| Current Path : /sys/dev/drm2/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //sys/dev/drm2/drm_irq.c |
/*-
* Copyright 2003 Eric Anholt
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* ERIC ANHOLT BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* Authors:
* Eric Anholt <anholt@FreeBSD.org>
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: release/9.1.0/sys/dev/drm2/drm_irq.c 235783 2012-05-22 11:07:44Z kib $");
/** @file drm_irq.c
* Support code for handling setup/teardown of interrupt handlers and
* handing interrupt handlers off to the drivers.
*/
#include <dev/drm2/drmP.h>
#include <dev/drm2/drm.h>
MALLOC_DEFINE(DRM_MEM_VBLANK, "drm_vblank", "DRM VBLANK Handling Data");
/* Access macro for slots in vblank timestamp ringbuffer. */
#define vblanktimestamp(dev, crtc, count) ( \
(dev)->_vblank_time[(crtc) * DRM_VBLANKTIME_RBSIZE + \
((count) % DRM_VBLANKTIME_RBSIZE)])
/* Retry timestamp calculation up to 3 times to satisfy
* drm_timestamp_precision before giving up.
*/
#define DRM_TIMESTAMP_MAXRETRIES 3
/* Threshold in nanoseconds for detection of redundant
* vblank irq in drm_handle_vblank(). 1 msec should be ok.
*/
#define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
int drm_irq_by_busid(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_irq_busid *irq = data;
if ((irq->busnum >> 8) != dev->pci_domain ||
(irq->busnum & 0xff) != dev->pci_bus ||
irq->devnum != dev->pci_slot ||
irq->funcnum != dev->pci_func)
return EINVAL;
irq->irq = dev->irq;
DRM_DEBUG("%d:%d:%d => IRQ %d\n",
irq->busnum, irq->devnum, irq->funcnum, irq->irq);
return 0;
}
static void
drm_irq_handler_wrap(void *arg)
{
struct drm_device *dev = arg;
mtx_lock(&dev->irq_lock);
dev->driver->irq_handler(arg);
mtx_unlock(&dev->irq_lock);
}
int
drm_irq_install(struct drm_device *dev)
{
int retcode;
if (dev->irq == 0 || dev->dev_private == NULL)
return (EINVAL);
DRM_DEBUG("irq=%d\n", dev->irq);
DRM_LOCK(dev);
if (dev->irq_enabled) {
DRM_UNLOCK(dev);
return EBUSY;
}
dev->irq_enabled = 1;
dev->context_flag = 0;
/* Before installing handler */
if (dev->driver->irq_preinstall)
dev->driver->irq_preinstall(dev);
DRM_UNLOCK(dev);
/* Install handler */
retcode = bus_setup_intr(dev->device, dev->irqr,
INTR_TYPE_TTY | INTR_MPSAFE, NULL,
(dev->driver->driver_features & DRIVER_LOCKLESS_IRQ) != 0 ?
drm_irq_handler_wrap : dev->driver->irq_handler,
dev, &dev->irqh);
if (retcode != 0)
goto err;
/* After installing handler */
DRM_LOCK(dev);
if (dev->driver->irq_postinstall)
dev->driver->irq_postinstall(dev);
DRM_UNLOCK(dev);
return (0);
err:
device_printf(dev->device, "Error setting interrupt: %d\n", retcode);
dev->irq_enabled = 0;
return (retcode);
}
int drm_irq_uninstall(struct drm_device *dev)
{
int i;
if (!dev->irq_enabled)
return EINVAL;
dev->irq_enabled = 0;
/*
* Wake up any waiters so they don't hang.
*/
if (dev->num_crtcs) {
mtx_lock(&dev->vbl_lock);
for (i = 0; i < dev->num_crtcs; i++) {
wakeup(&dev->_vblank_count[i]);
dev->vblank_enabled[i] = 0;
dev->last_vblank[i] =
dev->driver->get_vblank_counter(dev, i);
}
mtx_unlock(&dev->vbl_lock);
}
DRM_DEBUG("irq=%d\n", dev->irq);
if (dev->driver->irq_uninstall)
dev->driver->irq_uninstall(dev);
DRM_UNLOCK(dev);
bus_teardown_intr(dev->device, dev->irqr, dev->irqh);
DRM_LOCK(dev);
return 0;
}
int drm_control(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
struct drm_control *ctl = data;
int err;
switch (ctl->func) {
case DRM_INST_HANDLER:
/* Handle drivers whose DRM used to require IRQ setup but the
* no longer does.
