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
= 1;
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
= 0;
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
= 0;
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
;
356 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
359 mutex_lock(&dev
->struct_mutex
);
360 irq_enabled
= dev
->irq_enabled
;
361 dev
->irq_enabled
= 0;
362 mutex_unlock(&dev
->struct_mutex
);
365 * Wake up any waiters so they don't hang.
367 if (dev
->num_crtcs
) {
368 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
369 for (i
= 0; i
< dev
->num_crtcs
; i
++) {
370 DRM_WAKEUP(&dev
->vblank
[i
].queue
);
371 dev
->vblank
[i
].enabled
= false;
372 dev
->vblank
[i
].last
=
373 dev
->driver
->get_vblank_counter(dev
, i
);
375 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
381 DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev
));
383 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
384 vga_client_register(dev
->pdev
, NULL
, NULL
, NULL
);
386 if (dev
->driver
->irq_uninstall
)
387 dev
->driver
->irq_uninstall(dev
);
389 free_irq(drm_dev_to_irq(dev
), dev
);
393 EXPORT_SYMBOL(drm_irq_uninstall
);
398 * \param inode device inode.
399 * \param file_priv DRM file private.
400 * \param cmd command.
401 * \param arg user argument, pointing to a drm_control structure.
402 * \return zero on success or a negative number on failure.
404 * Calls irq_install() or irq_uninstall() according to \p arg.
406 int drm_control(struct drm_device
*dev
, void *data
,
407 struct drm_file
*file_priv
)
409 struct drm_control
*ctl
= data
;
411 /* if we haven't irq we fallback for compatibility reasons -
412 * this used to be a separate function in drm_dma.h
417 case DRM_INST_HANDLER
:
418 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
420 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
422 if (dev
->if_version
< DRM_IF_VERSION(1, 2) &&
423 ctl
->irq
!= drm_dev_to_irq(dev
))
425 return drm_irq_install(dev
);
426 case DRM_UNINST_HANDLER
:
427 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
429 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
431 return drm_irq_uninstall(dev
);
438 * drm_calc_timestamping_constants - Calculate and
439 * store various constants which are later needed by
440 * vblank and swap-completion timestamping, e.g, by
441 * drm_calc_vbltimestamp_from_scanoutpos().
442 * They are derived from crtc's true scanout timing,
443 * so they take things like panel scaling or other
444 * adjustments into account.
446 * @crtc drm_crtc whose timestamp constants should be updated.
449 void drm_calc_timestamping_constants(struct drm_crtc
*crtc
)
451 s64 linedur_ns
= 0, pixeldur_ns
= 0, framedur_ns
= 0;
454 /* Dot clock in Hz: */
455 dotclock
= (u64
) crtc
->hwmode
.clock
* 1000;
457 /* Fields of interlaced scanout modes are only halve a frame duration.
458 * Double the dotclock to get halve the frame-/line-/pixelduration.
460 if (crtc
->hwmode
.flags
& DRM_MODE_FLAG_INTERLACE
)
463 /* Valid dotclock? */
466 /* Convert scanline length in pixels and video dot clock to
467 * line duration, frame duration and pixel duration in
470 pixeldur_ns
= (s64
) div64_u64(1000000000, dotclock
);
471 linedur_ns
= (s64
) div64_u64(((u64
) crtc
->hwmode
.crtc_htotal
*
472 1000000000), dotclock
);
473 frame_size
= crtc
->hwmode
.crtc_htotal
*
474 crtc
->hwmode
.crtc_vtotal
;
475 framedur_ns
= (s64
) div64_u64((u64
) frame_size
* 1000000000,
478 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
481 crtc
->pixeldur_ns
= pixeldur_ns
;
482 crtc
->linedur_ns
= linedur_ns
;
483 crtc
->framedur_ns
= framedur_ns
;
485 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
486 crtc
->base
.id
, crtc
->hwmode
.crtc_htotal
,
487 crtc
->hwmode
.crtc_vtotal
, crtc
->hwmode
.crtc_vdisplay
);
488 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
489 crtc
->base
.id
, (int) dotclock
/1000, (int) framedur_ns
,
490 (int) linedur_ns
, (int) pixeldur_ns
);
492 EXPORT_SYMBOL(drm_calc_timestamping_constants
);
495 * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
496 * drivers. Implements calculation of exact vblank timestamps from
497 * given drm_display_mode timings and current video scanout position
498 * of a crtc. This can be called from within get_vblank_timestamp()
499 * implementation of a kms driver to implement the actual timestamping.
