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>
44 /* Access macro for slots in vblank timestamp ringbuffer. */
45 #define vblanktimestamp(dev, crtc, count) ( \
46 (dev)->_vblank_time[(crtc) * DRM_VBLANKTIME_RBSIZE + \
47 ((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_time[crtc * DRM_VBLANKTIME_RBSIZE], 0,
92 DRM_VBLANKTIME_RBSIZE * sizeof(struct timeval));
96 * Disable vblank irq's on crtc, make sure that last vblank count
97 * of hardware and corresponding consistent software vblank counter
98 * are preserved, even if there are any spurious vblank irq's after
101 static void vblank_disable_and_save(struct drm_device *dev, int crtc)
103 unsigned long irqflags;
107 struct timeval tvblank;
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_enabled[crtc] = 0;
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->last_vblank[crtc] = dev->driver->get_vblank_counter(dev, crtc);
132 vblrc = drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0);
133 } while (dev->last_vblank[crtc] != dev->driver->get_vblank_counter(dev, crtc));
135 /* Compute time difference to stored timestamp of last vblank
136 * as updated by last invocation of drm_handle_vblank() in vblank irq.
138 vblcount = atomic_read(&dev->_vblank_count[crtc]);
139 diff_ns = timeval_to_ns(&tvblank) -
140 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
142 /* If there is at least 1 msec difference between the last stored
143 * timestamp and tvblank, then we are currently executing our
144 * disable inside a new vblank interval, the tvblank timestamp
145 * corresponds to this new vblank interval and the irq handler
146 * for this vblank didn't run yet and won't run due to our disable.
147 * Therefore we need to do the job of drm_handle_vblank() and
148 * increment the vblank counter by one to account for this vblank.
150 * Skip this step if there isn't any high precision timestamp
151 * available. In that case we can't account for this and just
154 if ((vblrc > 0) && (abs64(diff_ns) > 1000000)) {
155 atomic_inc(&dev->_vblank_count[crtc]);
156 smp_mb__after_atomic_inc();
159 /* Invalidate all timestamps while vblank irq's are off. */
160 clear_vblank_timestamps(dev, crtc);
162 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
165 static void vblank_disable_fn(unsigned long arg)
167 struct drm_device *dev = (struct drm_device *)arg;
168 unsigned long irqflags;
171 if (!dev->vblank_disable_allowed)
174 for (i = 0; i < dev->num_crtcs; i++) {
175 spin_lock_irqsave(&dev->vbl_lock, irqflags);
176 if (atomic_read(&dev->vblank_refcount[i]) == 0 &&
177 dev->vblank_enabled[i]) {
178 DRM_DEBUG("disabling vblank on crtc %d\n", i);
179 vblank_disable_and_save(dev, i);
181 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
185 void drm_vblank_cleanup(struct drm_device *dev)
187 /* Bail if the driver didn't call drm_vblank_init() */
188 if (dev->num_crtcs == 0)
191 del_timer(&dev->vblank_disable_timer);
193 vblank_disable_fn((unsigned long)dev);
195 kfree(dev->vbl_queue);
196 kfree(dev->_vblank_count);
197 kfree(dev->vblank_refcount);
198 kfree(dev->vblank_enabled);
199 kfree(dev->last_vblank);
200 kfree(dev->last_vblank_wait);
201 kfree(dev->vblank_inmodeset);
202 kfree(dev->_vblank_time);
206 EXPORT_SYMBOL(drm_vblank_cleanup);
208 int drm_vblank_init(struct drm_device *dev, int num_crtcs)
210 int i, ret = -ENOMEM;
212 setup_timer(&dev->vblank_disable_timer, vblank_disable_fn,
214 spin_lock_init(&dev->vbl_lock);
215 spin_lock_init(&dev->vblank_time_lock);
217 dev->num_crtcs = num_crtcs;
219 dev->vbl_queue = kmalloc(sizeof(wait_queue_head_t) * num_crtcs,
224 dev->_vblank_count = kmalloc(sizeof(atomic_t) * num_crtcs, GFP_KERNEL);
225 if (!dev->_vblank_count)
228 dev->vblank_refcount = kmalloc(sizeof(atomic_t) * num_crtcs,
230 if (!dev->vblank_refcount)
