Initial commit from HTC m7ul-3.4.10-jb-crc-ddcfb8c
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
new file mode 100644
index 0000000..c869436
--- /dev/null
+++ b/drivers/gpu/drm/drm_irq.c
@@ -0,0 +1,1348 @@
+/**
+ * \file drm_irq.c
+ * IRQ 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 "drmP.h"
+#include "drm_trace.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_time[(crtc) * DRM_VBLANKTIME_RBSIZE + \
+ ((count) % DRM_VBLANKTIME_RBSIZE)])
+
+/* Retry timestamp calculation up to 3 times to satisfy
+ * drm_timestamp_precision before giving up.
+ */
+#define DRM_TIMESTAMP_MAXRETRIES 3
+
+/* Threshold in nanoseconds for detection of redundant
+ * vblank irq in drm_handle_vblank(). 1 msec should be ok.
+ */
+#define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
+
+/**
+ * Get interrupt from bus id.
+ *
+ * \param inode device inode.
+ * \param file_priv DRM file private.
+ * \param cmd command.
+ * \param arg user argument, pointing to a drm_irq_busid structure.
+ * \return zero on success or a negative number on failure.
+ *
+ * Finds the PCI device with the specified bus id and gets its IRQ number.
+ * This IOCTL is deprecated, and will now return EINVAL for any busid not equal
+ * to that of the device that this DRM instance attached to.
+ */
+int drm_irq_by_busid(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
+{
+ struct drm_irq_busid *p = data;
+
+ if (!dev->driver->bus->irq_by_busid)
+ return -EINVAL;
+
+ if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
+ return -EINVAL;
+
+ return dev->driver->bus->irq_by_busid(dev, p);
+}
+
+/*
+ * Clear vblank timestamp buffer for a crtc.
+ */
+static void clear_vblank_timestamps(struct drm_device *dev, int crtc)
+{
+ memset(&dev->_vblank_time[crtc * DRM_VBLANKTIME_RBSIZE], 0,
+ DRM_VBLANKTIME_RBSIZE * sizeof(struct timeval));
+}
+
+/*
+ * 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)
+{
+ unsigned long irqflags;
+ u32 vblcount;
+ s64 diff_ns;
+ int vblrc;
+ struct timeval tvblank;
+
+ /* Prevent vblank irq processing while disabling vblank irqs,
+ * so no updates of timestamps or count can happen after we've
+ * disabled. Needed to prevent races in case of delayed irq's.
+ */
+ spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
+
+ dev->driver->disable_vblank(dev, crtc);
+ dev->vblank_enabled[crtc] = 0;
+
+ /* No further vblank irq's will be processed after
+ * this point. Get current hardware vblank count and
+ * vblank timestamp, repeat until they are consistent.
+ *
+ * FIXME: There is still a race condition here and in
+ * drm_update_vblank_count() which can cause off-by-one
+ * reinitialization of software vblank counter. If gpu
+ * vblank counter doesn't increment exactly at the leading
+ * edge of a vblank interval, then we can lose 1 count if
+ * we happen to execute between start of vblank and the
+ * delayed gpu counter increment.
+ */
+ do {
+ dev->last_vblank[crtc] = dev->driver->get_vblank_counter(dev, crtc);
+ vblrc = drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0);
+ } while (dev->last_vblank[crtc] != dev->driver->get_vblank_counter(dev, crtc));
+
+ /* Compute time difference to stored timestamp of last vblank
+ * as updated by last invocation of drm_handle_vblank() in vblank irq.
+ */
+ vblcount = atomic_read(&dev->_vblank_count[crtc]);
+ diff_ns = timeval_to_ns(&tvblank) -
+ timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
+
+ /* If there is at least 1 msec difference between the last stored
+ * timestamp and tvblank, then we are currently executing our
+ * disable inside a new vblank interval, the tvblank timestamp
+ * corresponds to this new vblank interval and the irq handler
+ * for this vblank didn't run yet and won't run due to our disable.
+ * Therefore we need to do the job of drm_handle_vblank() and
+ * increment the vblank counter by one to account for this vblank.
+ *
+ * Skip this step if there isn't any high precision timestamp
+ * available. In that case we can't account for this and just
+ * hope for the best.
