linux-stable/drivers/gpu/drm/drm_irq.c
Daniel Vetter ee3c7795e5 drm: WARN if drm_handle_vblank is called errornously
KMS drivers are in full control of their irq and vblank handling, if
they get a vblank interrupt before drm_vblank_init or after
drm_vblank_cleanup that's just a driver bug.

For ums driver there's only r128 and radeon which support vblank, and
they call drm_vblank_init in their driver load functions. Which again
means that userspace can do whatever it wants with interrupt, vblank
structures will always be there.

So this should never happen, let's catch driver issues with a WARN_ON.
Motivated by some discussions with Imre.

v2: Use WARN_ON_ONCE as suggested by Imre.

Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2015-02-23 10:54:29 +01:00

1769 lines
52 KiB
C

/*
* drm_irq.c IRQ and vblank support
*
* \author Rickard E. (Rik) Faith <faith@valinux.com>
* \author Gareth Hughes <gareth@valinux.com>
*/
/*
* Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
*
* Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
* Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
* 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
* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS 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.
*/
#include <drm/drmP.h>
#include "drm_trace.h"
#include "drm_internal.h"
#include <linux/interrupt.h> /* For task queue support */
#include <linux/slab.h>
#include <linux/vgaarb.h>
#include <linux/export.h>
/* Access macro for slots in vblank timestamp ringbuffer. */
#define vblanktimestamp(dev, crtc, count) \
((dev)->vblank[crtc].time[(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
static bool
drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
struct timeval *tvblank, unsigned flags);
static unsigned int drm_timestamp_precision = 20; /* Default to 20 usecs. */
/*
* Default to use monotonic timestamps for wait-for-vblank and page-flip
* complete events.
*/
unsigned int drm_timestamp_monotonic = 1;
static int drm_vblank_offdelay = 5000; /* Default to 5000 msecs. */
module_param_named(vblankoffdelay, drm_vblank_offdelay, int, 0600);
module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600);
module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600);
/**
* 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)
{
struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
u32 cur_vblank, diff, tslot;
bool 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 - vblank->last;
if (cur_vblank < vblank->last) {
diff += dev->max_vblank_count;
DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
crtc, vblank->last, cur_vblank, diff);
}
DRM_DEBUG("updating vblank count on crtc %d, missed %d\n",
crtc, diff);
if (diff == 0)
return;
/* 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(&vblank->count) + diff;
vblanktimestamp(dev, crtc, tslot) = t_vblank;
}
smp_mb__before_atomic();
atomic_add(diff, &vblank->count);
smp_mb__after_atomic();
}
/*
* 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)
{
struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
unsigned long irqflags;
u32 vblcount;
s64 diff_ns;
bool vblrc;
struct timeval tvblank;
int count = DRM_TIMESTAMP_MAXRETRIES;
/* 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.
*/
spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
/*
* If the vblank interrupt was already disabled update the count
* and timestamp to maintain the appearance that the counter
* has been ticking all along until this time. This makes the
* count account for the entire time between drm_vblank_on() and
* drm_vblank_off().
*
* But only do this if precise vblank timestamps are available.
* Otherwise we might read a totally bogus timestamp since drivers
* lacking precise timestamp support rely upon sampling the system clock
* at vblank interrupt time. Which obviously won't work out well if the
* vblank interrupt is disabled.
*/
if (!vblank->enabled &&
drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0)) {
drm_update_vblank_count(dev, crtc);
spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
return;
}
dev->driver->disable_vblank(dev, crtc);
vblank->enabled = false;
/* 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 {
vblank->last = dev->driver->get_vblank_counter(dev, crtc);
vblrc = drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0);
} while (vblank->last != dev->driver->get_vblank_counter(dev, crtc) && (--count) && vblrc);
if (!count)
vblrc = 0;
/* Compute time difference to stored timestamp of last vblank
* as updated by last invocation of drm_handle_vblank() in vblank irq.
*/
vblcount = atomic_read(&vblank->count);
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 && (abs64(diff_ns) > 1000000)) {
/* Store new timestamp in ringbuffer. */
vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
/* Increment cooked vblank count. This also atomically commits
* the timestamp computed above.
*/
smp_mb__before_atomic();
atomic_inc(&vblank->count);
smp_mb__after_atomic();
}
spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
}
static void vblank_disable_fn(unsigned long arg)
{
struct drm_vblank_crtc *vblank = (void *)arg;
struct drm_device *dev = vblank->dev;
unsigned long irqflags;
int crtc = vblank->crtc;
if (!dev->vblank_disable_allowed)
return;
spin_lock_irqsave(&dev->vbl_lock, irqflags);
if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) {
DRM_DEBUG("disabling vblank on crtc %d\n", crtc);
vblank_disable_and_save(dev, crtc);
}
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
}
/**
* drm_vblank_cleanup - cleanup vblank support
* @dev: DRM device
*
* This function cleans up any resources allocated in drm_vblank_init.