501 * Should return timestamps conforming to the OML_sync_control OpenML
502 * extension specification. The timestamp corresponds to the end of
503 * the vblank interval, aka start of scanout of topmost-leftmost display
504 * pixel in the following video frame.
506 * Requires support for optional dev->driver->get_scanout_position()
507 * in kms driver, plus a bit of setup code to provide a drm_display_mode
508 * that corresponds to the true scanout timing.
510 * The current implementation only handles standard video modes. It
511 * returns as no operation if a doublescan or interlaced video mode is
512 * active. Higher level code is expected to handle this.
515 * @crtc: Which crtc's vblank timestamp to retrieve.
516 * @max_error: Desired maximum allowable error in timestamps (nanosecs).
517 * On return contains true maximum error of timestamp.
518 * @vblank_time: Pointer to struct timeval which should receive the timestamp.
519 * @flags: Flags to pass to driver:
521 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
522 * @refcrtc: drm_crtc* of crtc which defines scanout timing.
524 * Returns negative value on error, failure or if not supported in current
527 * -EINVAL - Invalid crtc.
528 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
529 * -ENOTSUPP - Function not supported in current display mode.
530 * -EIO - Failed, e.g., due to failed scanout position query.
532 * Returns or'ed positive status flags on success:
534 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
535 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
538 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device
*dev
, int crtc
,
540 struct timeval
*vblank_time
,
542 struct drm_crtc
*refcrtc
)
544 ktime_t stime
, etime
, mono_time_offset
;
545 struct timeval tv_etime
;
546 struct drm_display_mode
*mode
;
547 int vbl_status
, vtotal
, vdisplay
;
549 s64 framedur_ns
, linedur_ns
, pixeldur_ns
, delta_ns
, duration_ns
;
552 if (crtc
< 0 || crtc
>= dev
->num_crtcs
) {
553 DRM_ERROR("Invalid crtc %d\n", crtc
);
557 /* Scanout position query not supported? Should not happen. */
558 if (!dev
->driver
->get_scanout_position
) {
559 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
563 mode
= &refcrtc
->hwmode
;
564 vtotal
= mode
->crtc_vtotal
;
565 vdisplay
= mode
->crtc_vdisplay
;
567 /* Durations of frames, lines, pixels in nanoseconds. */
568 framedur_ns
= refcrtc
->framedur_ns
;
569 linedur_ns
= refcrtc
->linedur_ns
;
570 pixeldur_ns
= refcrtc
->pixeldur_ns
;
572 /* If mode timing undefined, just return as no-op:
573 * Happens during initial modesetting of a crtc.
575 if (vtotal
<= 0 || vdisplay
<= 0 || framedur_ns
== 0) {
576 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc
);
580 /* Get current scanout position with system timestamp.
581 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
582 * if single query takes longer than max_error nanoseconds.
584 * This guarantees a tight bound on maximum error if
585 * code gets preempted or delayed for some reason.
587 for (i
= 0; i
< DRM_TIMESTAMP_MAXRETRIES
; i
++) {
588 /* Disable preemption to make it very likely to
589 * succeed in the first iteration even on PREEMPT_RT kernel.