+ */
+ if ((vblrc > 0) && (abs64(diff_ns) > 1000000)) {
+ atomic_inc(&dev->_vblank_count[crtc]);
+ smp_mb__after_atomic_inc();
+ }
+
+ /* Invalidate all timestamps while vblank irq's are off. */
+ clear_vblank_timestamps(dev, crtc);
+
+ spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
+}
+
+static void vblank_disable_fn(unsigned long arg)
+{
+ struct drm_device *dev = (struct drm_device *)arg;
+ unsigned long irqflags;
+ int i;
+
+ if (!dev->vblank_disable_allowed)
+ return;
+
+ for (i = 0; i < dev->num_crtcs; i++) {
+ spin_lock_irqsave(&dev->vbl_lock, irqflags);
+ if (atomic_read(&dev->vblank_refcount[i]) == 0 &&
+ dev->vblank_enabled[i]) {
+ DRM_DEBUG("disabling vblank on crtc %d\n", i);
+ vblank_disable_and_save(dev, i);
+ }
+ spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+ }
+}
+
+void drm_vblank_cleanup(struct drm_device *dev)
+{
+ /* Bail if the driver didn't call drm_vblank_init() */
+ if (dev->num_crtcs == 0)
+ return;
+
+ del_timer(&dev->vblank_disable_timer);
+
+ vblank_disable_fn((unsigned long)dev);
+
+ kfree(dev->vbl_queue);
+ kfree(dev->_vblank_count);
+ kfree(dev->vblank_refcount);
+ kfree(dev->vblank_enabled);
+ kfree(dev->last_vblank);
+ kfree(dev->last_vblank_wait);
+ kfree(dev->vblank_inmodeset);
+ kfree(dev->_vblank_time);
+
+ dev->num_crtcs = 0;
+}
+EXPORT_SYMBOL(drm_vblank_cleanup);
+
+int drm_vblank_init(struct drm_device *dev, int num_crtcs)
+{
+ int i, ret = -ENOMEM;
+
+ setup_timer(&dev->vblank_disable_timer, vblank_disable_fn,
+ (unsigned long)dev);
+ spin_lock_init(&dev->vbl_lock);
+ spin_lock_init(&dev->vblank_time_lock);
+
+ dev->num_crtcs = num_crtcs;
+
+ dev->vbl_queue = kmalloc(sizeof(wait_queue_head_t) * num_crtcs,
+ GFP_KERNEL);
+ if (!dev->vbl_queue)
+ goto err;
+
+ dev->_vblank_count = kmalloc(sizeof(atomic_t) * num_crtcs, GFP_KERNEL);
+ if (!dev->_vblank_count)
+ goto err;
+
+ dev->vblank_refcount = kmalloc(sizeof(atomic_t) * num_crtcs,
+ GFP_KERNEL);
+ if (!dev->vblank_refcount)
+ goto err;
+
+ dev->vblank_enabled = kcalloc(num_crtcs, sizeof(int), GFP_KERNEL);
+ if (!dev->vblank_enabled)
+ goto err;
+
+ dev->last_vblank = kcalloc(num_crtcs, sizeof(u32), GFP_KERNEL);
+ if (!dev->last_vblank)
+ goto err;
+
+ dev->last_vblank_wait = kcalloc(num_crtcs, sizeof(u32), GFP_KERNEL);
+ if (!dev->last_vblank_wait)
+ goto err;
+
+ dev->vblank_inmodeset = kcalloc(num_crtcs, sizeof(int), GFP_KERNEL);
+ if (!dev->vblank_inmodeset)
+ goto err;
+
+ dev->_vblank_time = kcalloc(num_crtcs * DRM_VBLANKTIME_RBSIZE,
+ sizeof(struct timeval), GFP_KERNEL);
+ if (!dev->_vblank_time)
+ goto err;
+
+ DRM_INFO("Supports vblank timestamp caching Rev 1 (10.10.2010).\n");
+
+ /* Driver specific high-precision vblank timestamping supported? */
+ if (dev->driver->get_vblank_timestamp)
+ DRM_INFO("Driver supports precise vblank timestamp query.\n");
+ else
+ DRM_INFO("No driver support for vblank timestamp query.\n");
+
+ /* Zero per-crtc vblank stuff */
+ for (i = 0; i < num_crtcs; i++) {
+ init_waitqueue_head(&dev->vbl_queue[i]);
+ atomic_set(&dev->_vblank_count[i], 0);
+ atomic_set(&dev->vblank_refcount[i], 0);
+ }
+
+ dev->vblank_disable_allowed = 0;
+ return 0;
+
+err:
+ drm_vblank_cleanup(dev);
+ 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);
+ }
+}
+
+/**
+ * Install IRQ handler.
+ *
+ * \param dev DRM device.
+ *
+ * Initializes the IRQ related data. Installs the handler, calling the driver
+ * \c irq_preinstall() and \c irq_postinstall() functions
+ * before and after the installation.
