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
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* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
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* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
32
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
33
* OTHER DEALINGS IN THE SOFTWARE.
37
#include "drm_trace.h"
39
#include <linux/interrupt.h> /* For task queue support */
40
#include <linux/slab.h>
42
#include <linux/vgaarb.h>
43
#include <linux/export.h>
45
/* Access macro for slots in vblank timestamp ringbuffer. */
46
#define vblanktimestamp(dev, crtc, count) ( \
47
(dev)->_vblank_time[(crtc) * DRM_VBLANKTIME_RBSIZE + \
48
((count) % DRM_VBLANKTIME_RBSIZE)])
50
/* Retry timestamp calculation up to 3 times to satisfy
51
* drm_timestamp_precision before giving up.
53
#define DRM_TIMESTAMP_MAXRETRIES 3
55
/* Threshold in nanoseconds for detection of redundant
56
* vblank irq in drm_handle_vblank(). 1 msec should be ok.
58
#define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
61
* Get interrupt from bus id.
63
* \param inode device inode.
64
* \param file_priv DRM file private.
66
* \param arg user argument, pointing to a drm_irq_busid structure.
67
* \return zero on success or a negative number on failure.
69
* Finds the PCI device with the specified bus id and gets its IRQ number.
70
* This IOCTL is deprecated, and will now return EINVAL for any busid not equal
71
* to that of the device that this DRM instance attached to.
73
int drm_irq_by_busid(struct drm_device *dev, void *data,
74
struct drm_file *file_priv)
76
struct drm_irq_busid *p = data;
78
if (!dev->driver->bus->irq_by_busid)
81
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
84
return dev->driver->bus->irq_by_busid(dev, p);
88
* Clear vblank timestamp buffer for a crtc.
90
static void clear_vblank_timestamps(struct drm_device *dev, int crtc)
92
memset(&dev->_vblank_time[crtc * DRM_VBLANKTIME_RBSIZE], 0,
93
DRM_VBLANKTIME_RBSIZE * sizeof(struct timeval));
97
* Disable vblank irq's on crtc, make sure that last vblank count
98
* of hardware and corresponding consistent software vblank counter
99
* are preserved, even if there are any spurious vblank irq's after
102
static void vblank_disable_and_save(struct drm_device *dev, int crtc)
104
unsigned long irqflags;
108
struct timeval tvblank;
110
/* Prevent vblank irq processing while disabling vblank irqs,
111
* so no updates of timestamps or count can happen after we've
112
* disabled. Needed to prevent races in case of delayed irq's.
114
spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
116
dev->driver->disable_vblank(dev, crtc);
117
dev->vblank_enabled[crtc] = 0;
119
/* No further vblank irq's will be processed after
120
* this point. Get current hardware vblank count and
121
* vblank timestamp, repeat until they are consistent.
123
* FIXME: There is still a race condition here and in
124
* drm_update_vblank_count() which can cause off-by-one
125
* reinitialization of software vblank counter. If gpu
126
* vblank counter doesn't increment exactly at the leading
127
* edge of a vblank interval, then we can lose 1 count if
128
* we happen to execute between start of vblank and the
129
* delayed gpu counter increment.
132
dev->last_vblank[crtc] = dev->driver->get_vblank_counter(dev, crtc);
133
vblrc = drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0);
134
} while (dev->last_vblank[crtc] != dev->driver->get_vblank_counter(dev, crtc));
136
/* Compute time difference to stored timestamp of last vblank
137
* as updated by last invocation of drm_handle_vblank() in vblank irq.
139
vblcount = atomic_read(&dev->_vblank_count[crtc]);
140
diff_ns = timeval_to_ns(&tvblank) -
141
timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
143
/* If there is at least 1 msec difference between the last stored
144
* timestamp and tvblank, then we are currently executing our
145
* disable inside a new vblank interval, the tvblank timestamp
146
* corresponds to this new vblank interval and the irq handler
147
* for this vblank didn't run yet and won't run due to our disable.
148
* Therefore we need to do the job of drm_handle_vblank() and
149
* increment the vblank counter by one to account for this vblank.
