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_time[(crtc) * DRM_VBLANKTIME_RBSIZE + \
48 ((count) % DRM_VBLANKTIME_RBSIZE)])
50 /* Retry timestamp calculation up to 3 times to satisfy
51 * drm_timestamp_precision before giving up.
53 #define DRM_TIMESTAMP_MAXRETRIES 3
55 /* Threshold in nanoseconds for detection of redundant
56 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
58 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
61 * Get interrupt from bus id.
63 * \param inode device inode.
64 * \param file_priv DRM file private.
66 * \param arg user argument, pointing to a drm_irq_busid structure.
67 * \return zero on success or a negative number on failure.
69 * Finds the PCI device with the specified bus id and gets its IRQ number.
70 * This IOCTL is deprecated, and will now return EINVAL for any busid not equal
71 * to that of the device that this DRM instance attached to.
73 int drm_irq_by_busid(struct drm_device *dev, void *data,
74 struct drm_file *file_priv)
76 struct drm_irq_busid *p = data;
78 if (!dev->driver->bus->irq_by_busid)
81 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
84 return dev->driver->bus->irq_by_busid(dev, p);
88 * Clear vblank timestamp buffer for a crtc.
90 static void clear_vblank_timestamps(struct drm_device *dev, int crtc)
92 memset(&dev->_vblank_time[crtc * DRM_VBLANKTIME_RBSIZE], 0,
93 DRM_VBLANKTIME_RBSIZE * sizeof(struct timeval));
97 * Disable vblank irq's on crtc, make sure that last vblank count
98 * of hardware and corresponding consistent software vblank counter
99 * are preserved, even if there are any spurious vblank irq's after
102 static void vblank_disable_and_save(struct drm_device *dev, int crtc)
104 unsigned long irqflags;
108 struct timeval tvblank;
109 int count = DRM_TIMESTAMP_MAXRETRIES;
111 /* Prevent vblank irq processing while disabling vblank irqs,
112 * so no updates of timestamps or count can happen after we've
113 * disabled. Needed to prevent races in case of delayed irq's.
115 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
117 dev->driver->disable_vblank(dev, crtc);
118 dev->vblank_enabled[crtc] = 0;
120 /* No further vblank irq's will be processed after
121 * this point. Get current hardware vblank count and
122 * vblank timestamp, repeat until they are consistent.
124 * FIXME: There is still a race condition here and in
125 * drm_update_vblank_count() which can cause off-by-one
126 * reinitialization of software vblank counter. If gpu
127 * vblank counter doesn't increment exactly at the leading
128 * edge of a vblank interval, then we can lose 1 count if
129 * we happen to execute between start of vblank and the
130 * delayed gpu counter increment.
133 dev->last_vblank[crtc] = dev->driver->get_vblank_counter(dev, crtc);
134 vblrc = drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0);
135 } while (dev->last_vblank[crtc] != dev->driver->get_vblank_counter(dev, crtc) && (--count) && vblrc);
140 /* Compute time difference to stored timestamp of last vblank
141 * as updated by last invocation of drm_handle_vblank() in vblank irq.
143 vblcount = atomic_read(&dev->_vblank_count[crtc]);
144 diff_ns = timeval_to_ns(&tvblank) -
145 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
147 /* If there is at least 1 msec difference between the last stored
148 * timestamp and tvblank, then we are currently executing our
149 * disable inside a new vblank interval, the tvblank timestamp
150 * corresponds to this new vblank interval and the irq handler
151 * for this vblank didn't run yet and won't run due to our disable.
152 * Therefore we need to do the job of drm_handle_vblank() and
153 * increment the vblank counter by one to account for this vblank.