593 /* Get system timestamp before query. */
596 /* Get vertical and horizontal scanout pos. vpos, hpos. */
597 vbl_status
= dev
->driver
->get_scanout_position(dev
, crtc
, &vpos
, &hpos
);
599 /* Get system timestamp after query. */
601 if (!drm_timestamp_monotonic
)
602 mono_time_offset
= ktime_get_monotonic_offset();
606 /* Return as no-op if scanout query unsupported or failed. */
607 if (!(vbl_status
& DRM_SCANOUTPOS_VALID
)) {
608 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
613 duration_ns
= ktime_to_ns(etime
) - ktime_to_ns(stime
);
615 /* Accept result with < max_error nsecs timing uncertainty. */
616 if (duration_ns
<= (s64
) *max_error
)
620 /* Noisy system timing? */
621 if (i
== DRM_TIMESTAMP_MAXRETRIES
) {
622 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
623 crtc
, (int) duration_ns
/1000, *max_error
/1000, i
);
626 /* Return upper bound of timestamp precision error. */
627 *max_error
= (int) duration_ns
;
629 /* Check if in vblank area:
630 * vpos is >=0 in video scanout area, but negative
631 * within vblank area, counting down the number of lines until
634 invbl
= vbl_status
& DRM_SCANOUTPOS_INVBL
;
636 /* Convert scanout position into elapsed time at raw_time query
637 * since start of scanout at first display scanline. delta_ns
638 * can be negative if start of scanout hasn't happened yet.
640 delta_ns
= (s64
) vpos
* linedur_ns
+ (s64
) hpos
* pixeldur_ns
;
642 /* Is vpos outside nominal vblank area, but less than
643 * 1/100 of a frame height away from start of vblank?
644 * If so, assume this isn't a massively delayed vblank
645 * interrupt, but a vblank interrupt that fired a few
646 * microseconds before true start of vblank. Compensate
647 * by adding a full frame duration to the final timestamp.
648 * Happens, e.g., on ATI R500, R600.
650 * We only do this if DRM_CALLED_FROM_VBLIRQ.
652 if ((flags
& DRM_CALLED_FROM_VBLIRQ
) && !invbl
&&
653 ((vdisplay
- vpos
) < vtotal
/ 100)) {
654 delta_ns
= delta_ns
- framedur_ns
;
656 /* Signal this correction as "applied". */
660 if (!drm_timestamp_monotonic
)
661 etime
= ktime_sub(etime
, mono_time_offset
);
663 /* save this only for debugging purposes */
664 tv_etime
= ktime_to_timeval(etime
);
665 /* Subtract time delta from raw timestamp to get final
666 * vblank_time timestamp for end of vblank.
669 etime
= ktime_add_ns(etime
, -delta_ns
);
671 etime
= ktime_sub_ns(etime
, delta_ns
);
672 *vblank_time
= ktime_to_timeval(etime
);
674 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
675 crtc
, (int)vbl_status
, hpos
, vpos
,
676 (long)tv_etime
.tv_sec
, (long)tv_etime
.tv_usec
,
677 (long)vblank_time
->tv_sec
, (long)vblank_time
->tv_usec
,
678 (int)duration_ns
/1000, i
);
680 vbl_status
= DRM_VBLANKTIME_SCANOUTPOS_METHOD
;
682 vbl_status
|= DRM_VBLANKTIME_INVBL
;
686 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos
);
688 static struct timeval
get_drm_timestamp(void)
693 if (!drm_timestamp_monotonic
)
694 now
= ktime_sub(now
, ktime_get_monotonic_offset());
696 return ktime_to_timeval(now
);
700 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
704 * @crtc: which crtc's vblank timestamp to retrieve
705 * @tvblank: Pointer to target struct timeval which should receive the timestamp
706 * @flags: Flags to pass to driver:
708 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
710 * Fetches the system timestamp corresponding to the time of the most recent
711 * vblank interval on specified crtc. May call into kms-driver to
712 * compute the timestamp with a high-precision GPU specific method.
714 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
715 * call, i.e., it isn't very precisely locked to the true vblank.
717 * Returns non-zero if timestamp is considered to be very precise.
719 u32
drm_get_last_vbltimestamp(struct drm_device
*dev
, int crtc
,
720 struct timeval
*tvblank
, unsigned flags
)
724 /* Define requested maximum error on timestamps (nanoseconds). */
725 int max_error
= (int) drm_timestamp_precision
* 1000;
727 /* Query driver if possible and precision timestamping enabled. */
728 if (dev
->driver
->get_vblank_timestamp
&& (max_error
> 0)) {
729 ret
= dev
->driver
->get_vblank_timestamp(dev
, crtc
, &max_error
,
735 /* GPU high precision timestamp query unsupported or failed.
