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 * Get interrupt from bus id.
62 * \param inode device inode.
63 * \param file_priv DRM file private.
65 * \param arg user argument, pointing to a drm_irq_busid structure.
66 * \return zero on success or a negative number on failure.
68 * Finds the PCI device with the specified bus id and gets its IRQ number.
69 * This IOCTL is deprecated, and will now return EINVAL for any busid not equal
70 * to that of the device that this DRM instance attached to.
72 int drm_irq_by_busid(struct drm_device *dev, void *data,
73 struct drm_file *file_priv)
75 struct drm_irq_busid *p = data;
77 if (!dev->driver->bus->irq_by_busid)
80 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
83 return dev->driver->bus->irq_by_busid(dev, p);
87 * Clear vblank timestamp buffer for a crtc.
89 static void clear_vblank_timestamps(struct drm_device *dev, int crtc)
91 memset(dev->vblank[crtc].time, 0, sizeof(dev->vblank[crtc].time));
95 * Disable vblank irq's on crtc, make sure that last vblank count
96 * of hardware and corresponding consistent software vblank counter
97 * are preserved, even if there are any spurious vblank irq's after
100 static void vblank_disable_and_save(struct drm_device *dev, int crtc)
102 unsigned long irqflags;
106 struct timeval tvblank;
107 int count = DRM_TIMESTAMP_MAXRETRIES;
109 /* Prevent vblank irq processing while disabling vblank irqs,
110 * so no updates of timestamps or count can happen after we've
111 * disabled. Needed to prevent races in case of delayed irq's.
113 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
115 dev->driver->disable_vblank(dev, crtc);
116 dev->vblank[crtc].enabled = false;
118 /* No further vblank irq's will be processed after
119 * this point. Get current hardware vblank count and
120 * vblank timestamp, repeat until they are consistent.
122 * FIXME: There is still a race condition here and in
123 * drm_update_vblank_count() which can cause off-by-one
124 * reinitialization of software vblank counter. If gpu
125 * vblank counter doesn't increment exactly at the leading
126 * edge of a vblank interval, then we can lose 1 count if
127 * we happen to execute between start of vblank and the
128 * delayed gpu counter increment.
131 dev->vblank[crtc].last = dev->driver->get_vblank_counter(dev, crtc);
132 vblrc = drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0);
133 } while (dev->vblank[crtc].last != dev->driver->get_vblank_counter(dev, crtc) && (--count) && vblrc);
138 /* Compute time difference to stored timestamp of last vblank
139 * as updated by last invocation of drm_handle_vblank() in vblank irq.
141 vblcount = atomic_read(&dev->vblank[crtc].count);
142 diff_ns = timeval_to_ns(&tvblank) -
143 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
145 /* If there is at least 1 msec difference between the last stored
146 * timestamp and tvblank, then we are currently executing our
147 * disable inside a new vblank interval, the tvblank timestamp
148 * corresponds to this new vblank interval and the irq handler
149 * for this vblank didn't run yet and won't run due to our disable.
150 * Therefore we need to do the job of drm_handle_vblank() and
151 * increment the vblank counter by one to account for this vblank.
153 * Skip this step if there isn't any high precision timestamp
154 * available. In that case we can't account for this and just
157 if ((vblrc > 0) && (abs64(diff_ns) > 1000000)) {
158 atomic_inc(&dev->vblank[crtc].count);
159 smp_mb__after_atomic_inc();
162 /* Invalidate all timestamps while vblank irq's are off. */
163 clear_vblank_timestamps(dev, crtc);
165 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
168 static void vblank_disable_fn(unsigned long arg)
170 struct drm_device *dev = (struct drm_device *)arg;
171 unsigned long irqflags;
174 if (!dev->vblank_disable_allowed)
177 for (i = 0; i < dev->num_crtcs; i++) {
178 spin_lock_irqsave(&dev->vbl_lock, irqflags);
179 if (atomic_read(&dev->vblank[i].refcount) == 0 &&
180 dev->vblank[i].enabled) {
181 DRM_DEBUG("disabling vblank on crtc %d\n", i);
182 vblank_disable_and_save(dev, i);
184 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
188 void drm_vblank_cleanup(struct drm_device *dev)
190 /* Bail if the driver didn't call drm_vblank_init() */
191 if (dev->num_crtcs == 0)
194 del_timer_sync(&dev->vblank_disable_timer);
196 vblank_disable_fn((unsigned long)dev);
202 EXPORT_SYMBOL(drm_vblank_cleanup);
204 int drm_vblank_init(struct drm_device *dev, int num_crtcs)
206 int i, ret = -ENOMEM;
208 setup_timer(&dev->vblank_disable_timer, vblank_disable_fn,
210 spin_lock_init(&dev->vbl_lock);
211 spin_lock_init(&dev->vblank_time_lock);
213 dev->num_crtcs = num_crtcs;
215 dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
219 for (i = 0; i < num_crtcs; i++)
220 init_waitqueue_head(&dev->vblank[i].queue);
222 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
224 /* Driver specific high-precision vblank timestamping supported? */
225 if (dev->driver->get_vblank_timestamp)
226 DRM_INFO("Driver supports precise vblank timestamp query.\n");
228 DRM_INFO("No driver support for vblank timestamp query.\n");
230 dev->vblank_disable_allowed = false;
235 drm_vblank_cleanup(dev);
238 EXPORT_SYMBOL(drm_vblank_init);
240 static void drm_irq_vgaarb_nokms(void *cookie, bool state)
242 struct drm_device *dev = cookie;
244 if (dev->driver->vgaarb_irq) {
245 dev->driver->vgaarb_irq(dev, state);
249 if (!dev->irq_enabled)
253 if (dev->driver->irq_uninstall)
254 dev->driver->irq_uninstall(dev);
256 if (dev->driver->irq_preinstall)
257 dev->driver->irq_preinstall(dev);
258 if (dev->driver->irq_postinstall)
259 dev->driver->irq_postinstall(dev);
264 * Install IRQ handler.