+ */
+int drm_irq_install(struct drm_device *dev)
+{
+ int ret = 0;
+ unsigned long sh_flags = 0;
+ char *irqname;
+
+ if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
+ return -EINVAL;
+
+ if (drm_dev_to_irq(dev) == 0)
+ return -EINVAL;
+
+ mutex_lock(&dev->struct_mutex);
+
+ /* Driver must have been initialized */
+ if (!dev->dev_private) {
+ mutex_unlock(&dev->struct_mutex);
+ return -EINVAL;
+ }
+
+ if (dev->irq_enabled) {
+ mutex_unlock(&dev->struct_mutex);
+ return -EBUSY;
+ }
+ dev->irq_enabled = 1;
+ mutex_unlock(&dev->struct_mutex);
+
+ DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev));
+
+ /* 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;
+
+ if (dev->devname)
+ irqname = dev->devname;
+ else
+ irqname = dev->driver->name;
+
+ ret = request_irq(drm_dev_to_irq(dev), dev->driver->irq_handler,
+ sh_flags, irqname, dev);
+
+ if (ret < 0) {
+ mutex_lock(&dev->struct_mutex);
+ dev->irq_enabled = 0;
+ mutex_unlock(&dev->struct_mutex);
+ 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) {
+ mutex_lock(&dev->struct_mutex);
+ dev->irq_enabled = 0;
+ mutex_unlock(&dev->struct_mutex);
+ if (!drm_core_check_feature(dev, DRIVER_MODESET))
+ vga_client_register(dev->pdev, NULL, NULL, NULL);
+ free_irq(drm_dev_to_irq(dev), dev);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_irq_install);
+
+/**
+ * Uninstall the IRQ handler.
+ *
+ * \param dev DRM device.
+ *
+ * Calls the driver's \c irq_uninstall() function, and stops the irq.
+ */
+int drm_irq_uninstall(struct drm_device *dev)
+{
+ unsigned long irqflags;
+ int irq_enabled, i;
+
+ if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
+ return -EINVAL;
+
+ mutex_lock(&dev->struct_mutex);
+ irq_enabled = dev->irq_enabled;
+ dev->irq_enabled = 0;
+ mutex_unlock(&dev->struct_mutex);
+
+ /*
+ * Wake up any waiters so they don't hang.
+ */
+ if (dev->num_crtcs) {
+ spin_lock_irqsave(&dev->vbl_lock, irqflags);
+ for (i = 0; i < dev->num_crtcs; i++) {
+ DRM_WAKEUP(&dev->vbl_queue[i]);
+ dev->vblank_enabled[i] = 0;
+ dev->last_vblank[i] =
+ dev->driver->get_vblank_counter(dev, i);
+ }
+ spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+ }
+
+ if (!irq_enabled)
+ return -EINVAL;
+
+ DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev));
+
+ 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(drm_dev_to_irq(dev), 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;
+
+ /* if we haven't irq we fallback for compatibility reasons -
+ * this used to be a separate function in drm_dma.h
+ */
+
+
+ switch (ctl->func) {
+ case DRM_INST_HANDLER:
+ if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
+ return 0;
+ if (drm_core_check_feature(dev, DRIVER_MODESET))
+ return 0;
+ if (dev->if_version < DRM_IF_VERSION(1, 2) &&
+ ctl->irq != drm_dev_to_irq(dev))
+ return -EINVAL;
+ return drm_irq_install(dev);
+ case DRM_UNINST_HANDLER:
+ if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
+ return 0;
+ if (drm_core_check_feature(dev, DRIVER_MODESET))
+ return 0;
+ return drm_irq_uninstall(dev);
+ default:
+ return -EINVAL;
+ }
+}
+
+/**
+ * drm_calc_timestamping_constants - 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.
+ *
+ * @crtc drm_crtc whose timestamp constants should be updated.
+ *
+ */
+void drm_calc_timestamping_constants(struct drm_crtc *crtc)
+{
+ s64 linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
+ u64 dotclock;
+
+ /* Dot clock in Hz: */
+ dotclock = (u64) crtc->hwmode.clock * 1000;
+
+ /* Fields of interlaced scanout modes are only halve a frame duration.
+ * Double the dotclock to get halve the frame-/line-/pixelduration.