736 * Return current monotonic/gettimeofday timestamp as best estimate.
738 *tvblank
= get_drm_timestamp();
742 EXPORT_SYMBOL(drm_get_last_vbltimestamp
);
745 * drm_vblank_count - retrieve "cooked" vblank counter value
747 * @crtc: which counter to retrieve
749 * Fetches the "cooked" vblank count value that represents the number of
750 * vblank events since the system was booted, including lost events due to
751 * modesetting activity.
753 u32
drm_vblank_count(struct drm_device
*dev
, int crtc
)
755 return atomic_read(&dev
->vblank
[crtc
].count
);
757 EXPORT_SYMBOL(drm_vblank_count
);
760 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
761 * and the system timestamp corresponding to that vblank counter value.
764 * @crtc: which counter to retrieve
765 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
767 * Fetches the "cooked" vblank count value that represents the number of
768 * vblank events since the system was booted, including lost events due to
769 * modesetting activity. Returns corresponding system timestamp of the time
770 * of the vblank interval that corresponds to the current value vblank counter
773 u32
drm_vblank_count_and_time(struct drm_device
*dev
, int crtc
,
774 struct timeval
*vblanktime
)
778 /* Read timestamp from slot of _vblank_time ringbuffer
779 * that corresponds to current vblank count. Retry if
780 * count has incremented during readout. This works like
784 cur_vblank
= atomic_read(&dev
->vblank
[crtc
].count
);
785 *vblanktime
= vblanktimestamp(dev
, crtc
, cur_vblank
);
787 } while (cur_vblank
!= atomic_read(&dev
->vblank
[crtc
].count
));
791 EXPORT_SYMBOL(drm_vblank_count_and_time
);
793 static void send_vblank_event(struct drm_device
*dev
,
794 struct drm_pending_vblank_event
*e
,
795 unsigned long seq
, struct timeval
*now
)
797 WARN_ON_SMP(!spin_is_locked(&dev
->event_lock
));
798 e
->event
.sequence
= seq
;
799 e
->event
.tv_sec
= now
->tv_sec
;
800 e
->event
.tv_usec
= now
->tv_usec
;
802 list_add_tail(&e
->base
.link
,
803 &e
->base
.file_priv
->event_list
);
804 wake_up_interruptible(&e
->base
.file_priv
->event_wait
);
805 trace_drm_vblank_event_delivered(e
->base
.pid
, e
->pipe
,
810 * drm_send_vblank_event - helper to send vblank event after pageflip
812 * @crtc: CRTC in question
813 * @e: the event to send
815 * Updates sequence # and timestamp on event, and sends it to userspace.
816 * Caller must hold event lock.
818 void drm_send_vblank_event(struct drm_device
*dev
, int crtc
,
819 struct drm_pending_vblank_event
*e
)
824 seq
= drm_vblank_count_and_time(dev
, crtc
, &now
);
828 now
= get_drm_timestamp();
831 send_vblank_event(dev
, e
, seq
, &now
);
833 EXPORT_SYMBOL(drm_send_vblank_event
);
836 * drm_update_vblank_count - update the master vblank counter
838 * @crtc: counter to update
840 * Call back into the driver to update the appropriate vblank counter
841 * (specified by @crtc). Deal with wraparound, if it occurred, and
842 * update the last read value so we can deal with wraparound on the next
845 * Only necessary when going from off->on, to account for frames we
846 * didn't get an interrupt for.
848 * Note: caller must hold dev->vbl_lock since this reads & writes
849 * device vblank fields.
851 static void drm_update_vblank_count(struct drm_device
*dev
, int crtc
)
853 u32 cur_vblank
, diff
, tslot
, rc
;
854 struct timeval t_vblank
;
857 * Interrupts were disabled prior to this call, so deal with counter
859 * NOTE! It's possible we lost a full dev->max_vblank_count events
860 * here if the register is small or we had vblank interrupts off for
863 * We repeat the hardware vblank counter & timestamp query until
864 * we get consistent results. This to prevent races between gpu
865 * updating its hardware counter while we are retrieving the
866 * corresponding vblank timestamp.