*/
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
return 0;
if (drm_core_check_feature(dev, DRIVER_MODESET))
return 0;
if (dev->if_version < DRM_IF_VERSION(1, 2) &&
ctl->irq != dev->irq)
return EINVAL;
return drm_irq_install(dev);
case DRM_UNINST_HANDLER:
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
return 0;
if (drm_core_check_feature(dev, DRIVER_MODESET))
return 0;
DRM_LOCK(dev);
err = drm_irq_uninstall(dev);
DRM_UNLOCK(dev);
return err;
default:
return EINVAL;
}
}
#define NSEC_PER_USEC 1000L
#define NSEC_PER_SEC 1000000000L
int64_t
timeval_to_ns(const struct timeval *tv)
{
return ((int64_t)tv->tv_sec * NSEC_PER_SEC) +
tv->tv_usec * NSEC_PER_USEC;
}
struct timeval
ns_to_timeval(const int64_t nsec)
{
struct timeval tv;
uint32_t rem;
if (nsec == 0) {
tv.tv_sec = 0;
tv.tv_usec = 0;
return (tv);
}
tv.tv_sec = nsec / NSEC_PER_SEC;
rem = nsec % NSEC_PER_SEC;
if (rem < 0) {
tv.tv_sec--;
rem += NSEC_PER_SEC;
}
tv.tv_usec = rem / 1000;
return (tv);
}
/*
* Clear vblank timestamp buffer for a crtc.
*/
static void clear_vblank_timestamps(struct drm_device *dev, int crtc)
{
memset(&dev->_vblank_time[crtc * DRM_VBLANKTIME_RBSIZE], 0,
DRM_VBLANKTIME_RBSIZE * sizeof(struct timeval));
}
static int64_t
abs64(int64_t x)
{
return (x < 0 ? -x : x);
}
/*
* Disable vblank irq's on crtc, make sure that last vblank count
* of hardware and corresponding consistent software vblank counter
* are preserved, even if there are any spurious vblank irq's after
* disable.
*/
static void vblank_disable_and_save(struct drm_device *dev, int crtc)
{
u32 vblcount;
int64_t diff_ns;
int vblrc;
struct timeval tvblank;
/* Prevent vblank irq processing while disabling vblank irqs,
* so no updates of timestamps or count can happen after we've
* disabled. Needed to prevent races in case of delayed irq's.
*/
mtx_lock(&dev->vblank_time_lock);
dev->driver->disable_vblank(dev, crtc);
dev->vblank_enabled[crtc] = 0;
/* No further vblank irq's will be processed after
* this point. Get current hardware vblank count and
* vblank timestamp, repeat until they are consistent.
*
* FIXME: There is still a race condition here and in
* drm_update_vblank_count() which can cause off-by-one
* reinitialization of software vblank counter. If gpu
* vblank counter doesn't increment exactly at the leading
* edge of a vblank interval, then we can lose 1 count if
* we happen to execute between start of vblank and the
* delayed gpu counter increment.
*/
do {
dev->last_vblank[crtc] = dev->driver->get_vblank_counter(dev, crtc);
vblrc = drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0);
} while (dev->last_vblank[crtc] != dev->driver->get_vblank_counter(dev, crtc));
/* Compute time difference to stored timestamp of last vblank
* as updated by last invocation of drm_handle_vblank() in vblank irq.
*/
vblcount = atomic_read(&dev->_vblank_count[crtc]);
diff_ns = timeval_to_ns(&tvblank) -
timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
/* If there is at least 1 msec difference between the last stored
* timestamp and tvblank, then we are currently executing our
* disable inside a new vblank interval, the tvblank timestamp
* corresponds to this new vblank interval and the irq handler
* for this vblank didn't run yet and won't run due to our disable.
* Therefore we need to do the job of drm_handle_vblank() and
* increment the vblank counter by one to account for this vblank.
*
* Skip this step if there isn't any high precision timestamp
* available. In that case we can't account for this and just
* hope for the best.