+ */
+ if (crtc->hwmode.flags & DRM_MODE_FLAG_INTERLACE)
+ dotclock *= 2;
+
+ /* Valid dotclock? */
+ if (dotclock > 0) {
+ /* Convert scanline length in pixels and video dot clock to
+ * line duration, frame duration and pixel duration in
+ * nanoseconds:
+ */
+ pixeldur_ns = (s64) div64_u64(1000000000, dotclock);
+ linedur_ns = (s64) div64_u64(((u64) crtc->hwmode.crtc_htotal *
+ 1000000000), dotclock);
+ framedur_ns = (s64) crtc->hwmode.crtc_vtotal * linedur_ns;
+ } else
+ DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
+ crtc->base.id);
+
+ crtc->pixeldur_ns = pixeldur_ns;
+ crtc->linedur_ns = linedur_ns;
+ crtc->framedur_ns = framedur_ns;
+
+ DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
+ crtc->base.id, crtc->hwmode.crtc_htotal,
+ crtc->hwmode.crtc_vtotal, crtc->hwmode.crtc_vdisplay);
+ DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
+ crtc->base.id, (int) dotclock/1000, (int) framedur_ns,
+ (int) linedur_ns, (int) pixeldur_ns);
+}
+EXPORT_SYMBOL(drm_calc_timestamping_constants);
+
+/**
+ * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
+ * drivers. Implements calculation of exact vblank timestamps from
+ * given drm_display_mode timings and current video scanout position
+ * of a crtc. This can be called from within get_vblank_timestamp()
+ * implementation of a kms driver to implement the actual timestamping.
+ *
+ * Should return timestamps conforming to the OML_sync_control OpenML
+ * extension specification. The timestamp corresponds to the end of
+ * the vblank interval, aka start of scanout of topmost-leftmost display
+ * pixel in the following video frame.
+ *
+ * Requires support for optional dev->driver->get_scanout_position()
+ * in kms driver, plus a bit of setup code to provide a drm_display_mode
+ * that corresponds to the true scanout timing.
+ *
+ * The current implementation only handles standard video modes. It
+ * returns as no operation if a doublescan or interlaced video mode is
+ * active. Higher level code is expected to handle this.
+ *
+ * @dev: DRM device.
+ * @crtc: Which crtc's vblank timestamp to retrieve.
+ * @max_error: Desired maximum allowable error in timestamps (nanosecs).
+ * On return contains true maximum error of timestamp.
+ * @vblank_time: Pointer to struct timeval which should receive the timestamp.
+ * @flags: Flags to pass to driver:
+ * 0 = Default.
+ * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
+ * @refcrtc: drm_crtc* of crtc which defines scanout timing.
+ *
+ * Returns negative value on error, failure or if not supported in current
+ * video mode:
+ *
+ * -EINVAL - Invalid crtc.
+ * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
+ * -ENOTSUPP - Function not supported in current display mode.
+ * -EIO - Failed, e.g., due to failed scanout position query.
+ *
+ * Returns or'ed positive status flags on success:
+ *
+ * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
+ * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
+ *
+ */
+int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
+ int *max_error,
+ struct timeval *vblank_time,
+ unsigned flags,
+ struct drm_crtc *refcrtc)
+{
+ struct timeval stime, raw_time;
+ struct drm_display_mode *mode;
+ int vbl_status, vtotal, vdisplay;
+ int vpos, hpos, i;
+ s64 framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
+ bool invbl;
+
+ if (crtc < 0 || crtc >= dev->num_crtcs) {
+ DRM_ERROR("Invalid crtc %d\n", crtc);
+ return -EINVAL;
+ }
+
+ /* Scanout position query not supported? Should not happen. */
+ if (!dev->driver->get_scanout_position) {
+ DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
+ return -EIO;
+ }
+
+ mode = &refcrtc->hwmode;
+ vtotal = mode->crtc_vtotal;
+ vdisplay = mode->crtc_vdisplay;
+
+ /* Durations of frames, lines, pixels in nanoseconds. */
+ framedur_ns = refcrtc->framedur_ns;
+ linedur_ns = refcrtc->linedur_ns;
+ pixeldur_ns = refcrtc->pixeldur_ns;
+
+ /* If mode timing undefined, just return as no-op:
+ * Happens during initial modesetting of a crtc.
+ */
+ if (vtotal <= 0 || vdisplay <= 0 || framedur_ns == 0) {
+ DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc);
+ return -EAGAIN;
+ }
+
+ /* Get current scanout position with system timestamp.
+ * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
+ * if single query takes longer than max_error nanoseconds.
+ *
+ * This guarantees a tight bound on maximum error if
+ * code gets preempted or delayed for some reason.
+ */
+ for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
+ /* Disable preemption to make it very likely to
+ * succeed in the first iteration even on PREEMPT_RT kernel.
