v4.19.13 snapshot.
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
new file mode 100644
index 0000000..28cdcf7
--- /dev/null
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -0,0 +1,1915 @@
+/*
+ * drm_irq.c IRQ and vblank support
+ *
+ * \author Rickard E. (Rik) Faith <faith@valinux.com>
+ * \author Gareth Hughes <gareth@valinux.com>
+ *
+ * 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/drm_vblank.h>
+#include <drm/drmP.h>
+#include <linux/export.h>
+
+#include "drm_trace.h"
+#include "drm_internal.h"
+
+/**
+ * DOC: vblank handling
+ *
+ * Vertical blanking plays a major role in graphics rendering. To achieve
+ * tear-free display, users must synchronize page flips and/or rendering to
+ * vertical blanking. The DRM API offers ioctls to perform page flips
+ * synchronized to vertical blanking and wait for vertical blanking.
+ *
+ * The DRM core handles most of the vertical blanking management logic, which
+ * involves filtering out spurious interrupts, keeping race-free blanking
+ * counters, coping with counter wrap-around and resets and keeping use counts.
+ * It relies on the driver to generate vertical blanking interrupts and
+ * optionally provide a hardware vertical blanking counter.
+ *
+ * Drivers must initialize the vertical blanking handling core with a call to
+ * drm_vblank_init(). Minimally, a driver needs to implement
+ * &drm_crtc_funcs.enable_vblank and &drm_crtc_funcs.disable_vblank plus call
+ * drm_crtc_handle_vblank() in it's vblank interrupt handler for working vblank
+ * support.
+ *
+ * Vertical blanking interrupts can be enabled by the DRM core or by drivers
+ * themselves (for instance to handle page flipping operations). The DRM core
+ * maintains a vertical blanking use count to ensure that the interrupts are not
+ * disabled while a user still needs them. To increment the use count, drivers
+ * call drm_crtc_vblank_get() and release the vblank reference again with
+ * drm_crtc_vblank_put(). In between these two calls vblank interrupts are
+ * guaranteed to be enabled.
+ *
+ * On many hardware disabling the vblank interrupt cannot be done in a race-free
+ * manner, see &drm_driver.vblank_disable_immediate and
+ * &drm_driver.max_vblank_count. In that case the vblank core only disables the
+ * vblanks after a timer has expired, which can be configured through the
+ * ``vblankoffdelay`` module parameter.
+ */
+
+/* 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, unsigned int pipe,
+ ktime_t *tvblank, bool in_vblank_irq);
+
+static unsigned int drm_timestamp_precision = 20; /* Default to 20 usecs. */
+
+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_PARM_DESC(vblankoffdelay, "Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)");
+MODULE_PARM_DESC(timestamp_precision_usec, "Max. error on timestamps [usecs]");
+
+static void store_vblank(struct drm_device *dev, unsigned int pipe,
+ u32 vblank_count_inc,
+ ktime_t t_vblank, u32 last)
+{
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+
+ assert_spin_locked(&dev->vblank_time_lock);
+
+ vblank->last = last;
+
+ write_seqlock(&vblank->seqlock);
+ vblank->time = t_vblank;
+ vblank->count += vblank_count_inc;
+ write_sequnlock(&vblank->seqlock);
+}
+
+/*
+ * "No hw counter" fallback implementation of .get_vblank_counter() hook,
+ * if there is no useable hardware frame counter available.
+ */
+static u32 drm_vblank_no_hw_counter(struct drm_device *dev, unsigned int pipe)
+{
+ WARN_ON_ONCE(dev->max_vblank_count != 0);
+ return 0;
+}
+
+static u32 __get_vblank_counter(struct drm_device *dev, unsigned int pipe)
+{
+ if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+ struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
+
+ if (WARN_ON(!crtc))
+ return 0;
+
+ if (crtc->funcs->get_vblank_counter)
+ return crtc->funcs->get_vblank_counter(crtc);
+ }
+
+ if (dev->driver->get_vblank_counter)
+ return dev->driver->get_vblank_counter(dev, pipe);
+
+ return drm_vblank_no_hw_counter(dev, pipe);
+}
+
+/*
+ * Reset the stored timestamp for the current vblank count to correspond
+ * to the last vblank occurred.
+ *
+ * Only to be called from drm_crtc_vblank_on().
+ *
+ * Note: caller must hold &drm_device.vbl_lock since this reads & writes
+ * device vblank fields.
+ */
+static void drm_reset_vblank_timestamp(struct drm_device *dev, unsigned int pipe)
+{
+ u32 cur_vblank;
+ bool rc;
+ ktime_t t_vblank;
+ int count = DRM_TIMESTAMP_MAXRETRIES;
+
+ spin_lock(&dev->vblank_time_lock);
+
+ /*
+ * sample the current counter to avoid random jumps
+ * when drm_vblank_enable() applies the diff
+ */
+ do {
+ cur_vblank = __get_vblank_counter(dev, pipe);
+ rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, false);
+ } while (cur_vblank != __get_vblank_counter(dev, pipe) && --count > 0);
+
+ /*
+ * Only reinitialize corresponding vblank timestamp if high-precision query
+ * available and didn't fail. Otherwise reinitialize delayed at next vblank
+ * interrupt and assign 0 for now, to mark the vblanktimestamp as invalid.
+ */
+ if (!rc)
+ t_vblank = 0;
+
+ /*
+ * +1 to make sure user will never see the same
+ * vblank counter value before and after a modeset
+ */
+ store_vblank(dev, pipe, 1, t_vblank, cur_vblank);
+
+ spin_unlock(&dev->vblank_time_lock);
+}
+
+/*
+ * Call back into the driver to update the appropriate vblank counter
+ * (specified by @pipe). 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 &drm_device.vbl_lock since this reads & writes
+ * device vblank fields.
+ */
+static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe,
+ bool in_vblank_irq)
+{
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+ u32 cur_vblank, diff;
+ bool rc;
+ ktime_t t_vblank;
+ int count = DRM_TIMESTAMP_MAXRETRIES;
+ int framedur_ns = vblank->framedur_ns;
+
+ /*
+ * 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 + 1 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 = __get_vblank_counter(dev, pipe);
+ rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, in_vblank_irq);
+ } while (cur_vblank != __get_vblank_counter(dev, pipe) && --count > 0);
+
+ if (dev->max_vblank_count != 0) {
+ /* trust the hw counter when it's around */
+ diff = (cur_vblank - vblank->last) & dev->max_vblank_count;
+ } else if (rc && framedur_ns) {
+ u64 diff_ns = ktime_to_ns(ktime_sub(t_vblank, vblank->time));
+
+ /*
+ * Figure out how many vblanks we've missed based
+ * on the difference in the timestamps and the
+ * frame/field duration.
