtc);
943 wake_up(&dev->vblank[crtc].queue);
945 /* Send any queued vblank events, lest the natives grow disquiet */
946 seq = drm_vblank_count_and_time(dev, crtc, &now);
948 spin_lock(&dev->event_lock);
949 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
952 DRM_DEBUG("Sending premature vblank event on disable: \
953 wanted %d, current %d\n",
954 e->event.sequence, seq);
955 list_del(&e->base.link);
956 drm_vblank_put(dev, e->pipe);
957 send_vblank_event(dev, e, seq, &now);
959 spin_unlock(&dev->event_lock);
961 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
963 EXPORT_SYMBOL(drm_vblank_off);
966 * drm_vblank_on - enable vblank events on a CRTC
968 * @crtc: CRTC in question
970 void drm_vblank_on(struct drm_device *dev, int crtc)
972 unsigned long irqflags;
974 spin_lock_irqsave(&dev->vbl_lock, irqflags);
975 /* re-enable interrupts if there's are users left */
976 if (atomic_read(&dev->vblank[crtc].refcount) != 0)
977 WARN_ON(drm_vblank_enable(dev, crtc));
978 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
980 EXPORT_SYMBOL(drm_vblank_on);
983 * drm_vblank_pre_modeset - account for vblanks across mode sets
985 * @crtc: CRTC in question
987 * Account for vblank events across mode setting events, which will likely
988 * reset the hardware frame counter.
990 void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
992 /* vblank is not initialized (IRQ not installed ?), or has been freed */
996 * To avoid all the problems that might happen if interrupts
997 * were enabled/disabled around or between these calls, we just
998 * have the kernel take a reference on the CRTC (just once though
999 * to avoid corrupting the count if multiple, mismatch calls occur),
1000 * so that interrupts remain enabled in the interim.
1002 if (!dev->vblank[crtc].inmodeset) {
1003 dev->vblank[crtc].inmodeset = 0x1;
1004 if (drm_vblank_get(dev, crtc) == 0)
1005 dev->vblank[crtc].inmodeset |= 0x2;
1008 EXPORT_SYMBOL(drm_vblank_pre_modeset);
1010 void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
1012 unsigned long irqflags;
1014 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1015 if (!dev->num_crtcs)
1018 if (dev->vblank[crtc].inmodeset) {
1019 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1020 dev->vblank_disable_allowed = true;
1021 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1023 if (dev->vblank[crtc].inmodeset & 0x2)
1024 drm_vblank_put(dev, crtc);
1026 dev->vblank[crtc].inmodeset = 0;
1029 EXPORT_SYMBOL(drm_vblank_post_modeset);
1032 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1033 * @DRM_IOCTL_ARGS: standard ioctl arguments
1035 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1036 * ioctls around modesetting so that any lost vblank events are accounted for.
1038 * Generally the counter will reset across mode sets. If interrupts are
1039 * enabled around this call, we don't have to do anything since the counter
1040 * will have already been incremented.
1042 int drm_modeset_ctl(struct drm_device *dev, void *data,
1043 struct drm_file *file_priv)
1045 struct drm_modeset_ctl *modeset = data;
1048 /* If drm_vblank_init() hasn't been called yet, just no-op */
1049 if (!dev->num_crtcs)
1052 /* KMS drivers handle this internally */
1053 if (drm_core_check_feature(dev, DRIVER_MODESET))
1056 crtc = modeset->crtc;
1057 if (crtc >= dev->num_crtcs)
1060 switch (modeset->cmd) {
1061 case _DRM_PRE_MODESET:
1062 drm_vblank_pre_modeset(dev, crtc);
1064 case _DRM_POST_MODESET:
1065 drm_vblank_post_modeset(dev, crtc);
1074 static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
1075 union drm_wait_vblank *vblwait,
1076 struct drm_file *file_priv)
1078 struct drm_pending_vblank_event *e;
1080 unsigned long flags;
1084 e = kzalloc(sizeof *e, GFP_KERNEL);
1091 e->base.pid = current->pid;
1092 e->event.base.type = DRM_EVENT_VBLANK;
1093 e->event.base.length = sizeof e->event;
1094 e->event.user_data = vblwait->request.signal;
1095 e->base.event = &e->event.base;
1096 e->base.file_priv = file_priv;
1097 e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
1099 spin_lock_irqsave(&dev->event_lock, flags);
1101 if (file_priv->event_space < sizeof e->event) {
1106 file_priv->event_space -= sizeof e->event;
1107 seq = drm_vblank_count_and_time(dev, pipe, &now);
1109 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1110 (seq - vblwait->request.sequence) <= (1 << 23)) {
1111 vblwait->request.sequence = seq + 1;
1112 vblwait->reply.sequence = vblwait->request.sequence;
1115 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1116 vblwait->request.sequence, seq, pipe);
1118 trace_drm_vblank_event_queued(current->pid, pipe,
1119 vblwait->request.sequence);
1121 e->event.sequence = vblwait->request.sequence;
1122 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1123 drm_vblank_put(dev, pipe);
1124 send_vblank_event(dev, e, seq, &now);
1125 vblwait->reply.sequence = seq;
1127 /* drm_handle_vblank_events will call drm_vblank_put */
1128 list_add_tail(&e->base.link, &dev->vblank_event_list);
1129 vblwait->reply.sequence = vblwait->request.sequence;
1132 spin_unlock_irqrestore(&dev->event_lock, flags);
1137 spin_unlock_irqrestore(&dev->event_lock, flags);
1140 drm_vblank_put(dev, pipe);
1147 * \param inode device inode.
1148 * \param file_priv DRM file private.