233 dev->vblank_enabled = kcalloc(num_crtcs, sizeof(int), GFP_KERNEL);
234 if (!dev->vblank_enabled)
237 dev->last_vblank = kcalloc(num_crtcs, sizeof(u32), GFP_KERNEL);
238 if (!dev->last_vblank)
241 dev->last_vblank_wait = kcalloc(num_crtcs, sizeof(u32), GFP_KERNEL);
242 if (!dev->last_vblank_wait)
245 dev->vblank_inmodeset = kcalloc(num_crtcs, sizeof(int), GFP_KERNEL);
246 if (!dev->vblank_inmodeset)
249 dev->_vblank_time = kcalloc(num_crtcs * DRM_VBLANKTIME_RBSIZE,
250 sizeof(struct timeval), GFP_KERNEL);
251 if (!dev->_vblank_time)
254 DRM_INFO("Supports vblank timestamp caching Rev 1 (10.10.2010).\n");
256 /* Driver specific high-precision vblank timestamping supported? */
257 if (dev->driver->get_vblank_timestamp)
258 DRM_INFO("Driver supports precise vblank timestamp query.\n");
260 DRM_INFO("No driver support for vblank timestamp query.\n");
262 /* Zero per-crtc vblank stuff */
263 for (i = 0; i < num_crtcs; i++) {
264 init_waitqueue_head(&dev->vbl_queue[i]);
265 atomic_set(&dev->_vblank_count[i], 0);
266 atomic_set(&dev->vblank_refcount[i], 0);
269 dev->vblank_disable_allowed = 0;
273 drm_vblank_cleanup(dev);
276 EXPORT_SYMBOL(drm_vblank_init);
278 static void drm_irq_vgaarb_nokms(void *cookie, bool state)
280 struct drm_device *dev = cookie;
282 if (dev->driver->vgaarb_irq) {
283 dev->driver->vgaarb_irq(dev, state);
287 if (!dev->irq_enabled)
291 if (dev->driver->irq_uninstall)
292 dev->driver->irq_uninstall(dev);
294 if (dev->driver->irq_preinstall)
295 dev->driver->irq_preinstall(dev);
296 if (dev->driver->irq_postinstall)
297 dev->driver->irq_postinstall(dev);
302 * Install IRQ handler.
304 * \param dev DRM device.
306 * Initializes the IRQ related data. Installs the handler, calling the driver
307 * \c irq_preinstall() and \c irq_postinstall() functions
308 * before and after the installation.
310 int drm_irq_install(struct drm_device *dev)
313 unsigned long sh_flags = 0;
316 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
319 if (drm_dev_to_irq(dev) == 0)
322 mutex_lock(&dev->struct_mutex);
324 /* Driver must have been initialized */
325 if (!dev->dev_private) {
326 mutex_unlock(&dev->struct_mutex);
330 if (dev->irq_enabled) {
331 mutex_unlock(&dev->struct_mutex);
334 dev->irq_enabled = 1;
335 mutex_unlock(&dev->struct_mutex);
337 DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev));
339 /* Before installing handler */
340 if (dev->driver->irq_preinstall)
341 dev->driver->irq_preinstall(dev);
343 /* Install handler */
344 if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
345 sh_flags = IRQF_SHARED;
348 irqname = dev->devname;
350 irqname = dev->driver->name;
352 ret = request_irq(drm_dev_to_irq(dev), dev->driver->irq_handler,
353 sh_flags, irqname, dev);
356 mutex_lock(&dev->struct_mutex);
357 dev->irq_enabled = 0;
358 mutex_unlock(&dev->struct_mutex);
362 if (!drm_core_check_feature(dev, DRIVER_MODESET))
363 vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
365 /* After installing handler */
366 if (dev->driver->irq_postinstall)
367 ret = dev->driver->irq_postinstall(dev);
370 mutex_lock(&dev->struct_mutex);
371 dev->irq_enabled = 0;
372 mutex_unlock(&dev->struct_mutex);
373 if (!drm_core_check_feature(dev, DRIVER_MODESET))
374 vga_client_register(dev->pdev, NULL, NULL, NULL);
375 free_irq(drm_dev_to_irq(dev), dev);
380 EXPORT_SYMBOL(drm_irq_install);
383 * Uninstall the IRQ handler.
385 * \param dev DRM device.
387 * Calls the driver's \c irq_uninstall() function, and stops the irq.
389 int drm_irq_uninstall(struct drm_device *dev)
391 unsigned long irqflags;
394 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
397 mutex_lock(&dev->struct_mutex);
398 irq_enabled = dev->irq_enabled;
399 dev->irq_enabled = 0;
400 mutex_unlock(&dev->struct_mutex);
403 * Wake up any waiters so they don't hang.