+ */
+ diff = DIV_ROUND_CLOSEST_ULL(diff_ns, framedur_ns);
+
+ if (diff == 0 && in_vblank_irq)
+ DRM_DEBUG_VBL("crtc %u: Redundant vblirq ignored."
+ " diff_ns = %lld, framedur_ns = %d)\n",
+ pipe, (long long) diff_ns, framedur_ns);
+ } else {
+ /* some kind of default for drivers w/o accurate vbl timestamping */
+ diff = in_vblank_irq ? 1 : 0;
+ }
+
+ /*
+ * Within a drm_vblank_pre_modeset - drm_vblank_post_modeset
+ * interval? If so then vblank irqs keep running and it will likely
+ * happen that the hardware vblank counter is not trustworthy as it
+ * might reset at some point in that interval and vblank timestamps
+ * are not trustworthy either in that interval. Iow. this can result
+ * in a bogus diff >> 1 which must be avoided as it would cause
+ * random large forward jumps of the software vblank counter.
+ */
+ if (diff > 1 && (vblank->inmodeset & 0x2)) {
+ DRM_DEBUG_VBL("clamping vblank bump to 1 on crtc %u: diffr=%u"
+ " due to pre-modeset.\n", pipe, diff);
+ diff = 1;
+ }
+
+ DRM_DEBUG_VBL("updating vblank count on crtc %u:"
+ " current=%llu, diff=%u, hw=%u hw_last=%u\n",
+ pipe, vblank->count, diff, cur_vblank, vblank->last);
+
+ if (diff == 0) {
+ WARN_ON_ONCE(cur_vblank != vblank->last);
+ return;
+ }
+
+ /*
+ * Only reinitialize corresponding vblank timestamp if high-precision query
+ * available and didn't fail, or we were called from the vblank interrupt.
+ * Otherwise reinitialize delayed at next vblank interrupt and assign 0
+ * for now, to mark the vblanktimestamp as invalid.
+ */
+ if (!rc && !in_vblank_irq)
+ t_vblank = 0;
+
+ store_vblank(dev, pipe, diff, t_vblank, cur_vblank);
+}
+
+static u64 drm_vblank_count(struct drm_device *dev, unsigned int pipe)
+{
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+
+ if (WARN_ON(pipe >= dev->num_crtcs))
+ return 0;
+
+ return vblank->count;
+}
+
+/**
+ * drm_crtc_accurate_vblank_count - retrieve the master vblank counter
+ * @crtc: which counter to retrieve
+ *
+ * This function is similar to drm_crtc_vblank_count() but this function
+ * interpolates to handle a race with vblank interrupts using the high precision
+ * timestamping support.
+ *
+ * This is mostly useful for hardware that can obtain the scanout position, but
+ * doesn't have a hardware frame counter.
+ */
+u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc)
+{
+ struct drm_device *dev = crtc->dev;
+ unsigned int pipe = drm_crtc_index(crtc);
+ u64 vblank;
+ unsigned long flags;
+
+ WARN_ONCE(drm_debug & DRM_UT_VBL && !dev->driver->get_vblank_timestamp,
+ "This function requires support for accurate vblank timestamps.");
+
+ spin_lock_irqsave(&dev->vblank_time_lock, flags);
+
+ drm_update_vblank_count(dev, pipe, false);
+ vblank = drm_vblank_count(dev, pipe);
+
+ spin_unlock_irqrestore(&dev->vblank_time_lock, flags);
+
+ return vblank;
+}
+EXPORT_SYMBOL(drm_crtc_accurate_vblank_count);
+
+static void __disable_vblank(struct drm_device *dev, unsigned int pipe)
+{
+ if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+ struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
+
+ if (WARN_ON(!crtc))
+ return;
+
+ if (crtc->funcs->disable_vblank) {
+ crtc->funcs->disable_vblank(crtc);
+ return;
+ }
+ }
+
+ dev->driver->disable_vblank(dev, pipe);
+}
+
+/*
+ * 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.
+ */
+void drm_vblank_disable_and_save(struct drm_device *dev, unsigned int pipe)
+{
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+ unsigned long irqflags;
+
+ assert_spin_locked(&dev->vbl_lock);
+
+ /* 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);
+
+ /*
+ * Update vblank count and disable vblank interrupts only if the
+ * interrupts were enabled. This avoids calling the ->disable_vblank()
+ * operation in atomic context with the hardware potentially runtime
+ * suspended.
+ */
+ if (!vblank->enabled)
+ goto out;
+
+ /*
+ * 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_crtc_vblank_on() and drm_crtc_vblank_off().
+ */
+ drm_update_vblank_count(dev, pipe, false);
+ __disable_vblank(dev, pipe);
+ vblank->enabled = false;
+
+out:
+ spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
+}
+
+static void vblank_disable_fn(struct timer_list *t)
+{
+ struct drm_vblank_crtc *vblank = from_timer(vblank, t, disable_timer);
+ struct drm_device *dev = vblank->dev;
+ unsigned int pipe = vblank->pipe;
+ unsigned long irqflags;
+
+ spin_lock_irqsave(&dev->vbl_lock, irqflags);
+ if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) {
+ DRM_DEBUG("disabling vblank on crtc %u\n", pipe);
+ drm_vblank_disable_and_save(dev, pipe);
+ }
+ spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+}
+
+void drm_vblank_cleanup(struct drm_device *dev)
+{
+ unsigned int pipe;
+
+ /* Bail if the driver didn't call drm_vblank_init() */
+ if (dev->num_crtcs == 0)
+ return;
+
+ for (pipe = 0; pipe < dev->num_crtcs; pipe++) {
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+
+ WARN_ON(READ_ONCE(vblank->enabled) &&
+ drm_core_check_feature(dev, DRIVER_MODESET));
+
+ del_timer_sync(&vblank->disable_timer);
+ }
+
+ kfree(dev->vblank);
+
+ dev->num_crtcs = 0;
+}
+
+/**
+ * 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.
+ * Cleanup is handled by the DRM core, or through calling drm_dev_fini() for
+ * drivers with a &drm_driver.release callback.
+ *
+ * Returns:
+ * Zero on success or a negative error code on failure.