+ */
+ preempt_disable();
+
+ /* Get system timestamp before query. */
+ do_gettimeofday(&stime);
+
+ /* Get vertical and horizontal scanout pos. vpos, hpos. */
+ vbl_status = dev->driver->get_scanout_position(dev, crtc, &vpos, &hpos);
+
+ /* Get system timestamp after query. */
+ do_gettimeofday(&raw_time);
+
+ preempt_enable();
+
+ /* Return as no-op if scanout query unsupported or failed. */
+ if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
+ DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
+ crtc, vbl_status);
+ return -EIO;
+ }
+
+ duration_ns = timeval_to_ns(&raw_time) - timeval_to_ns(&stime);
+
+ /* Accept result with < max_error nsecs timing uncertainty. */
+ if (duration_ns <= (s64) *max_error)
+ break;
+ }
+
+ /* Noisy system timing? */
+ if (i == DRM_TIMESTAMP_MAXRETRIES) {
+ DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
+ crtc, (int) duration_ns/1000, *max_error/1000, i);
+ }
+
+ /* Return upper bound of timestamp precision error. */
+ *max_error = (int) duration_ns;
+
+ /* Check if in vblank area:
+ * vpos is >=0 in video scanout area, but negative
+ * within vblank area, counting down the number of lines until
+ * start of scanout.
+ */
+ invbl = vbl_status & DRM_SCANOUTPOS_INVBL;
+
+ /* Convert scanout position into elapsed time at raw_time query
+ * since start of scanout at first display scanline. delta_ns
+ * can be negative if start of scanout hasn't happened yet.
+ */
+ delta_ns = (s64) vpos * linedur_ns + (s64) hpos * pixeldur_ns;
+
+ /* Is vpos outside nominal vblank area, but less than
+ * 1/100 of a frame height away from start of vblank?
+ * If so, assume this isn't a massively delayed vblank
+ * interrupt, but a vblank interrupt that fired a few
+ * microseconds before true start of vblank. Compensate
+ * by adding a full frame duration to the final timestamp.
+ * Happens, e.g., on ATI R500, R600.
+ *
+ * We only do this if DRM_CALLED_FROM_VBLIRQ.
+ */
+ if ((flags & DRM_CALLED_FROM_VBLIRQ) && !invbl &&
+ ((vdisplay - vpos) < vtotal / 100)) {
+ delta_ns = delta_ns - framedur_ns;
+
+ /* Signal this correction as "applied". */
+ vbl_status |= 0x8;
+ }
+
+ /* Subtract time delta from raw timestamp to get final
+ * vblank_time timestamp for end of vblank.
+ */
+ *vblank_time = ns_to_timeval(timeval_to_ns(&raw_time) - delta_ns);
+
+ DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
+ crtc, (int)vbl_status, hpos, vpos,
+ (long)raw_time.tv_sec, (long)raw_time.tv_usec,
+ (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
+ (int)duration_ns/1000, i);
+
+ vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
+ if (invbl)
+ vbl_status |= DRM_VBLANKTIME_INVBL;
+
+ return vbl_status;
+}
+EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
+
+/**
+ * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
+ * vblank interval.
+ *
+ * @dev: DRM device
+ * @crtc: which crtc's vblank timestamp to retrieve
+ * @tvblank: Pointer to target struct timeval which should receive the timestamp
+ * @flags: Flags to pass to driver:
+ * 0 = Default.
+ * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
+ *
+ * Fetches the system timestamp corresponding to the time of the most recent
+ * vblank interval on specified crtc. May call into kms-driver to
+ * compute the timestamp with a high-precision GPU specific method.
+ *
+ * Returns zero if timestamp originates from uncorrected do_gettimeofday()
+ * call, i.e., it isn't very precisely locked to the true vblank.
+ *
+ * Returns non-zero if timestamp is considered to be very precise.
+ */
+u32 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
+ struct timeval *tvblank, unsigned flags)
+{
+ int ret = 0;
+
+ /* Define requested maximum error on timestamps (nanoseconds). */
+ int max_error = (int) drm_timestamp_precision * 1000;
+
+ /* Query driver if possible and precision timestamping enabled. */
+ if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
+ ret = dev->driver->get_vblank_timestamp(dev, crtc, &max_error,
+ tvblank, flags);
+ if (ret > 0)
+ return (u32) ret;
+ }
+
+ /* GPU high precision timestamp query unsupported or failed.
+ * Return gettimeofday timestamp as best estimate.
+ */
+ do_gettimeofday(tvblank);
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_get_last_vbltimestamp);
+
+/**
+ * drm_vblank_count - retrieve "cooked" vblank counter value
+ * @dev: DRM device
+ * @crtc: which counter to retrieve
+ *
+ * Fetches the "cooked" vblank count value that represents the number of
+ * vblank events since the system was booted, including lost events due to
+ * modesetting activity.