266 * \param dev DRM device.
268 * Initializes the IRQ related data. Installs the handler, calling the driver
269 * \c irq_preinstall() and \c irq_postinstall() functions
270 * before and after the installation.
272 int drm_irq_install(struct drm_device *dev)
275 unsigned long sh_flags = 0;
278 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
281 if (drm_dev_to_irq(dev) == 0)
284 mutex_lock(&dev->struct_mutex);
286 /* Driver must have been initialized */
287 if (!dev->dev_private) {
288 mutex_unlock(&dev->struct_mutex);
292 if (dev->irq_enabled) {
293 mutex_unlock(&dev->struct_mutex);
296 dev->irq_enabled = true;
297 mutex_unlock(&dev->struct_mutex);
299 DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev));
301 /* Before installing handler */
302 if (dev->driver->irq_preinstall)
303 dev->driver->irq_preinstall(dev);
305 /* Install handler */
306 if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
307 sh_flags = IRQF_SHARED;
310 irqname = dev->devname;
312 irqname = dev->driver->name;
314 ret = request_irq(drm_dev_to_irq(dev), dev->driver->irq_handler,
315 sh_flags, irqname, dev);
318 mutex_lock(&dev->struct_mutex);
319 dev->irq_enabled = false;
320 mutex_unlock(&dev->struct_mutex);
324 if (!drm_core_check_feature(dev, DRIVER_MODESET))
325 vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
327 /* After installing handler */
328 if (dev->driver->irq_postinstall)
329 ret = dev->driver->irq_postinstall(dev);
332 mutex_lock(&dev->struct_mutex);
333 dev->irq_enabled = false;
334 mutex_unlock(&dev->struct_mutex);
335 if (!drm_core_check_feature(dev, DRIVER_MODESET))
336 vga_client_register(dev->pdev, NULL, NULL, NULL);
337 free_irq(drm_dev_to_irq(dev), dev);
342 EXPORT_SYMBOL(drm_irq_install);
345 * Uninstall the IRQ handler.
347 * \param dev DRM device.
349 * Calls the driver's \c irq_uninstall() function, and stops the irq.
351 int drm_irq_uninstall(struct drm_device *dev)
353 unsigned long irqflags;
357 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
360 mutex_lock(&dev->struct_mutex);
361 irq_enabled = dev->irq_enabled;
362 dev->irq_enabled = false;
363 mutex_unlock(&dev->struct_mutex);
366 * Wake up any waiters so they don't hang.
368 if (dev->num_crtcs) {
369 spin_lock_irqsave(&dev->vbl_lock, irqflags);
370 for (i = 0; i < dev->num_crtcs; i++) {
371 wake_up(&dev->vblank[i].queue);
372 dev->vblank[i].enabled = false;
373 dev->vblank[i].last =
374 dev->driver->get_vblank_counter(dev, i);
376 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
382 DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev));
384 if (!drm_core_check_feature(dev, DRIVER_MODESET))
385 vga_client_register(dev->pdev, NULL, NULL, NULL);
387 if (dev->driver->irq_uninstall)
388 dev->driver->irq_uninstall(dev);
390 free_irq(drm_dev_to_irq(dev), dev);
394 EXPORT_SYMBOL(drm_irq_uninstall);
399 * \param inode device inode.