+ */
+int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs)
+{
+ int ret = -ENOMEM;
+ unsigned int i;
+
+ 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->pipe = i;
+ init_waitqueue_head(&vblank->queue);
+ timer_setup(&vblank->disable_timer, vblank_disable_fn, 0);
+ seqlock_init(&vblank->seqlock);
+ }
+
+ 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");
+
+ /* Must have precise timestamping for reliable vblank instant disable */
+ if (dev->vblank_disable_immediate && !dev->driver->get_vblank_timestamp) {
+ dev->vblank_disable_immediate = false;
+ DRM_INFO("Setting vblank_disable_immediate to false because "
+ "get_vblank_timestamp == NULL\n");
+ }
+
+ return 0;
+
+err:
+ dev->num_crtcs = 0;
+ return ret;
+}
+EXPORT_SYMBOL(drm_vblank_init);
+
+/**
+ * drm_crtc_vblank_waitqueue - get vblank waitqueue for the CRTC
+ * @crtc: which CRTC's vblank waitqueue to retrieve
+ *
+ * This function returns a pointer to the vblank waitqueue for the CRTC.
+ * Drivers can use this to implement vblank waits using wait_event() and related
+ * functions.
+ */
+wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc)
+{
+ return &crtc->dev->vblank[drm_crtc_index(crtc)].queue;
+}
+EXPORT_SYMBOL(drm_crtc_vblank_waitqueue);
+
+
+/**
+ * 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)
+{
+ struct drm_device *dev = crtc->dev;
+ unsigned int pipe = drm_crtc_index(crtc);
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+ int linedur_ns = 0, framedur_ns = 0;
+ int dotclock = mode->crtc_clock;
+
+ if (!dev->num_crtcs)
+ return;
+
+ if (WARN_ON(pipe >= dev->num_crtcs))
+ return;
+
+ /* 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 and frame duration
+ * in nanoseconds:
+ */
+ 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 %u: Can't calculate constants, dotclock = 0!\n",
+ crtc->base.id);
+
+ vblank->linedur_ns = linedur_ns;
+ vblank->framedur_ns = framedur_ns;
+ vblank->hwmode = *mode;
+
+ DRM_DEBUG("crtc %u: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
+ crtc->base.id, mode->crtc_htotal,
+ mode->crtc_vtotal, mode->crtc_vdisplay);
+ DRM_DEBUG("crtc %u: clock %d kHz framedur %d linedur %d\n",
+ crtc->base.id, dotclock, framedur_ns, linedur_ns);
+}
+EXPORT_SYMBOL(drm_calc_timestamping_constants);
+
+/**
+ * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
+ * @dev: DRM device
+ * @pipe: index of CRTC whose 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 time which should receive the timestamp
+ * @in_vblank_irq:
+ * True when called from drm_crtc_handle_vblank(). Some drivers
+ * need to apply some workarounds for gpu-specific vblank irq quirks
+ * if flag is set.
+ *
+ * Implements calculation of exact vblank timestamps from given drm_display_mode
+ * timings and current video scanout position of a CRTC. This can be directly
+ * used as the &drm_driver.get_vblank_timestamp implementation of a kms driver
+ * if &drm_driver.get_scanout_position is implemented.
+ *
+ * The current implementation only handles standard video modes. For double scan
+ * and interlaced modes the driver is supposed to adjust the hardware mode
+ * (taken from &drm_crtc_state.adjusted mode for atomic modeset drivers) to
+ * match the scanout position reported.
+ *
+ * Note that atomic drivers must call drm_calc_timestamping_constants() before
+ * enabling a CRTC. The atomic helpers already take care of that in
+ * drm_atomic_helper_update_legacy_modeset_state().
+ *
+ * Returns:
+ *
+ * Returns true on success, and false on failure, i.e. when no accurate
+ * timestamp could be acquired.
+ */
+bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
+ unsigned int pipe,
+ int *max_error,
+ ktime_t *vblank_time,
+ bool in_vblank_irq)
+{
+ struct timespec64 ts_etime, ts_vblank_time;
+ ktime_t stime, etime;
+ bool vbl_status;
+ struct drm_crtc *crtc;
+ const struct drm_display_mode *mode;
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+ int vpos, hpos, i;
+ int delta_ns, duration_ns;
+
+ if (!drm_core_check_feature(dev, DRIVER_MODESET))
+ return false;
+
+ crtc = drm_crtc_from_index(dev, pipe);
+
+ if (pipe >= dev->num_crtcs || !crtc) {
+ DRM_ERROR("Invalid crtc %u\n", pipe);
+ return false;
+ }
+
+ /* 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 false;
+ }
+
+ if (drm_drv_uses_atomic_modeset(dev))
+ mode = &vblank->hwmode;
+ else
+ mode = &crtc->hwmode;
+
+ /* If mode timing undefined, just return as no-op:
+ * Happens during initial modesetting of a crtc.
+ */
+ if (mode->crtc_clock == 0) {
+ DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe);
+ WARN_ON_ONCE(drm_drv_uses_atomic_modeset(dev));
+
+ return false;
+ }
+
+ /* 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, pipe,
+ in_vblank_irq,
+ &vpos, &hpos,
+ &stime, &etime,
+ mode);
+
+ /* Return as no-op if scanout query unsupported or failed. */
+ if (!vbl_status) {
+ DRM_DEBUG("crtc %u : scanoutpos query failed.\n",
+ pipe);
+ return false;
+ }
+
+ /* 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 %u: Noisy timestamp %d us > %d us [%d reps].\n",
+ pipe, duration_ns/1000, *max_error/1000, i);
+ }
+
+ /* Return upper bound of timestamp precision error. */
+ *max_error = duration_ns;
+
+ /* 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 = div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos),
+ mode->crtc_clock);
+
+ /* Subtract time delta from raw timestamp to get final
+ * vblank_time timestamp for end of vblank.
+ */
+ *vblank_time = ktime_sub_ns(etime, delta_ns);
+
+ if ((drm_debug & DRM_UT_VBL) == 0)
+ return true;
+
+ ts_etime = ktime_to_timespec64(etime);
+ ts_vblank_time = ktime_to_timespec64(*vblank_time);
+
+ DRM_DEBUG_VBL("crtc %u : v p(%d,%d)@ %lld.%06ld -> %lld.%06ld [e %d us, %d rep]\n",
+ pipe, hpos, vpos,
+ (u64)ts_etime.tv_sec, ts_etime.tv_nsec / 1000,
+ (u64)ts_vblank_time.tv_sec, ts_vblank_time.tv_nsec / 1000,
+ duration_ns / 1000, i);
+
+ return true;
+}
+EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
+
+/**
+ * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
+ * vblank interval
+ * @dev: DRM device
+ * @pipe: index of CRTC whose vblank timestamp to retrieve
+ * @tvblank: Pointer to target time which should receive the timestamp
+ * @in_vblank_irq:
+ * True when called from drm_crtc_handle_vblank(). Some drivers
+ * need to apply some workarounds for gpu-specific vblank irq quirks
+ * if flag is set.