155 * Skip this step if there isn't any high precision timestamp
156 * available. In that case we can't account for this and just
159 if ((vblrc > 0) && (abs64(diff_ns) > 1000000)) {
160 atomic_inc(&dev->_vblank_count[crtc]);
161 smp_mb__after_atomic_inc();
164 /* Invalidate all timestamps while vblank irq's are off. */
165 clear_vblank_timestamps(dev, crtc);
167 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
170 static void vblank_disable_fn(unsigned long arg)
172 struct drm_device *dev = (struct drm_device *)arg;
173 unsigned long irqflags;
176 if (!dev->vblank_disable_allowed)
179 for (i = 0; i < dev->num_crtcs; i++) {
180 spin_lock_irqsave(&dev->vbl_lock, irqflags);
181 if (atomic_read(&dev->vblank_refcount[i]) == 0 &&
182 dev->vblank_enabled[i]) {
183 DRM_DEBUG("disabling vblank on crtc %d\n", i);
184 vblank_disable_and_save(dev, i);
186 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
190 void drm_vblank_cleanup(struct drm_device *dev)
192 /* Bail if the driver didn't call drm_vblank_init() */
193 if (dev->num_crtcs == 0)
196 del_timer_sync(&dev->vblank_disable_timer);
198 vblank_disable_fn((unsigned long)dev);
200 kfree(dev->vbl_queue);
201 kfree(dev->_vblank_count);
202 kfree(dev->vblank_refcount);
203 kfree(dev->vblank_enabled);
204 kfree(dev->last_vblank);
205 kfree(dev->last_vblank_wait);
206 kfree(dev->vblank_inmodeset);
207 kfree(dev->_vblank_time);
211 EXPORT_SYMBOL(drm_vblank_cleanup);
213 int drm_vblank_init(struct drm_device *dev, int num_crtcs)
215 int i, ret = -ENOMEM;
217 setup_timer(&dev->vblank_disable_timer, vblank_disable_fn,
219 spin_lock_init(&dev->vbl_lock);
220 spin_lock_init(&dev->vblank_time_lock);
222 dev->num_crtcs = num_crtcs;
224 dev->vbl_queue = kmalloc(sizeof(wait_queue_head_t) * num_crtcs,
229 dev->_vblank_count = kmalloc(sizeof(atomic_t) * num_crtcs, GFP_KERNEL);
230 if (!dev->_vblank_count)
233 dev->vblank_refcount = kmalloc(sizeof(atomic_t) * num_crtcs,
235 if (!dev->vblank_refcount)
238 dev->vblank_enabled = kcalloc(num_crtcs, sizeof(int), GFP_KERNEL);
239 if (!dev->vblank_enabled)
242 dev->last_vblank = kcalloc(num_crtcs, sizeof(u32), GFP_KERNEL);
243 if (!dev->last_vblank)
246 dev->last_vblank_wait = kcalloc(num_crtcs, sizeof(u32), GFP_KERNEL);
247 if (!dev->last_vblank_wait)
250 dev->vblank_inmodeset = kcalloc(num_crtcs, sizeof(int), GFP_KERNEL);
251 if (!dev->vblank_inmodeset)
254 dev->_vblank_time = kcalloc(num_crtcs * DRM_VBLANKTIME_RBSIZE,
255 sizeof(struct timeval), GFP_KERNEL);
256 if (!dev->_vblank_time)
259 DRM_INFO("Supports vblank timestamp caching Rev 1 (10.10.2010).\n");
261 /* Driver specific high-precision vblank timestamping supported? */
262 if (dev->driver->get_vblank_timestamp)
263 DRM_INFO("Driver supports precise vblank timestamp query.\n");
265 DRM_INFO("No driver support for vblank timestamp query.\n");
267 /* Zero per-crtc vblank stuff */
268 for (i = 0; i < num_crtcs; i++) {
269 init_waitqueue_head(&dev->vbl_queue[i]);
270 atomic_set(&dev->_vblank_count[i], 0);
271 atomic_set(&dev->vblank_refcount[i], 0);
274 dev->vblank_disable_allowed = 0;
278 drm_vblank_cleanup(dev);
281 EXPORT_SYMBOL(drm_vblank_init);
283 static void drm_irq_vgaarb_nokms(void *cookie, bool state)
285 struct drm_device *dev = cookie;
287 if (dev->driver->vgaarb_irq) {
288 dev->driver->vgaarb_irq(dev, state);
292 if (!dev->irq_enabled)
296 if (dev->driver->irq_uninstall)
297 dev->driver->irq_uninstall(dev);
299 if (dev->driver->irq_preinstall)
300 dev->driver->irq_preinstall(dev);
301 if (dev->driver->irq_postinstall)
302 dev->driver->irq_postinstall(dev);
307 * Install IRQ handler.
309 * \param dev DRM device.
311 * Initializes the IRQ related data. Installs the handler, calling the driver
312 * \c irq_preinstall() and \c irq_postinstall() functions
313 * before and after the installation.
315 int drm_irq_install(struct drm_device *dev)
318 unsigned long sh_flags = 0;
321 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
324 if (drm_dev_to_irq(dev) == 0)
327 mutex_lock(&dev->struct_mutex);
329 /* Driver must have been initialized */
330 if (!dev->dev_private) {
331 mutex_unlock(&dev->struct_mutex);
335 if (dev->irq_enabled) {
336 mutex_unlock(&dev->struct_mutex);
339 dev->irq_enabled = 1;
340 mutex_unlock(&dev->struct_mutex);
342 DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev));
344 /* Before installing handler */
345 if (dev->driver->irq_preinstall)
346 dev->driver->irq_preinstall(dev);
348 /* Install handler */
349 if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
350 sh_flags = IRQF_SHARED;
353 irqname = dev->devname;
355 irqname = dev->driver->name;
357 ret = request_irq(drm_dev_to_irq(dev), dev->driver->irq_handler,
358 sh_flags, irqname, dev);
361 mutex_lock(&dev->struct_mutex);
362 dev->irq_enabled = 0;
363 mutex_unlock(&dev->struct_mutex);
367 if (!drm_core_check_feature(dev, DRIVER_MODESET))
368 vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
370 /* After installing handler */
371 if (dev->driver->irq_postinstall)
372 ret = dev->driver->irq_postinstall(dev);
375 mutex_lock(&dev->struct_mutex);
376 dev->irq_enabled = 0;
377 mutex_unlock(&dev->struct_mutex);
378 if (!drm_core_check_feature(dev, DRIVER_MODESET))
379 vga_client_register(dev->pdev, NULL, NULL, NULL);
380 free_irq(drm_dev_to_irq(dev), dev);
385 EXPORT_SYMBOL(drm_irq_install);
388 * Uninstall the IRQ handler.