400 * \param file_priv DRM file private.
401 * \param cmd command.
402 * \param arg user argument, pointing to a drm_control structure.
403 * \return zero on success or a negative number on failure.
405 * Calls irq_install() or irq_uninstall() according to \p arg.
407 int drm_control(struct drm_device *dev, void *data,
408 struct drm_file *file_priv)
410 struct drm_control *ctl = data;
412 /* if we haven't irq we fallback for compatibility reasons -
413 * this used to be a separate function in drm_dma.h
418 case DRM_INST_HANDLER:
419 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
421 if (drm_core_check_feature(dev, DRIVER_MODESET))
423 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
424 ctl->irq != drm_dev_to_irq(dev))
426 return drm_irq_install(dev);
427 case DRM_UNINST_HANDLER:
428 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
430 if (drm_core_check_feature(dev, DRIVER_MODESET))
432 return drm_irq_uninstall(dev);
439 * drm_calc_timestamping_constants - Calculate and
440 * store various constants which are later needed by
441 * vblank and swap-completion timestamping, e.g, by
442 * drm_calc_vbltimestamp_from_scanoutpos().
443 * They are derived from crtc's true scanout timing,
444 * so they take things like panel scaling or other
445 * adjustments into account.
447 * @crtc drm_crtc whose timestamp constants should be updated.
448 * @mode display mode containing the scanout timings
451 void drm_calc_timestamping_constants(struct drm_crtc *crtc,
452 const struct drm_display_mode *mode)
454 s64 linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
457 /* Dot clock in Hz: */
458 dotclock = (u64) mode->clock * 1000;
460 /* Fields of interlaced scanout modes are only half a frame duration.
461 * Double the dotclock to get half the frame-/line-/pixelduration.
463 if (mode->flags & DRM_MODE_FLAG_INTERLACE)
466 /* Valid dotclock? */
469 /* Convert scanline length in pixels and video dot clock to
470 * line duration, frame duration and pixel duration in
473 pixeldur_ns = (s64) div64_u64(1000000000, dotclock);
474 linedur_ns = (s64) div64_u64(((u64) mode->crtc_htotal *
475 1000000000), dotclock);
476 frame_size = mode->crtc_htotal * mode->crtc_vtotal;
477 framedur_ns = (s64) div64_u64((u64) frame_size * 1000000000,
480 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
483 crtc->pixeldur_ns = pixeldur_ns;
484 crtc->linedur_ns = linedur_ns;
485 crtc->framedur_ns = framedur_ns;
487 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
488 crtc->base.id, mode->crtc_htotal,
489 mode->crtc_vtotal, mode->crtc_vdisplay);
490 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
491 crtc->base.id, (int) dotclock/1000, (int) framedur_ns,
492 (int) linedur_ns, (int) pixeldur_ns);
494 EXPORT_SYMBOL(drm_calc_timestamping_constants);
497 * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
498 * drivers. Implements calculation of exact vblank timestamps from
499 * given drm_display_mode timings and current video scanout position
500 * of a crtc. This can be called from within get_vblank_timestamp()
501 * implementation of a kms driver to implement the actual timestamping.
503 * Should return timestamps conforming to the OML_sync_control OpenML
504 * extension specification. The timestamp corresponds to the end of
505 * the vblank interval, aka start of scanout of topmost-leftmost display
506 * pixel in the following video frame.
508 * Requires support for optional dev->driver->get_scanout_position()
509 * in kms driver, plus a bit of setup code to provide a drm_display_mode
510 * that corresponds to the true scanout timing.
512 * The current implementation only handles standard video modes. It
513 * returns as no operation if a doublescan or interlaced video mode is
514 * active. Higher level code is expected to handle this.
517 * @crtc: Which crtc's vblank timestamp to retrieve.
518 * @max_error: Desired maximum allowable error in timestamps (nanosecs).
519 * On return contains true maximum error of timestamp.
520 * @vblank_time: Pointer to struct timeval which should receive the timestamp.
521 * @flags: Flags to pass to driver:
523 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
524 * @refcrtc: drm_crtc* of crtc which defines scanout timing.
526 * Returns negative value on error, failure or if not supported in current
529 * -EINVAL - Invalid crtc.
530 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
531 * -ENOTSUPP - Function not supported in current display mode.
532 * -EIO - Failed, e.g., due to failed scanout position query.