869 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, crtc
);
870 rc
= drm_get_last_vbltimestamp(dev
, crtc
, &t_vblank
, 0);
871 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, crtc
));
873 /* Deal with counter wrap */
874 diff
= cur_vblank
- dev
->vblank
[crtc
].last
;
875 if (cur_vblank
< dev
->vblank
[crtc
].last
) {
876 diff
+= dev
->max_vblank_count
;
878 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
879 crtc
, dev
->vblank
[crtc
].last
, cur_vblank
, diff
);
882 DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
885 /* Reinitialize corresponding vblank timestamp if high-precision query
886 * available. Skip this step if query unsupported or failed. Will
887 * reinitialize delayed at next vblank interrupt in that case.
890 tslot
= atomic_read(&dev
->vblank
[crtc
].count
) + diff
;
891 vblanktimestamp(dev
, crtc
, tslot
) = t_vblank
;
894 smp_mb__before_atomic_inc();
895 atomic_add(diff
, &dev
->vblank
[crtc
].count
);
896 smp_mb__after_atomic_inc();
900 * drm_vblank_get - get a reference count on vblank events
902 * @crtc: which CRTC to own
904 * Acquire a reference count on vblank events to avoid having them disabled
908 * Zero on success, nonzero on failure.
910 int drm_vblank_get(struct drm_device
*dev
, int crtc
)
912 unsigned long irqflags
, irqflags2
;
915 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
916 /* Going from 0->1 means we have to enable interrupts again */
917 if (atomic_add_return(1, &dev
->vblank
[crtc
].refcount
) == 1) {
918 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags2
);
919 if (!dev
->vblank
[crtc
].enabled
) {
920 /* Enable vblank irqs under vblank_time_lock protection.
921 * All vblank count & timestamp updates are held off
922 * until we are done reinitializing master counter and
923 * timestamps. Filtercode in drm_handle_vblank() will
924 * prevent double-accounting of same vblank interval.
926 ret
= dev
->driver
->enable_vblank(dev
, crtc
);
927 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n",
930 atomic_dec(&dev
->vblank
[crtc
].refcount
);
932 dev
->vblank
[crtc
].enabled
= true;
933 drm_update_vblank_count(dev
, crtc
);
936 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags2
);
938 if (!dev
->vblank
[crtc
].enabled
) {
939 atomic_dec(&dev
->vblank
[crtc
].refcount
);
943 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
947 EXPORT_SYMBOL(drm_vblank_get
);
950 * drm_vblank_put - give up ownership of vblank events
952 * @crtc: which counter to give up
954 * Release ownership of a given vblank counter, turning off interrupts
955 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
957 void drm_vblank_put(struct drm_device
*dev
, int crtc
)
959 BUG_ON(atomic_read(&dev
->vblank
[crtc
].refcount
) == 0);
961 /* Last user schedules interrupt disable */
962 if (atomic_dec_and_test(&dev
->vblank
[crtc
].refcount
) &&
963 (drm_vblank_offdelay
> 0))
964 mod_timer(&dev
->vblank_disable_timer
,
965 jiffies
+ ((drm_vblank_offdelay
* DRM_HZ
)/1000));
967 EXPORT_SYMBOL(drm_vblank_put
);
970 * drm_vblank_off - disable vblank events on a CRTC
972 * @crtc: CRTC in question
974 * Caller must hold event lock.