*/
if ((vblrc > 0) && (abs64(diff_ns) > 1000000)) {
atomic_inc(&dev->_vblank_count[crtc]);
}
/* Invalidate all timestamps while vblank irq's are off. */
clear_vblank_timestamps(dev, crtc);
mtx_unlock(&dev->vblank_time_lock);
}
static void vblank_disable_fn(void * arg)
{
struct drm_device *dev = (struct drm_device *)arg;
int i;
if (!dev->vblank_disable_allowed)
return;
for (i = 0; i < dev->num_crtcs; i++) {
mtx_lock(&dev->vbl_lock);
if (atomic_read(&dev->vblank_refcount[i]) == 0 &&
dev->vblank_enabled[i]) {
DRM_DEBUG("disabling vblank on crtc %d\n", i);
vblank_disable_and_save(dev, i);
}
mtx_unlock(&dev->vbl_lock);
}
}
void drm_vblank_cleanup(struct drm_device *dev)
{
/* Bail if the driver didn't call drm_vblank_init() */
if (dev->num_crtcs == 0)
return;
callout_stop(&dev->vblank_disable_callout);
vblank_disable_fn(dev);
free(dev->_vblank_count, DRM_MEM_VBLANK);
free(dev->vblank_refcount, DRM_MEM_VBLANK);
free(dev->vblank_enabled, DRM_MEM_VBLANK);
free(dev->last_vblank, DRM_MEM_VBLANK);
free(dev->last_vblank_wait, DRM_MEM_VBLANK);
free(dev->vblank_inmodeset, DRM_MEM_VBLANK);
free(dev->_vblank_time, DRM_MEM_VBLANK);
dev->num_crtcs = 0;
}
int drm_vblank_init(struct drm_device *dev, int num_crtcs)
{
int i;
callout_init(&dev->vblank_disable_callout, CALLOUT_MPSAFE);
#if 0
mtx_init(&dev->vbl_lock, "drmvbl", NULL, MTX_DEF);
#endif
mtx_init(&dev->vblank_time_lock, "drmvtl", NULL, MTX_DEF);
dev->num_crtcs = num_crtcs;
dev->_vblank_count = malloc(sizeof(atomic_t) * num_crtcs,
DRM_MEM_VBLANK, M_WAITOK);
dev->vblank_refcount = malloc(sizeof(atomic_t) * num_crtcs,
DRM_MEM_VBLANK, M_WAITOK);
dev->vblank_enabled = malloc(num_crtcs * sizeof(int),
DRM_MEM_VBLANK, M_WAITOK | M_ZERO);
dev->last_vblank = malloc(num_crtcs * sizeof(u32),
DRM_MEM_VBLANK, M_WAITOK | M_ZERO);
dev->last_vblank_wait = malloc(num_crtcs * sizeof(u32),
DRM_MEM_VBLANK, M_WAITOK | M_ZERO);
dev->vblank_inmodeset = malloc(num_crtcs * sizeof(int),
DRM_MEM_VBLANK, M_WAITOK | M_ZERO);
dev->_vblank_time = malloc(num_crtcs * DRM_VBLANKTIME_RBSIZE *
sizeof(struct timeval), DRM_MEM_VBLANK, M_WAITOK | M_ZERO);
DRM_INFO("Supports vblank timestamp caching Rev 1 (10.10.2010).\n");
/* Driver specific high-precision vblank timestamping supported? */
if (dev->driver->get_vblank_timestamp)
DRM_INFO("Driver supports precise vblank timestamp query.\n");
else
DRM_INFO("No driver support for vblank timestamp query.\n");
/* Zero per-crtc vblank stuff */
for (i = 0; i < num_crtcs; i++) {
atomic_set(&dev->_vblank_count[i], 0);
atomic_set(&dev->vblank_refcount[i], 0);
}
dev->vblank_disable_allowed = 0;
return 0;
}
void
drm_calc_timestamping_constants(struct drm_crtc *crtc)
{
int64_t linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
uint64_t dotclock;
/* Dot clock in Hz: */
dotclock = (uint64_t) crtc->hwmode.clock * 1000;
/* Fields of interlaced scanout modes are only halve a frame duration.
* Double the dotclock to get halve the frame-/line-/pixelduration.
*/
if (crtc->hwmode.flags & DRM_MODE_FLAG_INTERLACE)
dotclock *= 2;
/* Valid dotclock? */
if (dotclock > 0) {
/* Convert scanline length in pixels and video dot clock to
* line duration, frame duration and pixel duration in
* nanoseconds:
*/
pixeldur_ns = (int64_t)1000000000 / dotclock;
linedur_ns = ((uint64_t)crtc->hwmode.crtc_htotal *
1000000000) / dotclock;
framedur_ns = (int64_t)crtc->hwmode.crtc_vtotal * linedur_ns;
} else
DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
crtc->base.id);
crtc->pixeldur_ns = pixeldur_ns;
crtc->linedur_ns = linedur_ns;
crtc->framedur_ns = framedur_ns;
DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
crtc->base.id, crtc->hwmode.crtc_htotal,
crtc->hwmode.crtc_vtotal, crtc->hwmode.crtc_vdisplay);
DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
crtc->base.id, (int) dotclock/1000, (int) framedur_ns,
(int) linedur_ns, (int) pixeldur_ns);
}
/**
* drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
* drivers. Implements calculation of exact vblank timestamps from
* given drm_display_mode timings and current video scanout position
* of a crtc. This can be called from within get_vblank_timestamp()
* implementation of a kms driver to implement the actual timestamping.
*
* Should return timestamps conforming to the OML_sync_control OpenML
* extension specification. The timestamp corresponds to the end of
* the vblank interval, aka start of scanout of topmost-leftmost display
* pixel in the following video frame.
*
* Requires support for optional dev->driver->get_scanout_position()
* in kms driver, plus a bit of setup code to provide a drm_display_mode
* that corresponds to the true scanout timing.
*
* The current implementation only handles standard video modes. It
* returns as no operation if a doublescan or interlaced video mode is
* active. Higher level code is expected to handle this.