390 * \param dev DRM device.
392 * Calls the driver's \c irq_uninstall() function, and stops the irq.
394 int drm_irq_uninstall(struct drm_device *dev)
396 unsigned long irqflags;
399 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
402 mutex_lock(&dev->struct_mutex);
403 irq_enabled = dev->irq_enabled;
404 dev->irq_enabled = 0;
405 mutex_unlock(&dev->struct_mutex);
408 * Wake up any waiters so they don't hang.
410 if (dev->num_crtcs) {
411 spin_lock_irqsave(&dev->vbl_lock, irqflags);
412 for (i = 0; i < dev->num_crtcs; i++) {
413 DRM_WAKEUP(&dev->vbl_queue[i]);
414 dev->vblank_enabled[i] = 0;
415 dev->last_vblank[i] =
416 dev->driver->get_vblank_counter(dev, i);
418 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
424 DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev));
426 if (!drm_core_check_feature(dev, DRIVER_MODESET))
427 vga_client_register(dev->pdev, NULL, NULL, NULL);
429 if (dev->driver->irq_uninstall)
430 dev->driver->irq_uninstall(dev);
432 free_irq(drm_dev_to_irq(dev), dev);
436 EXPORT_SYMBOL(drm_irq_uninstall);
441 * \param inode device inode.
442 * \param file_priv DRM file private.
443 * \param cmd command.
444 * \param arg user argument, pointing to a drm_control structure.
445 * \return zero on success or a negative number on failure.
447 * Calls irq_install() or irq_uninstall() according to \p arg.
449 int drm_control(struct drm_device *dev, void *data,
450 struct drm_file *file_priv)
452 struct drm_control *ctl = data;
454 /* if we haven't irq we fallback for compatibility reasons -
455 * this used to be a separate function in drm_dma.h
460 case DRM_INST_HANDLER:
461 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
463 if (drm_core_check_feature(dev, DRIVER_MODESET))
465 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
466 ctl->irq != drm_dev_to_irq(dev))
468 return drm_irq_install(dev);
469 case DRM_UNINST_HANDLER:
470 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
472 if (drm_core_check_feature(dev, DRIVER_MODESET))
474 return drm_irq_uninstall(dev);
481 * drm_calc_timestamping_constants - Calculate and
482 * store various constants which are later needed by
483 * vblank and swap-completion timestamping, e.g, by
484 * drm_calc_vbltimestamp_from_scanoutpos().
485 * They are derived from crtc's true scanout timing,
486 * so they take things like panel scaling or other
487 * adjustments into account.
489 * @crtc drm_crtc whose timestamp constants should be updated.
492 void drm_calc_timestamping_constants(struct drm_crtc *crtc)
494 s64 linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
497 /* Dot clock in Hz: */
498 dotclock = (u64) crtc->hwmode.clock * 1000;
500 /* Fields of interlaced scanout modes are only halve a frame duration.
501 * Double the dotclock to get halve the frame-/line-/pixelduration.
503 if (crtc->hwmode.flags & DRM_MODE_FLAG_INTERLACE)
506 /* Valid dotclock? */
508 /* Convert scanline length in pixels and video dot clock to
509 * line duration, frame duration and pixel duration in
512 pixeldur_ns = (s64) div64_u64(1000000000, dotclock);
513 linedur_ns = (s64) div64_u64(((u64) crtc->hwmode.crtc_htotal *
514 1000000000), dotclock);
515 framedur_ns = (s64) crtc->hwmode.crtc_vtotal * linedur_ns;
517 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
520 crtc->pixeldur_ns = pixeldur_ns;
521 crtc->linedur_ns = linedur_ns;
522 crtc->framedur_ns = framedur_ns;
524 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
525 crtc->base.id, crtc->hwmode.crtc_htotal,
526 crtc->hwmode.crtc_vtotal, crtc->hwmode.crtc_vdisplay);
527 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
528 crtc->base.id, (int) dotclock/1000, (int) framedur_ns,
529 (int) linedur_ns, (int) pixeldur_ns);
531 EXPORT_SYMBOL(drm_calc_timestamping_constants);
534 * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
535 * drivers. Implements calculation of exact vblank timestamps from
536 * given drm_display_mode timings and current video scanout position
537 * of a crtc. This can be called from within get_vblank_timestamp()
538 * implementation of a kms driver to implement the actual timestamping.