*/
void drm_vblank_cleanup(struct drm_device *dev)
{
int crtc;
/* Bail if the driver didn't call drm_vblank_init() */
if (dev->num_crtcs == 0)
return;
for (crtc = 0; crtc < dev->num_crtcs; crtc++) {
struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
WARN_ON(vblank->enabled &&
drm_core_check_feature(dev, DRIVER_MODESET));
del_timer_sync(&vblank->disable_timer);
}
kfree(dev->vblank);
dev->num_crtcs = 0;
}
EXPORT_SYMBOL(drm_vblank_cleanup);
/**
* drm_vblank_init - initialize vblank support
* @dev: drm_device
* @num_crtcs: number of crtcs supported by @dev
*
* This function initializes vblank support for @num_crtcs display pipelines.
*
* Returns:
* Zero on success or a negative error code on failure.
*/
int drm_vblank_init(struct drm_device *dev, int num_crtcs)
{
int i, ret = -ENOMEM;
spin_lock_init(&dev->vbl_lock);
spin_lock_init(&dev->vblank_time_lock);
dev->num_crtcs = num_crtcs;
dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
if (!dev->vblank)
goto err;
for (i = 0; i < num_crtcs; i++) {
struct drm_vblank_crtc *vblank = &dev->vblank[i];
vblank->dev = dev;
vblank->crtc = i;
init_waitqueue_head(&vblank->queue);
setup_timer(&vblank->disable_timer, vblank_disable_fn,
(unsigned long)vblank);
}
DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\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");
dev->vblank_disable_allowed = false;
return 0;
err:
dev->num_crtcs = 0;
return ret;
}
EXPORT_SYMBOL(drm_vblank_init);
static void drm_irq_vgaarb_nokms(void *cookie, bool state)
{
struct drm_device *dev = cookie;
if (dev->driver->vgaarb_irq) {
dev->driver->vgaarb_irq(dev, state);
return;
}
if (!dev->irq_enabled)
return;
if (state) {
if (dev->driver->irq_uninstall)
dev->driver->irq_uninstall(dev);
} else {
if (dev->driver->irq_preinstall)
dev->driver->irq_preinstall(dev);
if (dev->driver->irq_postinstall)
dev->driver->irq_postinstall(dev);
}
}
/**
* drm_irq_install - install IRQ handler
* @dev: DRM device
* @irq: IRQ number to install the handler for
*
* Initializes the IRQ related data. Installs the handler, calling the driver
* irq_preinstall() and irq_postinstall() functions before and after the
* installation.
*
* This is the simplified helper interface provided for drivers with no special
* needs. Drivers which need to install interrupt handlers for multiple
* interrupts must instead set drm_device->irq_enabled to signal the DRM core
* that vblank interrupts are available.
*
* Returns:
* Zero on success or a negative error code on failure.
*/
int drm_irq_install(struct drm_device *dev, int irq)
{
int ret;
unsigned long sh_flags = 0;
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
return -EINVAL;
if (irq == 0)
return -EINVAL;
/* Driver must have been initialized */
if (!dev->dev_private)
return -EINVAL;
if (dev->irq_enabled)
return -EBUSY;
dev->irq_enabled = true;
DRM_DEBUG("irq=%d\n", irq);
/* Before installing handler */
if (dev->driver->irq_preinstall)
dev->driver->irq_preinstall(dev);
/* Install handler */
if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
sh_flags = IRQF_SHARED;
ret = request_irq(irq, dev->driver->irq_handler,
sh_flags, dev->driver->name, dev);
if (ret < 0) {
dev->irq_enabled = false;
return ret;
}
if (!drm_core_check_feature(dev, DRIVER_MODESET))
vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
/* After installing handler */
if (dev->driver->irq_postinstall)
ret = dev->driver->irq_postinstall(dev);
if (ret < 0) {
dev->irq_enabled = false;
if (!drm_core_check_feature(dev, DRIVER_MODESET))
vga_client_register(dev->pdev, NULL, NULL, NULL);
free_irq(irq, dev);
} else {
dev->irq = irq;
}
return ret;
}
EXPORT_SYMBOL(drm_irq_install);
/**
* drm_irq_uninstall - uninstall the IRQ handler
* @dev: DRM device
*
* Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
* This should only be called by drivers which used drm_irq_install() to set up
* their interrupt handler. Other drivers must only reset
* drm_device->irq_enabled to false.