151
* Skip this step if there isn't any high precision timestamp
152
* available. In that case we can't account for this and just
155
if ((vblrc > 0) && (abs64(diff_ns) > 1000000)) {
156
atomic_inc(&dev->_vblank_count[crtc]);
157
smp_mb__after_atomic_inc();
160
/* Invalidate all timestamps while vblank irq's are off. */
161
clear_vblank_timestamps(dev, crtc);
163
spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
166
static void vblank_disable_fn(unsigned long arg)
168
struct drm_device *dev = (struct drm_device *)arg;
169
unsigned long irqflags;
172
if (!dev->vblank_disable_allowed)
175
for (i = 0; i < dev->num_crtcs; i++) {
176
spin_lock_irqsave(&dev->vbl_lock, irqflags);
177
if (atomic_read(&dev->vblank_refcount[i]) == 0 &&
178
dev->vblank_enabled[i]) {
179
DRM_DEBUG("disabling vblank on crtc %d\n", i);
180
vblank_disable_and_save(dev, i);
182
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
186
void drm_vblank_cleanup(struct drm_device *dev)
188
/* Bail if the driver didn't call drm_vblank_init() */
189
if (dev->num_crtcs == 0)
192
del_timer(&dev->vblank_disable_timer);
194
vblank_disable_fn((unsigned long)dev);
196
kfree(dev->vbl_queue);
197
kfree(dev->_vblank_count);
198
kfree(dev->vblank_refcount);
199
kfree(dev->vblank_enabled);
200
kfree(dev->last_vblank);
201
kfree(dev->last_vblank_wait);
202
kfree(dev->vblank_inmodeset);
203
kfree(dev->_vblank_time);
207
EXPORT_SYMBOL(drm_vblank_cleanup);
209
int drm_vblank_init(struct drm_device *dev, int num_crtcs)
211
int i, ret = -ENOMEM;
213
setup_timer(&dev->vblank_disable_timer, vblank_disable_fn,
215
spin_lock_init(&dev->vbl_lock);
216
spin_lock_init(&dev->vblank_time_lock);
218
dev->num_crtcs = num_crtcs;
220
dev->vbl_queue = kmalloc(sizeof(wait_queue_head_t) * num_crtcs,
225
dev->_vblank_count = kmalloc(sizeof(atomic_t) * num_crtcs, GFP_KERNEL);
226
if (!dev->_vblank_count)
229
dev->vblank_refcount = kmalloc(sizeof(atomic_t) * num_crtcs,
231
if (!dev->vblank_refcount)
234
dev->vblank_enabled = kcalloc(num_crtcs, sizeof(int), GFP_KERNEL);
235
if (!dev->vblank_enabled)
238
dev->last_vblank = kcalloc(num_crtcs, sizeof(u32), GFP_KERNEL);
239
if (!dev->last_vblank)
242
dev->last_vblank_wait = kcalloc(num_crtcs, sizeof(u32), GFP_KERNEL);
243
if (!dev->last_vblank_wait)
246
dev->vblank_inmodeset = kcalloc(num_crtcs, sizeof(int), GFP_KERNEL);
247
if (!dev->vblank_inmodeset)
250
dev->_vblank_time = kcalloc(num_crtcs * DRM_VBLANKTIME_RBSIZE,
251
sizeof(struct timeval), GFP_KERNEL);
252
if (!dev->_vblank_time)
255
DRM_INFO("Supports vblank timestamp caching Rev 1 (10.10.2010).\n");
257
/* Driver specific high-precision vblank timestamping supported? */
258
if (dev->driver->get_vblank_timestamp)
259
DRM_INFO("Driver supports precise vblank timestamp query.\n");
261
DRM_INFO("No driver support for vblank timestamp query.\n");
263
/* Zero per-crtc vblank stuff */
264
for (i = 0; i < num_crtcs; i++) {
265
init_waitqueue_head(&dev->vbl_queue[i]);
266
atomic_set(&dev->_vblank_count[i], 0);
267
atomic_set(&dev->vblank_refcount[i], 0);
270
dev->vblank_disable_allowed = 0;
274
drm_vblank_cleanup(dev);
277
EXPORT_SYMBOL(drm_vblank_init);
279
static void drm_irq_vgaarb_nokms(void *cookie, bool state)
281
struct drm_device *dev = cookie;
283
if (dev->driver->vgaarb_irq) {
284
dev->driver->vgaarb_irq(dev, state);
288
if (!dev->irq_enabled)
292
if (dev->driver->irq_uninstall)
293
dev->driver->irq_uninstall(dev);
295
if (dev->driver->irq_preinstall)
296
dev->driver->irq_preinstall(dev);
297
if (dev->driver->irq_postinstall)
298
dev->driver->irq_postinstall(dev);
303
* Install IRQ handler.
305
* \param dev DRM device.
307
* Initializes the IRQ related data. Installs the handler, calling the driver
308
* \c drm_driver_irq_preinstall() and \c drm_driver_irq_postinstall() functions
309
* before and after the installation.