+ *
+ * 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, unsigned int pipe,
+ ktime_t *tvblank, bool in_vblank_irq)
+{
+ bool ret = false;
+
+ /* 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, pipe, &max_error,
+ tvblank, in_vblank_irq);
+
+ /* GPU high precision timestamp query unsupported or failed.
+ * Return current monotonic/gettimeofday timestamp as best estimate.
+ */
+ if (!ret)
+ *tvblank = ktime_get();
+
+ return ret;
+}
+
+/**
+ * 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. Note that this timer isn't correct against a racing
+ * vblank interrupt (since it only reports the software vblank counter), see
+ * drm_crtc_accurate_vblank_count() for such use-cases.
+ *
+ * Returns:
+ * The software vblank counter.
+ */
+u64 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
+ * @pipe: index of CRTC whose counter to retrieve
+ * @vblanktime: Pointer to ktime_t 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.
+ *
+ * This is the legacy version of drm_crtc_vblank_count_and_time().
+ */
+static u64 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe,
+ ktime_t *vblanktime)
+{
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+ u64 vblank_count;
+ unsigned int seq;
+
+ if (WARN_ON(pipe >= dev->num_crtcs)) {
+ *vblanktime = 0;
+ return 0;
+ }
+
+ do {
+ seq = read_seqbegin(&vblank->seqlock);
+ vblank_count = vblank->count;
+ *vblanktime = vblank->time;
+ } while (read_seqretry(&vblank->seqlock, seq));
+
+ return vblank_count;
+}
+
+/**
+ * drm_crtc_vblank_count_and_time - retrieve "cooked" vblank counter value
+ * and the system timestamp corresponding to that vblank counter value
+ * @crtc: which counter to retrieve
+ * @vblanktime: Pointer to time 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.
+ */
+u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
+ ktime_t *vblanktime)
+{
+ return drm_vblank_count_and_time(crtc->dev, drm_crtc_index(crtc),
+ vblanktime);
+}
+EXPORT_SYMBOL(drm_crtc_vblank_count_and_time);
+
+static void send_vblank_event(struct drm_device *dev,
+ struct drm_pending_vblank_event *e,
+ u64 seq, ktime_t now)
+{
+ struct timespec64 tv;
+
+ switch (e->event.base.type) {
+ case DRM_EVENT_VBLANK:
+ case DRM_EVENT_FLIP_COMPLETE:
+ tv = ktime_to_timespec64(now);
+ e->event.vbl.sequence = seq;
+ /*
+ * e->event is a user space structure, with hardcoded unsigned
+ * 32-bit seconds/microseconds. This is safe as we always use
+ * monotonic timestamps since linux-4.15
+ */
+ e->event.vbl.tv_sec = tv.tv_sec;
+ e->event.vbl.tv_usec = tv.tv_nsec / 1000;
+ break;
+ case DRM_EVENT_CRTC_SEQUENCE:
+ if (seq)
+ e->event.seq.sequence = seq;
+ e->event.seq.time_ns = ktime_to_ns(now);
+ break;
+ }
+ trace_drm_vblank_event_delivered(e->base.file_priv, e->pipe, seq);
+ drm_send_event_locked(dev, &e->base);
+}
+
+/**
+ * drm_crtc_arm_vblank_event - arm vblank event after pageflip
+ * @crtc: the source CRTC of the vblank event
+ * @e: the event to send
+ *
+ * A lot of drivers need to generate vblank events for the very next vblank
+ * interrupt. For example when the page flip interrupt happens when the page
+ * flip gets armed, but not when it actually executes within the next vblank
+ * period. This helper function implements exactly the required vblank arming
+ * behaviour.
+ *
+ * NOTE: Drivers using this to send out the &drm_crtc_state.event as part of an
+ * atomic commit must ensure that the next vblank happens at exactly the same
+ * time as the atomic commit is committed to the hardware. This function itself
+ * does **not** protect against the next vblank interrupt racing with either this
+ * function call or the atomic commit operation. A possible sequence could be:
+ *
+ * 1. Driver commits new hardware state into vblank-synchronized registers.
+ * 2. A vblank happens, committing the hardware state. Also the corresponding
+ * vblank interrupt is fired off and fully processed by the interrupt
+ * handler.
+ * 3. The atomic commit operation proceeds to call drm_crtc_arm_vblank_event().
+ * 4. The event is only send out for the next vblank, which is wrong.
+ *
+ * An equivalent race can happen when the driver calls
+ * drm_crtc_arm_vblank_event() before writing out the new hardware state.
+ *
+ * The only way to make this work safely is to prevent the vblank from firing
+ * (and the hardware from committing anything else) until the entire atomic
+ * commit sequence has run to completion. If the hardware does not have such a
+ * feature (e.g. using a "go" bit), then it is unsafe to use this functions.
+ * Instead drivers need to manually send out the event from their interrupt
+ * handler by calling drm_crtc_send_vblank_event() and make sure that there's no
+ * possible race with the hardware committing the atomic update.
+ *
+ * Caller must hold a vblank reference for the event @e, which will be dropped
+ * when the next vblank arrives.
+ */
+void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
+ struct drm_pending_vblank_event *e)
+{
+ struct drm_device *dev = crtc->dev;
+ unsigned int pipe = drm_crtc_index(crtc);
+
+ assert_spin_locked(&dev->event_lock);
+
+ e->pipe = pipe;
+ e->sequence = drm_crtc_accurate_vblank_count(crtc) + 1;
+ list_add_tail(&e->base.link, &dev->vblank_event_list);
+}
+EXPORT_SYMBOL(drm_crtc_arm_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 for the most recently processed
+ * vblank, and sends it to userspace. Caller must hold event lock.
+ *
+ * See drm_crtc_arm_vblank_event() for a helper which can be used in certain
+ * situation, especially to send out events for atomic commit operations.
