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 1 (10.10.2010).\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 DRM_WAKEUP(&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.
450 void drm_calc_timestamping_constants(struct drm_crtc
*crtc
)
452 s64 linedur_ns
= 0, pixeldur_ns
= 0, framedur_ns
= 0;
455 /* Dot clock in Hz: */
456 dotclock
= (u64
) crtc
->hwmode
.clock
* 1000;
458 /* Fields of interlaced scanout modes are only halve a frame duration.
459 * Double the dotclock to get halve the frame-/line-/pixelduration.
461 if (crtc
->hwmode
.flags
& DRM_MODE_FLAG_INTERLACE
)
464 /* Valid dotclock? */
467 /* Convert scanline length in pixels and video dot clock to
468 * line duration, frame duration and pixel duration in
471 pixeldur_ns
= (s64
) div64_u64(1000000000, dotclock
);
472 linedur_ns
= (s64
) div64_u64(((u64
) crtc
->hwmode
.crtc_htotal
*
473 1000000000), dotclock
);
474 frame_size
= crtc
->hwmode
.crtc_htotal
*
475 crtc
->hwmode
.crtc_vtotal
;
476 framedur_ns
= (s64
) div64_u64((u64
) frame_size
* 1000000000,
479 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
482 crtc
->pixeldur_ns
= pixeldur_ns
;
483 crtc
->linedur_ns
= linedur_ns
;
484 crtc
->framedur_ns
= framedur_ns
;
486 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
487 crtc
->base
.id
, crtc
->hwmode
.crtc_htotal
,
488 crtc
->hwmode
.crtc_vtotal
, crtc
->hwmode
.crtc_vdisplay
);
489 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
490 crtc
->base
.id
, (int) dotclock
/1000, (int) framedur_ns
,
491 (int) linedur_ns
, (int) pixeldur_ns
);
493 EXPORT_SYMBOL(drm_calc_timestamping_constants
);
496 * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
497 * drivers. Implements calculation of exact vblank timestamps from
498 * given drm_display_mode timings and current video scanout position
499 * of a crtc. This can be called from within get_vblank_timestamp()
500 * implementation of a kms driver to implement the actual timestamping.
502 * Should return timestamps conforming to the OML_sync_control OpenML
503 * extension specification. The timestamp corresponds to the end of
504 * the vblank interval, aka start of scanout of topmost-leftmost display
505 * pixel in the following video frame.
507 * Requires support for optional dev->driver->get_scanout_position()
508 * in kms driver, plus a bit of setup code to provide a drm_display_mode
509 * that corresponds to the true scanout timing.
511 * The current implementation only handles standard video modes. It
512 * returns as no operation if a doublescan or interlaced video mode is
513 * active. Higher level code is expected to handle this.
516 * @crtc: Which crtc's vblank timestamp to retrieve.
517 * @max_error: Desired maximum allowable error in timestamps (nanosecs).
518 * On return contains true maximum error of timestamp.
519 * @vblank_time: Pointer to struct timeval which should receive the timestamp.
520 * @flags: Flags to pass to driver:
522 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
523 * @refcrtc: drm_crtc* of crtc which defines scanout timing.
525 * Returns negative value on error, failure or if not supported in current
528 * -EINVAL - Invalid crtc.
529 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
530 * -ENOTSUPP - Function not supported in current display mode.
531 * -EIO - Failed, e.g., due to failed scanout position query.
533 * Returns or'ed positive status flags on success:
535 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
536 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
539 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device
*dev
, int crtc
,
541 struct timeval
*vblank_time
,
543 struct drm_crtc
*refcrtc
)
545 ktime_t stime
, etime
, mono_time_offset
;
546 struct timeval tv_etime
;
547 struct drm_display_mode
*mode
;
548 int vbl_status
, vtotal
, vdisplay
;
550 s64 framedur_ns
, linedur_ns
, pixeldur_ns
, delta_ns
, duration_ns
;
553 if (crtc
< 0 || crtc
>= dev
->num_crtcs
) {
554 DRM_ERROR("Invalid crtc %d\n", crtc
);
558 /* Scanout position query not supported? Should not happen. */
559 if (!dev
->driver
->get_scanout_position
) {
560 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
564 mode
= &refcrtc
->hwmode
;
565 vtotal
= mode
->crtc_vtotal
;
566 vdisplay
= mode
->crtc_vdisplay
;
568 /* Durations of frames, lines, pixels in nanoseconds. */
569 framedur_ns
= refcrtc
->framedur_ns
;
570 linedur_ns
= refcrtc
->linedur_ns
;
571 pixeldur_ns
= refcrtc
->pixeldur_ns
;
573 /* If mode timing undefined, just return as no-op:
574 * Happens during initial modesetting of a crtc.