311
int drm_irq_install(struct drm_device *dev)
314
unsigned long sh_flags = 0;
317
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
320
if (drm_dev_to_irq(dev) == 0)
323
mutex_lock(&dev->struct_mutex);
325
/* Driver must have been initialized */
326
if (!dev->dev_private) {
327
mutex_unlock(&dev->struct_mutex);
331
if (dev->irq_enabled) {
332
mutex_unlock(&dev->struct_mutex);
335
dev->irq_enabled = 1;
336
mutex_unlock(&dev->struct_mutex);
338
DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev));
340
/* Before installing handler */
341
if (dev->driver->irq_preinstall)
342
dev->driver->irq_preinstall(dev);
344
/* Install handler */
345
if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
346
sh_flags = IRQF_SHARED;
349
irqname = dev->devname;
351
irqname = dev->driver->name;
353
ret = request_irq(drm_dev_to_irq(dev), dev->driver->irq_handler,
354
sh_flags, irqname, dev);
357
mutex_lock(&dev->struct_mutex);
358
dev->irq_enabled = 0;
359
mutex_unlock(&dev->struct_mutex);
363
if (!drm_core_check_feature(dev, DRIVER_MODESET))
364
vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
366
/* After installing handler */
367
if (dev->driver->irq_postinstall)
368
ret = dev->driver->irq_postinstall(dev);
371
mutex_lock(&dev->struct_mutex);
372
dev->irq_enabled = 0;
373
mutex_unlock(&dev->struct_mutex);
374
if (!drm_core_check_feature(dev, DRIVER_MODESET))
375
vga_client_register(dev->pdev, NULL, NULL, NULL);
376
free_irq(drm_dev_to_irq(dev), dev);
381
EXPORT_SYMBOL(drm_irq_install);
384
* Uninstall the IRQ handler.
386
* \param dev DRM device.
388
* Calls the driver's \c drm_driver_irq_uninstall() function, and stops the irq.
390
int drm_irq_uninstall(struct drm_device *dev)
392
unsigned long irqflags;
395
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
398
mutex_lock(&dev->struct_mutex);
399
irq_enabled = dev->irq_enabled;
400
dev->irq_enabled = 0;
401
mutex_unlock(&dev->struct_mutex);
404
* Wake up any waiters so they don't hang.
406
if (dev->num_crtcs) {
407
spin_lock_irqsave(&dev->vbl_lock, irqflags);
408
for (i = 0; i < dev->num_crtcs; i++) {
409
DRM_WAKEUP(&dev->vbl_queue[i]);
410
dev->vblank_enabled[i] = 0;
411
dev->last_vblank[i] =
412
dev->driver->get_vblank_counter(dev, i);
414
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
420
DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev));
422
if (!drm_core_check_feature(dev, DRIVER_MODESET))
423
vga_client_register(dev->pdev, NULL, NULL, NULL);
425
if (dev->driver->irq_uninstall)
426
dev->driver->irq_uninstall(dev);
428
free_irq(drm_dev_to_irq(dev), dev);
432
EXPORT_SYMBOL(drm_irq_uninstall);
437
* \param inode device inode.
438
* \param file_priv DRM file private.
439
* \param cmd command.
440
* \param arg user argument, pointing to a drm_control structure.
441
* \return zero on success or a negative number on failure.
443
* Calls irq_install() or irq_uninstall() according to \p arg.
445
int drm_control(struct drm_device *dev, void *data,
446
struct drm_file *file_priv)
448
struct drm_control *ctl = data;
450
/* if we haven't irq we fallback for compatibility reasons -
451
* this used to be a separate function in drm_dma.h
456
case DRM_INST_HANDLER:
457
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
459
if (drm_core_check_feature(dev, DRIVER_MODESET))
461
if (dev->if_version < DRM_IF_VERSION(1, 2) &&
462
ctl->irq != drm_dev_to_irq(dev))
464
return drm_irq_install(dev);
465
case DRM_UNINST_HANDLER:
466
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
468
if (drm_core_check_feature(dev, DRIVER_MODESET))
470
return drm_irq_uninstall(dev);
477
* drm_calc_timestamping_constants - Calculate and
478
* store various constants which are later needed by
479
* vblank and swap-completion timestamping, e.g, by
480
* drm_calc_vbltimestamp_from_scanoutpos().
481
* They are derived from crtc's true scanout timing,
482
* so they take things like panel scaling or other
483
* adjustments into account.
485
* @crtc drm_crtc whose timestamp constants should be updated.
488
void drm_calc_timestamping_constants(struct drm_crtc *crtc)
490
s64 linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
493
/* Dot clock in Hz: */
494
dotclock = (u64) crtc->hwmode.clock * 1000;
496
/* Fields of interlaced scanout modes are only halve a frame duration.
497
* Double the dotclock to get halve the frame-/line-/pixelduration.
499
if (crtc->hwmode.flags & DRM_MODE_FLAG_INTERLACE)
502
/* Valid dotclock? */
504
/* Convert scanline length in pixels and video dot clock to
505
* line duration, frame duration and pixel duration in
508
pixeldur_ns = (s64) div64_u64(1000000000, dotclock);
509
linedur_ns = (s64) div64_u64(((u64) crtc->hwmode.crtc_htotal *
510
1000000000), dotclock);
511
framedur_ns = (s64) crtc->hwmode.crtc_vtotal * linedur_ns;
513
DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
516
crtc->pixeldur_ns = pixeldur_ns;
517
crtc->linedur_ns = linedur_ns;
518
crtc->framedur_ns = framedur_ns;
520
DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
521
crtc->base.id, crtc->hwmode.crtc_htotal,
522
crtc->hwmode.crtc_vtotal, crtc->hwmode.crtc_vdisplay);
523
DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
524
crtc->base.id, (int) dotclock/1000, (int) framedur_ns,
525
(int) linedur_ns, (int) pixeldur_ns);
527
EXPORT_SYMBOL(drm_calc_timestamping_constants);
530
* drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
531
* drivers. Implements calculation of exact vblank timestamps from
532
* given drm_display_mode timings and current video scanout position
533
* of a crtc. This can be called from within get_vblank_timestamp()
534
* implementation of a kms driver to implement the actual timestamping.