*
* Note that for kernel modesetting drivers it is a bug if this function fails.
* The sanity checks are only to catch buggy user modesetting drivers which call
* the same function through an ioctl.
*
* Returns:
* Zero on success or a negative error code on failure.
*/
int drm_irq_uninstall(struct drm_device *dev)
{
unsigned long irqflags;
bool irq_enabled;
int i;
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
return -EINVAL;
irq_enabled = dev->irq_enabled;
dev->irq_enabled = false;
/*
* Wake up any waiters so they don't hang. This is just to paper over
* isssues for UMS drivers which aren't in full control of their
* vblank/irq handling. KMS drivers must ensure that vblanks are all
* disabled when uninstalling the irq handler.
*/
if (dev->num_crtcs) {
spin_lock_irqsave(&dev->vbl_lock, irqflags);
for (i = 0; i < dev->num_crtcs; i++) {
struct drm_vblank_crtc *vblank = &dev->vblank[i];
if (!vblank->enabled)
continue;
WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));
vblank_disable_and_save(dev, i);
wake_up(&vblank->queue);
}
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
}
if (!irq_enabled)
return -EINVAL;
DRM_DEBUG("irq=%d\n", dev->irq);
if (!drm_core_check_feature(dev, DRIVER_MODESET))
vga_client_register(dev->pdev, NULL, NULL, NULL);
if (dev->driver->irq_uninstall)
dev->driver->irq_uninstall(dev);
free_irq(dev->irq, dev);
return 0;
}
EXPORT_SYMBOL(drm_irq_uninstall);
/*
* IRQ control ioctl.
*
* \param inode device inode.
* \param file_priv DRM file private.
* \param cmd command.
* \param arg user argument, pointing to a drm_control structure.
* \return zero on success or a negative number on failure.
*
* Calls irq_install() or irq_uninstall() according to \p arg.
*/
int drm_control(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_control *ctl = data;
int ret = 0, irq;
/* if we haven't irq we fallback for compatibility reasons -
* this used to be a separate function in drm_dma.h
*/
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
return 0;
if (drm_core_check_feature(dev, DRIVER_MODESET))
return 0;
/* UMS was only ever support on pci devices. */
if (WARN_ON(!dev->pdev))
return -EINVAL;
switch (ctl->func) {
case DRM_INST_HANDLER:
irq = dev->pdev->irq;
if (dev->if_version < DRM_IF_VERSION(1, 2) &&
ctl->irq != irq)
return -EINVAL;
mutex_lock(&dev->struct_mutex);
ret = drm_irq_install(dev, irq);
mutex_unlock(&dev->struct_mutex);
return ret;
case DRM_UNINST_HANDLER:
mutex_lock(&dev->struct_mutex);
ret = drm_irq_uninstall(dev);
mutex_unlock(&dev->struct_mutex);
return ret;
default:
return -EINVAL;
}
}
/**
* drm_calc_timestamping_constants - calculate vblank timestamp constants
* @crtc: drm_crtc whose timestamp constants should be updated.
* @mode: display mode containing the scanout timings
*
* Calculate and store various constants which are later
* needed by vblank and swap-completion timestamping, e.g,
* by drm_calc_vbltimestamp_from_scanoutpos(). They are
* derived from CRTC's true scanout timing, so they take
* things like panel scaling or other adjustments into account.
*/
void drm_calc_timestamping_constants(struct drm_crtc *crtc,
const struct drm_display_mode *mode)
{
int linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
int dotclock = mode->crtc_clock;
/* Valid dotclock? */
if (dotclock > 0) {
int frame_size = mode->crtc_htotal * mode->crtc_vtotal;
/*
* Convert scanline length in pixels and video
* dot clock to line duration, frame duration
* and pixel duration in nanoseconds:
*/
pixeldur_ns = 1000000 / dotclock;
linedur_ns = div_u64((u64) mode->crtc_htotal * 1000000, dotclock);
framedur_ns = div_u64((u64) frame_size * 1000000, dotclock);
/*
* Fields of interlaced scanout modes are only half a frame duration.
*/
if (mode->flags & DRM_MODE_FLAG_INTERLACE)
framedur_ns /= 2;
} 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, mode->crtc_htotal,
mode->crtc_vtotal, mode->crtc_vdisplay);
DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
crtc->base.id, dotclock, framedur_ns,
linedur_ns, pixeldur_ns);
}
EXPORT_SYMBOL(drm_calc_timestamping_constants);
/**
* drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
* @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: CRTC which defines scanout timing
* @mode: mode which defines the scanout timings
*
* 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.