576 if (vtotal
<= 0 || vdisplay
<= 0 || framedur_ns
== 0) {
577 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc
);
581 /* Get current scanout position with system timestamp.
582 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
583 * if single query takes longer than max_error nanoseconds.
585 * This guarantees a tight bound on maximum error if
586 * code gets preempted or delayed for some reason.
588 for (i
= 0; i
< DRM_TIMESTAMP_MAXRETRIES
; i
++) {
589 /* Disable preemption to make it very likely to
590 * succeed in the first iteration even on PREEMPT_RT kernel.
594 /* Get system timestamp before query. */
597 /* Get vertical and horizontal scanout pos. vpos, hpos. */
598 vbl_status
= dev
->driver
->get_scanout_position(dev
, crtc
, &vpos
, &hpos
);
600 /* Get system timestamp after query. */
602 if (!drm_timestamp_monotonic
)
603 mono_time_offset
= ktime_get_monotonic_offset();
607 /* Return as no-op if scanout query unsupported or failed. */
608 if (!(vbl_status
& DRM_SCANOUTPOS_VALID
)) {
609 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
614 duration_ns
= ktime_to_ns(etime
) - ktime_to_ns(stime
);
616 /* Accept result with < max_error nsecs timing uncertainty. */
617 if (duration_ns
<= (s64
) *max_error
)
621 /* Noisy system timing? */
622 if (i
== DRM_TIMESTAMP_MAXRETRIES
) {
623 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
624 crtc
, (int) duration_ns
/1000, *max_error
/1000, i
);
627 /* Return upper bound of timestamp precision error. */
628 *max_error
= (int) duration_ns
;
630 /* Check if in vblank area:
631 * vpos is >=0 in video scanout area, but negative
632 * within vblank area, counting down the number of lines until
635 invbl
= vbl_status
& DRM_SCANOUTPOS_INVBL
;
637 /* Convert scanout position into elapsed time at raw_time query
638 * since start of scanout at first display scanline. delta_ns
639 * can be negative if start of scanout hasn't happened yet.
641 delta_ns
= (s64
) vpos
* linedur_ns
+ (s64
) hpos
* pixeldur_ns
;
643 /* Is vpos outside nominal vblank area, but less than
644 * 1/100 of a frame height away from start of vblank?
645 * If so, assume this isn't a massively delayed vblank
646 * interrupt, but a vblank interrupt that fired a few
647 * microseconds before true start of vblank. Compensate
648 * by adding a full frame duration to the final timestamp.
649 * Happens, e.g., on ATI R500, R600.
651 * We only do this if DRM_CALLED_FROM_VBLIRQ.
653 if ((flags
& DRM_CALLED_FROM_VBLIRQ
) && !invbl
&&
654 ((vdisplay
- vpos
) < vtotal
/ 100)) {
655 delta_ns
= delta_ns
- framedur_ns
;
657 /* Signal this correction as "applied". */
661 if (!drm_timestamp_monotonic
)
662 etime
= ktime_sub(etime
, mono_time_offset
);
664 /* save this only for debugging purposes */
665 tv_etime
= ktime_to_timeval(etime
);
666 /* Subtract time delta from raw timestamp to get final
667 * vblank_time timestamp for end of vblank.
670 etime
= ktime_add_ns(etime
, -delta_ns
);
672 etime
= ktime_sub_ns(etime
, delta_ns
);
673 *vblank_time
= ktime_to_timeval(etime
);
675 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
676 crtc
, (int)vbl_status
, hpos
, vpos
,
677 (long)tv_etime
.tv_sec
, (long)tv_etime
.tv_usec
,
678 (long)vblank_time
->tv_sec
, (long)vblank_time
->tv_usec
,
679 (int)duration_ns
/1000, i
);
681 vbl_status
= DRM_VBLANKTIME_SCANOUTPOS_METHOD
;
683 vbl_status
|= DRM_VBLANKTIME_INVBL
;
687 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos
);
689 static struct timeval
get_drm_timestamp(void)
694 if (!drm_timestamp_monotonic
)
695 now
= ktime_sub(now
, ktime_get_monotonic_offset());
697 return ktime_to_timeval(now
);
701 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
705 * @crtc: which crtc's vblank timestamp to retrieve
706 * @tvblank: Pointer to target struct timeval which should receive the timestamp
707 * @flags: Flags to pass to driver:
709 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
711 * Fetches the system timestamp corresponding to the time of the most recent
712 * vblank interval on specified crtc. May call into kms-driver to
713 * compute the timestamp with a high-precision GPU specific method.