405 if (dev->num_crtcs) {
406 spin_lock_irqsave(&dev->vbl_lock, irqflags);
407 for (i = 0; i < dev->num_crtcs; i++) {
408 DRM_WAKEUP(&dev->vbl_queue[i]);
409 dev->vblank_enabled[i] = 0;
410 dev->last_vblank[i] =
411 dev->driver->get_vblank_counter(dev, i);
413 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
419 DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev));
421 if (!drm_core_check_feature(dev, DRIVER_MODESET))
422 vga_client_register(dev->pdev, NULL, NULL, NULL);
424 if (dev->driver->irq_uninstall)
425 dev->driver->irq_uninstall(dev);
427 free_irq(drm_dev_to_irq(dev), dev);
431 EXPORT_SYMBOL(drm_irq_uninstall);
436 * \param inode device inode.
437 * \param file_priv DRM file private.
438 * \param cmd command.
439 * \param arg user argument, pointing to a drm_control structure.
440 * \return zero on success or a negative number on failure.
442 * Calls irq_install() or irq_uninstall() according to \p arg.
444 int drm_control(struct drm_device *dev, void *data,
445 struct drm_file *file_priv)
447 struct drm_control *ctl = data;
449 /* if we haven't irq we fallback for compatibility reasons -
450 * this used to be a separate function in drm_dma.h
455 case DRM_INST_HANDLER:
456 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
458 if (drm_core_check_feature(dev, DRIVER_MODESET))
460 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
461 ctl->irq != drm_dev_to_irq(dev))
463 return drm_irq_install(dev);
464 case DRM_UNINST_HANDLER:
465 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
467 if (drm_core_check_feature(dev, DRIVER_MODESET))
469 return drm_irq_uninstall(dev);
476 * drm_calc_timestamping_constants - Calculate and
477 * store various constants which are later needed by
478 * vblank and swap-completion timestamping, e.g, by
479 * drm_calc_vbltimestamp_from_scanoutpos().
480 * They are derived from crtc's true scanout timing,
481 * so they take things like panel scaling or other
482 * adjustments into account.
484 * @crtc drm_crtc whose timestamp constants should be updated.
487 void drm_calc_timestamping_constants(struct drm_crtc *crtc)
489 s64 linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
492 /* Dot clock in Hz: */
493 dotclock = (u64) crtc->hwmode.clock * 1000;
495 /* Fields of interlaced scanout modes are only halve a frame duration.
496 * Double the dotclock to get halve the frame-/line-/pixelduration.
498 if (crtc->hwmode.flags & DRM_MODE_FLAG_INTERLACE)
501 /* Valid dotclock? */
503 /* Convert scanline length in pixels and video dot clock to
504 * line duration, frame duration and pixel duration in
507 pixeldur_ns = (s64) div64_u64(1000000000, dotclock);
508 linedur_ns = (s64) div64_u64(((u64) crtc->hwmode.crtc_htotal *
509 1000000000), dotclock);
510 framedur_ns = (s64) crtc->hwmode.crtc_vtotal * linedur_ns;
512 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
515 crtc->pixeldur_ns = pixeldur_ns;
516 crtc->linedur_ns = linedur_ns;
517 crtc->framedur_ns = framedur_ns;
519 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
520 crtc->base.id, crtc->hwmode.crtc_htotal,
521 crtc->hwmode.crtc_vtotal, crtc->hwmode.crtc_vdisplay);
522 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
523 crtc->base.id, (int) dotclock/1000, (int) framedur_ns,
524 (int) linedur_ns, (int) pixeldur_ns);
526 EXPORT_SYMBOL(drm_calc_timestamping_constants);
529 * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
530 * drivers. Implements calculation of exact vblank timestamps from
531 * given drm_display_mode timings and current video scanout position
532 * of a crtc. This can be called from within get_vblank_timestamp()
533 * implementation of a kms driver to implement the actual timestamping.
535 * Should return timestamps conforming to the OML_sync_control OpenML
536 * extension specification. The timestamp corresponds to the end of
537 * the vblank interval, aka start of scanout of topmost-leftmost display
538 * pixel in the following video frame.
540 * Requires support for optional dev->driver->get_scanout_position()
541 * in kms driver, plus a bit of setup code to provide a drm_display_mode
542 * that corresponds to the true scanout timing.
544 * The current implementation only handles standard video modes. It
545 * returns as no operation if a doublescan or interlaced video mode is
546 * active. Higher level code is expected to handle this.
549 * @crtc: Which crtc's vblank timestamp to retrieve.
550 * @max_error: Desired maximum allowable error in timestamps (nanosecs).
551 * On return contains true maximum error of timestamp.