*
* 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,
const struct drm_crtc *refcrtc,
const struct drm_display_mode *mode)
{
struct timeval tv_etime;
ktime_t stime, etime;
int vbl_status;
int vpos, hpos, i;
int 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;
}
/* 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 (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++) {
/*
* Get vertical and horizontal scanout position vpos, hpos,
* and bounding timestamps stime, etime, pre/post query.
*/
vbl_status = dev->driver->get_scanout_position(dev, crtc, flags, &vpos,
&hpos, &stime, &etime);
/* 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;
}
/* Compute uncertainty in timestamp of scanout position query. */
duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
/* Accept result with < max_error nsecs timing uncertainty. */
if (duration_ns <= *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, duration_ns/1000, *max_error/1000, i);
}
/* Return upper bound of timestamp precision error. */
*max_error = 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_IN_VBLANK;
/* 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 = vpos * linedur_ns + hpos * pixeldur_ns;
if (!drm_timestamp_monotonic)
etime = ktime_mono_to_real(etime);
/* save this only for debugging purposes */
tv_etime = ktime_to_timeval(etime);
/* Subtract time delta from raw timestamp to get final
* vblank_time timestamp for end of vblank.
*/
if (delta_ns < 0)
etime = ktime_add_ns(etime, -delta_ns);
else
etime = ktime_sub_ns(etime, delta_ns);
*vblank_time = ktime_to_timeval(etime);
DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
crtc, (int)vbl_status, hpos, vpos,
(long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
(long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
duration_ns/1000, i);
vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
if (invbl)
vbl_status |= DRM_VBLANKTIME_IN_VBLANK;
return vbl_status;
}
EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
static struct timeval get_drm_timestamp(void)
{
ktime_t now;
now = drm_timestamp_monotonic ? ktime_get() : ktime_get_real();
return ktime_to_timeval(now);
}
/**
* 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:
* True if timestamp is considered to be very precise, false otherwise.
*/
static bool
drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
struct timeval *tvblank, unsigned flags)
{
int ret;
/* 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 true;
}
/* GPU high precision timestamp query unsupported or failed.
* Return current monotonic/gettimeofday timestamp as best estimate.
*/
*tvblank = get_drm_timestamp();
return false;
}
/**
* 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.
*
* This is the legacy version of drm_crtc_vblank_count().
*
* Returns:
* The software vblank counter.
*/
u32 drm_vblank_count(struct drm_device *dev, int crtc)
{
struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
if (WARN_ON(crtc >= dev->num_crtcs))
return 0;
return atomic_read(&vblank->count);
}
EXPORT_SYMBOL(drm_vblank_count);
/**
* drm_crtc_vblank_count - retrieve "cooked" vblank counter value
* @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.
*
* This is the native KMS version of drm_vblank_count().
*
* Returns:
* The software vblank counter.
*/
u32 drm_crtc_vblank_count(struct drm_crtc *crtc)
{
return drm_vblank_count(crtc->dev, drm_crtc_index(crtc));
}
EXPORT_SYMBOL(drm_crtc_vblank_count);
/**
* 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 vblank counter value.
*/
u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
struct timeval *vblanktime)
{
struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
u32 cur_vblank;
if (WARN_ON(crtc >= dev->num_crtcs))
return 0;
/* 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(&vblank->count);
*vblanktime = vblanktimestamp(dev, crtc, cur_vblank);
smp_rmb();
} while (cur_vblank != atomic_read(&vblank->count));
return cur_vblank;
}
EXPORT_SYMBOL(drm_vblank_count_and_time);
static void send_vblank_event(struct drm_device *dev,
struct drm_pending_vblank_event *e,
unsigned long seq, struct timeval *now)
{
WARN_ON_SMP(!spin_is_locked(&dev->event_lock));
e->event.sequence = seq;
e->event.tv_sec = now->tv_sec;
e->event.tv_usec = now->tv_usec;
list_add_tail(&e->base.link,
&e->base.file_priv->event_list);
wake_up_interruptible(&e->base.file_priv->event_wait);
trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
e->event.sequence);
}
/**
* drm_send_vblank_event - helper to send vblank event after pageflip
* @dev: DRM device
* @crtc: CRTC in question
* @e: the event to send
*
* Updates sequence # and timestamp on event, and sends it to userspace.
* Caller must hold event lock.
*
* This is the legacy version of drm_crtc_send_vblank_event().