715 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
716 * call, i.e., it isn't very precisely locked to the true vblank.
718 * Returns non-zero if timestamp is considered to be very precise.
720 u32
drm_get_last_vbltimestamp(struct drm_device
*dev
, int crtc
,
721 struct timeval
*tvblank
, unsigned flags
)
725 /* Define requested maximum error on timestamps (nanoseconds). */
726 int max_error
= (int) drm_timestamp_precision
* 1000;
728 /* Query driver if possible and precision timestamping enabled. */
729 if (dev
->driver
->get_vblank_timestamp
&& (max_error
> 0)) {
730 ret
= dev
->driver
->get_vblank_timestamp(dev
, crtc
, &max_error
,
736 /* GPU high precision timestamp query unsupported or failed.
737 * Return current monotonic/gettimeofday timestamp as best estimate.
739 *tvblank
= get_drm_timestamp();
743 EXPORT_SYMBOL(drm_get_last_vbltimestamp
);
746 * drm_vblank_count - retrieve "cooked" vblank counter value
748 * @crtc: which counter to retrieve
750 * Fetches the "cooked" vblank count value that represents the number of
751 * vblank events since the system was booted, including lost events due to
752 * modesetting activity.
754 u32
drm_vblank_count(struct drm_device
*dev
, int crtc
)
756 return atomic_read(&dev
->vblank
[crtc
].count
);
758 EXPORT_SYMBOL(drm_vblank_count
);
761 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
762 * and the system timestamp corresponding to that vblank counter value.
765 * @crtc: which counter to retrieve
766 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
768 * Fetches the "cooked" vblank count value that represents the number of
769 * vblank events since the system was booted, including lost events due to
770 * modesetting activity. Returns corresponding system timestamp of the time
771 * of the vblank interval that corresponds to the current value vblank counter
774 u32
drm_vblank_count_and_time(struct drm_device
*dev
, int crtc
,
775 struct timeval
*vblanktime
)
779 /* Read timestamp from slot of _vblank_time ringbuffer
780 * that corresponds to current vblank count. Retry if
781 * count has incremented during readout. This works like
785 cur_vblank
= atomic_read(&dev
->vblank
[crtc
].count
);
786 *vblanktime
= vblanktimestamp(dev
, crtc
, cur_vblank
);
788 } while (cur_vblank
!= atomic_read(&dev
->vblank
[crtc
].count
));
792 EXPORT_SYMBOL(drm_vblank_count_and_time
);
794 static void send_vblank_event(struct drm_device
*dev
,
795 struct drm_pending_vblank_event
*e
,
796 unsigned long seq
, struct timeval
*now
)
798 WARN_ON_SMP(!spin_is_locked(&dev
->event_lock
));
799 e
->event
.sequence
= seq
;
800 e
->event
.tv_sec
= now
->tv_sec
;
801 e
->event
.tv_usec
= now
->tv_usec
;
803 list_add_tail(&e
->base
.link
,
804 &e
->base
.file_priv
->event_list
);
805 wake_up_interruptible(&e
->base
.file_priv
->event_wait
);
806 trace_drm_vblank_event_delivered(e
->base
.pid
, e
->pipe
,
811 * drm_send_vblank_event - helper to send vblank event after pageflip
813 * @crtc: CRTC in question
814 * @e: the event to send
816 * Updates sequence # and timestamp on event, and sends it to userspace.
817 * Caller must hold event lock.