540 * Should return timestamps conforming to the OML_sync_control OpenML
541 * extension specification. The timestamp corresponds to the end of
542 * the vblank interval, aka start of scanout of topmost-leftmost display
543 * pixel in the following video frame.
545 * Requires support for optional dev->driver->get_scanout_position()
546 * in kms driver, plus a bit of setup code to provide a drm_display_mode
547 * that corresponds to the true scanout timing.
549 * The current implementation only handles standard video modes. It
550 * returns as no operation if a doublescan or interlaced video mode is
551 * active. Higher level code is expected to handle this.
554 * @crtc: Which crtc's vblank timestamp to retrieve.
555 * @max_error: Desired maximum allowable error in timestamps (nanosecs).
556 * On return contains true maximum error of timestamp.
557 * @vblank_time: Pointer to struct timeval which should receive the timestamp.
558 * @flags: Flags to pass to driver:
560 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
561 * @refcrtc: drm_crtc* of crtc which defines scanout timing.
563 * Returns negative value on error, failure or if not supported in current
566 * -EINVAL - Invalid crtc.
567 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
568 * -ENOTSUPP - Function not supported in current display mode.
569 * -EIO - Failed, e.g., due to failed scanout position query.
571 * Returns or'ed positive status flags on success:
573 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
574 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
577 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
579 struct timeval *vblank_time,
581 struct drm_crtc *refcrtc)
583 ktime_t stime, etime, mono_time_offset;
584 struct timeval tv_etime;
585 struct drm_display_mode *mode;
586 int vbl_status, vtotal, vdisplay;
588 s64 framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
591 if (crtc < 0 || crtc >= dev->num_crtcs) {
592 DRM_ERROR("Invalid crtc %d\n", crtc);
596 /* Scanout position query not supported? Should not happen. */
597 if (!dev->driver->get_scanout_position) {
598 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
602 mode = &refcrtc->hwmode;
603 vtotal = mode->crtc_vtotal;
604 vdisplay = mode->crtc_vdisplay;
606 /* Durations of frames, lines, pixels in nanoseconds. */
607 framedur_ns = refcrtc->framedur_ns;
608 linedur_ns = refcrtc->linedur_ns;
609 pixeldur_ns = refcrtc->pixeldur_ns;
611 /* If mode timing undefined, just return as no-op:
612 * Happens during initial modesetting of a crtc.
614 if (vtotal <= 0 || vdisplay <= 0 || framedur_ns == 0) {
615 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc);
619 /* Get current scanout position with system timestamp.
620 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
621 * if single query takes longer than max_error nanoseconds.
623 * This guarantees a tight bound on maximum error if
624 * code gets preempted or delayed for some reason.
626 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
627 /* Disable preemption to make it very likely to
628 * succeed in the first iteration even on PREEMPT_RT kernel.
632 /* Get system timestamp before query. */
635 /* Get vertical and horizontal scanout pos. vpos, hpos. */
636 vbl_status = dev->driver->get_scanout_position(dev, crtc, &vpos, &hpos);
638 /* Get system timestamp after query. */
640 if (!drm_timestamp_monotonic)
641 mono_time_offset = ktime_get_monotonic_offset();
645 /* Return as no-op if scanout query unsupported or failed. */
646 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
647 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
652 duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
654 /* Accept result with < max_error nsecs timing uncertainty. */
655 if (duration_ns <= (s64) *max_error)
659 /* Noisy system timing? */
660 if (i == DRM_TIMESTAMP_MAXRETRIES) {
661 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
662 crtc, (int) duration_ns/1000, *max_error/1000, i);
665 /* Return upper bound of timestamp precision error. */
666 *max_error = (int) duration_ns;
668 /* Check if in vblank area:
669 * vpos is >=0 in video scanout area, but negative
670 * within vblank area, counting down the number of lines until
673 invbl = vbl_status & DRM_SCANOUTPOS_INVBL;
675 /* Convert scanout position into elapsed time at raw_time query
676 * since start of scanout at first display scanline. delta_ns
677 * can be negative if start of scanout hasn't happened yet.
679 delta_ns = (s64) vpos * linedur_ns + (s64) hpos * pixeldur_ns;
681 /* Is vpos outside nominal vblank area, but less than
682 * 1/100 of a frame height away from start of vblank?
683 * If so, assume this isn't a massively delayed vblank
684 * interrupt, but a vblank interrupt that fired a few
685 * microseconds before true start of vblank. Compensate
686 * by adding a full frame duration to the final timestamp.
687 * Happens, e.g., on ATI R500, R600.
689 * We only do this if DRM_CALLED_FROM_VBLIRQ.
691 if ((flags & DRM_CALLED_FROM_VBLIRQ) && !invbl &&
692 ((vdisplay - vpos) < vtotal / 100)) {
693 delta_ns = delta_ns - framedur_ns;
695 /* Signal this correction as "applied". */
699 if (!drm_timestamp_monotonic)
700 etime = ktime_sub(etime, mono_time_offset);
702 /* save this only for debugging purposes */
703 tv_etime = ktime_to_timeval(etime);
704 /* Subtract time delta from raw timestamp to get final
705 * vblank_time timestamp for end of vblank.