534 * Returns or'ed positive status flags on success:
536 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
537 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
540 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
542 struct timeval *vblank_time,
544 struct drm_crtc *refcrtc)
546 ktime_t stime, etime, mono_time_offset;
547 struct timeval tv_etime;
548 struct drm_display_mode *mode;
549 int vbl_status, vtotal, vdisplay;
551 s64 framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
554 if (crtc < 0 || crtc >= dev->num_crtcs) {
555 DRM_ERROR("Invalid crtc %d\n", crtc);
559 /* Scanout position query not supported? Should not happen. */
560 if (!dev->driver->get_scanout_position) {
561 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
565 mode = &refcrtc->hwmode;
566 vtotal = mode->crtc_vtotal;
567 vdisplay = mode->crtc_vdisplay;
569 /* Durations of frames, lines, pixels in nanoseconds. */
570 framedur_ns = refcrtc->framedur_ns;
571 linedur_ns = refcrtc->linedur_ns;
572 pixeldur_ns = refcrtc->pixeldur_ns;
574 /* If mode timing undefined, just return as no-op:
575 * Happens during initial modesetting of a crtc.
577 if (vtotal <= 0 || vdisplay <= 0 || framedur_ns == 0) {
578 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc);
582 /* Get current scanout position with system timestamp.
583 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
584 * if single query takes longer than max_error nanoseconds.
586 * This guarantees a tight bound on maximum error if
587 * code gets preempted or delayed for some reason.
589 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
591 * Get vertical and horizontal scanout position vpos, hpos,
592 * and bounding timestamps stime, etime, pre/post query.
594 vbl_status = dev->driver->get_scanout_position(dev, crtc, &vpos,
595 &hpos, &stime, &etime);
598 * Get correction for CLOCK_MONOTONIC -> CLOCK_REALTIME if
599 * CLOCK_REALTIME is requested.
601 if (!drm_timestamp_monotonic)
602 mono_time_offset = ktime_get_monotonic_offset();
604 /* Return as no-op if scanout query unsupported or failed. */
605 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
606 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
611 /* Compute uncertainty in timestamp of scanout position query. */
612 duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
614 /* Accept result with < max_error nsecs timing uncertainty. */
615 if (duration_ns <= (s64) *max_error)
619 /* Noisy system timing? */
620 if (i == DRM_TIMESTAMP_MAXRETRIES) {
621 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
622 crtc, (int) duration_ns/1000, *max_error/1000, i);
625 /* Return upper bound of timestamp precision error. */
626 *max_error = (int) duration_ns;
628 /* Check if in vblank area:
629 * vpos is >=0 in video scanout area, but negative
630 * within vblank area, counting down the number of lines until
633 invbl = vbl_status & DRM_SCANOUTPOS_INVBL;
635 /* Convert scanout position into elapsed time at raw_time query
636 * since start of scanout at first display scanline. delta_ns
637 * can be negative if start of scanout hasn't happened yet.
639 delta_ns = (s64) vpos * linedur_ns + (s64) hpos * pixeldur_ns;
641 /* Is vpos outside nominal vblank area, but less than
642 * 1/100 of a frame height away from start of vblank?
643 * If so, assume this isn't a massively delayed vblank
644 * interrupt, but a vblank interrupt that fired a few
645 * microseconds before true start of vblank. Compensate
646 * by adding a full frame duration to the final timestamp.
647 * Happens, e.g., on ATI R500, R600.
649 * We only do this if DRM_CALLED_FROM_VBLIRQ.
651 if ((flags & DRM_CALLED_FROM_VBLIRQ) && !invbl &&
652 ((vdisplay - vpos) < vtotal / 100)) {
653 delta_ns = delta_ns - framedur_ns;
655 /* Signal this correction as "applied". */
659 if (!drm_timestamp_monotonic)
660 etime = ktime_sub(etime, mono_time_offset);
662 /* save this only for debugging purposes */
663 tv_etime = ktime_to_timeval(etime);
664 /* Subtract time delta from raw timestamp to get final
665 * vblank_time timestamp for end of vblank.
668 etime = ktime_add_ns(etime, -delta_ns);
670 etime = ktime_sub_ns(etime, delta_ns);
671 *vblank_time = ktime_to_timeval(etime);
673 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
674 crtc, (int)vbl_status, hpos, vpos,
675 (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
676 (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
677 (int)duration_ns/1000, i);
679 vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
681 vbl_status |= DRM_VBLANKTIME_INVBL;
685 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
687 static struct timeval get_drm_timestamp(void)
692 if (!drm_timestamp_monotonic)
693 now = ktime_sub(now, ktime_get_monotonic_offset());
695 return ktime_to_timeval(now);
699 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
703 * @crtc: which crtc's vblank timestamp to retrieve
704 * @tvblank: Pointer to target struct timeval which should receive the timestamp
705 * @flags: Flags to pass to driver:
707 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
709 * Fetches the system timestamp corresponding to the time of the most recent
710 * vblank interval on specified crtc. May call into kms-driver to
711 * compute the timestamp with a high-precision GPU specific method.