976 void drm_vblank_off(struct drm_device
*dev
, int crtc
)
978 struct drm_pending_vblank_event
*e
, *t
;
980 unsigned long irqflags
;
983 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
984 vblank_disable_and_save(dev
, crtc
);
985 DRM_WAKEUP(&dev
->vblank
[crtc
].queue
);
987 /* Send any queued vblank events, lest the natives grow disquiet */
988 seq
= drm_vblank_count_and_time(dev
, crtc
, &now
);
990 spin_lock(&dev
->event_lock
);
991 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
994 DRM_DEBUG("Sending premature vblank event on disable: \
995 wanted %d, current %d\n",
996 e
->event
.sequence
, seq
);
997 list_del(&e
->base
.link
);
998 drm_vblank_put(dev
, e
->pipe
);
999 send_vblank_event(dev
, e
, seq
, &now
);
1001 spin_unlock(&dev
->event_lock
);
1003 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1005 EXPORT_SYMBOL(drm_vblank_off
);
1008 * drm_vblank_pre_modeset - account for vblanks across mode sets
1010 * @crtc: CRTC in question
1012 * Account for vblank events across mode setting events, which will likely
1013 * reset the hardware frame counter.
1015 void drm_vblank_pre_modeset(struct drm_device
*dev
, int crtc
)
1017 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1018 if (!dev
->num_crtcs
)
1021 * To avoid all the problems that might happen if interrupts
1022 * were enabled/disabled around or between these calls, we just
1023 * have the kernel take a reference on the CRTC (just once though
1024 * to avoid corrupting the count if multiple, mismatch calls occur),
1025 * so that interrupts remain enabled in the interim.
1027 if (!dev
->vblank
[crtc
].inmodeset
) {
1028 dev
->vblank
[crtc
].inmodeset
= 0x1;
1029 if (drm_vblank_get(dev
, crtc
) == 0)
1030 dev
->vblank
[crtc
].inmodeset
|= 0x2;
1033 EXPORT_SYMBOL(drm_vblank_pre_modeset
);
1035 void drm_vblank_post_modeset(struct drm_device
*dev
, int crtc
)
1037 unsigned long irqflags
;
1039 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1040 if (!dev
->num_crtcs
)
1043 if (dev
->vblank
[crtc
].inmodeset
) {
1044 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1045 dev
->vblank_disable_allowed
= true;
1046 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1048 if (dev
->vblank
[crtc
].inmodeset
& 0x2)
1049 drm_vblank_put(dev
, crtc
);
1051 dev
->vblank
[crtc
].inmodeset
= 0;
1054 EXPORT_SYMBOL(drm_vblank_post_modeset
);
1057 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1058 * @DRM_IOCTL_ARGS: standard ioctl arguments
1060 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1061 * ioctls around modesetting so that any lost vblank events are accounted for.
1063 * Generally the counter will reset across mode sets. If interrupts are
1064 * enabled around this call, we don't have to do anything since the counter
1065 * will have already been incremented.
1067 int drm_modeset_ctl(struct drm_device
*dev
, void *data
,
1068 struct drm_file
*file_priv
)
1070 struct drm_modeset_ctl
*modeset
= data
;
1073 /* If drm_vblank_init() hasn't been called yet, just no-op */
1074 if (!dev
->num_crtcs
)
1077 /* KMS drivers handle this internally */
1078 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
1081 crtc
= modeset
->crtc
;
1082 if (crtc
>= dev
->num_crtcs
)
1085 switch (modeset
->cmd
) {
1086 case _DRM_PRE_MODESET
:
1087 drm_vblank_pre_modeset(dev
, crtc
);
1089 case _DRM_POST_MODESET
:
1090 drm_vblank_post_modeset(dev
, crtc
);
1099 static int drm_queue_vblank_event(struct drm_device
*dev
, int pipe
,
1100 union drm_wait_vblank
*vblwait
,
1101 struct drm_file
*file_priv
)
1103 struct drm_pending_vblank_event
*e
;
1105 unsigned long flags
;
1109 e
= kzalloc(sizeof *e
, GFP_KERNEL
);
1116 e
->base
.pid
= current
->pid
;
1117 e
->event
.base
.type
= DRM_EVENT_VBLANK
;
1118 e
->event
.base
.length
= sizeof e
->event
;
1119 e
->event
.user_data
= vblwait
->request
.signal
;
1120 e
->base
.event
= &e
->event
.base
;
1121 e
->base
.file_priv
= file_priv
;
1122 e
->base
.destroy
= (void (*) (struct drm_pending_event
*)) kfree
;
1124 spin_lock_irqsave(&dev
->event_lock
, flags
);
1126 if (file_priv
->event_space
< sizeof e
->event
) {
1131 file_priv
->event_space
-= sizeof e
->event
;
1132 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1134 if ((vblwait
->request
.type
& _DRM_VBLANK_NEXTONMISS
) &&
1135 (seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1136 vblwait
->request
.sequence
= seq
+ 1;
1137 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1140 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1141 vblwait
->request
.sequence
, seq
, pipe
);
1143 trace_drm_vblank_event_queued(current
->pid
, pipe
,
1144 vblwait
->request
.sequence
);
1146 e
->event
.sequence
= vblwait
->request
.sequence
;
1147 if ((seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1148 drm_vblank_put(dev
, pipe
);
1149 send_vblank_event(dev
, e
, seq
, &now
);
1150 vblwait
->reply
.sequence
= seq
;
1152 /* drm_handle_vblank_events will call drm_vblank_put */
1153 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1154 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1157 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1162 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1165 drm_vblank_put(dev
, pipe
);
1172 * \param inode device inode.