707 etime = ktime_sub_ns(etime, delta_ns);
708 *vblank_time = ktime_to_timeval(etime);
710 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
711 crtc, (int)vbl_status, hpos, vpos,
712 (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
713 (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
714 (int)duration_ns/1000, i);
716 vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
718 vbl_status |= DRM_VBLANKTIME_INVBL;
722 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
724 static struct timeval get_drm_timestamp(void)
729 if (!drm_timestamp_monotonic)
730 now = ktime_sub(now, ktime_get_monotonic_offset());
732 return ktime_to_timeval(now);
736 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
740 * @crtc: which crtc's vblank timestamp to retrieve
741 * @tvblank: Pointer to target struct timeval which should receive the timestamp
742 * @flags: Flags to pass to driver:
744 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
746 * Fetches the system timestamp corresponding to the time of the most recent
747 * vblank interval on specified crtc. May call into kms-driver to
748 * compute the timestamp with a high-precision GPU specific method.
750 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
751 * call, i.e., it isn't very precisely locked to the true vblank.
753 * Returns non-zero if timestamp is considered to be very precise.
755 u32 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
756 struct timeval *tvblank, unsigned flags)
760 /* Define requested maximum error on timestamps (nanoseconds). */
761 int max_error = (int) drm_timestamp_precision * 1000;
763 /* Query driver if possible and precision timestamping enabled. */
764 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
765 ret = dev->driver->get_vblank_timestamp(dev, crtc, &max_error,
771 /* GPU high precision timestamp query unsupported or failed.
772 * Return current monotonic/gettimeofday timestamp as best estimate.
774 *tvblank = get_drm_timestamp();
778 EXPORT_SYMBOL(drm_get_last_vbltimestamp);
781 * drm_vblank_count - retrieve "cooked" vblank counter value
783 * @crtc: which counter to retrieve
785 * Fetches the "cooked" vblank count value that represents the number of
786 * vblank events since the system was booted, including lost events due to
787 * modesetting activity.
789 u32 drm_vblank_count(struct drm_device *dev, int crtc)
791 return atomic_read(&dev->_vblank_count[crtc]);
793 EXPORT_SYMBOL(drm_vblank_count);
796 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
797 * and the system timestamp corresponding to that vblank counter value.
800 * @crtc: which counter to retrieve
801 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
803 * Fetches the "cooked" vblank count value that represents the number of
804 * vblank events since the system was booted, including lost events due to
805 * modesetting activity. Returns corresponding system timestamp of the time
806 * of the vblank interval that corresponds to the current value vblank counter
809 u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
810 struct timeval *vblanktime)
814 /* Read timestamp from slot of _vblank_time ringbuffer
815 * that corresponds to current vblank count. Retry if
816 * count has incremented during readout. This works like
820 cur_vblank = atomic_read(&dev->_vblank_count[crtc]);
821 *vblanktime = vblanktimestamp(dev, crtc, cur_vblank);
823 } while (cur_vblank != atomic_read(&dev->_vblank_count[crtc]));
827 EXPORT_SYMBOL(drm_vblank_count_and_time);
829 static void send_vblank_event(struct drm_device *dev,
830 struct drm_pending_vblank_event *e,
831 unsigned long seq, struct timeval *now)
833 WARN_ON_SMP(!spin_is_locked(&dev->event_lock));
834 e->event.sequence = seq;
835 e->event.tv_sec = now->tv_sec;
836 e->event.tv_usec = now->tv_usec;
838 list_add_tail(&e->base.link,
839 &e->base.file_priv->event_list);
840 wake_up_interruptible(&e->base.file_priv->event_wait);
841 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
846 * drm_send_vblank_event - helper to send vblank event after pageflip
848 * @crtc: CRTC in question
849 * @e: the event to send
851 * Updates sequence # and timestamp on event, and sends it to userspace.
852 * Caller must hold event lock.
854 void drm_send_vblank_event(struct drm_device *dev, int crtc,
855 struct drm_pending_vblank_event *e)
860 seq = drm_vblank_count_and_time(dev, crtc, &now);
864 now = get_drm_timestamp();
866 send_vblank_event(dev, e, seq, &now);
868 EXPORT_SYMBOL(drm_send_vblank_event);
871 * drm_update_vblank_count - update the master vblank counter
873 * @crtc: counter to update
875 * Call back into the driver to update the appropriate vblank counter
876 * (specified by @crtc). Deal with wraparound, if it occurred, and
877 * update the last read value so we can deal with wraparound on the next
880 * Only necessary when going from off->on, to account for frames we
881 * didn't get an interrupt for.
883 * Note: caller must hold dev->vbl_lock since this reads & writes
884 * device vblank fields.