1149 * \param cmd command.
1150 * \param data user argument, pointing to a drm_wait_vblank structure.
1151 * \return zero on success or a negative number on failure.
1153 * This function enables the vblank interrupt on the pipe requested, then
1154 * sleeps waiting for the requested sequence number to occur, and drops
1155 * the vblank interrupt refcount afterwards. (vblank irq disable follows that
1156 * after a timeout with no further vblank waits scheduled).
1158 int drm_wait_vblank(struct drm_device *dev, void *data,
1159 struct drm_file *file_priv)
1161 union drm_wait_vblank *vblwait = data;
1163 unsigned int flags, seq, crtc, high_crtc;
1165 if (!dev->irq_enabled)
1168 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1171 if (vblwait->request.type &
1172 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1173 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1174 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1175 vblwait->request.type,
1176 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1177 _DRM_VBLANK_HIGH_CRTC_MASK));
1181 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1182 high_crtc = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1184 crtc = high_crtc >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1186 crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1187 if (crtc >= dev->num_crtcs)
1190 ret = drm_vblank_get(dev, crtc);
1192 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1195 seq = drm_vblank_count(dev, crtc);
1197 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1198 case _DRM_VBLANK_RELATIVE:
1199 vblwait->request.sequence += seq;
1200 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1201 case _DRM_VBLANK_ABSOLUTE:
1208 if (flags & _DRM_VBLANK_EVENT) {
1209 /* must hold on to the vblank ref until the event fires
1210 * drm_vblank_put will be called asynchronously
1212 return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
1215 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1216 (seq - vblwait->request.sequence) <= (1<<23)) {
1217 vblwait->request.sequence = seq + 1;
1220 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1221 vblwait->request.sequence, crtc);
1222 dev->vblank[crtc].last_wait = vblwait->request.sequence;
1223 DRM_WAIT_ON(ret, dev->vblank[crtc].queue, 3 * HZ,
1224 (((drm_vblank_count(dev, crtc) -
1225 vblwait->request.sequence) <= (1 << 23)) ||
1226 !dev->vblank[crtc].enabled ||
1227 !dev->irq_enabled));
1229 if (ret != -EINTR) {
1232 vblwait->reply.sequence = drm_vblank_count_and_time(dev, crtc, &now);
1233 vblwait->reply.tval_sec = now.tv_sec;
1234 vblwait->reply.tval_usec = now.tv_usec;
1236 DRM_DEBUG("returning %d to client\n",
1237 vblwait->reply.sequence);
1239 DRM_DEBUG("vblank wait interrupted by signal\n");
1243 drm_vblank_put(dev, crtc);
1247 static void drm_handle_vblank_events(struct drm_device *dev, int crtc)
1249 struct drm_pending_vblank_event *e, *t;
1251 unsigned long flags;
1254 seq = drm_vblank_count_and_time(dev, crtc, &now);
1256 spin_lock_irqsave(&dev->event_lock, flags);
1258 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1259 if (e->pipe != crtc)
1261 if ((seq - e->event.sequence) > (1<<23))
1264 DRM_DEBUG("vblank event on %d, current %d\n",
1265 e->event.sequence, seq);
1267 list_del(&e->base.link);
1268 drm_vblank_put(dev, e->pipe);
1269 send_vblank_event(dev, e, seq, &now);
1272 spin_unlock_irqrestore(&dev->event_lock, flags);
1274 trace_drm_vblank_event(crtc, seq);
1278 * drm_handle_vblank - handle a vblank event
1280 * @crtc: where this event occurred
1282 * Drivers should call this routine in their vblank interrupt handlers to
1283 * update the vblank counter and send any signals that may be pending.
1285 bool drm_handle_vblank(struct drm_device *dev, int crtc)
1289 struct timeval tvblank;
1290 unsigned long irqflags;
1292 if (!dev->num_crtcs)
1295 /* Need timestamp lock to prevent concurrent execution with
1296 * vblank enable/disable, as this would cause inconsistent
1297 * or corrupted timestamps and vblank counts.
1299 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
1301 /* Vblank irq handling disabled. Nothing to do. */
1302 if (!dev->vblank[crtc].enabled) {
1303 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
1307 /* Fetch corresponding timestamp for this vblank interval from
1308 * driver and store it in proper slot of timestamp ringbuffer.
1311 /* Get current timestamp and count. */
1312 vblcount = atomic_read(&dev->vblank[crtc].count);
1313 drm_get_last_vbltimestamp(dev, crtc, &tvblank, DRM_CALLED_FROM_VBLIRQ);
1315 /* Compute time difference to timestamp of last vblank */
1316 diff_ns = timeval_to_ns(&tvblank) -
1317 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
1319 /* Update vblank timestamp and count if at least
1320 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1321 * difference between last stored timestamp and current
1322 * timestamp. A smaller difference means basically
1323 * identical timestamps. Happens if this vblank has
1324 * been already processed and this is a redundant call,
1325 * e.g., due to spurious vblank interrupts. We need to
1326 * ignore those for accounting.
1328 if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) {
1329 /* Store new timestamp in ringbuffer. */
1330 vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
1332 /* Increment cooked vblank count. This also atomically commits
1333 * the timestamp computed above.
1335 smp_mb__before_atomic_inc();
1336 atomic_inc(&dev->vblank[crtc].count);
1337 smp_mb__after_atomic_inc();
1339 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1340 crtc, (int) diff_ns);
1343 wake_up(&dev->vblank[crtc].queue);
1344 drm_handle_vblank_events(dev, crtc);
1346 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
1349 EXPORT_SYMBOL(drm_handle_vblank);