+ */
+void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
+ struct drm_pending_vblank_event *e)
+{
+ struct drm_device *dev = crtc->dev;
+ u64 seq;
+ unsigned int pipe = drm_crtc_index(crtc);
+ ktime_t now;
+
+ if (dev->num_crtcs > 0) {
+ seq = drm_vblank_count_and_time(dev, pipe, &now);
+ } else {
+ seq = 0;
+
+ now = ktime_get();
+ }
+ e->pipe = pipe;
+ send_vblank_event(dev, e, seq, now);
+}
+EXPORT_SYMBOL(drm_crtc_send_vblank_event);
+
+static int __enable_vblank(struct drm_device *dev, unsigned int pipe)
+{
+ if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+ struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
+
+ if (WARN_ON(!crtc))
+ return 0;
+
+ if (crtc->funcs->enable_vblank)
+ return crtc->funcs->enable_vblank(crtc);
+ }
+
+ return dev->driver->enable_vblank(dev, pipe);
+}
+
+static int drm_vblank_enable(struct drm_device *dev, unsigned int pipe)
+{
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+ 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 = __enable_vblank(dev, pipe);
+ DRM_DEBUG("enabling vblank on crtc %u, ret: %d\n", pipe, ret);
+ if (ret) {
+ atomic_dec(&vblank->refcount);
+ } else {
+ drm_update_vblank_count(dev, pipe, 0);
+ /* drm_update_vblank_count() includes a wmb so we just
+ * need to ensure that the compiler emits the write
+ * to mark the vblank as enabled after the call
+ * to drm_update_vblank_count().
+ */
+ WRITE_ONCE(vblank->enabled, true);
+ }
+ }
+
+ spin_unlock(&dev->vblank_time_lock);
+
+ return ret;
+}
+
+static int drm_vblank_get(struct drm_device *dev, unsigned int pipe)
+{
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+ unsigned long irqflags;
+ int ret = 0;
+
+ if (!dev->num_crtcs)
+ return -EINVAL;
+
+ if (WARN_ON(pipe >= 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, pipe);
+ } else {
+ if (!vblank->enabled) {
+ atomic_dec(&vblank->refcount);
+ ret = -EINVAL;
+ }
+ }
+ spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+
+ return ret;
+}
+
+/**
+ * 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.
+ *
+ * Returns:
+ * Zero on success or a negative error code 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);
+
+static void drm_vblank_put(struct drm_device *dev, unsigned int pipe)
+{
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+
+ if (WARN_ON(pipe >= dev->num_crtcs))
+ return;
+
+ if (WARN_ON(atomic_read(&vblank->refcount) == 0))
+ return;
+
+ /* Last user schedules interrupt disable */
+ if (atomic_dec_and_test(&vblank->refcount)) {
+ if (drm_vblank_offdelay == 0)
+ return;
+ else if (drm_vblank_offdelay < 0)
+ vblank_disable_fn(&vblank->disable_timer);
+ else if (!dev->vblank_disable_immediate)
+ mod_timer(&vblank->disable_timer,
+ jiffies + ((drm_vblank_offdelay * HZ)/1000));
+ }
+}
+
+/**
+ * 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.
+ */
+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
+ * @pipe: CRTC index
+ *
+ * This waits for one vblank to pass on @pipe, using the irq driver interfaces.
+ * It is a failure to call this when the vblank irq for @pipe is disabled, e.g.
+ * due to lack of driver support or because the crtc is off.
+ *
+ * This is the legacy version of drm_crtc_wait_one_vblank().
+ */
+void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe)
+{
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+ int ret;
+ u64 last;
+
+ if (WARN_ON(pipe >= dev->num_crtcs))
+ return;
+
+ ret = drm_vblank_get(dev, pipe);
+ if (WARN(ret, "vblank not available on crtc %i, ret=%i\n", pipe, ret))
+ return;
+
+ last = drm_vblank_count(dev, pipe);
+
+ ret = wait_event_timeout(vblank->queue,
+ last != drm_vblank_count(dev, pipe),
+ msecs_to_jiffies(100));
+
+ WARN(ret == 0, "vblank wait timed out on crtc %i\n", pipe);
+
+ drm_vblank_put(dev, pipe);
+}
+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_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 or disabling the @crtc in general.
+ */
+void drm_crtc_vblank_off(struct drm_crtc *crtc)
+{
+ struct drm_device *dev = crtc->dev;
+ unsigned int pipe = drm_crtc_index(crtc);
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+ struct drm_pending_vblank_event *e, *t;
+
+ ktime_t now;
+ unsigned long irqflags;
+ u64 seq;
+
+ if (WARN_ON(pipe >= dev->num_crtcs))
+ return;
+
+ spin_lock_irqsave(&dev->event_lock, irqflags);
+
+ spin_lock(&dev->vbl_lock);
+ DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
+ pipe, vblank->enabled, vblank->inmodeset);
+
+ /* Avoid redundant vblank disables without previous
+ * drm_crtc_vblank_on(). */
+ if (drm_core_check_feature(dev, DRIVER_ATOMIC) || !vblank->inmodeset)
+ drm_vblank_disable_and_save(dev, pipe);
+
+ 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, pipe, &now);
+
+ list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
+ if (e->pipe != pipe)
+ continue;
+ DRM_DEBUG("Sending premature vblank event on disable: "
+ "wanted %llu, current %llu\n",
+ e->sequence, seq);
+ list_del(&e->base.link);
+ drm_vblank_put(dev, pipe);
+ send_vblank_event(dev, e, seq, now);
+ }
+ spin_unlock_irqrestore(&dev->event_lock, irqflags);
+
+ /* Will be reset by the modeset helpers when re-enabling the crtc by
+ * calling drm_calc_timestamping_constants(). */
+ vblank->hwmode.crtc_clock = 0;
+}
+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.
+ *
+ * This is useful for recovering driver state e.g. on driver load, or on resume.
+ */
+void drm_crtc_vblank_reset(struct drm_crtc *crtc)
+{
+ struct drm_device *dev = crtc->dev;
+ unsigned long irqflags;
+ unsigned int pipe = drm_crtc_index(crtc);
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+
+ 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_crtc_vblank_on - enable vblank events on a CRTC
+ * @crtc: CRTC in question
+ *
+ * This functions restores the vblank interrupt state captured with
+ * drm_crtc_vblank_off() again and is generally called when enabling @crtc. Note
+ * that calls to drm_crtc_vblank_on() and drm_crtc_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.