*
* @dev: DRM device.
* @crtc: Which crtc's vblank timestamp to retrieve.
* @max_error: Desired maximum allowable error in timestamps (nanosecs).
* On return contains true maximum error of timestamp.
* @vblank_time: Pointer to struct timeval which should receive the timestamp.
* @flags: Flags to pass to driver:
* 0 = Default.
* DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
* @refcrtc: drm_crtc* of crtc which defines scanout timing.
*
* Returns negative value on error, failure or if not supported in current
* video mode:
*
* -EINVAL - Invalid crtc.
* -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
* -ENOTSUPP - Function not supported in current display mode.
* -EIO - Failed, e.g., due to failed scanout position query.
*
* Returns or'ed positive status flags on success:
*
* DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
* DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
*
*/
int
drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
int *max_error, struct timeval *vblank_time, unsigned flags,
struct drm_crtc *refcrtc)
{
struct timeval stime, raw_time;
struct drm_display_mode *mode;
int vbl_status, vtotal, vdisplay;
int vpos, hpos, i;
int64_t framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
bool invbl;
if (crtc < 0 || crtc >= dev->num_crtcs) {
DRM_ERROR("Invalid crtc %d\n", crtc);
return -EINVAL;
}
/* Scanout position query not supported? Should not happen. */
if (!dev->driver->get_scanout_position) {
DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
return -EIO;
}
mode = &refcrtc->hwmode;
vtotal = mode->crtc_vtotal;
vdisplay = mode->crtc_vdisplay;
/* Durations of frames, lines, pixels in nanoseconds. */
framedur_ns = refcrtc->framedur_ns;
linedur_ns = refcrtc->linedur_ns;
pixeldur_ns = refcrtc->pixeldur_ns;
/* If mode timing undefined, just return as no-op:
* Happens during initial modesetting of a crtc.
*/
if (vtotal <= 0 || vdisplay <= 0 || framedur_ns == 0) {
DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc);
return -EAGAIN;
}
/* Get current scanout position with system timestamp.
* Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
* if single query takes longer than max_error nanoseconds.
*
* This guarantees a tight bound on maximum error if
* code gets preempted or delayed for some reason.
*/
for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
/* Disable preemption to make it very likely to
* succeed in the first iteration.
*/
critical_enter();
/* Get system timestamp before query. */
getmicrouptime(&stime);
/* Get vertical and horizontal scanout pos. vpos, hpos. */
vbl_status = dev->driver->get_scanout_position(dev, crtc, &vpos, &hpos);
/* Get system timestamp after query. */
getmicrouptime(&raw_time);
critical_exit();
/* Return as no-op if scanout query unsupported or failed. */
if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
crtc, vbl_status);
return -EIO;
}
duration_ns = timeval_to_ns(&raw_time) - timeval_to_ns(&stime);
/* Accept result with < max_error nsecs timing uncertainty. */
if (duration_ns <= (int64_t) *max_error)
break;
}
/* Noisy system timing? */
if (i == DRM_TIMESTAMP_MAXRETRIES) {
DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
crtc, (int) duration_ns/1000, *max_error/1000, i);
}
/* Return upper bound of timestamp precision error. */
*max_error = (int) duration_ns;
/* Check if in vblank area:
* vpos is >=0 in video scanout area, but negative
* within vblank area, counting down the number of lines until
* start of scanout.
*/
invbl = vbl_status & DRM_SCANOUTPOS_INVBL;
/* Convert scanout position into elapsed time at raw_time query
* since start of scanout at first display scanline. delta_ns
* can be negative if start of scanout hasn't happened yet.
*/
delta_ns = (int64_t)vpos * linedur_ns + (int64_t)hpos * pixeldur_ns;
/* Is vpos outside nominal vblank area, but less than
* 1/100 of a frame height away from start of vblank?
* If so, assume this isn't a massively delayed vblank
* interrupt, but a vblank interrupt that fired a few
* microseconds before true start of vblank. Compensate
* by adding a full frame duration to the final timestamp.
* Happens, e.g., on ATI R500, R600.
*
* We only do this if DRM_CALLED_FROM_VBLIRQ.
*/
if ((flags & DRM_CALLED_FROM_VBLIRQ) && !invbl &&
((vdisplay - vpos) < vtotal / 100)) {
delta_ns = delta_ns - framedur_ns;
/* Signal this correction as "applied". */
vbl_status |= 0x8;
}
/* Subtract time delta from raw timestamp to get final
* vblank_time timestamp for end of vblank.
*/
*vblank_time = ns_to_timeval(timeval_to_ns(&raw_time) - delta_ns);
DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %jd.%jd -> %jd.%jd [e %d us, %d rep]\n",
crtc, (int)vbl_status, hpos, vpos, (uintmax_t)raw_time.tv_sec,
(uintmax_t)raw_time.tv_usec, (uintmax_t)vblank_time->tv_sec,
(uintmax_t)vblank_time->tv_usec, (int)duration_ns/1000, i);
vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
if (invbl)
vbl_status |= DRM_VBLANKTIME_INVBL;
return vbl_status;
}
/**
* drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
* vblank interval.