713 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
714 * call, i.e., it isn't very precisely locked to the true vblank.
716 * Returns non-zero if timestamp is considered to be very precise.
718 u32 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
719 struct timeval *tvblank, unsigned flags)
723 /* Define requested maximum error on timestamps (nanoseconds). */
724 int max_error = (int) drm_timestamp_precision * 1000;
726 /* Query driver if possible and precision timestamping enabled. */
727 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
728 ret = dev->driver->get_vblank_timestamp(dev, crtc, &max_error,
734 /* GPU high precision timestamp query unsupported or failed.
735 * Return current monotonic/gettimeofday timestamp as best estimate.
737 *tvblank = get_drm_timestamp();
741 EXPORT_SYMBOL(drm_get_last_vbltimestamp);
744 * drm_vblank_count - retrieve "cooked" vblank counter value
746 * @crtc: which counter to retrieve
748 * Fetches the "cooked" vblank count value that represents the number of
749 * vblank events since the system was booted, including lost events due to
750 * modesetting activity.
752 u32 drm_vblank_count(struct drm_device *dev, int crtc)
754 return atomic_read(&dev->vblank[crtc].count);
756 EXPORT_SYMBOL(drm_vblank_count);
759 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
760 * and the system timestamp corresponding to that vblank counter value.
763 * @crtc: which counter to retrieve
764 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
766 * Fetches the "cooked" vblank count value that represents the number of
767 * vblank events since the system was booted, including lost events due to
768 * modesetting activity. Returns corresponding system timestamp of the time
769 * of the vblank interval that corresponds to the current value vblank counter
772 u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
773 struct timeval *vblanktime)
777 /* Read timestamp from slot of _vblank_time ringbuffer
778 * that corresponds to current vblank count. Retry if
779 * count has incremented during readout. This works like
783 cur_vblank = atomic_read(&dev->vblank[crtc].count);
784 *vblanktime = vblanktimestamp(dev, crtc, cur_vblank);
786 } while (cur_vblank != atomic_read(&dev->vblank[crtc].count));
790 EXPORT_SYMBOL(drm_vblank_count_and_time);
792 static void send_vblank_event(struct drm_device *dev,
793 struct drm_pending_vblank_event *e,
794 unsigned long seq, struct timeval *now)
796 WARN_ON_SMP(!spin_is_locked(&dev->event_lock));
797 e->event.sequence = seq;
798 e->event.tv_sec = now->tv_sec;
799 e->event.tv_usec = now->tv_usec;
801 list_add_tail(&e->base.link,
802 &e->base.file_priv->event_list);
803 wake_up_interruptible(&e->base.file_priv->event_wait);
804 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
809 * drm_send_vblank_event - helper to send vblank event after pageflip
811 * @crtc: CRTC in question
812 * @e: the event to send
814 * Updates sequence # and timestamp on event, and sends it to userspace.
815 * Caller must hold event lock.
817 void drm_send_vblank_event(struct drm_device *dev, int crtc,
818 struct drm_pending_vblank_event *e)
823 seq = drm_vblank_count_and_time(dev, crtc, &now);
827 now = get_drm_timestamp();
830 send_vblank_event(dev, e, seq, &now);
832 EXPORT_SYMBOL(drm_send_vblank_event);
835 * drm_update_vblank_count - update the master vblank counter
837 * @crtc: counter to update
839 * Call back into the driver to update the appropriate vblank counter
840 * (specified by @crtc). Deal with wraparound, if it occurred, and
841 * update the last read value so we can deal with wraparound on the next
844 * Only necessary when going from off->on, to account for frames we
845 * didn't get an interrupt for.
847 * Note: caller must hold dev->vbl_lock since this reads & writes
848 * device vblank fields.
850 static void drm_update_vblank_count(struct drm_device *dev, int crtc)
852 u32 cur_vblank, diff, tslot, rc;
853 struct timeval t_vblank;
856 * Interrupts were disabled prior to this call, so deal with counter
858 * NOTE! It's possible we lost a full dev->max_vblank_count events
859 * here if the register is small or we had vblank interrupts off for
862 * We repeat the hardware vblank counter & timestamp query until
863 * we get consistent results. This to prevent races between gpu
864 * updating its hardware counter while we are retrieving the
865 * corresponding vblank timestamp.