+ */
+u32 drm_vblank_count(struct drm_device *dev, int crtc)
+{
+ return atomic_read(&dev->_vblank_count[crtc]);
+}
+EXPORT_SYMBOL(drm_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 value vblank counter
+ * value.
+ */
+u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
+ struct timeval *vblanktime)
+{
+ u32 cur_vblank;
+
+ /* Read timestamp from slot of _vblank_time ringbuffer
+ * that corresponds to current vblank count. Retry if
+ * count has incremented during readout. This works like
+ * a seqlock.
+ */
+ do {
+ cur_vblank = atomic_read(&dev->_vblank_count[crtc]);
+ *vblanktime = vblanktimestamp(dev, crtc, cur_vblank);
+ smp_rmb();
+ } while (cur_vblank != atomic_read(&dev->_vblank_count[crtc]));
+
+ return cur_vblank;
+}
+EXPORT_SYMBOL(drm_vblank_count_and_time);
+
+/**
+ * drm_update_vblank_count - update the master vblank counter
+ * @dev: DRM device
+ * @crtc: counter to update
+ *
+ * Call back into the driver to update the appropriate vblank counter
+ * (specified by @crtc). Deal with wraparound, if it occurred, and
+ * update the last read value so we can deal with wraparound on the next
+ * call if necessary.
+ *
+ * Only necessary when going from off->on, to account for frames we
+ * didn't get an interrupt for.
+ *
+ * Note: caller must hold dev->vbl_lock since this reads & writes
+ * device vblank fields.
+ */
+static void drm_update_vblank_count(struct drm_device *dev, int crtc)
+{
+ u32 cur_vblank, diff, tslot, rc;
+ struct timeval t_vblank;
+
+ /*
+ * Interrupts were disabled prior to this call, so deal with counter
+ * wrap if needed.
+ * NOTE! It's possible we lost a full dev->max_vblank_count events
+ * here if the register is small or we had vblank interrupts off for
+ * a long time.
+ *
+ * We repeat the hardware vblank counter & timestamp query until
+ * we get consistent results. This to prevent races between gpu
+ * updating its hardware counter while we are retrieving the
+ * corresponding vblank timestamp.
+ */
+ do {
+ cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
+ rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0);
+ } while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc));
+
+ /* Deal with counter wrap */
+ diff = cur_vblank - dev->last_vblank[crtc];
+ if (cur_vblank < dev->last_vblank[crtc]) {
+ diff += dev->max_vblank_count;
+
+ DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
+ crtc, dev->last_vblank[crtc], cur_vblank, diff);
+ }
+
+ DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
+ crtc, diff);
+
+ /* Reinitialize corresponding vblank timestamp if high-precision query
+ * available. Skip this step if query unsupported or failed. Will
+ * reinitialize delayed at next vblank interrupt in that case.
+ */
+ if (rc) {
+ tslot = atomic_read(&dev->_vblank_count[crtc]) + diff;
+ vblanktimestamp(dev, crtc, tslot) = t_vblank;
+ }
+
+ smp_mb__before_atomic_inc();
+ atomic_add(diff, &dev->_vblank_count[crtc]);
+ smp_mb__after_atomic_inc();
+}
+
+/**
+ * drm_vblank_get - get a reference count on vblank events
+ * @dev: DRM device
+ * @crtc: which CRTC to own
+ *
+ * Acquire a reference count on vblank events to avoid having them disabled
+ * while in use.
+ *
+ * RETURNS
+ * Zero on success, nonzero on failure.
+ */
+int drm_vblank_get(struct drm_device *dev, int crtc)
+{
+ unsigned long irqflags, irqflags2;
+ int ret = 0;
+
+ spin_lock_irqsave(&dev->vbl_lock, irqflags);
+ /* Going from 0->1 means we have to enable interrupts again */
+ if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1) {
+ spin_lock_irqsave(&dev->vblank_time_lock, irqflags2);
+ if (!dev->vblank_enabled[crtc]) {
+ /* Enable vblank irqs under vblank_time_lock protection.
+ * All vblank count & timestamp updates are held off
+ * until we are done reinitializing master counter and
+ * timestamps. Filtercode in drm_handle_vblank() will
+ * prevent double-accounting of same vblank interval.
+ */
+ ret = dev->driver->enable_vblank(dev, crtc);
+ DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n",
+ crtc, ret);
+ if (ret)
+ atomic_dec(&dev->vblank_refcount[crtc]);
+ else {
+ dev->vblank_enabled[crtc] = 1;
+ drm_update_vblank_count(dev, crtc);
+ }
+ }
+ spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags2);
+ } else {
+ if (!dev->vblank_enabled[crtc]) {
+ atomic_dec(&dev->vblank_refcount[crtc]);
+ ret = -EINVAL;
+ }
+ }
+ spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_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.