886 static void drm_update_vblank_count(struct drm_device *dev, int crtc)
888 u32 cur_vblank, diff, tslot, rc;
889 struct timeval t_vblank;
892 * Interrupts were disabled prior to this call, so deal with counter
894 * NOTE! It's possible we lost a full dev->max_vblank_count events
895 * here if the register is small or we had vblank interrupts off for
898 * We repeat the hardware vblank counter & timestamp query until
899 * we get consistent results. This to prevent races between gpu
900 * updating its hardware counter while we are retrieving the
901 * corresponding vblank timestamp.
904 cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
905 rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0);
906 } while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc));
908 /* Deal with counter wrap */
909 diff = cur_vblank - dev->last_vblank[crtc];
910 if (cur_vblank < dev->last_vblank[crtc]) {
911 diff += dev->max_vblank_count;
913 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
914 crtc, dev->last_vblank[crtc], cur_vblank, diff);
917 DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
920 /* Reinitialize corresponding vblank timestamp if high-precision query
921 * available. Skip this step if query unsupported or failed. Will
922 * reinitialize delayed at next vblank interrupt in that case.
925 tslot = atomic_read(&dev->_vblank_count[crtc]) + diff;
926 vblanktimestamp(dev, crtc, tslot) = t_vblank;
929 smp_mb__before_atomic_inc();
930 atomic_add(diff, &dev->_vblank_count[crtc]);
931 smp_mb__after_atomic_inc();
935 * drm_vblank_get - get a reference count on vblank events
937 * @crtc: which CRTC to own
939 * Acquire a reference count on vblank events to avoid having them disabled
943 * Zero on success, nonzero on failure.
945 int drm_vblank_get(struct drm_device *dev, int crtc)
947 unsigned long irqflags, irqflags2;
950 spin_lock_irqsave(&dev->vbl_lock, irqflags);
951 /* Going from 0->1 means we have to enable interrupts again */
952 if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1) {
953 spin_lock_irqsave(&dev->vblank_time_lock, irqflags2);
954 if (!dev->vblank_enabled[crtc]) {
955 /* Enable vblank irqs under vblank_time_lock protection.
956 * All vblank count & timestamp updates are held off
957 * until we are done reinitializing master counter and
958 * timestamps. Filtercode in drm_handle_vblank() will
959 * prevent double-accounting of same vblank interval.
961 ret = dev->driver->enable_vblank(dev, crtc);
962 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n",
965 atomic_dec(&dev->vblank_refcount[crtc]);
967 dev->vblank_enabled[crtc] = 1;
968 drm_update_vblank_count(dev, crtc);
971 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags2);
973 if (!dev->vblank_enabled[crtc]) {
974 atomic_dec(&dev->vblank_refcount[crtc]);
978 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
982 EXPORT_SYMBOL(drm_vblank_get);
985 * drm_vblank_put - give up ownership of vblank events
987 * @crtc: which counter to give up
989 * Release ownership of a given vblank counter, turning off interrupts
990 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
992 void drm_vblank_put(struct drm_device *dev, int crtc)
994 BUG_ON(atomic_read(&dev->vblank_refcount[crtc]) == 0);
996 /* Last user schedules interrupt disable */
997 if (atomic_dec_and_test(&dev->vblank_refcount[crtc]) &&
998 (drm_vblank_offdelay > 0))
999 mod_timer(&dev->vblank_disable_timer,
1000 jiffies + ((drm_vblank_offdelay * DRM_HZ)/1000));
1002 EXPORT_SYMBOL(drm_vblank_put);
1005 * drm_vblank_off - disable vblank events on a CRTC
1007 * @crtc: CRTC in question
1009 * Caller must hold event lock.
1011 void drm_vblank_off(struct drm_device *dev, int crtc)
1013 struct drm_pending_vblank_event *e, *t;
1015 unsigned long irqflags;
1018 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1019 vblank_disable_and_save(dev, crtc);
1020 DRM_WAKEUP(&dev->vbl_queue[crtc]);
1022 /* Send any queued vblank events, lest the natives grow disquiet */
1023 seq = drm_vblank_count_and_time(dev, crtc, &now);
1025 spin_lock(&dev->event_lock);
1026 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1027 if (e->pipe != crtc)
1029 DRM_DEBUG("Sending premature vblank event on disable: \
1030 wanted %d, current %d\n",
1031 e->event.sequence, seq);
1032 list_del(&e->base.link);
1033 drm_vblank_put(dev, e->pipe);
1034 send_vblank_event(dev, e, seq, &now);
1036 spin_unlock(&dev->event_lock);
1038 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1040 EXPORT_SYMBOL(drm_vblank_off);
1043 * drm_vblank_pre_modeset - account for vblanks across mode sets
1045 * @crtc: CRTC in question
1047 * Account for vblank events across mode setting events, which will likely
1048 * reset the hardware frame counter.