*/
void drm_send_vblank_event(struct drm_device *dev, int crtc,
struct drm_pending_vblank_event *e)
{
struct timeval now;
unsigned int seq;
if (crtc >= 0) {
seq = drm_vblank_count_and_time(dev, crtc, &now);
} else {
seq = 0;
now = get_drm_timestamp();
}
e->pipe = crtc;
send_vblank_event(dev, e, seq, &now);
}
EXPORT_SYMBOL(drm_send_vblank_event);
/**
* drm_crtc_send_vblank_event - helper to send vblank event after pageflip
* @crtc: the source CRTC of the vblank event
* @e: the event to send
*
* Updates sequence # and timestamp on event, and sends it to userspace.
* Caller must hold event lock.
*
* This is the native KMS version of drm_send_vblank_event().
*/
void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
struct drm_pending_vblank_event *e)
{
drm_send_vblank_event(crtc->dev, drm_crtc_index(crtc), e);
}
EXPORT_SYMBOL(drm_crtc_send_vblank_event);
/**
* drm_vblank_enable - enable the vblank interrupt on a CRTC
* @dev: DRM device
* @crtc: CRTC in question
*/
static int drm_vblank_enable(struct drm_device *dev, int crtc)
{
struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
int ret = 0;
assert_spin_locked(&dev->vbl_lock);
spin_lock(&dev->vblank_time_lock);
if (!vblank->enabled) {
/*
* 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(&vblank->refcount);
else {
vblank->enabled = true;
drm_update_vblank_count(dev, crtc);
}
}
spin_unlock(&dev->vblank_time_lock);
return ret;
}
/**
* 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.
*
* This is the legacy version of drm_crtc_vblank_get().
*
* Returns:
* Zero on success, nonzero on failure.
*/
int drm_vblank_get(struct drm_device *dev, int crtc)
{
struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
unsigned long irqflags;
int ret = 0;
if (WARN_ON(crtc >= dev->num_crtcs))
return -EINVAL;
spin_lock_irqsave(&dev->vbl_lock, irqflags);
/* Going from 0->1 means we have to enable interrupts again */
if (atomic_add_return(1, &vblank->refcount) == 1) {
ret = drm_vblank_enable(dev, crtc);
} else {
if (!vblank->enabled) {
atomic_dec(&vblank->refcount);
ret = -EINVAL;
}
}
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
return ret;
}
EXPORT_SYMBOL(drm_vblank_get);
/**
* drm_crtc_vblank_get - get a reference count on vblank events
* @crtc: which CRTC to own
*
* Acquire a reference count on vblank events to avoid having them disabled
* while in use.
*
* This is the native kms version of drm_vblank_off().
*
* Returns:
* Zero on success, nonzero on failure.
*/
int drm_crtc_vblank_get(struct drm_crtc *crtc)
{
return drm_vblank_get(crtc->dev, drm_crtc_index(crtc));
}
EXPORT_SYMBOL(drm_crtc_vblank_get);
/**
* 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.
*
* This is the legacy version of drm_crtc_vblank_put().
*/
void drm_vblank_put(struct drm_device *dev, int crtc)
{
struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
if (WARN_ON(atomic_read(&vblank->refcount) == 0))
return;
if (WARN_ON(crtc >= dev->num_crtcs))
return;
/* Last user schedules interrupt disable */
if (atomic_dec_and_test(&vblank->refcount)) {
if (drm_vblank_offdelay == 0)
return;
else if (dev->vblank_disable_immediate || drm_vblank_offdelay < 0)
vblank_disable_fn((unsigned long)vblank);
else
mod_timer(&vblank->disable_timer,
jiffies + ((drm_vblank_offdelay * HZ)/1000));
}
}
EXPORT_SYMBOL(drm_vblank_put);
/**
* drm_crtc_vblank_put - give up ownership of vblank events
* @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.
*
* This is the native kms version of drm_vblank_put().
*/
void drm_crtc_vblank_put(struct drm_crtc *crtc)
{
drm_vblank_put(crtc->dev, drm_crtc_index(crtc));
}
EXPORT_SYMBOL(drm_crtc_vblank_put);
/**
* drm_wait_one_vblank - wait for one vblank
* @dev: DRM device
* @crtc: crtc index
*
* This waits for one vblank to pass on @crtc, using the irq driver interfaces.
* It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
* due to lack of driver support or because the crtc is off.