+ */
+void drm_vblank_put(struct drm_device *dev, int crtc)
+{
+ BUG_ON(atomic_read(&dev->vblank_refcount[crtc]) == 0);
+
+ /* Last user schedules interrupt disable */
+ if (atomic_dec_and_test(&dev->vblank_refcount[crtc]) &&
+ (drm_vblank_offdelay > 0))
+ mod_timer(&dev->vblank_disable_timer,
+ jiffies + ((drm_vblank_offdelay * DRM_HZ)/1000));
+}
+EXPORT_SYMBOL(drm_vblank_put);
+
+void drm_vblank_off(struct drm_device *dev, int crtc)
+{
+ struct drm_pending_vblank_event *e, *t;
+ struct timeval now;
+ unsigned long irqflags;
+ unsigned int seq;
+
+ spin_lock_irqsave(&dev->vbl_lock, irqflags);
+ vblank_disable_and_save(dev, crtc);
+ DRM_WAKEUP(&dev->vbl_queue[crtc]);
+
+ /* Send any queued vblank events, lest the natives grow disquiet */
+ seq = drm_vblank_count_and_time(dev, crtc, &now);
+ list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
+ if (e->pipe != crtc)
+ continue;
+ DRM_DEBUG("Sending premature vblank event on disable: \
+ wanted %d, current %d\n",
+ e->event.sequence, seq);
+
+ e->event.sequence = seq;
+ e->event.tv_sec = now.tv_sec;
+ e->event.tv_usec = now.tv_usec;
+ drm_vblank_put(dev, e->pipe);
+ list_move_tail(&e->base.link, &e->base.file_priv->event_list);
+ wake_up_interruptible(&e->base.file_priv->event_wait);
+ trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
+ e->event.sequence);
+ }
+
+ spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+}
+EXPORT_SYMBOL(drm_vblank_off);
+
+/**
+ * drm_vblank_pre_modeset - account for vblanks across mode sets
+ * @dev: DRM device
+ * @crtc: CRTC in question
+ * @post: post or pre mode set?
+ *
+ * Account for vblank events across mode setting events, which will likely
+ * reset the hardware frame counter.
+ */
+void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
+{
+ /* vblank is not initialized (IRQ not installed ?) */
+ if (!dev->num_crtcs)
+ return;
+ /*
+ * To avoid all the problems that might happen if interrupts
+ * were enabled/disabled around or between these calls, we just
+ * have the kernel take a reference on the CRTC (just once though
+ * to avoid corrupting the count if multiple, mismatch calls occur),
+ * so that interrupts remain enabled in the interim.
+ */
+ if (!dev->vblank_inmodeset[crtc]) {
+ dev->vblank_inmodeset[crtc] = 0x1;
+ if (drm_vblank_get(dev, crtc) == 0)
+ dev->vblank_inmodeset[crtc] |= 0x2;
+ }
+}
+EXPORT_SYMBOL(drm_vblank_pre_modeset);
+
+void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
+{
+ unsigned long irqflags;
+
+ if (dev->vblank_inmodeset[crtc]) {
+ spin_lock_irqsave(&dev->vbl_lock, irqflags);
+ dev->vblank_disable_allowed = 1;
+ spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+
+ if (dev->vblank_inmodeset[crtc] & 0x2)
+ drm_vblank_put(dev, crtc);
+
+ dev->vblank_inmodeset[crtc] = 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;
+ int ret = 0;
+ unsigned int crtc;
+
+ /* If drm_vblank_init() hasn't been called yet, just no-op */
+ if (!dev->num_crtcs)
+ goto out;
+
+ crtc = modeset->crtc;
+ if (crtc >= dev->num_crtcs) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ switch (modeset->cmd) {
+ case _DRM_PRE_MODESET:
+ drm_vblank_pre_modeset(dev, crtc);
+ break;
+ case _DRM_POST_MODESET:
+ drm_vblank_post_modeset(dev, crtc);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+out:
+ return ret;
+}
+
+static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
+ union drm_wait_vblank *vblwait,
+ struct drm_file *file_priv)
+{
+ struct drm_pending_vblank_event *e;
+ struct timeval now;
+ unsigned 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);
+
+ 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)) {
+ e->event.sequence = seq;
+ e->event.tv_sec = now.tv_sec;
+ e->event.tv_usec = now.tv_usec;
+ drm_vblank_put(dev, pipe);
+ list_add_tail(&e->base.link, &e->base.file_priv->event_list);
+ wake_up_interruptible(&e->base.file_priv->event_wait);
+ vblwait->reply.sequence = seq;
+ trace_drm_vblank_event_delivered(current->pid, pipe,
+ vblwait->request.sequence);
+ } else {
+ /* drm_handle_vblank_events will call drm_vblank_put */
+ list_add_tail(&e->base.link, &dev->vblank_event_list);