552 * @vblank_time: Pointer to struct timeval which should receive the timestamp.
553 * @flags: Flags to pass to driver:
555 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
556 * @refcrtc: drm_crtc* of crtc which defines scanout timing.
558 * Returns negative value on error, failure or if not supported in current
561 * -EINVAL - Invalid crtc.
562 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
563 * -ENOTSUPP - Function not supported in current display mode.
564 * -EIO - Failed, e.g., due to failed scanout position query.
566 * Returns or'ed positive status flags on success:
568 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
569 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
572 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
574 struct timeval *vblank_time,
576 struct drm_crtc *refcrtc)
578 struct timeval stime, raw_time;
579 struct drm_display_mode *mode;
580 int vbl_status, vtotal, vdisplay;
582 s64 framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
585 if (crtc < 0 || crtc >= dev->num_crtcs) {
586 DRM_ERROR("Invalid crtc %d\n", crtc);
590 /* Scanout position query not supported? Should not happen. */
591 if (!dev->driver->get_scanout_position) {
592 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
596 mode = &refcrtc->hwmode;
597 vtotal = mode->crtc_vtotal;
598 vdisplay = mode->crtc_vdisplay;
600 /* Durations of frames, lines, pixels in nanoseconds. */
601 framedur_ns = refcrtc->framedur_ns;
602 linedur_ns = refcrtc->linedur_ns;
603 pixeldur_ns = refcrtc->pixeldur_ns;
605 /* If mode timing undefined, just return as no-op:
606 * Happens during initial modesetting of a crtc.
608 if (vtotal <= 0 || vdisplay <= 0 || framedur_ns == 0) {
609 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc);
613 /* Get current scanout position with system timestamp.
614 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
615 * if single query takes longer than max_error nanoseconds.
617 * This guarantees a tight bound on maximum error if
618 * code gets preempted or delayed for some reason.
620 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
621 /* Disable preemption to make it very likely to
622 * succeed in the first iteration even on PREEMPT_RT kernel.
626 /* Get system timestamp before query. */
627 do_gettimeofday(&stime);
629 /* Get vertical and horizontal scanout pos. vpos, hpos. */
630 vbl_status = dev->driver->get_scanout_position(dev, crtc, &vpos, &hpos);
632 /* Get system timestamp after query. */
633 do_gettimeofday(&raw_time);
637 /* Return as no-op if scanout query unsupported or failed. */
638 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
639 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
644 duration_ns = timeval_to_ns(&raw_time) - timeval_to_ns(&stime);
646 /* Accept result with < max_error nsecs timing uncertainty. */
647 if (duration_ns <= (s64) *max_error)
651 /* Noisy system timing? */
652 if (i == DRM_TIMESTAMP_MAXRETRIES) {
653 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
654 crtc, (int) duration_ns/1000, *max_error/1000, i);
657 /* Return upper bound of timestamp precision error. */
658 *max_error = (int) duration_ns;
660 /* Check if in vblank area:
661 * vpos is >=0 in video scanout area, but negative
662 * within vblank area, counting down the number of lines until
665 invbl = vbl_status & DRM_SCANOUTPOS_INVBL;
667 /* Convert scanout position into elapsed time at raw_time query
668 * since start of scanout at first display scanline. delta_ns
669 * can be negative if start of scanout hasn't happened yet.
671 delta_ns = (s64) vpos * linedur_ns + (s64) hpos * pixeldur_ns;
673 /* Is vpos outside nominal vblank area, but less than
674 * 1/100 of a frame height away from start of vblank?
675 * If so, assume this isn't a massively delayed vblank
676 * interrupt, but a vblank interrupt that fired a few
677 * microseconds before true start of vblank. Compensate
678 * by adding a full frame duration to the final timestamp.
679 * Happens, e.g., on ATI R500, R600.
681 * We only do this if DRM_CALLED_FROM_VBLIRQ.
683 if ((flags & DRM_CALLED_FROM_VBLIRQ) && !invbl &&
684 ((vdisplay - vpos) < vtotal / 100)) {
685 delta_ns = delta_ns - framedur_ns;
687 /* Signal this correction as "applied". */
691 /* Subtract time delta from raw timestamp to get final
692 * vblank_time timestamp for end of vblank.