*/
void drm_wait_one_vblank(struct drm_device *dev, int crtc)
{
int ret;
u32 last;
ret = drm_vblank_get(dev, crtc);
if (WARN(ret, "vblank not available on crtc %i, ret=%i\n", crtc, ret))
return;
last = drm_vblank_count(dev, crtc);
ret = wait_event_timeout(dev->vblank[crtc].queue,
last != drm_vblank_count(dev, crtc),
msecs_to_jiffies(100));
WARN(ret == 0, "vblank wait timed out on crtc %i\n", crtc);
drm_vblank_put(dev, crtc);
}
EXPORT_SYMBOL(drm_wait_one_vblank);
/**
* drm_crtc_wait_one_vblank - wait for one vblank
* @crtc: DRM crtc
*
* This waits for one vblank to pass on @crtc, using the irq driver interfaces.
* It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
* due to lack of driver support or because the crtc is off.
*/
void drm_crtc_wait_one_vblank(struct drm_crtc *crtc)
{
drm_wait_one_vblank(crtc->dev, drm_crtc_index(crtc));
}
EXPORT_SYMBOL(drm_crtc_wait_one_vblank);
/**
* drm_vblank_off - disable vblank events on a CRTC
* @dev: DRM device
* @crtc: CRTC in question
*
* Drivers can use this function to shut down the vblank interrupt handling when
* disabling a crtc. This function ensures that the latest vblank frame count is
* stored so that drm_vblank_on() can restore it again.
*
* Drivers must use this function when the hardware vblank counter can get
* reset, e.g. when suspending.
*
* This is the legacy version of drm_crtc_vblank_off().
*/
void drm_vblank_off(struct drm_device *dev, int crtc)
{
struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
struct drm_pending_vblank_event *e, *t;
struct timeval now;
unsigned long irqflags;
unsigned int seq;
if (WARN_ON(crtc >= dev->num_crtcs))
return;
spin_lock_irqsave(&dev->event_lock, irqflags);
spin_lock(&dev->vbl_lock);
vblank_disable_and_save(dev, crtc);
wake_up(&vblank->queue);
/*
* Prevent subsequent drm_vblank_get() from re-enabling
* the vblank interrupt by bumping the refcount.
*/
if (!vblank->inmodeset) {
atomic_inc(&vblank->refcount);
vblank->inmodeset = 1;
}
spin_unlock(&dev->vbl_lock);
/* 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);
list_del(&e->base.link);
drm_vblank_put(dev, e->pipe);
send_vblank_event(dev, e, seq, &now);
}
spin_unlock_irqrestore(&dev->event_lock, irqflags);
}
EXPORT_SYMBOL(drm_vblank_off);
/**
* drm_crtc_vblank_off - disable vblank events on a CRTC
* @crtc: CRTC in question
*
* Drivers can use this function to shut down the vblank interrupt handling when
* disabling a crtc. This function ensures that the latest vblank frame count is
* stored so that drm_vblank_on can restore it again.
*
* Drivers must use this function when the hardware vblank counter can get
* reset, e.g. when suspending.
*
* This is the native kms version of drm_vblank_off().
*/
void drm_crtc_vblank_off(struct drm_crtc *crtc)
{
drm_vblank_off(crtc->dev, drm_crtc_index(crtc));
}
EXPORT_SYMBOL(drm_crtc_vblank_off);
/**
* drm_crtc_vblank_reset - reset vblank state to off on a CRTC
* @crtc: CRTC in question
*
* Drivers can use this function to reset the vblank state to off at load time.
* Drivers should use this together with the drm_crtc_vblank_off() and
* drm_crtc_vblank_on() functions. The difference compared to
* drm_crtc_vblank_off() is that this function doesn't save the vblank counter
* and hence doesn't need to call any driver hooks.
*/
void drm_crtc_vblank_reset(struct drm_crtc *drm_crtc)
{
struct drm_device *dev = drm_crtc->dev;
unsigned long irqflags;
int crtc = drm_crtc_index(drm_crtc);
struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
spin_lock_irqsave(&dev->vbl_lock, irqflags);
/*
* Prevent subsequent drm_vblank_get() from enabling the vblank
* interrupt by bumping the refcount.
*/
if (!vblank->inmodeset) {
atomic_inc(&vblank->refcount);
vblank->inmodeset = 1;
}
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
WARN_ON(!list_empty(&dev->vblank_event_list));
}
EXPORT_SYMBOL(drm_crtc_vblank_reset);
/**
* drm_vblank_on - enable vblank events on a CRTC
* @dev: DRM device
* @crtc: CRTC in question
*
* This functions restores the vblank interrupt state captured with
* drm_vblank_off() again. Note that calls to drm_vblank_on() and
* drm_vblank_off() can be unbalanced and so can also be unconditionally called
* in driver load code to reflect the current hardware state of the crtc.