1050 void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
1052 /* vblank is not initialized (IRQ not installed ?) */
1053 if (!dev->num_crtcs)
1056 * To avoid all the problems that might happen if interrupts
1057 * were enabled/disabled around or between these calls, we just
1058 * have the kernel take a reference on the CRTC (just once though
1059 * to avoid corrupting the count if multiple, mismatch calls occur),
1060 * so that interrupts remain enabled in the interim.
1062 if (!dev->vblank_inmodeset[crtc]) {
1063 dev->vblank_inmodeset[crtc] = 0x1;
1064 if (drm_vblank_get(dev, crtc) == 0)
1065 dev->vblank_inmodeset[crtc] |= 0x2;
1068 EXPORT_SYMBOL(drm_vblank_pre_modeset);
1070 void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
1072 unsigned long irqflags;
1074 if (dev->vblank_inmodeset[crtc]) {
1075 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1076 dev->vblank_disable_allowed = 1;
1077 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1079 if (dev->vblank_inmodeset[crtc] & 0x2)
1080 drm_vblank_put(dev, crtc);
1082 dev->vblank_inmodeset[crtc] = 0;
1085 EXPORT_SYMBOL(drm_vblank_post_modeset);
1088 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1089 * @DRM_IOCTL_ARGS: standard ioctl arguments
1091 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1092 * ioctls around modesetting so that any lost vblank events are accounted for.
1094 * Generally the counter will reset across mode sets. If interrupts are
1095 * enabled around this call, we don't have to do anything since the counter
1096 * will have already been incremented.
1098 int drm_modeset_ctl(struct drm_device *dev, void *data,
1099 struct drm_file *file_priv)
1101 struct drm_modeset_ctl *modeset = data;
1104 /* If drm_vblank_init() hasn't been called yet, just no-op */
1105 if (!dev->num_crtcs)
1108 /* KMS drivers handle this internally */
1109 if (drm_core_check_feature(dev, DRIVER_MODESET))
1112 crtc = modeset->crtc;
1113 if (crtc >= dev->num_crtcs)
1116 switch (modeset->cmd) {
1117 case _DRM_PRE_MODESET:
1118 drm_vblank_pre_modeset(dev, crtc);
1120 case _DRM_POST_MODESET:
1121 drm_vblank_post_modeset(dev, crtc);
1130 static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
1131 union drm_wait_vblank *vblwait,
1132 struct drm_file *file_priv)
1134 struct drm_pending_vblank_event *e;
1136 unsigned long flags;
1140 e = kzalloc(sizeof *e, GFP_KERNEL);
1147 e->base.pid = current->pid;
1148 e->event.base.type = DRM_EVENT_VBLANK;
1149 e->event.base.length = sizeof e->event;
1150 e->event.user_data = vblwait->request.signal;
1151 e->base.event = &e->event.base;
1152 e->base.file_priv = file_priv;
1153 e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
1155 spin_lock_irqsave(&dev->event_lock, flags);
1157 if (file_priv->event_space < sizeof e->event) {
1162 file_priv->event_space -= sizeof e->event;
1163 seq = drm_vblank_count_and_time(dev, pipe, &now);
1165 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1166 (seq - vblwait->request.sequence) <= (1 << 23)) {
1167 vblwait->request.sequence = seq + 1;
1168 vblwait->reply.sequence = vblwait->request.sequence;
1171 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1172 vblwait->request.sequence, seq, pipe);
1174 trace_drm_vblank_event_queued(current->pid, pipe,
1175 vblwait->request.sequence);
1177 e->event.sequence = vblwait->request.sequence;
1178 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1179 drm_vblank_put(dev, pipe);
1180 send_vblank_event(dev, e, seq, &now);
1181 vblwait->reply.sequence = seq;
1183 /* drm_handle_vblank_events will call drm_vblank_put */
1184 list_add_tail(&e->base.link, &dev->vblank_event_list);
1185 vblwait->reply.sequence = vblwait->request.sequence;
1188 spin_unlock_irqrestore(&dev->event_lock, flags);
1193 spin_unlock_irqrestore(&dev->event_lock, flags);
1196 drm_vblank_put(dev, pipe);
1203 * \param inode device inode.
1204 * \param file_priv DRM file private.
1205 * \param cmd command.
1206 * \param data user argument, pointing to a drm_wait_vblank structure.
1207 * \return zero on success or a negative number on failure.
1209 * This function enables the vblank interrupt on the pipe requested, then
1210 * sleeps waiting for the requested sequence number to occur, and drops
1211 * the vblank interrupt refcount afterwards. (vblank irq disable follows that
1212 * after a timeout with no further vblank waits scheduled).