868 cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
869 rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0);
870 } while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc));
872 /* Deal with counter wrap */
873 diff = cur_vblank - dev->vblank[crtc].last;
874 if (cur_vblank < dev->vblank[crtc].last) {
875 diff += dev->max_vblank_count;
877 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
878 crtc, dev->vblank[crtc].last, cur_vblank, diff);
881 DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
884 /* Reinitialize corresponding vblank timestamp if high-precision query
885 * available. Skip this step if query unsupported or failed. Will
886 * reinitialize delayed at next vblank interrupt in that case.
889 tslot = atomic_read(&dev->vblank[crtc].count) + diff;
890 vblanktimestamp(dev, crtc, tslot) = t_vblank;
893 smp_mb__before_atomic_inc();
894 atomic_add(diff, &dev->vblank[crtc].count);
895 smp_mb__after_atomic_inc();
899 * drm_vblank_get - get a reference count on vblank events
901 * @crtc: which CRTC to own
903 * Acquire a reference count on vblank events to avoid having them disabled
907 * Zero on success, nonzero on failure.
909 int drm_vblank_get(struct drm_device *dev, int crtc)
911 unsigned long irqflags, irqflags2;
914 spin_lock_irqsave(&dev->vbl_lock, irqflags);
915 /* Going from 0->1 means we have to enable interrupts again */
916 if (atomic_add_return(1, &dev->vblank[crtc].refcount) == 1) {
917 spin_lock_irqsave(&dev->vblank_time_lock, irqflags2);
918 if (!dev->vblank[crtc].enabled) {
919 /* Enable vblank irqs under vblank_time_lock protection.
920 * All vblank count & timestamp updates are held off
921 * until we are done reinitializing master counter and
922 * timestamps. Filtercode in drm_handle_vblank() will
923 * prevent double-accounting of same vblank interval.
925 ret = dev->driver->enable_vblank(dev, crtc);
926 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n",
929 atomic_dec(&dev->vblank[crtc].refcount);
931 dev->vblank[crtc].enabled = true;
932 drm_update_vblank_count(dev, crtc);
935 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags2);
937 if (!dev->vblank[crtc].enabled) {
938 atomic_dec(&dev->vblank[crtc].refcount);
942 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
946 EXPORT_SYMBOL(drm_vblank_get);
949 * drm_vblank_put - give up ownership of vblank events
951 * @crtc: which counter to give up
953 * Release ownership of a given vblank counter, turning off interrupts
954 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
956 void drm_vblank_put(struct drm_device *dev, int crtc)
958 BUG_ON(atomic_read(&dev->vblank[crtc].refcount) == 0);
960 /* Last user schedules interrupt disable */
961 if (atomic_dec_and_test(&dev->vblank[crtc].refcount) &&
962 (drm_vblank_offdelay > 0))
963 mod_timer(&dev->vblank_disable_timer,
964 jiffies + ((drm_vblank_offdelay * HZ)/1000));
966 EXPORT_SYMBOL(drm_vblank_put);
969 * drm_vblank_off - disable vblank events on a CRTC
971 * @crtc: CRTC in question
973 * Caller must hold event lock.
975 void drm_vblank_off(struct drm_device *dev, int crtc)
977 struct drm_pending_vblank_event *e, *t;
979 unsigned long irqflags;
982 spin_lock_irqsave(&dev->vbl_lock, irqflags);
983 vblank_disable_and_save(dev, crtc);
984 wake_up(&dev->vblank[crtc].queue);
986 /* Send any queued vblank events, lest the natives grow disquiet */
987 seq = drm_vblank_count_and_time(dev, crtc, &now);
989 spin_lock(&dev->event_lock);
990 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
993 DRM_DEBUG("Sending premature vblank event on disable: \
994 wanted %d, current %d\n",
995 e->event.sequence, seq);
996 list_del(&e->base.link);
997 drm_vblank_put(dev, e->pipe);
998 send_vblank_event(dev, e, seq, &now);
1000 spin_unlock(&dev->event_lock);
1002 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1004 EXPORT_SYMBOL(drm_vblank_off);
1007 * drm_vblank_pre_modeset - account for vblanks across mode sets
1009 * @crtc: CRTC in question
1011 * Account for vblank events across mode setting events, which will likely
1012 * reset the hardware frame counter.
1014 void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
1016 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1017 if (!dev->num_crtcs)
1020 * To avoid all the problems that might happen if interrupts
1021 * were enabled/disabled around or between these calls, we just
1022 * have the kernel take a reference on the CRTC (just once though
1023 * to avoid corrupting the count if multiple, mismatch calls occur),
1024 * so that interrupts remain enabled in the interim.