+ */
+void drm_crtc_vblank_on(struct drm_crtc *crtc)
+{
+ struct drm_device *dev = crtc->dev;
+ unsigned int pipe = drm_crtc_index(crtc);
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+ unsigned long irqflags;
+
+ if (WARN_ON(pipe >= dev->num_crtcs))
+ return;
+
+ spin_lock_irqsave(&dev->vbl_lock, irqflags);
+ DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
+ pipe, vblank->enabled, vblank->inmodeset);
+
+ /* Drop our private "prevent drm_vblank_get" refcount */
+ if (vblank->inmodeset) {
+ atomic_dec(&vblank->refcount);
+ vblank->inmodeset = 0;
+ }
+
+ drm_reset_vblank_timestamp(dev, pipe);
+
+ /*
+ * 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 || drm_vblank_offdelay == 0)
+ WARN_ON(drm_vblank_enable(dev, pipe));
+ spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+}
+EXPORT_SYMBOL(drm_crtc_vblank_on);
+
+/**
+ * drm_vblank_restore - estimate missed vblanks and update vblank count.
+ * @dev: DRM device
+ * @pipe: CRTC index
+ *
+ * Power manamement features can cause frame counter resets between vblank
+ * disable and enable. Drivers can use this function in their
+ * &drm_crtc_funcs.enable_vblank implementation to estimate missed vblanks since
+ * the last &drm_crtc_funcs.disable_vblank using timestamps and update the
+ * vblank counter.
+ *
+ * This function is the legacy version of drm_crtc_vblank_restore().
+ */
+void drm_vblank_restore(struct drm_device *dev, unsigned int pipe)
+{
+ ktime_t t_vblank;
+ struct drm_vblank_crtc *vblank;
+ int framedur_ns;
+ u64 diff_ns;
+ u32 cur_vblank, diff = 1;
+ int count = DRM_TIMESTAMP_MAXRETRIES;
+
+ if (WARN_ON(pipe >= dev->num_crtcs))
+ return;
+
+ assert_spin_locked(&dev->vbl_lock);
+ assert_spin_locked(&dev->vblank_time_lock);
+
+ vblank = &dev->vblank[pipe];
+ WARN_ONCE((drm_debug & DRM_UT_VBL) && !vblank->framedur_ns,
+ "Cannot compute missed vblanks without frame duration\n");
+ framedur_ns = vblank->framedur_ns;
+
+ do {
+ cur_vblank = __get_vblank_counter(dev, pipe);
+ drm_get_last_vbltimestamp(dev, pipe, &t_vblank, false);
+ } while (cur_vblank != __get_vblank_counter(dev, pipe) && --count > 0);
+
+ diff_ns = ktime_to_ns(ktime_sub(t_vblank, vblank->time));
+ if (framedur_ns)
+ diff = DIV_ROUND_CLOSEST_ULL(diff_ns, framedur_ns);
+
+
+ DRM_DEBUG_VBL("missed %d vblanks in %lld ns, frame duration=%d ns, hw_diff=%d\n",
+ diff, diff_ns, framedur_ns, cur_vblank - vblank->last);
+ store_vblank(dev, pipe, diff, t_vblank, cur_vblank);
+}
+EXPORT_SYMBOL(drm_vblank_restore);
+
+/**
+ * drm_crtc_vblank_restore - estimate missed vblanks and update vblank count.
+ * @crtc: CRTC in question
+ *
+ * Power manamement features can cause frame counter resets between vblank
+ * disable and enable. Drivers can use this function in their
+ * &drm_crtc_funcs.enable_vblank implementation to estimate missed vblanks since
+ * the last &drm_crtc_funcs.disable_vblank using timestamps and update the
+ * vblank counter.
+ */
+void drm_crtc_vblank_restore(struct drm_crtc *crtc)
+{
+ drm_vblank_restore(crtc->dev, drm_crtc_index(crtc));
+}
+EXPORT_SYMBOL(drm_crtc_vblank_restore);
+
+static void drm_legacy_vblank_pre_modeset(struct drm_device *dev,
+ unsigned int pipe)
+{
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+
+ /* vblank is not initialized (IRQ not installed ?), or has been freed */
+ if (!dev->num_crtcs)
+ return;
+
+ if (WARN_ON(pipe >= 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, pipe) == 0)
+ vblank->inmodeset |= 0x2;
+ }
+}
+
+static void drm_legacy_vblank_post_modeset(struct drm_device *dev,
+ unsigned int pipe)
+{
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+ unsigned long irqflags;
+
+ /* vblank is not initialized (IRQ not installed ?), or has been freed */
+ if (!dev->num_crtcs)
+ return;
+
+ if (WARN_ON(pipe >= dev->num_crtcs))
+ return;
+
+ if (vblank->inmodeset) {
+ spin_lock_irqsave(&dev->vbl_lock, irqflags);
+ drm_reset_vblank_timestamp(dev, pipe);
+ spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+
+ if (vblank->inmodeset & 0x2)
+ drm_vblank_put(dev, pipe);
+
+ vblank->inmodeset = 0;
+ }
+}
+
+int drm_legacy_modeset_ctl_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
+{
+ struct drm_modeset_ctl *modeset = data;
+ unsigned int pipe;
+
+ /* 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_LEGACY))
+ return 0;
+
+ pipe = modeset->crtc;
+ if (pipe >= dev->num_crtcs)
+ return -EINVAL;
+
+ switch (modeset->cmd) {
+ case _DRM_PRE_MODESET:
+ drm_legacy_vblank_pre_modeset(dev, pipe);
+ break;
+ case _DRM_POST_MODESET:
+ drm_legacy_vblank_post_modeset(dev, pipe);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static inline bool vblank_passed(u64 seq, u64 ref)
+{
+ return (seq - ref) <= (1 << 23);
+}
+
+static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe,
+ u64 req_seq,
+ union drm_wait_vblank *vblwait,
+ struct drm_file *file_priv)
+{
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+ struct drm_pending_vblank_event *e;
+ ktime_t now;
+ unsigned long flags;
+ u64 seq;
+ int ret;
+
+ e = kzalloc(sizeof(*e), GFP_KERNEL);
+ if (e == NULL) {
+ ret = -ENOMEM;
+ goto err_put;
+ }
+
+ e->pipe = pipe;
+ e->event.base.type = DRM_EVENT_VBLANK;
+ e->event.base.length = sizeof(e->event.vbl);
+ e->event.vbl.user_data = vblwait->request.signal;
+ e->event.vbl.crtc_id = 0;
+ if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+ struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
+ if (crtc)
+ e->event.vbl.crtc_id = crtc->base.id;
+ }
+
+ spin_lock_irqsave(&dev->event_lock, flags);
+
+ /*
+ * drm_crtc_vblank_off() might have been called after we called
+ * drm_vblank_get(). drm_crtc_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 (!READ_ONCE(vblank->enabled)) {
+ ret = -EINVAL;
+ goto err_unlock;
+ }
+
+ ret = drm_event_reserve_init_locked(dev, file_priv, &e->base,
+ &e->event.base);
+
+ if (ret)
+ goto err_unlock;
+
+ seq = drm_vblank_count_and_time(dev, pipe, &now);
+
+ DRM_DEBUG("event on vblank count %llu, current %llu, crtc %u\n",
+ req_seq, seq, pipe);
+
+ trace_drm_vblank_event_queued(file_priv, pipe, req_seq);
+
+ e->sequence = req_seq;
+ if (vblank_passed(seq, req_seq)) {
+ 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 = req_seq;
+ }
+
+ 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;
+}
+
+static bool drm_wait_vblank_is_query(union drm_wait_vblank *vblwait)
+{
+ if (vblwait->request.sequence)
+ return false;
+
+ return _DRM_VBLANK_RELATIVE ==
+ (vblwait->request.type & (_DRM_VBLANK_TYPES_MASK |
+ _DRM_VBLANK_EVENT |
+ _DRM_VBLANK_NEXTONMISS));
+}
+
+/*
+ * Widen a 32-bit param to 64-bits.