536
* Should return timestamps conforming to the OML_sync_control OpenML
537
* extension specification. The timestamp corresponds to the end of
538
* the vblank interval, aka start of scanout of topmost-leftmost display
539
* pixel in the following video frame.
541
* Requires support for optional dev->driver->get_scanout_position()
542
* in kms driver, plus a bit of setup code to provide a drm_display_mode
543
* that corresponds to the true scanout timing.
545
* The current implementation only handles standard video modes. It
546
* returns as no operation if a doublescan or interlaced video mode is
547
* active. Higher level code is expected to handle this.
550
* @crtc: Which crtc's vblank timestamp to retrieve.
551
* @max_error: Desired maximum allowable error in timestamps (nanosecs).
552
* On return contains true maximum error of timestamp.
553
* @vblank_time: Pointer to struct timeval which should receive the timestamp.
554
* @flags: Flags to pass to driver:
556
* DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
557
* @refcrtc: drm_crtc* of crtc which defines scanout timing.
559
* Returns negative value on error, failure or if not supported in current
562
* -EINVAL - Invalid crtc.
563
* -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
564
* -ENOTSUPP - Function not supported in current display mode.
565
* -EIO - Failed, e.g., due to failed scanout position query.
567
* Returns or'ed positive status flags on success:
569
* DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
570
* DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
573
int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
575
struct timeval *vblank_time,
577
struct drm_crtc *refcrtc)
579
struct timeval stime, raw_time;
580
struct drm_display_mode *mode;
581
int vbl_status, vtotal, vdisplay;
583
s64 framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
586
if (crtc < 0 || crtc >= dev->num_crtcs) {
587
DRM_ERROR("Invalid crtc %d\n", crtc);
591
/* Scanout position query not supported? Should not happen. */
592
if (!dev->driver->get_scanout_position) {
593
DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
597
mode = &refcrtc->hwmode;
598
vtotal = mode->crtc_vtotal;
599
vdisplay = mode->crtc_vdisplay;
601
/* Durations of frames, lines, pixels in nanoseconds. */
602
framedur_ns = refcrtc->framedur_ns;
603
linedur_ns = refcrtc->linedur_ns;
604
pixeldur_ns = refcrtc->pixeldur_ns;
606
/* If mode timing undefined, just return as no-op:
607
* Happens during initial modesetting of a crtc.
609
if (vtotal <= 0 || vdisplay <= 0 || framedur_ns == 0) {
610
DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc);
614
/* Get current scanout position with system timestamp.
615
* Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
616
* if single query takes longer than max_error nanoseconds.
618
* This guarantees a tight bound on maximum error if
619
* code gets preempted or delayed for some reason.
621
for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
622
/* Disable preemption to make it very likely to
623
* succeed in the first iteration even on PREEMPT_RT kernel.
627
/* Get system timestamp before query. */
628
do_gettimeofday(&stime);
630
/* Get vertical and horizontal scanout pos. vpos, hpos. */
631
vbl_status = dev->driver->get_scanout_position(dev, crtc, &vpos, &hpos);
633
/* Get system timestamp after query. */
634
do_gettimeofday(&raw_time);
638
/* Return as no-op if scanout query unsupported or failed. */
639
if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
640
DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
645
duration_ns = timeval_to_ns(&raw_time) - timeval_to_ns(&stime);
647
/* Accept result with < max_error nsecs timing uncertainty. */
648
if (duration_ns <= (s64) *max_error)
652
/* Noisy system timing? */
653
if (i == DRM_TIMESTAMP_MAXRETRIES) {
654
DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
655
crtc, (int) duration_ns/1000, *max_error/1000, i);
658
/* Return upper bound of timestamp precision error. */
659
*max_error = (int) duration_ns;
661
/* Check if in vblank area:
662
* vpos is >=0 in video scanout area, but negative
663
* within vblank area, counting down the number of lines until
666
invbl = vbl_status & DRM_SCANOUTPOS_INVBL;
668
/* Convert scanout position into elapsed time at raw_time query
669
* since start of scanout at first display scanline. delta_ns
670
* can be negative if start of scanout hasn't happened yet.
672
delta_ns = (s64) vpos * linedur_ns + (s64) hpos * pixeldur_ns;
674
/* Is vpos outside nominal vblank area, but less than
675
* 1/100 of a frame height away from start of vblank?