1173 * \param file_priv DRM file private.
1174 * \param cmd command.
1175 * \param data user argument, pointing to a drm_wait_vblank structure.
1176 * \return zero on success or a negative number on failure.
1178 * This function enables the vblank interrupt on the pipe requested, then
1179 * sleeps waiting for the requested sequence number to occur, and drops
1180 * the vblank interrupt refcount afterwards. (vblank irq disable follows that
1181 * after a timeout with no further vblank waits scheduled).
1183 int drm_wait_vblank(struct drm_device
*dev
, void *data
,
1184 struct drm_file
*file_priv
)
1186 union drm_wait_vblank
*vblwait
= data
;
1188 unsigned int flags
, seq
, crtc
, high_crtc
;
1190 if (drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
1191 if ((!drm_dev_to_irq(dev
)) || (!dev
->irq_enabled
))
1194 if (vblwait
->request
.type
& _DRM_VBLANK_SIGNAL
)
1197 if (vblwait
->request
.type
&
1198 ~(_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1199 _DRM_VBLANK_HIGH_CRTC_MASK
)) {
1200 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1201 vblwait
->request
.type
,
1202 (_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1203 _DRM_VBLANK_HIGH_CRTC_MASK
));
1207 flags
= vblwait
->request
.type
& _DRM_VBLANK_FLAGS_MASK
;
1208 high_crtc
= (vblwait
->request
.type
& _DRM_VBLANK_HIGH_CRTC_MASK
);
1210 crtc
= high_crtc
>> _DRM_VBLANK_HIGH_CRTC_SHIFT
;
1212 crtc
= flags
& _DRM_VBLANK_SECONDARY
? 1 : 0;
1213 if (crtc
>= dev
->num_crtcs
)
1216 ret
= drm_vblank_get(dev
, crtc
);
1218 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret
);
1221 seq
= drm_vblank_count(dev
, crtc
);
1223 switch (vblwait
->request
.type
& _DRM_VBLANK_TYPES_MASK
) {
1224 case _DRM_VBLANK_RELATIVE
:
1225 vblwait
->request
.sequence
+= seq
;
1226 vblwait
->request
.type
&= ~_DRM_VBLANK_RELATIVE
;
1227 case _DRM_VBLANK_ABSOLUTE
:
1234 if (flags
& _DRM_VBLANK_EVENT
) {
1235 /* must hold on to the vblank ref until the event fires
1236 * drm_vblank_put will be called asynchronously
1238 return drm_queue_vblank_event(dev
, crtc
, vblwait
, file_priv
);
1241 if ((flags
& _DRM_VBLANK_NEXTONMISS
) &&
1242 (seq
- vblwait
->request
.sequence
) <= (1<<23)) {
1243 vblwait
->request
.sequence
= seq
+ 1;
1246 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1247 vblwait
->request
.sequence
, crtc
);
1248 dev
->vblank
[crtc
].last_wait
= vblwait
->request
.sequence
;
1249 DRM_WAIT_ON(ret
, dev
->vblank
[crtc
].queue
, 3 * DRM_HZ
,
1250 (((drm_vblank_count(dev
, crtc
) -
1251 vblwait
->request
.sequence
) <= (1 << 23)) ||
1252 !dev
->irq_enabled
));
1254 if (ret
!= -EINTR
) {
1257 vblwait
->reply
.sequence
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1258 vblwait
->reply
.tval_sec
= now
.tv_sec
;
1259 vblwait
->reply
.tval_usec
= now
.tv_usec
;
1261 DRM_DEBUG("returning %d to client\n",
1262 vblwait
->reply
.sequence
);
1264 DRM_DEBUG("vblank wait interrupted by signal\n");
1268 drm_vblank_put(dev
, crtc
);
1272 static void drm_handle_vblank_events(struct drm_device
*dev