*
* This is the legacy version of drm_crtc_vblank_on().
*/
void drm_vblank_on(struct drm_device *dev, int crtc)
{
struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
unsigned long irqflags;
if (WARN_ON(crtc >= dev->num_crtcs))
return;
spin_lock_irqsave(&dev->vbl_lock, irqflags);
/* Drop our private "prevent drm_vblank_get" refcount */
if (vblank->inmodeset) {
atomic_dec(&vblank->refcount);
vblank->inmodeset = 0;
}
/*
* sample the current counter to avoid random jumps
* when drm_vblank_enable() applies the diff
*
* -1 to make sure user will never see the same
* vblank counter value before and after a modeset
*/
vblank->last =
(dev->driver->get_vblank_counter(dev, crtc) - 1) &
dev->max_vblank_count;
/*
* re-enable interrupts if there are users left, or the
* user wishes vblank interrupts to be enabled all the time.
*/
if (atomic_read(&vblank->refcount) != 0 ||
(!dev->vblank_disable_immediate && drm_vblank_offdelay == 0))
WARN_ON(drm_vblank_enable(dev, crtc));
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
}
EXPORT_SYMBOL(drm_vblank_on);
/**
* drm_crtc_vblank_on - enable vblank events on a CRTC
* @crtc: CRTC in question
*
* This functions restores the vblank interrupt state captured with
* drm_vblank_off() again. Note that calls to drm_vblank_on() and
* drm_vblank_off() can be unbalanced and so can also be unconditionally called
* in driver load code to reflect the current hardware state of the crtc.
*
* This is the native kms version of drm_vblank_on().
*/
void drm_crtc_vblank_on(struct drm_crtc *crtc)
{
drm_vblank_on(crtc->dev, drm_crtc_index(crtc));
}
EXPORT_SYMBOL(drm_crtc_vblank_on);
/**
* drm_vblank_pre_modeset - account for vblanks across mode sets
* @dev: DRM device
* @crtc: CRTC in question
*
* Account for vblank events across mode setting events, which will likely
* reset the hardware frame counter.
*
* This is done by grabbing a temporary vblank reference to ensure that the
* vblank interrupt keeps running across the modeset sequence. With this the
* software-side vblank frame counting will ensure that there are no jumps or
* discontinuities.
*
* Unfortunately this approach is racy and also doesn't work when the vblank
* interrupt stops running, e.g. across system suspend resume. It is therefore
* highly recommended that drivers use the newer drm_vblank_off() and
* drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
* using "cooked" software vblank frame counters and not relying on any hardware
* counters.
*
* Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
* again.
*/
void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
{
struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
/* vblank is not initialized (IRQ not installed ?), or has been freed */
if (!dev->num_crtcs)
return;
if (WARN_ON(crtc >= 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 (!vblank->inmodeset) {
vblank->inmodeset = 0x1;
if (drm_vblank_get(dev, crtc) == 0)
vblank->inmodeset |= 0x2;
}
}
EXPORT_SYMBOL(drm_vblank_pre_modeset);
/**
* drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
* @dev: DRM device
* @crtc: CRTC in question
*
* This function again drops the temporary vblank reference acquired in
* drm_vblank_pre_modeset.
*/
void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
{
struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
unsigned long irqflags;
/* vblank is not initialized (IRQ not installed ?), or has been freed */
if (!dev->num_crtcs)
return;
if (vblank->inmodeset) {
spin_lock_irqsave(&dev->vbl_lock, irqflags);
dev->vblank_disable_allowed = true;
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
if (vblank->inmodeset & 0x2)
drm_vblank_put(dev, crtc);
vblank->inmodeset = 0;
}
}
EXPORT_SYMBOL(drm_vblank_post_modeset);
/*
* 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;
unsigned int crtc;
/* If drm_vblank_init() hasn't been called yet, just no-op */
if (!dev->num_crtcs)
return 0;
/* KMS drivers handle this internally */
if (drm_core_check_feature(dev, DRIVER_MODESET))
return 0;
crtc = modeset->crtc;
if (crtc >= dev->num_crtcs)
return -EINVAL;
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:
return -EINVAL;
}
return 0;
}
static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
union drm_wait_vblank *vblwait,
struct drm_file *file_priv)
{
struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
struct drm_pending_vblank_event *e;
struct timeval now;
unsigned long flags;
unsigned int seq;
int ret;
e = kzalloc(sizeof(*e), GFP_KERNEL);
if (e == NULL) {
ret = -ENOMEM;
goto err_put;
}
e->pipe = pipe;
e->base.pid = current->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 = (void (*) (struct drm_pending_event *)) kfree;
spin_lock_irqsave(&dev->event_lock, flags);
/*
* drm_vblank_off() might have been called after we called
* drm_vblank_get(). drm_vblank_off() holds event_lock
* around the vblank disable, so no need for further locking.