676
* If so, assume this isn't a massively delayed vblank
677
* interrupt, but a vblank interrupt that fired a few
678
* microseconds before true start of vblank. Compensate
679
* by adding a full frame duration to the final timestamp.
680
* Happens, e.g., on ATI R500, R600.
682
* We only do this if DRM_CALLED_FROM_VBLIRQ.
684
if ((flags & DRM_CALLED_FROM_VBLIRQ) && !invbl &&
685
((vdisplay - vpos) < vtotal / 100)) {
686
delta_ns = delta_ns - framedur_ns;
688
/* Signal this correction as "applied". */
692
/* Subtract time delta from raw timestamp to get final
693
* vblank_time timestamp for end of vblank.
695
*vblank_time = ns_to_timeval(timeval_to_ns(&raw_time) - delta_ns);
697
DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
698
crtc, (int)vbl_status, hpos, vpos,
699
(long)raw_time.tv_sec, (long)raw_time.tv_usec,
700
(long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
701
(int)duration_ns/1000, i);
703
vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
705
vbl_status |= DRM_VBLANKTIME_INVBL;
709
EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
712
* drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
716
* @crtc: which crtc's vblank timestamp to retrieve
717
* @tvblank: Pointer to target struct timeval which should receive the timestamp
718
* @flags: Flags to pass to driver:
720
* DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
722
* Fetches the system timestamp corresponding to the time of the most recent
723
* vblank interval on specified crtc. May call into kms-driver to
724
* compute the timestamp with a high-precision GPU specific method.
726
* Returns zero if timestamp originates from uncorrected do_gettimeofday()
727
* call, i.e., it isn't very precisely locked to the true vblank.
729
* Returns non-zero if timestamp is considered to be very precise.
731
u32 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
732
struct timeval *tvblank, unsigned flags)
736
/* Define requested maximum error on timestamps (nanoseconds). */
737
int max_error = (int) drm_timestamp_precision * 1000;
739
/* Query driver if possible and precision timestamping enabled. */
740
if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
741
ret = dev->driver->get_vblank_timestamp(dev, crtc, &max_error,
747
/* GPU high precision timestamp query unsupported or failed.
748
* Return gettimeofday timestamp as best estimate.
750
do_gettimeofday(tvblank);
754
EXPORT_SYMBOL(drm_get_last_vbltimestamp);
757
* drm_vblank_count - retrieve "cooked" vblank counter value
759
* @crtc: which counter to retrieve
761
* Fetches the "cooked" vblank count value that represents the number of
762
* vblank events since the system was booted, including lost events due to
763
* modesetting activity.
765
u32 drm_vblank_count(struct drm_device *dev, int crtc)
767
return atomic_read(&dev->_vblank_count[crtc]);
769
EXPORT_SYMBOL(drm_vblank_count);
772
* drm_vblank_count_and_time - retrieve "cooked" vblank counter value
773
* and the system timestamp corresponding to that vblank counter value.
776
* @crtc: which counter to retrieve
777
* @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
779
* Fetches the "cooked" vblank count value that represents the number of
780
* vblank events since the system was booted, including lost events due to
781
* modesetting activity. Returns corresponding system timestamp of the time
782
* of the vblank interval that corresponds to the current value vblank counter
785
u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
786
struct timeval *vblanktime)
790
/* Read timestamp from slot of _vblank_time ringbuffer
791
* that corresponds to current vblank count. Retry if
792
* count has incremented during readout. This works like
796
cur_vblank = atomic_read(&dev->_vblank_count[crtc]);
797
*vblanktime = vblanktimestamp(dev, crtc, cur_vblank);
799
} while (cur_vblank != atomic_read(&dev->_vblank_count[crtc]));
803
EXPORT_SYMBOL(drm_vblank_count_and_time);
806
* drm_update_vblank_count - update the master vblank counter
808
* @crtc: counter to update
810
* Call back into the driver to update the appropriate vblank counter
811
* (specified by @crtc). Deal with wraparound, if it occurred, and
812
* update the last read value so we can deal with wraparound on the next
815
* Only necessary when going from off->on, to account for frames we
816
* didn't get an interrupt for.
818
* Note: caller must hold dev->vbl_lock since this reads & writes
819
* device vblank fields.
821
static void drm_update_vblank_count(struct drm_device *dev, int crtc)
823
u32 cur_vblank, diff, tslot, rc;
824
struct timeval t_vblank;
827
* Interrupts were disabled prior to this call, so deal with counter
829
* NOTE! It's possible we lost a full dev->max_vblank_count events
830
* here if the register is small or we had vblank interrupts off for
833
* We repeat the hardware vblank counter & timestamp query until
834
* we get consistent results. This to prevent races between gpu
835
* updating its hardware counter while we are retrieving the
836
* corresponding vblank timestamp.