694 *vblank_time = ns_to_timeval(timeval_to_ns(&raw_time) - delta_ns);
696 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
697 crtc, (int)vbl_status, hpos, vpos,
698 (long)raw_time.tv_sec, (long)raw_time.tv_usec,
699 (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
700 (int)duration_ns/1000, i);
702 vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
704 vbl_status |= DRM_VBLANKTIME_INVBL;
708 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
711 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
715 * @crtc: which crtc's vblank timestamp to retrieve
716 * @tvblank: Pointer to target struct timeval which should receive the timestamp
717 * @flags: Flags to pass to driver:
719 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
721 * Fetches the system timestamp corresponding to the time of the most recent
722 * vblank interval on specified crtc. May call into kms-driver to
723 * compute the timestamp with a high-precision GPU specific method.
725 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
726 * call, i.e., it isn't very precisely locked to the true vblank.
728 * Returns non-zero if timestamp is considered to be very precise.
730 u32 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
731 struct timeval *tvblank, unsigned flags)
735 /* Define requested maximum error on timestamps (nanoseconds). */
736 int max_error = (int) drm_timestamp_precision * 1000;
738 /* Query driver if possible and precision timestamping enabled. */
739 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
740 ret = dev->driver->get_vblank_timestamp(dev, crtc, &max_error,
746 /* GPU high precision timestamp query unsupported or failed.
747 * Return gettimeofday timestamp as best estimate.
749 do_gettimeofday(tvblank);
753 EXPORT_SYMBOL(drm_get_last_vbltimestamp);
756 * drm_vblank_count - retrieve "cooked" vblank counter value
758 * @crtc: which counter to retrieve
760 * Fetches the "cooked" vblank count value that represents the number of
761 * vblank events since the system was booted, including lost events due to
762 * modesetting activity.
764 u32 drm_vblank_count(struct drm_device *dev, int crtc)
766 return atomic_read(&dev->_vblank_count[crtc]);
768 EXPORT_SYMBOL(drm_vblank_count);
771 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
772 * and the system timestamp corresponding to that vblank counter value.
775 * @crtc: which counter to retrieve
776 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
778 * Fetches the "cooked" vblank count value that represents the number of
779 * vblank events since the system was booted, including lost events due to
780 * modesetting activity. Returns corresponding system timestamp of the time
781 * of the vblank interval that corresponds to the current value vblank counter
784 u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
785 struct timeval *vblanktime)
789 /* Read timestamp from slot of _vblank_time ringbuffer
790 * that corresponds to current vblank count. Retry if
791 * count has incremented during readout. This works like
795 cur_vblank = atomic_read(&dev->_vblank_count[crtc]);
796 *vblanktime = vblanktimestamp(dev, crtc, cur_vblank);
798 } while (cur_vblank != atomic_read(&dev->_vblank_count[crtc]));
802 EXPORT_SYMBOL(drm_vblank_count_and_time);
805 * drm_update_vblank_count - update the master vblank counter
807 * @crtc: counter to update
809 * Call back into the driver to update the appropriate vblank counter
810 * (specified by @crtc). Deal with wraparound, if it occurred, and
811 * update the last read value so we can deal with wraparound on the next
814 * Only necessary when going from off->on, to account for frames we
815 * didn't get an interrupt for.
817 * Note: caller must hold dev->vbl_lock since this reads & writes
818 * device vblank fields.
820 static void drm_update_vblank_count(struct drm_device *dev, int crtc)
822 u32 cur_vblank, diff, tslot, rc;
823 struct timeval t_vblank;
826 * Interrupts were disabled prior to this call, so deal with counter
828 * NOTE! It's possible we lost a full dev->max_vblank_count events
829 * here if the register is small or we had vblank interrupts off for
832 * We repeat the hardware vblank counter & timestamp query until
833 * we get consistent results. This to prevent races between gpu
834 * updating its hardware counter while we are retrieving the
835 * corresponding vblank timestamp.
838 cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
839 rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0);
840 } while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc));
842 /* Deal with counter wrap */
843 diff = cur_vblank - dev->last_vblank[crtc];
844 if (cur_vblank < dev->last_vblank[crtc]) {
845 diff += dev->max_vblank_count;
847 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
848 crtc, dev->last_vblank[crtc], cur_vblank, diff);
851 DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
854 /* Reinitialize corresponding vblank timestamp if high-precision query
855 * available. Skip this step if query unsupported or failed. Will
856 * reinitialize delayed at next vblank interrupt in that case.
859 tslot = atomic_read(&dev->_vblank_count[crtc]) + diff;
860 vblanktimestamp(dev, crtc, tslot) = t_vblank;
863 smp_mb__before_atomic_inc();
864 atomic_add(diff, &dev->_vblank_count[crtc]);
865 smp_mb__after_atomic_inc();
869 * drm_vblank_get - get a reference count on vblank events
871 * @crtc: which CRTC to own
873 * Acquire a reference count on vblank events to avoid having them disabled
877 * Zero on success, nonzero on failure.