819 void drm_send_vblank_event(struct drm_device
*dev
, int crtc
,
820 struct drm_pending_vblank_event
*e
)
825 seq
= drm_vblank_count_and_time(dev
, crtc
, &now
);
829 now
= get_drm_timestamp();
832 send_vblank_event(dev
, e
, seq
, &now
);
834 EXPORT_SYMBOL(drm_send_vblank_event
);
837 * drm_update_vblank_count - update the master vblank counter
839 * @crtc: counter to update
841 * Call back into the driver to update the appropriate vblank counter
842 * (specified by @crtc). Deal with wraparound, if it occurred, and
843 * update the last read value so we can deal with wraparound on the next
846 * Only necessary when going from off->on, to account for frames we
847 * didn't get an interrupt for.
849 * Note: caller must hold dev->vbl_lock since this reads & writes
850 * device vblank fields.
852 static void drm_update_vblank_count(struct drm_device
*dev
, int crtc
)
854 u32 cur_vblank
, diff
, tslot
, rc
;
855 struct timeval t_vblank
;
858 * Interrupts were disabled prior to this call, so deal with counter
860 * NOTE! It's possible we lost a full dev->max_vblank_count events
861 * here if the register is small or we had vblank interrupts off for
864 * We repeat the hardware vblank counter & timestamp query until
865 * we get consistent results. This to prevent races between gpu
866 * updating its hardware counter while we are retrieving the
867 * corresponding vblank timestamp.
870 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, crtc
);
871 rc
= drm_get_last_vbltimestamp(dev
, crtc
, &t_vblank
, 0);
872 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, crtc
));
874 /* Deal with counter wrap */
875 diff
= cur_vblank
- dev
->vblank
[crtc
].last
;
876 if (cur_vblank
< dev
->vblank
[crtc
].last
) {
877 diff
+= dev
->max_vblank_count
;
879 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
880 crtc
, dev
->vblank
[crtc
].last
, cur_vblank
, diff
);
883 DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
886 /* Reinitialize corresponding vblank timestamp if high-precision query
887 * available. Skip this step if query unsupported or failed. Will
888 * reinitialize delayed at next vblank interrupt in that case.
891 tslot
= atomic_read(&dev
->vblank
[crtc
].count
) + diff
;
892 vblanktimestamp(dev
, crtc
, tslot
) = t_vblank
;
895 smp_mb__before_atomic_inc();
896 atomic_add(diff
, &dev
->vblank
[crtc
].count
);
897 smp_mb__after_atomic_inc();
901 * drm_vblank_get - get a reference count on vblank events
903 * @crtc: which CRTC to own
905 * Acquire a reference count on vblank events to avoid having them disabled
909 * Zero on success, nonzero on failure.
911 int drm_vblank_get(struct drm_device
*dev
, int crtc
)
913 unsigned long irqflags
, irqflags2
;
916 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
917 /* Going from 0->1 means we have to enable interrupts again */
918 if (atomic_add_return(1, &dev
->vblank
[crtc
].refcount
) == 1) {
919 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags2
);
920 if (!dev
->vblank
[crtc
].enabled
) {
921 /* Enable vblank irqs under vblank_time_lock protection.
922 * All vblank count & timestamp updates are held off
923 * until we are done reinitializing master counter and
924 * timestamps. Filtercode in drm_handle_vblank() will
925 * prevent double-accounting of same vblank interval.
927 ret
= dev
->driver
->enable_vblank(dev
, crtc
);
928 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n",
931 atomic_dec(&dev
->vblank
[crtc
].refcount
);
933 dev
->vblank
[crtc
].enabled
= true;
934 drm_update_vblank_count(dev
, crtc
);
937 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags2
);
939 if (!dev
->vblank
[crtc
].enabled
) {
940 atomic_dec(&dev
->vblank
[crtc
].refcount
);
944 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
948 EXPORT_SYMBOL(drm_vblank_get
);
951 * drm_vblank_put - give up ownership of vblank events
953 * @crtc: which counter to give up
955 * Release ownership of a given vblank counter, turning off interrupts
956 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
958 void drm_vblank_put(struct drm_device
*dev
, int crtc
)
960 BUG_ON(atomic_read(&dev
->vblank
[crtc
].refcount
) == 0);
962 /* Last user schedules interrupt disable */
963 if (atomic_dec_and_test(&dev
->vblank
[crtc
].refcount
) &&
964 (drm_vblank_offdelay
> 0))
965 mod_timer(&dev
->vblank_disable_timer
,
966 jiffies
+ ((drm_vblank_offdelay
* DRM_HZ
)/1000));
968 EXPORT_SYMBOL(drm_vblank_put
);
971 * drm_vblank_off - disable vblank events on a CRTC
973 * @crtc: CRTC in question
975 * Caller must hold event lock.