839
cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
840
rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0);
841
} while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc));
843
/* Deal with counter wrap */
844
diff = cur_vblank - dev->last_vblank[crtc];
845
if (cur_vblank < dev->last_vblank[crtc]) {
846
diff += dev->max_vblank_count;
848
DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
849
crtc, dev->last_vblank[crtc], cur_vblank, diff);
852
DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
855
/* Reinitialize corresponding vblank timestamp if high-precision query
856
* available. Skip this step if query unsupported or failed. Will
857
* reinitialize delayed at next vblank interrupt in that case.
860
tslot = atomic_read(&dev->_vblank_count[crtc]) + diff;
861
vblanktimestamp(dev, crtc, tslot) = t_vblank;
864
smp_mb__before_atomic_inc();
865
atomic_add(diff, &dev->_vblank_count[crtc]);
866
smp_mb__after_atomic_inc();
870
* drm_vblank_get - get a reference count on vblank events
872
* @crtc: which CRTC to own
874
* Acquire a reference count on vblank events to avoid having them disabled
878
* Zero on success, nonzero on failure.
880
int drm_vblank_get(struct drm_device *dev, int crtc)
882
unsigned long irqflags, irqflags2;
885
spin_lock_irqsave(&dev->vbl_lock, irqflags);
886
/* Going from 0->1 means we have to enable interrupts again */
887
if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1) {
888
spin_lock_irqsave(&dev->vblank_time_lock, irqflags2);
889
if (!dev->vblank_enabled[crtc]) {
890
/* Enable vblank irqs under vblank_time_lock protection.
891
* All vblank count & timestamp updates are held off
892
* until we are done reinitializing master counter and
893
* timestamps. Filtercode in drm_handle_vblank() will
894
* prevent double-accounting of same vblank interval.
896
ret = dev->driver->enable_vblank(dev, crtc);
897
DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n",
900
atomic_dec(&dev->vblank_refcount[crtc]);
902
dev->vblank_enabled[crtc] = 1;
903
drm_update_vblank_count(dev, crtc);
906
spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags2);
908
if (!dev->vblank_enabled[crtc]) {
909
atomic_dec(&dev->vblank_refcount[crtc]);
913
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
917
EXPORT_SYMBOL(drm_vblank_get);
920
* drm_vblank_put - give up ownership of vblank events
922
* @crtc: which counter to give up
924
* Release ownership of a given vblank counter, turning off interrupts
925
* if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
927
void drm_vblank_put(struct drm_device *dev, int crtc)
929
BUG_ON(atomic_read(&dev->vblank_refcount[crtc]) == 0);
931
/* Last user schedules interrupt disable */
932
if (atomic_dec_and_test(&dev->vblank_refcount[crtc]) &&
933
(drm_vblank_offdelay > 0))
934
mod_timer(&dev->vblank_disable_timer,
935
jiffies + ((drm_vblank_offdelay * DRM_HZ)/1000));
937
EXPORT_SYMBOL(drm_vblank_put);
939
void drm_vblank_off(struct drm_device *dev, int crtc)
941
struct drm_pending_vblank_event *e, *t;
943
unsigned long irqflags;
946
spin_lock_irqsave(&dev->vbl_lock, irqflags);
947
vblank_disable_and_save(dev, crtc);
948
DRM_WAKEUP(&dev->vbl_queue[crtc]);
950
/* Send any queued vblank events, lest the natives grow disquiet */
951
seq = drm_vblank_count_and_time(dev, crtc, &now);
952
list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
955
DRM_DEBUG("Sending premature vblank event on disable: \
956
wanted %d, current %d\n",
957
e->event.sequence, seq);
959
e->event.sequence = seq;
960
e->event.tv_sec = now.tv_sec;
961
e->event.tv_usec = now.tv_usec;
962
drm_vblank_put(dev, e->pipe);
963
list_move_tail(&e->base.link, &e->base.file_priv->event_list);
964
wake_up_interruptible(&e->base.file_priv->event_wait);
965
trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
969
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
971
EXPORT_SYMBOL(drm_vblank_off);
974
* drm_vblank_pre_modeset - account for vblanks across mode sets
976
* @crtc: CRTC in question
977
* @post: post or pre mode set?
979
* Account for vblank events across mode setting events, which will likely
980
* reset the hardware frame counter.
982
void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
984
/* vblank is not initialized (IRQ not installed ?) */
988
* To avoid all the problems that might happen if interrupts
989
* were enabled/disabled around or between these calls, we just
990
* have the kernel take a reference on the CRTC (just once though
991
* to avoid corrupting the count if multiple, mismatch calls occur),
992
* so that interrupts remain enabled in the interim.