1026 if (!dev->vblank[crtc].inmodeset) {
1027 dev->vblank[crtc].inmodeset = 0x1;
1028 if (drm_vblank_get(dev, crtc) == 0)
1029 dev->vblank[crtc].inmodeset |= 0x2;
1032 EXPORT_SYMBOL(drm_vblank_pre_modeset);
1034 void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
1036 unsigned long irqflags;
1038 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1039 if (!dev->num_crtcs)
1042 if (dev->vblank[crtc].inmodeset) {
1043 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1044 dev->vblank_disable_allowed = true;
1045 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1047 if (dev->vblank[crtc].inmodeset & 0x2)
1048 drm_vblank_put(dev, crtc);
1050 dev->vblank[crtc].inmodeset = 0;
1053 EXPORT_SYMBOL(drm_vblank_post_modeset);
1056 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1057 * @DRM_IOCTL_ARGS: standard ioctl arguments
1059 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1060 * ioctls around modesetting so that any lost vblank events are accounted for.
1062 * Generally the counter will reset across mode sets. If interrupts are
1063 * enabled around this call, we don't have to do anything since the counter
1064 * will have already been incremented.
1066 int drm_modeset_ctl(struct drm_device *dev, void *data,
1067 struct drm_file *file_priv)
1069 struct drm_modeset_ctl *modeset = data;
1072 /* If drm_vblank_init() hasn't been called yet, just no-op */
1073 if (!dev->num_crtcs)
1076 /* KMS drivers handle this internally */
1077 if (drm_core_check_feature(dev, DRIVER_MODESET))
1080 crtc = modeset->crtc;
1081 if (crtc >= dev->num_crtcs)
1084 switch (modeset->cmd) {
1085 case _DRM_PRE_MODESET:
1086 drm_vblank_pre_modeset(dev, crtc);
1088 case _DRM_POST_MODESET:
1089 drm_vblank_post_modeset(dev, crtc);
1098 static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
1099 union drm_wait_vblank *vblwait,
1100 struct drm_file *file_priv)
1102 struct drm_pending_vblank_event *e;
1104 unsigned long flags;
1108 e = kzalloc(sizeof *e, GFP_KERNEL);
1115 e->base.pid = current->pid;
1116 e->event.base.type = DRM_EVENT_VBLANK;
1117 e->event.base.length = sizeof e->event;
1118 e->event.user_data = vblwait->request.signal;
1119 e->base.event = &e->event.base;
1120 e->base.file_priv = file_priv;
1121 e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
1123 spin_lock_irqsave(&dev->event_lock, flags);
1125 if (file_priv->event_space < sizeof e->event) {
1130 file_priv->event_space -= sizeof e->event;
1131 seq = drm_vblank_count_and_time(dev, pipe, &now);
1133 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1134 (seq - vblwait->request.sequence) <= (1 << 23)) {
1135 vblwait->request.sequence = seq + 1;
1136 vblwait->reply.sequence = vblwait->request.sequence;
1139 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1140 vblwait->request.sequence, seq, pipe);
1142 trace_drm_vblank_event_queued(current->pid, pipe,
1143 vblwait->request.sequence);
1145 e->event.sequence = vblwait->request.sequence;
1146 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1147 drm_vblank_put(dev, pipe);
1148 send_vblank_event(dev, e, seq, &now);
1149 vblwait->reply.sequence = seq;
1151 /* drm_handle_vblank_events will call drm_vblank_put */
1152 list_add_tail(&e->base.link, &dev->vblank_event_list);
1153 vblwait->reply.sequence = vblwait->request.sequence;
1156 spin_unlock_irqrestore(&dev->event_lock, flags);
1161 spin_unlock_irqrestore(&dev->event_lock, flags);
1164 drm_vblank_put(dev, pipe);
1171 * \param inode device inode.
1172 * \param file_priv DRM file private.
1173 * \param cmd command.
1174 * \param data user argument, pointing to a drm_wait_vblank structure.
1175 * \return zero on success or a negative number on failure.
1177 * This function enables the vblank interrupt on the pipe requested, then
1178 * sleeps waiting for the requested sequence number to occur, and drops
1179 * the vblank interrupt refcount afterwards. (vblank irq disable follows that
1180 * after a timeout with no further vblank waits scheduled).