+ *
+ * \param narrow 32-bit value (missing upper 32 bits)
+ * \param near 64-bit value that should be 'close' to near
+ *
+ * This function returns a 64-bit value using the lower 32-bits from
+ * 'narrow' and constructing the upper 32-bits so that the result is
+ * as close as possible to 'near'.
+ */
+
+static u64 widen_32_to_64(u32 narrow, u64 near)
+{
+ return near + (s32) (narrow - near);
+}
+
+static void drm_wait_vblank_reply(struct drm_device *dev, unsigned int pipe,
+ struct drm_wait_vblank_reply *reply)
+{
+ ktime_t now;
+ struct timespec64 ts;
+
+ /*
+ * drm_wait_vblank_reply is a UAPI structure that uses 'long'
+ * to store the seconds. This is safe as we always use monotonic
+ * timestamps since linux-4.15.
+ */
+ reply->sequence = drm_vblank_count_and_time(dev, pipe, &now);
+ ts = ktime_to_timespec64(now);
+ reply->tval_sec = (u32)ts.tv_sec;
+ reply->tval_usec = ts.tv_nsec / 1000;
+}
+
+int drm_wait_vblank_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
+{
+ struct drm_crtc *crtc;
+ struct drm_vblank_crtc *vblank;
+ union drm_wait_vblank *vblwait = data;
+ int ret;
+ u64 req_seq, seq;
+ unsigned int pipe_index;
+ unsigned int flags, pipe, high_pipe;
+
+ 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_pipe = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
+ if (high_pipe)
+ pipe_index = high_pipe >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
+ else
+ pipe_index = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
+
+ /* Convert lease-relative crtc index into global crtc index */
+ if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+ pipe = 0;
+ drm_for_each_crtc(crtc, dev) {
+ if (drm_lease_held(file_priv, crtc->base.id)) {
+ if (pipe_index == 0)
+ break;
+ pipe_index--;
+ }
+ pipe++;
+ }
+ } else {
+ pipe = pipe_index;
+ }
+
+ if (pipe >= dev->num_crtcs)
+ return -EINVAL;
+
+ vblank = &dev->vblank[pipe];
+
+ /* If the counter is currently enabled and accurate, short-circuit
+ * queries to return the cached timestamp of the last vblank.
+ */
+ if (dev->vblank_disable_immediate &&
+ drm_wait_vblank_is_query(vblwait) &&
+ READ_ONCE(vblank->enabled)) {
+ drm_wait_vblank_reply(dev, pipe, &vblwait->reply);
+ return 0;
+ }
+
+ ret = drm_vblank_get(dev, pipe);
+ if (ret) {
+ DRM_DEBUG("crtc %d failed to acquire vblank counter, %d\n", pipe, ret);
+ return ret;
+ }
+ seq = drm_vblank_count(dev, pipe);
+
+ switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
+ case _DRM_VBLANK_RELATIVE:
+ req_seq = seq + vblwait->request.sequence;
+ vblwait->request.sequence = req_seq;
+ vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
+ break;
+ case _DRM_VBLANK_ABSOLUTE:
+ req_seq = widen_32_to_64(vblwait->request.sequence, seq);
+ break;
+ default:
+ ret = -EINVAL;
+ goto done;
+ }
+
+ if ((flags & _DRM_VBLANK_NEXTONMISS) &&
+ vblank_passed(seq, req_seq)) {
+ req_seq = seq + 1;
+ vblwait->request.type &= ~_DRM_VBLANK_NEXTONMISS;
+ vblwait->request.sequence = req_seq;
+ }
+
+ 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, pipe, req_seq, vblwait, file_priv);
+ }
+
+ if (req_seq != seq) {
+ DRM_DEBUG("waiting on vblank count %llu, crtc %u\n",
+ req_seq, pipe);
+ DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
+ vblank_passed(drm_vblank_count(dev, pipe),
+ req_seq) ||
+ !READ_ONCE(vblank->enabled));
+ }
+
+ if (ret != -EINTR) {
+ drm_wait_vblank_reply(dev, pipe, &vblwait->reply);
+
+ DRM_DEBUG("crtc %d returning %u to client\n",
+ pipe, vblwait->reply.sequence);
+ } else {
+ DRM_DEBUG("crtc %d vblank wait interrupted by signal\n", pipe);
+ }
+
+done:
+ drm_vblank_put(dev, pipe);
+ return ret;
+}
+
+static void drm_handle_vblank_events(struct drm_device *dev, unsigned int pipe)
+{
+ struct drm_pending_vblank_event *e, *t;
+ ktime_t now;
+ u64 seq;
+
+ assert_spin_locked(&dev->event_lock);
+
+ seq = drm_vblank_count_and_time(dev, pipe, &now);
+
+ list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
+ if (e->pipe != pipe)
+ continue;
+ if (!vblank_passed(seq, e->sequence))
+ continue;
+
+ DRM_DEBUG("vblank event on %llu, current %llu\n",
+ e->sequence, seq);
+
+ list_del(&e->base.link);
+ drm_vblank_put(dev, pipe);
+ send_vblank_event(dev, e, seq, now);
+ }
+
+ trace_drm_vblank_event(pipe, seq);
+}
+
+/**
+ * drm_handle_vblank - handle a vblank event
+ * @dev: DRM device
+ * @pipe: index of 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, unsigned int pipe)
+{
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+ unsigned long irqflags;
+ bool disable_irq;
+
+ if (WARN_ON_ONCE(!dev->num_crtcs))
+ return false;
+
+ if (WARN_ON(pipe >= 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;
+ }
+
+ drm_update_vblank_count(dev, pipe, true);
+
+ spin_unlock(&dev->vblank_time_lock);
+
+ wake_up(&vblank->queue);
+
+ /* With instant-off, we defer disabling the interrupt until after
+ * we finish processing the following vblank after all events have
+ * been signaled. The disable has to be last (after
+ * drm_handle_vblank_events) so that the timestamp is always accurate.