*
* @dev: DRM device
* @crtc: which crtc's vblank timestamp to retrieve
* @tvblank: Pointer to target struct timeval which should receive the timestamp
* @flags: Flags to pass to driver:
* 0 = Default.
* DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
*
* Fetches the system timestamp corresponding to the time of the most recent
* vblank interval on specified crtc. May call into kms-driver to
* compute the timestamp with a high-precision GPU specific method.
*
* Returns zero if timestamp originates from uncorrected do_gettimeofday()
* call, i.e., it isn't very precisely locked to the true vblank.
*
* Returns non-zero if timestamp is considered to be very precise.
*/
u32 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
struct timeval *tvblank, unsigned flags)
{
int ret = 0;
/* Define requested maximum error on timestamps (nanoseconds). */
int max_error = (int) drm_timestamp_precision * 1000;
/* Query driver if possible and precision timestamping enabled. */
if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
ret = dev->driver->get_vblank_timestamp(dev, crtc, &max_error,
tvblank, flags);
if (ret > 0)
return (u32) ret;
}
/* GPU high precision timestamp query unsupported or failed.
* Return gettimeofday timestamp as best estimate.
*/
microtime(tvblank);
return 0;
}
/**
* drm_vblank_count - retrieve "cooked" vblank counter value
* @dev: DRM device
* @crtc: which counter to retrieve
*
* Fetches the "cooked" vblank count value that represents the number of
* vblank events since the system was booted, including lost events due to
* modesetting activity.
*/
u32 drm_vblank_count(struct drm_device *dev, int crtc)
{
return atomic_read(&dev->_vblank_count[crtc]);
}
/**
* drm_vblank_count_and_time - retrieve "cooked" vblank counter value
* and the system timestamp corresponding to that vblank counter value.
*
* @dev: DRM device
* @crtc: which counter to retrieve
* @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
*
* Fetches the "cooked" vblank count value that represents the number of
* vblank events since the system was booted, including lost events due to
* modesetting activity. Returns corresponding system timestamp of the time
* of the vblank interval that corresponds to the current value vblank counter
* value.
*/
u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
struct timeval *vblanktime)
{
u32 cur_vblank;
/* Read timestamp from slot of _vblank_time ringbuffer
* that corresponds to current vblank count. Retry if
* count has incremented during readout. This works like
* a seqlock.
*/
do {
cur_vblank = atomic_read(&dev->_vblank_count[crtc]);
*vblanktime = vblanktimestamp(dev, crtc, cur_vblank);
rmb();
} while (cur_vblank != atomic_read(&dev->_vblank_count[crtc]));
return cur_vblank;
}
/**
* drm_update_vblank_count - update the master vblank counter
* @dev: DRM device
* @crtc: counter to update
*
* Call back into the driver to update the appropriate vblank counter
* (specified by @crtc). Deal with wraparound, if it occurred, and
* update the last read value so we can deal with wraparound on the next
* call if necessary.
*
* Only necessary when going from off->on, to account for frames we
* didn't get an interrupt for.
*
* Note: caller must hold dev->vbl_lock since this reads & writes
* device vblank fields.
*/
static void drm_update_vblank_count(struct drm_device *dev, int crtc)
{
u32 cur_vblank, diff, tslot, rc;
struct timeval t_vblank;
/*
* Interrupts were disabled prior to this call, so deal with counter
* wrap if needed.
* NOTE! It's possible we lost a full dev->max_vblank_count events
* here if the register is small or we had vblank interrupts off for
* a long time.
*
* We repeat the hardware vblank counter & timestamp query until
* we get consistent results. This to prevent races between gpu
* updating its hardware counter while we are retrieving the
* corresponding vblank timestamp.
*/
do {
cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0);
} while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc));
/* Deal with counter wrap */
diff = cur_vblank - dev->last_vblank[crtc];
if (cur_vblank < dev->last_vblank[crtc]) {
diff += dev->max_vblank_count;
DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
crtc, dev->last_vblank[crtc], cur_vblank, diff);
}
DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
crtc, diff);
/* Reinitialize corresponding vblank timestamp if high-precision query
* available. Skip this step if query unsupported or failed. Will
* reinitialize delayed at next vblank interrupt in that case.
*/
if (rc) {
tslot = atomic_read(&dev->_vblank_count[crtc]) + diff;
vblanktimestamp(dev, crtc, tslot) = t_vblank;
}
atomic_add(diff, &dev->_vblank_count[crtc]);
}
/**
* drm_vblank_get - get a reference count on vblank events
* @dev: DRM device
* @crtc: which CRTC to own
*
* Acquire a reference count on vblank events to avoid having them disabled
* while in use.