1182 int drm_wait_vblank(struct drm_device *dev, void *data,
1183 struct drm_file *file_priv)
1185 union drm_wait_vblank *vblwait = data;
1187 unsigned int flags, seq, crtc, high_crtc;
1189 if (drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
1190 if ((!drm_dev_to_irq(dev)) || (!dev->irq_enabled))
1193 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1196 if (vblwait->request.type &
1197 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1198 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1199 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1200 vblwait->request.type,
1201 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1202 _DRM_VBLANK_HIGH_CRTC_MASK));
1206 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1207 high_crtc = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1209 crtc = high_crtc >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1211 crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1212 if (crtc >= dev->num_crtcs)
1215 ret = drm_vblank_get(dev, crtc);
1217 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1220 seq = drm_vblank_count(dev, crtc);
1222 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1223 case _DRM_VBLANK_RELATIVE:
1224 vblwait->request.sequence += seq;
1225 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1226 case _DRM_VBLANK_ABSOLUTE:
1233 if (flags & _DRM_VBLANK_EVENT) {
1234 /* must hold on to the vblank ref until the event fires
1235 * drm_vblank_put will be called asynchronously
1237 return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
1240 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1241 (seq - vblwait->request.sequence) <= (1<<23)) {
1242 vblwait->request.sequence = seq + 1;
1245 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1246 vblwait->request.sequence, crtc);
1247 dev->vblank[crtc].last_wait = vblwait->request.sequence;
1248 DRM_WAIT_ON(ret, dev->vblank[crtc].queue, 3 * HZ,
1249 (((drm_vblank_count(dev, crtc) -
1250 vblwait->request.sequence) <= (1 << 23)) ||
1251 !dev->irq_enabled));
1253 if (ret != -EINTR) {
1256 vblwait->reply.sequence = drm_vblank_count_and_time(dev, crtc, &now);
1257 vblwait->reply.tval_sec = now.tv_sec;
1258 vblwait->reply.tval_usec = now.tv_usec;
1260 DRM_DEBUG("returning %d to client\n",
1261 vblwait->reply.sequence);
1263 DRM_DEBUG("vblank wait interrupted by signal\n");
1267 drm_vblank_put(dev, crtc);
1271 static void drm_handle_vblank_events(struct drm_device *dev, int crtc)
1273 struct drm_pending_vblank_event *e, *t;
1275 unsigned long flags;
1278 seq = drm_vblank_count_and_time(dev, crtc, &now);
1280 spin_lock_irqsave(&dev->event_lock, flags);
1282 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1283 if (e->pipe != crtc)
1285 if ((seq - e->event.sequence) > (1<<23))
1288 DRM_DEBUG("vblank event on %d, current %d\n",
1289 e->event.sequence, seq);
1291 list_del(&e->base.link);
1292 drm_vblank_put(dev, e->pipe);
1293 send_vblank_event(dev, e, seq, &now);
1296 spin_unlock_irqrestore(&dev->event_lock, flags);
1298 trace_drm_vblank_event(crtc, seq);
1302 * drm_handle_vblank - handle a vblank event
1304 * @crtc: where this event occurred
1306 * Drivers should call this routine in their vblank interrupt handlers to
1307 * update the vblank counter and send any signals that may be pending.
1309 bool drm_handle_vblank(struct drm_device *dev, int crtc)
1313 struct timeval tvblank;
1314 unsigned long irqflags;
1316 if (!dev->num_crtcs)
1319 /* Need timestamp lock to prevent concurrent execution with
1320 * vblank enable/disable, as this would cause inconsistent
1321 * or corrupted timestamps and vblank counts.
1323 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
1325 /* Vblank irq handling disabled. Nothing to do. */
1326 if (!dev->vblank[crtc].enabled) {
1327 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
1331 /* Fetch corresponding timestamp for this vblank interval from
1332 * driver and store it in proper slot of timestamp ringbuffer.
1335 /* Get current timestamp and count. */
1336 vblcount = atomic_read(&dev->vblank[crtc].count);
1337 drm_get_last_vbltimestamp(dev, crtc, &tvblank, DRM_CALLED_FROM_VBLIRQ);
1339 /* Compute time difference to timestamp of last vblank */
1340 diff_ns = timeval_to_ns(&tvblank) -
1341 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
1343 /* Update vblank timestamp and count if at least
1344 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1345 * difference between last stored timestamp and current
1346 * timestamp. A smaller difference means basically
1347 * identical timestamps. Happens if this vblank has
1348 * been already processed and this is a redundant call,
1349 * e.g., due to spurious vblank interrupts. We need to
1350 * ignore those for accounting.
1352 if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) {
1353 /* Store new timestamp in ringbuffer. */
1354 vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
1356 /* Increment cooked vblank count. This also atomically commits
1357 * the timestamp computed above.
1359 smp_mb__before_atomic_inc();
1360 atomic_inc(&dev->vblank[crtc].count);
1361 smp_mb__after_atomic_inc();
1363 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1364 crtc, (int) diff_ns);
1367 wake_up(&dev->vblank[crtc].queue);
1368 drm_handle_vblank_events(dev, crtc);
1370 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
1373 EXPORT_SYMBOL(drm_handle_vblank);