, int crtc
)
1274 struct drm_pending_vblank_event
*e
, *t
;
1276 unsigned long flags
;
1279 seq
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1281 spin_lock_irqsave(&dev
->event_lock
, flags
);
1283 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1284 if (e
->pipe
!= crtc
)
1286 if ((seq
- e
->event
.sequence
) > (1<<23))
1289 DRM_DEBUG("vblank event on %d, current %d\n",
1290 e
->event
.sequence
, seq
);
1292 list_del(&e
->base
.link
);
1293 drm_vblank_put(dev
, e
->pipe
);
1294 send_vblank_event(dev
, e
, seq
, &now
);
1297 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1299 trace_drm_vblank_event(crtc
, seq
);
1303 * drm_handle_vblank - handle a vblank event
1305 * @crtc: where this event occurred
1307 * Drivers should call this routine in their vblank interrupt handlers to
1308 * update the vblank counter and send any signals that may be pending.
1310 bool drm_handle_vblank(struct drm_device
*dev
, int crtc
)
1314 struct timeval tvblank
;
1315 unsigned long irqflags
;
1317 if (!dev
->num_crtcs
)
1320 /* Need timestamp lock to prevent concurrent execution with
1321 * vblank enable/disable, as this would cause inconsistent
1322 * or corrupted timestamps and vblank counts.
1324 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags
);
1326 /* Vblank irq handling disabled. Nothing to do. */
1327 if (!dev
->vblank
[crtc
].enabled
) {
1328 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
1332 /* Fetch corresponding timestamp for this vblank interval from
1333 * driver and store it in proper slot of timestamp ringbuffer.
1336 /* Get current timestamp and count. */
1337 vblcount
= atomic_read(&dev
->vblank
[crtc
].count
);
1338 drm_get_last_vbltimestamp(dev
, crtc
, &tvblank
, DRM_CALLED_FROM_VBLIRQ
);
1340 /* Compute time difference to timestamp of last vblank */
1341 diff_ns
= timeval_to_ns(&tvblank
) -
1342 timeval_to_ns(&vblanktimestamp(dev
, crtc
, vblcount
));
1344 /* Update vblank timestamp and count if at least
1345 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1346 * difference between last stored timestamp and current
1347 * timestamp. A smaller difference means basically
1348 * identical timestamps. Happens if this vblank has
1349 * been already processed and this is a redundant call,
1350 * e.g., due to spurious vblank interrupts. We need to
1351 * ignore those for accounting.
1353 if (abs64(diff_ns
) > DRM_REDUNDANT_VBLIRQ_THRESH_NS
) {
1354 /* Store new timestamp in ringbuffer. */
1355 vblanktimestamp(dev
, crtc
, vblcount
+ 1) = tvblank
;
1357 /* Increment cooked vblank count. This also atomically commits
1358 * the timestamp computed above.
1360 smp_mb__before_atomic_inc();
1361 atomic_inc(&dev
->vblank
[crtc
].count
);
1362 smp_mb__after_atomic_inc();
1364 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1365 crtc
, (int) diff_ns
);
1368 DRM_WAKEUP(&dev
->vblank
[crtc
].queue
);
1369 drm_handle_vblank_events(dev
, crtc
);
1371 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
1374 EXPORT_SYMBOL(drm_handle_vblank
);