*
* RETURNS
* Zero on success, nonzero on failure.
*/
int drm_vblank_get(struct drm_device *dev, int crtc)
{
int ret = 0;
mtx_lock(&dev->vbl_lock);
/* Going from 0->1 means we have to enable interrupts again */
if (atomic_fetchadd_int(&dev->vblank_refcount[crtc], 1) == 0) {
mtx_lock(&dev->vblank_time_lock);
if (!dev->vblank_enabled[crtc]) {
/* Enable vblank irqs under vblank_time_lock protection.
* All vblank count & timestamp updates are held off
* until we are done reinitializing master counter and
* timestamps. Filtercode in drm_handle_vblank() will
* prevent double-accounting of same vblank interval.
*/
ret = -dev->driver->enable_vblank(dev, crtc);
DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n",
crtc, ret);
if (ret)
atomic_dec(&dev->vblank_refcount[crtc]);
else {
dev->vblank_enabled[crtc] = 1;
drm_update_vblank_count(dev, crtc);
}
}
mtx_unlock(&dev->vblank_time_lock);
} else {
if (!dev->vblank_enabled[crtc]) {
atomic_dec(&dev->vblank_refcount[crtc]);
ret = EINVAL;
}
}
mtx_unlock(&dev->vbl_lock);
return ret;
}
/**
* drm_vblank_put - give up ownership of vblank events
* @dev: DRM device
* @crtc: which counter to give up
*
* Release ownership of a given vblank counter, turning off interrupts
* if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
*/
void drm_vblank_put(struct drm_device *dev, int crtc)
{
KASSERT(atomic_read(&dev->vblank_refcount[crtc]) != 0,
("Too many drm_vblank_put for crtc %d", crtc));
/* Last user schedules interrupt disable */
if (atomic_fetchadd_int(&dev->vblank_refcount[crtc], -1) == 1 &&
(drm_vblank_offdelay > 0))
callout_reset(&dev->vblank_disable_callout,
(drm_vblank_offdelay * DRM_HZ) / 1000,
vblank_disable_fn, dev);
}
void drm_vblank_off(struct drm_device *dev, int crtc)
{
struct drm_pending_vblank_event *e, *t;
struct timeval now;
unsigned int seq;
mtx_lock(&dev->vbl_lock);
vblank_disable_and_save(dev, crtc);
mtx_lock(&dev->event_lock);
wakeup(&dev->_vblank_count[crtc]);
/* Send any queued vblank events, lest the natives grow disquiet */
seq = drm_vblank_count_and_time(dev, crtc, &now);
list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
if (e->pipe != crtc)
continue;
DRM_DEBUG("Sending premature vblank event on disable: \
wanted %d, current %d\n",
e->event.sequence, seq);
e->event.sequence = seq;
e->event.tv_sec = now.tv_sec;
e->event.tv_usec = now.tv_usec;
drm_vblank_put(dev, e->pipe);
list_move_tail(&e->base.link, &e->base.file_priv->event_list);
drm_event_wakeup(&e->base);
CTR3(KTR_DRM, "vblank_event_delivered %d %d %d",
e->base.pid, e->pipe, e->event.sequence);
}
mtx_unlock(&dev->event_lock);
mtx_unlock(&dev->vbl_lock);
}
/**
* drm_vblank_pre_modeset - account for vblanks across mode sets
* @dev: DRM device
* @crtc: CRTC in question
* @post: post or pre mode set?
*
* Account for vblank events across mode setting events, which will likely
* reset the hardware frame counter.
*/
void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
{
/* vblank is not initialized (IRQ not installed ?) */
if (!dev->num_crtcs)
return;
/*
* To avoid all the problems that might happen if interrupts
* were enabled/disabled around or between these calls, we just
* have the kernel take a reference on the CRTC (just once though
* to avoid corrupting the count if multiple, mismatch calls occur),
* so that interrupts remain enabled in the interim.
*/
if (!dev->vblank_inmodeset[crtc]) {
dev->vblank_inmodeset[crtc] = 0x1;
if (drm_vblank_get(dev, crtc) == 0)
dev->vblank_inmodeset[crtc] |= 0x2;
}
}
void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
{
if (dev->vblank_inmodeset[crtc]) {
mtx_lock(&dev->vbl_lock);
dev->vblank_disable_allowed = 1;
mtx_unlock(&dev->vbl_lock);
if (dev->vblank_inmodeset[crtc] & 0x2)
drm_vblank_put(dev, crtc);
dev->vblank_inmodeset[crtc] = 0;
}
}
/**
* drm_modeset_ctl - handle vblank event counter changes across mode switch
* @DRM_IOCTL_ARGS: standard ioctl arguments
*
* Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
* ioctls around modesetting so that any lost vblank events are accounted for.