1214 int drm_wait_vblank(struct drm_device *dev, void *data,
1215 struct drm_file *file_priv)
1217 union drm_wait_vblank *vblwait = data;
1219 unsigned int flags, seq, crtc, high_crtc;
1221 if ((!drm_dev_to_irq(dev)) || (!dev->irq_enabled))
1224 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1227 if (vblwait->request.type &
1228 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1229 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1230 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1231 vblwait->request.type,
1232 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1233 _DRM_VBLANK_HIGH_CRTC_MASK));
1237 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1238 high_crtc = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1240 crtc = high_crtc >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1242 crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1243 if (crtc >= dev->num_crtcs)
1246 ret = drm_vblank_get(dev, crtc);
1248 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1251 seq = drm_vblank_count(dev, crtc);
1253 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1254 case _DRM_VBLANK_RELATIVE:
1255 vblwait->request.sequence += seq;
1256 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1257 case _DRM_VBLANK_ABSOLUTE:
1264 if (flags & _DRM_VBLANK_EVENT) {
1265 /* must hold on to the vblank ref until the event fires
1266 * drm_vblank_put will be called asynchronously
1268 return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
1271 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1272 (seq - vblwait->request.sequence) <= (1<<23)) {
1273 vblwait->request.sequence = seq + 1;
1276 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1277 vblwait->request.sequence, crtc);
1278 dev->last_vblank_wait[crtc] = vblwait->request.sequence;
1279 DRM_WAIT_ON(ret, dev->vbl_queue[crtc], 3 * DRM_HZ,
1280 (((drm_vblank_count(dev, crtc) -
1281 vblwait->request.sequence) <= (1 << 23)) ||
1282 !dev->irq_enabled));
1284 if (ret != -EINTR) {
1287 vblwait->reply.sequence = drm_vblank_count_and_time(dev, crtc, &now);
1288 vblwait->reply.tval_sec = now.tv_sec;
1289 vblwait->reply.tval_usec = now.tv_usec;
1291 DRM_DEBUG("returning %d to client\n",
1292 vblwait->reply.sequence);
1294 DRM_DEBUG("vblank wait interrupted by signal\n");
1298 drm_vblank_put(dev, crtc);
1302 static void drm_handle_vblank_events(struct drm_device *dev, int crtc)
1304 struct drm_pending_vblank_event *e, *t;
1306 unsigned long flags;
1309 seq = drm_vblank_count_and_time(dev, crtc, &now);
1311 spin_lock_irqsave(&dev->event_lock, flags);
1313 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1314 if (e->pipe != crtc)
1316 if ((seq - e->event.sequence) > (1<<23))
1319 DRM_DEBUG("vblank event on %d, current %d\n",
1320 e->event.sequence, seq);
1322 list_del(&e->base.link);
1323 drm_vblank_put(dev, e->pipe);
1324 send_vblank_event(dev, e, seq, &now);
1327 spin_unlock_irqrestore(&dev->event_lock, flags);
1329 trace_drm_vblank_event(crtc, seq);
1333 * drm_handle_vblank - handle a vblank event
1335 * @crtc: where this event occurred
1337 * Drivers should call this routine in their vblank interrupt handlers to
1338 * update the vblank counter and send any signals that may be pending.
1340 bool drm_handle_vblank(struct drm_device *dev, int crtc)
1344 struct timeval tvblank;
1345 unsigned long irqflags;
1347 if (!dev->num_crtcs)
1350 /* Need timestamp lock to prevent concurrent execution with
1351 * vblank enable/disable, as this would cause inconsistent
1352 * or corrupted timestamps and vblank counts.
1354 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
1356 /* Vblank irq handling disabled. Nothing to do. */
1357 if (!dev->vblank_enabled[crtc]) {
1358 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
1362 /* Fetch corresponding timestamp for this vblank interval from
1363 * driver and store it in proper slot of timestamp ringbuffer.
1366 /* Get current timestamp and count. */
1367 vblcount = atomic_read(&dev->_vblank_count[crtc]);
1368 drm_get_last_vbltimestamp(dev, crtc, &tvblank, DRM_CALLED_FROM_VBLIRQ);
1370 /* Compute time difference to timestamp of last vblank */
1371 diff_ns = timeval_to_ns(&tvblank) -
1372 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
1374 /* Update vblank timestamp and count if at least
1375 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1376 * difference between last stored timestamp and current
1377 * timestamp. A smaller difference means basically
1378 * identical timestamps. Happens if this vblank has
1379 * been already processed and this is a redundant call,
1380 * e.g., due to spurious vblank interrupts. We need to
1381 * ignore those for accounting.
1383 if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) {
1384 /* Store new timestamp in ringbuffer. */
1385 vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
1387 /* Increment cooked vblank count. This also atomically commits
1388 * the timestamp computed above.
1390 smp_mb__before_atomic_inc();
1391 atomic_inc(&dev->_vblank_count[crtc]);
1392 smp_mb__after_atomic_inc();
1394 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1395 crtc, (int) diff_ns);
1398 DRM_WAKEUP(&dev->vbl_queue[crtc]);
1399 drm_handle_vblank_events(dev, crtc);
1401 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
1404 EXPORT_SYMBOL(drm_handle_vblank);