977 void drm_vblank_off(struct drm_device
*dev
, int crtc
)
979 struct drm_pending_vblank_event
*e
, *t
;
981 unsigned long irqflags
;
984 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
985 vblank_disable_and_save(dev
, crtc
);
986 DRM_WAKEUP(&dev
->vblank
[crtc
].queue
);
988 /* Send any queued vblank events, lest the natives grow disquiet */
989 seq
= drm_vblank_count_and_time(dev
, crtc
, &now
);
991 spin_lock(&dev
->event_lock
);
992 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
995 DRM_DEBUG("Sending premature vblank event on disable: \
996 wanted %d, current %d\n",
997 e
->event
.sequence
, seq
);
998 list_del(&e
->base
.link
);
999 drm_vblank_put(dev
, e
->pipe
);
1000 send_vblank_event(dev
, e
, seq
, &now
);
1002 spin_unlock(&dev
->event_lock
);
1004 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1006 EXPORT_SYMBOL(drm_vblank_off
);
1009 * drm_vblank_pre_modeset - account for vblanks across mode sets
1011 * @crtc: CRTC in question
1013 * Account for vblank events across mode setting events, which will likely
1014 * reset the hardware frame counter.
1016 void drm_vblank_pre_modeset(struct drm_device
*dev
, int crtc
)
1018 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1019 if (!dev
->num_crtcs
)
1022 * To avoid all the problems that might happen if interrupts
1023 * were enabled/disabled around or between these calls, we just
1024 * have the kernel take a reference on the CRTC (just once though
1025 * to avoid corrupting the count if multiple, mismatch calls occur),
1026 * so that interrupts remain enabled in the interim.
1028 if (!dev
->vblank
[crtc
].inmodeset
) {
1029 dev
->vblank
[crtc
].inmodeset
= 0x1;
1030 if (drm_vblank_get(dev
, crtc
) == 0)
1031 dev
->vblank
[crtc
].inmodeset
|= 0x2;
1034 EXPORT_SYMBOL(drm_vblank_pre_modeset
);
1036 void drm_vblank_post_modeset(struct drm_device
*dev
, int crtc
)
1038 unsigned long irqflags
;
1040 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1041 if (!dev
->num_crtcs
)
1044 if (dev
->vblank
[crtc
].inmodeset
) {
1045 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1046 dev
->vblank_disable_allowed
= true;
1047 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1049 if (dev
->vblank
[crtc
].inmodeset
& 0x2)
1050 drm_vblank_put(dev
, crtc
);
1052 dev
->vblank
[crtc
].inmodeset
= 0;
1055 EXPORT_SYMBOL(drm_vblank_post_modeset
);
1058 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1059 * @DRM_IOCTL_ARGS: standard ioctl arguments
1061 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1062 * ioctls around modesetting so that any lost vblank events are accounted for.
1064 * Generally the counter will reset across mode sets. If interrupts are
1065 * enabled around this call, we don't have to do anything since the counter
1066 * will have already been incremented.