879 int drm_vblank_get(struct drm_device *dev, int crtc)
881 unsigned long irqflags, irqflags2;
884 spin_lock_irqsave(&dev->vbl_lock, irqflags);
885 /* Going from 0->1 means we have to enable interrupts again */
886 if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1) {
887 spin_lock_irqsave(&dev->vblank_time_lock, irqflags2);
888 if (!dev->vblank_enabled[crtc]) {
889 /* Enable vblank irqs under vblank_time_lock protection.
890 * All vblank count & timestamp updates are held off
891 * until we are done reinitializing master counter and
892 * timestamps. Filtercode in drm_handle_vblank() will
893 * prevent double-accounting of same vblank interval.
895 ret = dev->driver->enable_vblank(dev, crtc);
896 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n",
899 atomic_dec(&dev->vblank_refcount[crtc]);
901 dev->vblank_enabled[crtc] = 1;
902 drm_update_vblank_count(dev, crtc);
905 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags2);
907 if (!dev->vblank_enabled[crtc]) {
908 atomic_dec(&dev->vblank_refcount[crtc]);
912 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
916 EXPORT_SYMBOL(drm_vblank_get);
919 * drm_vblank_put - give up ownership of vblank events
921 * @crtc: which counter to give up
923 * Release ownership of a given vblank counter, turning off interrupts
924 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
926 void drm_vblank_put(struct drm_device *dev, int crtc)
928 BUG_ON(atomic_read(&dev->vblank_refcount[crtc]) == 0);
930 /* Last user schedules interrupt disable */
931 if (atomic_dec_and_test(&dev->vblank_refcount[crtc]) &&
932 (drm_vblank_offdelay > 0))
933 mod_timer(&dev->vblank_disable_timer,
934 jiffies + ((drm_vblank_offdelay * DRM_HZ)/1000));
936 EXPORT_SYMBOL(drm_vblank_put);
938 void drm_vblank_off(struct drm_device *dev, int crtc)
940 struct drm_pending_vblank_event *e, *t;
942 unsigned long irqflags;
945 spin_lock_irqsave(&dev->vbl_lock, irqflags);
946 vblank_disable_and_save(dev, crtc);
947 DRM_WAKEUP(&dev->vbl_queue[crtc]);
949 /* Send any queued vblank events, lest the natives grow disquiet */
950 seq = drm_vblank_count_and_time(dev, crtc, &now);
951 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
954 DRM_DEBUG("Sending premature vblank event on disable: \
955 wanted %d, current %d\n",
956 e->event.sequence, seq);
958 e->event.sequence = seq;
959 e->event.tv_sec = now.tv_sec;
960 e->event.tv_usec = now.tv_usec;
961 drm_vblank_put(dev, e->pipe);
962 list_move_tail(&e->base.link, &e->base.file_priv->event_list);
963 wake_up_interruptible(&e->base.file_priv->event_wait);
964 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
968 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
970 EXPORT_SYMBOL(drm_vblank_off);
973 * drm_vblank_pre_modeset - account for vblanks across mode sets
975 * @crtc: CRTC in question
976 * @post: post or pre mode set?
978 * Account for vblank events across mode setting events, which will likely
979 * reset the hardware frame counter.
981 void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
983 /* vblank is not initialized (IRQ not installed ?), or has been freed */
987 * To avoid all the problems that might happen if interrupts
988 * were enabled/disabled around or between these calls, we just
989 * have the kernel take a reference on the CRTC (just once though
990 * to avoid corrupting the count if multiple, mismatch calls occur),
991 * so that interrupts remain enabled in the interim.
993 if (!dev->vblank_inmodeset[crtc]) {
994 dev->vblank_inmodeset[crtc] = 0x1;
995 if (drm_vblank_get(dev, crtc) == 0)
996 dev->vblank_inmodeset[crtc] |= 0x2;
999 EXPORT_SYMBOL(drm_vblank_pre_modeset);
1001 void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
1003 unsigned long irqflags;
1005 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1006 if (!dev->num_crtcs)
1009 if (dev->vblank_inmodeset[crtc]) {
1010 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1011 dev->vblank_disable_allowed = 1;
1012 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1014 if (dev->vblank_inmodeset[crtc] & 0x2)
1015 drm_vblank_put(dev, crtc);
1017 dev->vblank_inmodeset[crtc] = 0;
1020 EXPORT_SYMBOL(drm_vblank_post_modeset);
1023 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1024 * @DRM_IOCTL_ARGS: standard ioctl arguments
1026 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1027 * ioctls around modesetting so that any lost vblank events are accounted for.