* The reference from drm_vblank_get() protects against
* vblank disable from another source.
*/
if (!vblank->enabled) {
ret = -EINVAL;
goto err_unlock;
}
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);
trace_drm_vblank_event_queued(current->pid, pipe,
vblwait->request.sequence);
e->event.sequence = vblwait->request.sequence;
if ((seq - vblwait->request.sequence) <= (1 << 23)) {
drm_vblank_put(dev, pipe);
send_vblank_event(dev, e, seq, &now);
vblwait->reply.sequence = seq;
} 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;
}
spin_unlock_irqrestore(&dev->event_lock, flags);
return 0;
err_unlock:
spin_unlock_irqrestore(&dev->event_lock, flags);
kfree(e);
err_put:
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)
{
struct drm_vblank_crtc *vblank;
union drm_wait_vblank *vblwait = data;
int ret;
unsigned int flags, seq, crtc, high_crtc;
if (!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;
vblank = &dev->vblank[crtc];
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;
}
DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
vblwait->request.sequence, crtc);
vblank->last_wait = vblwait->request.sequence;
DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
(((drm_vblank_count(dev, crtc) -
vblwait->request.sequence) <= (1 << 23)) ||
!vblank->enabled ||
!dev->irq_enabled));
if (ret != -EINTR) {
struct timeval now;
vblwait->reply.sequence = drm_vblank_count_and_time(dev, crtc, &now);
vblwait->reply.tval_sec = now.tv_sec;
vblwait->reply.tval_usec = now.tv_usec;
DRM_DEBUG("returning %d to client\n",
vblwait->reply.sequence);
} else {
DRM_DEBUG("vblank wait interrupted by signal\n");
}
done:
drm_vblank_put(dev, crtc);
return ret;
}
static void drm_handle_vblank_events(struct drm_device *dev, int crtc)
{
struct drm_pending_vblank_event *e, *t;
struct timeval now;
unsigned int seq;
assert_spin_locked(&dev->event_lock);
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;
if ((seq - e->event.sequence) > (1<<23))
continue;
DRM_DEBUG("vblank event on %d, current %d\n",
e->event.sequence, seq);
list_del(&e->base.link);
drm_vblank_put(dev, e->pipe);
send_vblank_event(dev, e, seq, &now);
}
trace_drm_vblank_event(crtc, seq);
}
/**
* 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.
*
* This is the legacy version of drm_crtc_handle_vblank().
*/
bool drm_handle_vblank(struct drm_device *dev, int crtc)
{
struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
u32 vblcount;
s64 diff_ns;
struct timeval tvblank;
unsigned long irqflags;
if (WARN_ON_ONCE(!dev->num_crtcs))
return false;
if (WARN_ON(crtc >= dev->num_crtcs))
return false;
spin_lock_irqsave(&dev->event_lock, irqflags);
/* Need timestamp lock to prevent concurrent execution with
* vblank enable/disable, as this would cause inconsistent
* or corrupted timestamps and vblank counts.
*/
spin_lock(&dev->vblank_time_lock);
/* Vblank irq handling disabled. Nothing to do. */
if (!vblank->enabled) {
spin_unlock(&dev->vblank_time_lock);
spin_unlock_irqrestore(&dev->event_lock, irqflags);
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(&vblank->count);
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.
*/
smp_mb__before_atomic();
atomic_inc(&vblank->count);
smp_mb__after_atomic();
} else {
DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
crtc, (int) diff_ns);
}
spin_unlock(&dev->vblank_time_lock);
wake_up(&vblank->queue);
drm_handle_vblank_events(dev, crtc);
spin_unlock_irqrestore(&dev->event_lock, irqflags);
return true;
}
EXPORT_SYMBOL(drm_handle_vblank);
/**
* drm_crtc_handle_vblank - handle a vblank event
* @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.
*
* This is the native KMS version of drm_handle_vblank().
*
* Returns:
* True if the event was successfully handled, false on failure.
*/
bool drm_crtc_handle_vblank(struct drm_crtc *crtc)
{
return drm_handle_vblank(crtc->dev, drm_crtc_index(crtc));
}
EXPORT_SYMBOL(drm_crtc_handle_vblank);