+ */
+ disable_irq = (dev->vblank_disable_immediate &&
+ drm_vblank_offdelay > 0 &&
+ !atomic_read(&vblank->refcount));
+
+ drm_handle_vblank_events(dev, pipe);
+
+ spin_unlock_irqrestore(&dev->event_lock, irqflags);
+
+ if (disable_irq)
+ vblank_disable_fn(&vblank->disable_timer);
+
+ 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);
+
+/*
+ * Get crtc VBLANK count.
+ *
+ * \param dev DRM device
+ * \param data user arguement, pointing to a drm_crtc_get_sequence structure.
+ * \param file_priv drm file private for the user's open file descriptor
+ */
+
+int drm_crtc_get_sequence_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
+{
+ struct drm_crtc *crtc;
+ struct drm_vblank_crtc *vblank;
+ int pipe;
+ struct drm_crtc_get_sequence *get_seq = data;
+ ktime_t now;
+ bool vblank_enabled;
+ int ret;
+
+ if (!drm_core_check_feature(dev, DRIVER_MODESET))
+ return -EINVAL;
+
+ if (!dev->irq_enabled)
+ return -EINVAL;
+
+ crtc = drm_crtc_find(dev, file_priv, get_seq->crtc_id);
+ if (!crtc)
+ return -ENOENT;
+
+ pipe = drm_crtc_index(crtc);
+
+ vblank = &dev->vblank[pipe];
+ vblank_enabled = dev->vblank_disable_immediate && READ_ONCE(vblank->enabled);
+
+ if (!vblank_enabled) {
+ ret = drm_crtc_vblank_get(crtc);
+ if (ret) {
+ DRM_DEBUG("crtc %d failed to acquire vblank counter, %d\n", pipe, ret);
+ return ret;
+ }
+ }
+ drm_modeset_lock(&crtc->mutex, NULL);
+ if (crtc->state)
+ get_seq->active = crtc->state->enable;
+ else
+ get_seq->active = crtc->enabled;
+ drm_modeset_unlock(&crtc->mutex);
+ get_seq->sequence = drm_vblank_count_and_time(dev, pipe, &now);
+ get_seq->sequence_ns = ktime_to_ns(now);
+ if (!vblank_enabled)
+ drm_crtc_vblank_put(crtc);
+ return 0;
+}
+
+/*
+ * Queue a event for VBLANK sequence
+ *
+ * \param dev DRM device
+ * \param data user arguement, pointing to a drm_crtc_queue_sequence structure.
+ * \param file_priv drm file private for the user's open file descriptor
+ */
+
+int drm_crtc_queue_sequence_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
+{
+ struct drm_crtc *crtc;
+ struct drm_vblank_crtc *vblank;
+ int pipe;
+ struct drm_crtc_queue_sequence *queue_seq = data;
+ ktime_t now;
+ struct drm_pending_vblank_event *e;
+ u32 flags;
+ u64 seq;
+ u64 req_seq;
+ int ret;
+ unsigned long spin_flags;
+
+ if (!drm_core_check_feature(dev, DRIVER_MODESET))
+ return -EINVAL;
+
+ if (!dev->irq_enabled)
+ return -EINVAL;
+
+ crtc = drm_crtc_find(dev, file_priv, queue_seq->crtc_id);
+ if (!crtc)
+ return -ENOENT;
+
+ flags = queue_seq->flags;
+ /* Check valid flag bits */
+ if (flags & ~(DRM_CRTC_SEQUENCE_RELATIVE|
+ DRM_CRTC_SEQUENCE_NEXT_ON_MISS))
+ return -EINVAL;
+
+ pipe = drm_crtc_index(crtc);
+
+ vblank = &dev->vblank[pipe];
+
+ e = kzalloc(sizeof(*e), GFP_KERNEL);
+ if (e == NULL)
+ return -ENOMEM;
+
+ ret = drm_crtc_vblank_get(crtc);
+ if (ret) {
+ DRM_DEBUG("crtc %d failed to acquire vblank counter, %d\n", pipe, ret);
+ goto err_free;
+ }
+
+ seq = drm_vblank_count_and_time(dev, pipe, &now);
+ req_seq = queue_seq->sequence;
+
+ if (flags & DRM_CRTC_SEQUENCE_RELATIVE)
+ req_seq += seq;
+
+ if ((flags & DRM_CRTC_SEQUENCE_NEXT_ON_MISS) && vblank_passed(seq, req_seq))
+ req_seq = seq + 1;
+
+ e->pipe = pipe;
+ e->event.base.type = DRM_EVENT_CRTC_SEQUENCE;
+ e->event.base.length = sizeof(e->event.seq);
+ e->event.seq.user_data = queue_seq->user_data;
+
+ spin_lock_irqsave(&dev->event_lock, spin_flags);
+
+ /*
+ * drm_crtc_vblank_off() might have been called after we called
+ * drm_crtc_vblank_get(). drm_crtc_vblank_off() holds event_lock around the
+ * vblank disable, so no need for further locking. The reference from
+ * drm_crtc_vblank_get() protects against vblank disable from another source.
+ */
+ if (!READ_ONCE(vblank->enabled)) {
+ ret = -EINVAL;
+ goto err_unlock;
+ }
+
+ ret = drm_event_reserve_init_locked(dev, file_priv, &e->base,
+ &e->event.base);
+
+ if (ret)
+ goto err_unlock;
+
+ e->sequence = req_seq;
+
+ if (vblank_passed(seq, req_seq)) {
+ drm_crtc_vblank_put(crtc);
+ send_vblank_event(dev, e, seq, now);
+ queue_seq->sequence = seq;
+ } else {
+ /* drm_handle_vblank_events will call drm_vblank_put */
+ list_add_tail(&e->base.link, &dev->vblank_event_list);
+ queue_seq->sequence = req_seq;
+ }
+
+ spin_unlock_irqrestore(&dev->event_lock, spin_flags);
+ return 0;
+
+err_unlock:
+ spin_unlock_irqrestore(&dev->event_lock, spin_flags);
+ drm_crtc_vblank_put(crtc);
+err_free:
+ kfree(e);
+ return ret;
+}