994
if (!dev->vblank_inmodeset[crtc]) {
995
dev->vblank_inmodeset[crtc] = 0x1;
996
if (drm_vblank_get(dev, crtc) == 0)
997
dev->vblank_inmodeset[crtc] |= 0x2;
1000
EXPORT_SYMBOL(drm_vblank_pre_modeset);
1002
void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
1004
unsigned long irqflags;
1006
if (dev->vblank_inmodeset[crtc]) {
1007
spin_lock_irqsave(&dev->vbl_lock, irqflags);
1008
dev->vblank_disable_allowed = 1;
1009
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1011
if (dev->vblank_inmodeset[crtc] & 0x2)
1012
drm_vblank_put(dev, crtc);
1014
dev->vblank_inmodeset[crtc] = 0;
1017
EXPORT_SYMBOL(drm_vblank_post_modeset);
1020
* drm_modeset_ctl - handle vblank event counter changes across mode switch
1021
* @DRM_IOCTL_ARGS: standard ioctl arguments
1023
* Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1024
* ioctls around modesetting so that any lost vblank events are accounted for.
1026
* Generally the counter will reset across mode sets. If interrupts are
1027
* enabled around this call, we don't have to do anything since the counter
1028
* will have already been incremented.
1030
int drm_modeset_ctl(struct drm_device *dev, void *data,
1031
struct drm_file *file_priv)
1033
struct drm_modeset_ctl *modeset = data;
1037
/* If drm_vblank_init() hasn't been called yet, just no-op */
1038
if (!dev->num_crtcs)
1041
crtc = modeset->crtc;
1042
if (crtc >= dev->num_crtcs) {
1047
switch (modeset->cmd) {
1048
case _DRM_PRE_MODESET:
1049
drm_vblank_pre_modeset(dev, crtc);
1051
case _DRM_POST_MODESET:
1052
drm_vblank_post_modeset(dev, crtc);
1063
static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
1064
union drm_wait_vblank *vblwait,
1065
struct drm_file *file_priv)
1067
struct drm_pending_vblank_event *e;
1069
unsigned long flags;
1073
e = kzalloc(sizeof *e, GFP_KERNEL);
1080
e->base.pid = current->pid;
1081
e->event.base.type = DRM_EVENT_VBLANK;
1082
e->event.base.length = sizeof e->event;
1083
e->event.user_data = vblwait->request.signal;
1084
e->base.event = &e->event.base;
1085
e->base.file_priv = file_priv;
1086
e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
1088
spin_lock_irqsave(&dev->event_lock, flags);
1090
if (file_priv->event_space < sizeof e->event) {
1095
file_priv->event_space -= sizeof e->event;
1096
seq = drm_vblank_count_and_time(dev, pipe, &now);
1098
if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1099
(seq - vblwait->request.sequence) <= (1 << 23)) {
1100
vblwait->request.sequence = seq + 1;
1101
vblwait->reply.sequence = vblwait->request.sequence;
1104
DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1105
vblwait->request.sequence, seq, pipe);
1107
trace_drm_vblank_event_queued(current->pid, pipe,
1108
vblwait->request.sequence);
1110
e->event.sequence = vblwait->request.sequence;
1111
if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1112
e->event.sequence = seq;
1113
e->event.tv_sec = now.tv_sec;
1114
e->event.tv_usec = now.tv_usec;
1115
drm_vblank_put(dev, pipe);
1116
list_add_tail(&e->base.link, &e->base.file_priv->event_list);
1117
wake_up_interruptible(&e->base.file_priv->event_wait);
1118
vblwait->reply.sequence = seq;
1119
trace_drm_vblank_event_delivered(current->pid, pipe,
1120
vblwait->request.sequence);
1122
/* drm_handle_vblank_events will call drm_vblank_put */
1123
list_add_tail(&e->base.link, &dev->vblank_event_list);
1124
vblwait->reply.sequence = vblwait->request.sequence;
1127
spin_unlock_irqrestore(&dev->event_lock, flags);
1132
spin_unlock_irqrestore(&dev->event_lock, flags);
1135
drm_vblank_put(dev, pipe);
1142
* \param inode device inode.
1143
* \param file_priv DRM file private.
1144
* \param cmd command.
1145
* \param data user argument, pointing to a drm_wait_vblank structure.
1146
* \return zero on success or a negative number on failure.
1148
* This function enables the vblank interrupt on the pipe requested, then
1149
* sleeps waiting for the requested sequence number to occur, and drops
1150
* the vblank interrupt refcount afterwards. (vblank irq disable follows that
1151
* after a timeout with no further vblank waits scheduled).