1029 * Generally the counter will reset across mode sets. If interrupts are
1030 * enabled around this call, we don't have to do anything since the counter
1031 * will have already been incremented.
1033 int drm_modeset_ctl(struct drm_device *dev, void *data,
1034 struct drm_file *file_priv)
1036 struct drm_modeset_ctl *modeset = data;
1040 /* If drm_vblank_init() hasn't been called yet, just no-op */
1041 if (!dev->num_crtcs)
1044 crtc = modeset->crtc;
1045 if (crtc >= dev->num_crtcs) {
1050 switch (modeset->cmd) {
1051 case _DRM_PRE_MODESET:
1052 drm_vblank_pre_modeset(dev, crtc);
1054 case _DRM_POST_MODESET:
1055 drm_vblank_post_modeset(dev, crtc);
1066 static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
1067 union drm_wait_vblank *vblwait,
1068 struct drm_file *file_priv)
1070 struct drm_pending_vblank_event *e;
1072 unsigned long flags;
1076 e = kzalloc(sizeof *e, GFP_KERNEL);
1083 e->base.pid = current->pid;
1084 e->event.base.type = DRM_EVENT_VBLANK;
1085 e->event.base.length = sizeof e->event;
1086 e->event.user_data = vblwait->request.signal;
1087 e->base.event = &e->event.base;
1088 e->base.file_priv = file_priv;
1089 e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
1091 spin_lock_irqsave(&dev->event_lock, flags);
1093 if (file_priv->event_space < sizeof e->event) {
1098 file_priv->event_space -= sizeof e->event;
1099 seq = drm_vblank_count_and_time(dev, pipe, &now);
1101 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1102 (seq - vblwait->request.sequence) <= (1 << 23)) {
1103 vblwait->request.sequence = seq + 1;
1104 vblwait->reply.sequence = vblwait->request.sequence;
1107 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1108 vblwait->request.sequence, seq, pipe);
1110 trace_drm_vblank_event_queued(current->pid, pipe,
1111 vblwait->request.sequence);
1113 e->event.sequence = vblwait->request.sequence;
1114 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1115 e->event.sequence = seq;
1116 e->event.tv_sec = now.tv_sec;
1117 e->event.tv_usec = now.tv_usec;
1118 drm_vblank_put(dev, pipe);
1119 list_add_tail(&e->base.link, &e->base.file_priv->event_list);
1120 wake_up_interruptible(&e->base.file_priv->event_wait);
1121 vblwait->reply.sequence = seq;
1122 trace_drm_vblank_event_delivered(current->pid, pipe,
1123 vblwait->request.sequence);
1125 /* drm_handle_vblank_events will call drm_vblank_put */
1126 list_add_tail(&e->base.link, &dev->vblank_event_list);
1127 vblwait->reply.sequence = vblwait->request.sequence;
1130 spin_unlock_irqrestore(&dev->event_lock, flags);
1135 spin_unlock_irqrestore(&dev->event_lock, flags);
1138 drm_vblank_put(dev, pipe);
1145 * \param inode device inode.
1146 * \param file_priv DRM file private.
1147 * \param cmd command.
1148 * \param data user argument, pointing to a drm_wait_vblank structure.
1149 * \return zero on success or a negative number on failure.
1151 * This function enables the vblank interrupt on the pipe requested, then
1152 * sleeps waiting for the requested sequence number to occur, and drops
1153 * the vblank interrupt refcount afterwards. (vblank irq disable follows that
1154 * after a timeout with no further vblank waits scheduled).