1068 int drm_modeset_ctl(struct drm_device
*dev
, void *data
,
1069 struct drm_file
*file_priv
)
1071 struct drm_modeset_ctl
*modeset
= data
;
1074 /* If drm_vblank_init() hasn't been called yet, just no-op */
1075 if (!dev
->num_crtcs
)
1078 /* KMS drivers handle this internally */
1079 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
1082 crtc
= modeset
->crtc
;
1083 if (crtc
>= dev
->num_crtcs
)
1086 switch (modeset
->cmd
) {
1087 case _DRM_PRE_MODESET
:
1088 drm_vblank_pre_modeset(dev
, crtc
);
1090 case _DRM_POST_MODESET
:
1091 drm_vblank_post_modeset(dev
, crtc
);
1100 static int drm_queue_vblank_event(struct drm_device
*dev
, int pipe
,
1101 union drm_wait_vblank
*vblwait
,
1102 struct drm_file
*file_priv
)
1104 struct drm_pending_vblank_event
*e
;
1106 unsigned long flags
;
1110 e
= kzalloc(sizeof *e
, GFP_KERNEL
);
1117 e
->base
.pid
= current
->pid
;
1118 e
->event
.base
.type
= DRM_EVENT_VBLANK
;
1119 e
->event
.base
.length
= sizeof e
->event
;
1120 e
->event
.user_data
= vblwait
->request
.signal
;
1121 e
->base
.event
= &e
->event
.base
;
1122 e
->base
.file_priv
= file_priv
;
1123 e
->base
.destroy
= (void (*) (struct drm_pending_event
*)) kfree
;
1125 spin_lock_irqsave(&dev
->event_lock
, flags
);
1127 if (file_priv
->event_space
< sizeof e
->event
) {
1132 file_priv
->event_space
-= sizeof e
->event
;
1133 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1135 if ((vblwait
->request
.type
& _DRM_VBLANK_NEXTONMISS
) &&
1136 (seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1137 vblwait
->request
.sequence
= seq
+ 1;
1138 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1141 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1142 vblwait
->request
.sequence
, seq
, pipe
);
1144 trace_drm_vblank_event_queued(current
->pid
, pipe
,
1145 vblwait
->request
.sequence
);
1147 e
->event
.sequence
= vblwait
->request
.sequence
;
1148 if ((seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1149 drm_vblank_put(dev
, pipe
);
1150 send_vblank_event(dev
, e
, seq
, &now
);
1151 vblwait
->reply
.sequence
= seq
;
1153 /* drm_handle_vblank_events will call drm_vblank_put */
1154 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1155 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1158 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1163 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1166 drm_vblank_put(dev
, pipe
);
1173 * \param inode device inode.
1174 * \param file_priv DRM file private.
1175 * \param cmd command.
1176 * \param data user argument, pointing to a drm_wait_vblank structure.
1177 * \return zero on success or a negative number on failure.
1179 * This function enables the vblank interrupt on the pipe requested, then
1180 * sleeps waiting for the requested sequence number to occur, and drops
1181 * the vblank interrupt refcount afterwards. (vblank irq disable follows that
1182 * after a timeout with no further vblank waits scheduled).
1184 int drm_wait_vblank(struct drm_device
*dev
, void *data
,
1185 struct drm_file
*file_priv
)
1187 union drm_wait_vblank
*vblwait
= data
;
1189 unsigned int flags
, seq
, crtc
, high_crtc
;
1191 if (drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
1192 if ((!drm_dev_to_irq(dev
)) || (!dev
->irq_enabled
))
1195 if (vblwait
->request
.type
& _DRM_VBLANK_SIGNAL
)
1198 if (vblwait
->request
.type
&
1199 ~(_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1200 _DRM_VBLANK_HIGH_CRTC_MASK
)) {
1201 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1202 vblwait
->request
.type
,
1203 (_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1204 _DRM_VBLANK_HIGH_CRTC_MASK
));
1208 flags
= vblwait
->request
.type
& _DRM_VBLANK_FLAGS_MASK
;
1209 high_crtc
= (vblwait
->request
.type
& _DRM_VBLANK_HIGH_CRTC_MASK
);
1211 crtc
= high_crtc
>> _DRM_VBLANK_HIGH_CRTC_SHIFT
;
1213 crtc
= flags
& _DRM_VBLANK_SECONDARY
? 1 : 0;
1214 if (crtc
>= dev
->num_crtcs
)
1217 ret
= drm_vblank_get(dev
, crtc
);
1219 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret
);
1222 seq
= drm_vblank_count(dev
, crtc
);
1224 switch (vblwait
->request
.type
& _DRM_VBLANK_TYPES_MASK
) {
1225 case _DRM_VBLANK_RELATIVE
:
1226 vblwait
->request
.sequence
+= seq
;
1227 vblwait
->request
.type