1153
int drm_wait_vblank(struct drm_device *dev, void *data,
1154
struct drm_file *file_priv)
1156
union drm_wait_vblank *vblwait = data;
1158
unsigned int flags, seq, crtc, high_crtc;
1160
if ((!drm_dev_to_irq(dev)) || (!dev->irq_enabled))
1163
if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1166
if (vblwait->request.type &
1167
~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1168
_DRM_VBLANK_HIGH_CRTC_MASK)) {
1169
DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1170
vblwait->request.type,
1171
(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1172
_DRM_VBLANK_HIGH_CRTC_MASK));
1176
flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1177
high_crtc = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1179
crtc = high_crtc >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1181
crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1182
if (crtc >= dev->num_crtcs)
1185
ret = drm_vblank_get(dev, crtc);
1187
DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1190
seq = drm_vblank_count(dev, crtc);
1192
switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1193
case _DRM_VBLANK_RELATIVE:
1194
vblwait->request.sequence += seq;
1195
vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1196
case _DRM_VBLANK_ABSOLUTE:
1203
if (flags & _DRM_VBLANK_EVENT) {
1204
/* must hold on to the vblank ref until the event fires
1205
* drm_vblank_put will be called asynchronously
1207
return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
1210
if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1211
(seq - vblwait->request.sequence) <= (1<<23)) {
1212
vblwait->request.sequence = seq + 1;
1215
DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1216
vblwait->request.sequence, crtc);
1217
dev->last_vblank_wait[crtc] = vblwait->request.sequence;
1218
DRM_WAIT_ON(ret, dev->vbl_queue[crtc], 3 * DRM_HZ,
1219
(((drm_vblank_count(dev, crtc) -
1220
vblwait->request.sequence) <= (1 << 23)) ||
1221
!dev->irq_enabled));
1223
if (ret != -EINTR) {
1226
vblwait->reply.sequence = drm_vblank_count_and_time(dev, crtc, &now);
1227
vblwait->reply.tval_sec = now.tv_sec;
1228
vblwait->reply.tval_usec = now.tv_usec;
1230
DRM_DEBUG("returning %d to client\n",
1231
vblwait->reply.sequence);
1233
DRM_DEBUG("vblank wait interrupted by signal\n");
1237
drm_vblank_put(dev, crtc);
1241
void drm_handle_vblank_events(struct drm_device *dev, int crtc)
1243
struct drm_pending_vblank_event *e, *t;
1245
unsigned long flags;
1248
seq = drm_vblank_count_and_time(dev, crtc, &now);
1250
spin_lock_irqsave(&dev->event_lock, flags);
1252
list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1253
if (e->pipe != crtc)
1255
if ((seq - e->event.sequence) > (1<<23))
1258
DRM_DEBUG("vblank event on %d, current %d\n",
1259
e->event.sequence, seq);
1261
e->event.sequence = seq;
1262
e->event.tv_sec = now.tv_sec;
1263
e->event.tv_usec = now.tv_usec;
1264
drm_vblank_put(dev, e->pipe);
1265
list_move_tail(&e->base.link, &e->base.file_priv->event_list);
1266
wake_up_interruptible(&e->base.file_priv->event_wait);
1267
trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
1271
spin_unlock_irqrestore(&dev->event_lock, flags);
1273
trace_drm_vblank_event(crtc, seq);
1277
* drm_handle_vblank - handle a vblank event
1279
* @crtc: where this event occurred
1281
* Drivers should call this routine in their vblank interrupt handlers to
1282
* update the vblank counter and send any signals that may be pending.
1284
bool drm_handle_vblank(struct drm_device *dev, int crtc)
1288
struct timeval tvblank;
1289
unsigned long irqflags;
1291
if (!dev->num_crtcs)
1294
/* Need timestamp lock to prevent concurrent execution with
1295
* vblank enable/disable, as this would cause inconsistent
1296
* or corrupted timestamps and vblank counts.
1298
spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
1300
/* Vblank irq handling disabled. Nothing to do. */
1301
if (!dev->vblank_enabled[crtc]) {
1302
spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
1306
/* Fetch corresponding timestamp for this vblank interval from
1307
* driver and store it in proper slot of timestamp ringbuffer.
1310
/* Get current timestamp and count. */
1311
vblcount = atomic_read(&dev->_vblank_count[crtc]);
1312
drm_get_last_vbltimestamp(dev, crtc, &tvblank, DRM_CALLED_FROM_VBLIRQ);
1314
/* Compute time difference to timestamp of last vblank */
1315
diff_ns = timeval_to_ns(&tvblank) -
1316
timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
1318
/* Update vblank timestamp and count if at least
1319
* DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1320
* difference between last stored timestamp and current
1321
* timestamp. A smaller difference means basically
1322
* identical timestamps. Happens if this vblank has
1323
* been already processed and this is a redundant call,
1324
* e.g., due to spurious vblank interrupts. We need to
1325
* ignore those for accounting.
1327
if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) {
1328
/* Store new timestamp in ringbuffer. */
1329
vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
1331
/* Increment cooked vblank count. This also atomically commits
1332
* the timestamp computed above.
1334
smp_mb__before_atomic_inc();
1335
atomic_inc(&dev->_vblank_count[crtc]);
1336
smp_mb__after_atomic_inc();
1338
DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1339
crtc, (int) diff_ns);
1342
DRM_WAKEUP(&dev->vbl_queue[crtc]);
1343
drm_handle_vblank_events(dev, crtc);
1345
spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
1348
EXPORT_SYMBOL(drm_handle_vblank);