*
* Generally the counter will reset across mode sets. If interrupts are
* enabled around this call, we don't have to do anything since the counter
* will have already been incremented.
*/
int drm_modeset_ctl(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_modeset_ctl *modeset = data;
int ret = 0;
unsigned int crtc;
/* If drm_vblank_init() hasn't been called yet, just no-op */
if (!dev->num_crtcs)
goto out;
crtc = modeset->crtc;
if (crtc >= dev->num_crtcs) {
ret = -EINVAL;
goto out;
}
switch (modeset->cmd) {
case _DRM_PRE_MODESET:
drm_vblank_pre_modeset(dev, crtc);
break;
case _DRM_POST_MODESET:
drm_vblank_post_modeset(dev, crtc);
break;
default:
ret = -EINVAL;
break;
}
out:
return ret;
}
static void
drm_vblank_event_destroy(struct drm_pending_event *e)
{
free(e, DRM_MEM_VBLANK);
}
static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
union drm_wait_vblank *vblwait,
struct drm_file *file_priv)
{
struct drm_pending_vblank_event *e;
struct timeval now;
unsigned int seq;
int ret;
e = malloc(sizeof *e, DRM_MEM_VBLANK, M_WAITOK | M_ZERO);
e->pipe = pipe;
e->base.pid = curproc->p_pid;
e->event.base.type = DRM_EVENT_VBLANK;
e->event.base.length = sizeof e->event;
e->event.user_data = vblwait->request.signal;
e->base.event = &e->event.base;
e->base.file_priv = file_priv;
e->base.destroy = drm_vblank_event_destroy;
mtx_lock(&dev->event_lock);
if (file_priv->event_space < sizeof e->event) {
ret = EBUSY;
goto err_unlock;
}
file_priv->event_space -= sizeof e->event;
seq = drm_vblank_count_and_time(dev, pipe, &now);
if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
(seq - vblwait->request.sequence) <= (1 << 23)) {
vblwait->request.sequence = seq + 1;
vblwait->reply.sequence = vblwait->request.sequence;
}
DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
vblwait->request.sequence, seq, pipe);
CTR4(KTR_DRM, "vblank_event_queued %d %d rt %x %d", curproc->p_pid, pipe,
vblwait->request.type, vblwait->request.sequence);
e->event.sequence = vblwait->request.sequence;
if ((seq - vblwait->request.sequence) <= (1 << 23)) {
e->event.sequence = seq;
e->event.tv_sec = now.tv_sec;
e->event.tv_usec = now.tv_usec;
drm_vblank_put(dev, pipe);
list_add_tail(&e->base.link, &e->base.file_priv->event_list);
drm_event_wakeup(&e->base);
vblwait->reply.sequence = seq;
CTR3(KTR_DRM, "vblank_event_wakeup p1 %d %d %d", curproc->p_pid,
pipe, vblwait->request.sequence);
} else {
/* drm_handle_vblank_events will call drm_vblank_put */
list_add_tail(&e->base.link, &dev->vblank_event_list);
vblwait->reply.sequence = vblwait->request.sequence;
}
mtx_unlock(&dev->event_lock);
return 0;
err_unlock:
mtx_unlock(&dev->event_lock);
free(e, DRM_MEM_VBLANK);
drm_vblank_put(dev, pipe);
return ret;
}
/**
* Wait for VBLANK.
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param data user argument, pointing to a drm_wait_vblank structure.
* \return zero on success or a negative number on failure.
*
* This function enables the vblank interrupt on the pipe requested, then
* sleeps waiting for the requested sequence number to occur, and drops
* the vblank interrupt refcount afterwards. (vblank irq disable follows that
* after a timeout with no further vblank waits scheduled).
*/
int drm_wait_vblank(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
union drm_wait_vblank *vblwait = data;
int ret = 0;
unsigned int flags, seq, crtc, high_crtc;
if (/*(!drm_dev_to_irq(dev)) || */(!dev->irq_enabled))
return (EINVAL);
if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
return (EINVAL);
if (vblwait->request.type &
~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
_DRM_VBLANK_HIGH_CRTC_MASK)) {
DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
vblwait->request.type,
(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
_DRM_VBLANK_HIGH_CRTC_MASK));
return (EINVAL);
}
flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
high_crtc = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
if (high_crtc)
crtc = high_crtc >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
else
crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
if (crtc >= dev->num_crtcs)
return (EINVAL);
ret = drm_vblank_get(dev, crtc);
if (ret) {
DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
return (ret);
}
seq = drm_vblank_count(dev, crtc);
switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
case _DRM_VBLANK_RELATIVE:
vblwait->request.sequence += seq;
vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
case _DRM_VBLANK_ABSOLUTE:
break;
default:
ret = (EINVAL);
goto done;
}
if (flags & _DRM_VBLANK_EVENT) {
/* must hold on to the vblank ref until the event fires
* drm_vblank_put will be called asynchronously
*/
return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
}
if ((flags & _DRM_VBLANK_NEXTONMISS) &&
(seq - vblwait->request.sequence) <= (1<<23)) {
vblwait->request.sequence = seq + 1;
}
dev->last_vblank_wait[crtc] = vblwait->request.sequence;
mtx_lock(&dev->vblank_time_lock);
while (((drm_vblank_count(dev, crtc) - vblwait->request.sequence) >
(1 << 23)) && dev->irq_enabled) {
/*
* The wakeups from the drm_irq_uninstall() and
* drm_vblank_off() may be lost there since vbl_lock
* is not held. Then, the timeout will wake us; the 3
* seconds delay should not be a problem for
* application when crtc is disabled or irq
* uninstalled anyway.