&= ~_DRM_VBLANK_RELATIVE
;
1228 case _DRM_VBLANK_ABSOLUTE
:
1235 if (flags
& _DRM_VBLANK_EVENT
) {
1236 /* must hold on to the vblank ref until the event fires
1237 * drm_vblank_put will be called asynchronously
1239 return drm_queue_vblank_event(dev
, crtc
, vblwait
, file_priv
);
1242 if ((flags
& _DRM_VBLANK_NEXTONMISS
) &&
1243 (seq
- vblwait
->request
.sequence
) <= (1<<23)) {
1244 vblwait
->request
.sequence
= seq
+ 1;
1247 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1248 vblwait
->request
.sequence
, crtc
);
1249 dev
->vblank
[crtc
].last_wait
= vblwait
->request
.sequence
;
1250 DRM_WAIT_ON(ret
, dev
->vblank
[crtc
].queue
, 3 * DRM_HZ
,
1251 (((drm_vblank_count(dev
, crtc
) -
1252 vblwait
->request
.sequence
) <= (1 << 23)) ||
1253 !dev
->irq_enabled
));
1255 if (ret
!= -EINTR
) {
1258 vblwait
->reply
.sequence
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1259 vblwait
->reply
.tval_sec
= now
.tv_sec
;
1260 vblwait
->reply
.tval_usec
= now
.tv_usec
;
1262 DRM_DEBUG("returning %d to client\n",
1263 vblwait
->reply
.sequence
);
1265 DRM_DEBUG("vblank wait interrupted by signal\n");
1269 drm_vblank_put(dev
, crtc
);
1273 static void drm_handle_vblank_events(struct drm_device
*dev
, int crtc
)
1275 struct drm_pending_vblank_event
*e
, *t
;
1277 unsigned long flags
;
1280 seq
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1282 spin_lock_irqsave(&dev
->event_lock
, flags
);
1284 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1285 if (e
->pipe
!= crtc
)
1287 if ((seq
- e
->event
.sequence
) > (1<<23))
1290 DRM_DEBUG("vblank event on %d, current %d\n",
1291 e
->event
.sequence
, seq
);
1293 list_del(&e
->base
.link
);
1294 drm_vblank_put(dev
, e
->pipe
);
1295 send_vblank_event(dev
, e
, seq
, &now
);
1298 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1300 trace_drm_vblank_event(crtc
, seq
);
1304 * drm_handle_vblank - handle a vblank event
1306 * @crtc: where this event occurred
1308 * Drivers should call this routine in their vblank interrupt handlers to
1309 * update the vblank counter and send any signals that may be pending.
1311 bool drm_handle_vblank(struct drm_device
*dev
, int crtc
)
1315 struct timeval tvblank
;
1316 unsigned long irqflags
;
1318 if (!dev
->num_crtcs
)
1321 /* Need timestamp lock to prevent concurrent execution with
1322 * vblank enable/disable, as this would cause inconsistent
1323 * or corrupted timestamps and vblank counts.
1325 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags
);
1327 /* Vblank irq handling disabled. Nothing to do. */
1328 if (!dev
->vblank
[crtc
].enabled
) {
1329 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
1333 /* Fetch corresponding timestamp for this vblank interval from
1334 * driver and store it in proper slot of timestamp ringbuffer.
1337 /* Get current timestamp and count. */
1338 vblcount
= atomic_read(&dev
->vblank
[crtc
].count
);
1339 drm_get_last_vbltimestamp(dev
, crtc
, &tvblank
, DRM_CALLED_FROM_VBLIRQ
);
1341 /* Compute time difference to timestamp of last vblank */
1342 diff_ns
= timeval_to_ns(&tvblank
) -
1343 timeval_to_ns(&vblanktimestamp(dev
, crtc
, vblcount
));
1345 /* Update vblank timestamp and count if at least
1346 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1347 * difference between last stored timestamp and current
1348 * timestamp. A smaller difference means basically
1349 * identical timestamps. Happens if this vblank has
1350 * been already processed and this is a redundant call,
1351 * e.g., due to spurious vblank interrupts. We need to
1352 * ignore those for accounting.
1354 if (abs64(diff_ns
) > DRM_REDUNDANT_VBLIRQ_THRESH_NS
) {
1355 /* Store new timestamp in ringbuffer. */
1356 vblanktimestamp(dev
, crtc
, vblcount
+ 1) = tvblank
;
1358 /* Increment cooked vblank count. This also atomically commits
1359 * the timestamp computed above.
1361 smp_mb__before_atomic_inc();
1362 atomic_inc(&dev
->vblank
[crtc
].count
);
1363 smp_mb__after_atomic_inc();
1365 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1366 crtc
, (int) diff_ns
);
1369 DRM_WAKEUP(&dev
->vblank
[crtc
].queue
);
1370 drm_handle_vblank_events(dev
, crtc
);
1372 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
1375 EXPORT_SYMBOL(drm_handle_vblank
);