1156 int drm_wait_vblank(struct drm_device *dev, void *data,
1157 struct drm_file *file_priv)
1159 union drm_wait_vblank *vblwait = data;
1161 unsigned int flags, seq, crtc, high_crtc;
1163 if ((!drm_dev_to_irq(dev)) || (!dev->irq_enabled))
1166 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1169 if (vblwait->request.type &
1170 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1171 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1172 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1173 vblwait->request.type,
1174 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1175 _DRM_VBLANK_HIGH_CRTC_MASK));
1179 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1180 high_crtc = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1182 crtc = high_crtc >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1184 crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1185 if (crtc >= dev->num_crtcs)
1188 ret = drm_vblank_get(dev, crtc);
1190 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1193 seq = drm_vblank_count(dev, crtc);
1195 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1196 case _DRM_VBLANK_RELATIVE:
1197 vblwait->request.sequence += seq;
1198 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1199 case _DRM_VBLANK_ABSOLUTE:
1206 if (flags & _DRM_VBLANK_EVENT) {
1207 /* must hold on to the vblank ref until the event fires
1208 * drm_vblank_put will be called asynchronously
1210 return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
1213 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1214 (seq - vblwait->request.sequence) <= (1<<23)) {
1215 vblwait->request.sequence = seq + 1;
1218 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1219 vblwait->request.sequence, crtc);
1220 dev->last_vblank_wait[crtc] = vblwait->request.sequence;
1221 DRM_WAIT_ON(ret, dev->vbl_queue[crtc], 3 * DRM_HZ,
1222 (((drm_vblank_count(dev, crtc) -
1223 vblwait->request.sequence) <= (1 << 23)) ||
1224 !dev->irq_enabled));
1226 if (ret != -EINTR) {
1229 vblwait->reply.sequence = drm_vblank_count_and_time(dev, crtc, &now);
1230 vblwait->reply.tval_sec = now.tv_sec;
1231 vblwait->reply.tval_usec = now.tv_usec;
1233 DRM_DEBUG("returning %d to client\n",
1234 vblwait->reply.sequence);
1236 DRM_DEBUG("vblank wait interrupted by signal\n");
1240 drm_vblank_put(dev, crtc);
1244 void drm_handle_vblank_events(struct drm_device *dev, int crtc)
1246 struct drm_pending_vblank_event *e, *t;
1248 unsigned long flags;
1251 seq = drm_vblank_count_and_time(dev, crtc, &now);
1253 spin_lock_irqsave(&dev->event_lock, flags);
1255 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1256 if (e->pipe != crtc)
1258 if ((seq - e->event.sequence) > (1<<23))
1261 DRM_DEBUG("vblank event on %d, current %d\n",
1262 e->event.sequence, seq);
1264 e->event.sequence = seq;
1265 e->event.tv_sec = now.tv_sec;
1266 e->event.tv_usec = now.tv_usec;
1267 drm_vblank_put(dev, e->pipe);
1268 list_move_tail(&e->base.link, &e->base.file_priv->event_list);
1269 wake_up_interruptible(&e->base.file_priv->event_wait);
1270 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
1274 spin_unlock_irqrestore(&dev->event_lock, flags);
1276 trace_drm_vblank_event(crtc, seq);
1280 * drm_handle_vblank - handle a vblank event
1282 * @crtc: where this event occurred
1284 * Drivers should call this routine in their vblank interrupt handlers to
1285 * update the vblank counter and send any signals that may be pending.
1287 bool drm_handle_vblank(struct drm_device *dev, int crtc)
1291 struct timeval tvblank;
1292 unsigned long irqflags;
1294 if (!dev->num_crtcs)
1297 /* Need timestamp lock to prevent concurrent execution with
1298 * vblank enable/disable, as this would cause inconsistent
1299 * or corrupted timestamps and vblank counts.
1301 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
1303 /* Vblank irq handling disabled. Nothing to do. */
1304 if (!dev->vblank_enabled[crtc]) {
1305 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
1309 /* Fetch corresponding timestamp for this vblank interval from
1310 * driver and store it in proper slot of timestamp ringbuffer.
1313 /* Get current timestamp and count. */
1314 vblcount = atomic_read(&dev->_vblank_count[crtc]);
1315 drm_get_last_vbltimestamp(dev, crtc, &tvblank, DRM_CALLED_FROM_VBLIRQ);
1317 /* Compute time difference to timestamp of last vblank */
1318 diff_ns = timeval_to_ns(&tvblank) -
1319 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
1321 /* Update vblank timestamp and count if at least
1322 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1323 * difference between last stored timestamp and current
1324 * timestamp. A smaller difference means basically
1325 * identical timestamps. Happens if this vblank has
1326 * been already processed and this is a redundant call,
1327 * e.g., due to spurious vblank interrupts. We need to
1328 * ignore those for accounting.
1330 if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) {
1331 /* Store new timestamp in ringbuffer. */
1332 vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
1334 /* Increment cooked vblank count. This also atomically commits
1335 * the timestamp computed above.
1337 smp_mb__before_atomic_inc();
1338 atomic_inc(&dev->_vblank_count[crtc]);
1339 smp_mb__after_atomic_inc();
1341 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1342 crtc, (int) diff_ns);
1345 DRM_WAKEUP(&dev->vbl_queue[crtc]);
1346 drm_handle_vblank_events(dev, crtc);
1348 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
1351 EXPORT_SYMBOL(drm_handle_vblank);