*/
ret = msleep(&dev->_vblank_count[crtc], &dev->vblank_time_lock,
PCATCH, "drmvbl", 3 * hz);
if (ret != 0)
break;
}
mtx_unlock(&dev->vblank_time_lock);
if (ret != EINTR) {
struct timeval now;
long reply_seq;
reply_seq = drm_vblank_count_and_time(dev, crtc, &now);
CTR5(KTR_DRM, "wait_vblank %d %d rt %x success %d %d",
curproc->p_pid, crtc, vblwait->request.type,
vblwait->request.sequence, reply_seq);
vblwait->reply.sequence = reply_seq;
vblwait->reply.tval_sec = now.tv_sec;
vblwait->reply.tval_usec = now.tv_usec;
} else {
CTR5(KTR_DRM, "wait_vblank %d %d rt %x error %d %d",
curproc->p_pid, crtc, vblwait->request.type, ret,
vblwait->request.sequence);
}
done:
drm_vblank_put(dev, crtc);
return ret;
}
void drm_handle_vblank_events(struct drm_device *dev, int crtc)
{
struct drm_pending_vblank_event *e, *t;
struct timeval now;
unsigned int seq;
seq = drm_vblank_count_and_time(dev, crtc, &now);
CTR2(KTR_DRM, "drm_handle_vblank_events %d %d", seq, crtc);
mtx_lock(&dev->event_lock);
list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
if (e->pipe != crtc)
continue;
if ((seq - e->event.sequence) > (1<<23))
continue;
e->event.sequence = seq;
e->event.tv_sec = now.tv_sec;
e->event.tv_usec = now.tv_usec;
drm_vblank_put(dev, e->pipe);
list_move_tail(&e->base.link, &e->base.file_priv->event_list);
drm_event_wakeup(&e->base);
CTR3(KTR_DRM, "vblank_event_wakeup p2 %d %d %d", e->base.pid,
e->pipe, e->event.sequence);
}
mtx_unlock(&dev->event_lock);
}
/**
* drm_handle_vblank - handle a vblank event
* @dev: DRM device
* @crtc: where this event occurred
*
* Drivers should call this routine in their vblank interrupt handlers to
* update the vblank counter and send any signals that may be pending.
*/
bool drm_handle_vblank(struct drm_device *dev, int crtc)
{
u32 vblcount;
int64_t diff_ns;
struct timeval tvblank;
if (!dev->num_crtcs)
return false;
/* Need timestamp lock to prevent concurrent execution with
* vblank enable/disable, as this would cause inconsistent
* or corrupted timestamps and vblank counts.
*/
mtx_lock(&dev->vblank_time_lock);
/* Vblank irq handling disabled. Nothing to do. */
if (!dev->vblank_enabled[crtc]) {
mtx_unlock(&dev->vblank_time_lock);
return false;
}
/* Fetch corresponding timestamp for this vblank interval from
* driver and store it in proper slot of timestamp ringbuffer.
*/
/* Get current timestamp and count. */
vblcount = atomic_read(&dev->_vblank_count[crtc]);
drm_get_last_vbltimestamp(dev, crtc, &tvblank, DRM_CALLED_FROM_VBLIRQ);
/* Compute time difference to timestamp of last vblank */
diff_ns = timeval_to_ns(&tvblank) -
timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
/* Update vblank timestamp and count if at least
* DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
* difference between last stored timestamp and current
* timestamp. A smaller difference means basically
* identical timestamps. Happens if this vblank has
* been already processed and this is a redundant call,
* e.g., due to spurious vblank interrupts. We need to
* ignore those for accounting.
*/
if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) {
/* Store new timestamp in ringbuffer. */
vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
/* Increment cooked vblank count. This also atomically commits
* the timestamp computed above.
*/
atomic_inc(&dev->_vblank_count[crtc]);
} else {
DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
crtc, (int) diff_ns);
}
wakeup(&dev->_vblank_count[crtc]);
drm_handle_vblank_events(dev, crtc);
mtx_unlock(&dev->vblank_time_lock);
return true;
}