+ vblwait->reply.sequence = vblwait->request.sequence;
+ }
+
+ 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)
+{
+ union drm_wait_vblank *vblwait = data;
+ int ret = 0;
+ unsigned int flags, seq, crtc, high_crtc;
+
+ if ((!drm_dev_to_irq(dev)) || (!dev->irq_enabled))
+ return -EINVAL;
+
+ if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
+ return -EINVAL;
+
+ if (vblwait->request.type &
+ ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
+ _DRM_VBLANK_HIGH_CRTC_MASK)) {
+ DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
+ vblwait->request.type,
+ (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
+ _DRM_VBLANK_HIGH_CRTC_MASK));
+ return -EINVAL;
+ }
+
+ flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
+ high_crtc = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
+ if (high_crtc)
+ crtc = high_crtc >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
+ else
+ crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
+ if (crtc >= dev->num_crtcs)
+ return -EINVAL;
+
+ ret = drm_vblank_get(dev, crtc);
+ if (ret) {
+ DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
+ return ret;
+ }
+ seq = drm_vblank_count(dev, crtc);
+
+ switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
+ case _DRM_VBLANK_RELATIVE:
+ vblwait->request.sequence += seq;
+ vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
+ case _DRM_VBLANK_ABSOLUTE:
+ break;
+ default:
+ ret = -EINVAL;
+ goto done;
+ }
+
+ if (flags & _DRM_VBLANK_EVENT) {
+ /* must hold on to the vblank ref until the event fires
+ * drm_vblank_put will be called asynchronously
+ */
+ return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
+ }
+
+ if ((flags & _DRM_VBLANK_NEXTONMISS) &&
+ (seq - vblwait->request.sequence) <= (1<<23)) {
+ vblwait->request.sequence = seq + 1;
+ }
+
+ DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
+ vblwait->request.sequence, crtc);
+ dev->last_vblank_wait[crtc] = vblwait->request.sequence;
+ DRM_WAIT_ON(ret, dev->vbl_queue[crtc], 3 * DRM_HZ,
+ (((drm_vblank_count(dev, crtc) -
+ vblwait->request.sequence) <= (1 << 23)) ||
+ !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;
+}
+
+void drm_handle_vblank_events(struct drm_device *dev, int crtc)
+{
+ struct drm_pending_vblank_event *e, *t;
+ struct timeval now;
+ unsigned long flags;
+ unsigned int seq;
+
+ seq = drm_vblank_count_and_time(dev, crtc, &now);
+
+ spin_lock_irqsave(&dev->event_lock, flags);
+
+ 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);
+
+ e->event.sequence = seq;
+ e->event.tv_sec = now.tv_sec;
+ e->event.tv_usec = now.tv_usec;
+ drm_vblank_put(dev, e->pipe);
+ list_move_tail(&e->base.link, &e->base.file_priv->event_list);
+ wake_up_interruptible(&e->base.file_priv->event_wait);
+ trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
+ e->event.sequence);
+ }
+
+ spin_unlock_irqrestore(&dev->event_lock, flags);
+
+ 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.
+ */
+bool drm_handle_vblank(struct drm_device *dev, int crtc)
+{
+ u32 vblcount;
+ s64 diff_ns;
+ struct timeval tvblank;
+ unsigned long irqflags;
+
+ if (!dev->num_crtcs)
+ return false;
+
+ /* Need timestamp lock to prevent concurrent execution with
+ * vblank enable/disable, as this would cause inconsistent
+ * or corrupted timestamps and vblank counts.
+ */
+ spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
+
+ /* Vblank irq handling disabled. Nothing to do. */
+ if (!dev->vblank_enabled[crtc]) {
+ spin_unlock_irqrestore(&dev->vblank_time_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(&dev->_vblank_count[crtc]);
+ drm_get_last_vbltimestamp(dev, crtc, &tvblank, DRM_CALLED_FROM_VBLIRQ);
+
+ /* Compute time difference to timestamp of last vblank */
+ diff_ns = timeval_to_ns(&tvblank) -
+ timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
+
+ /* Update vblank timestamp and count if at least
+ * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
+ * difference between last stored timestamp and current
+ * timestamp. A smaller difference means basically
+ * identical timestamps. Happens if this vblank has
+ * been already processed and this is a redundant call,
+ * e.g., due to spurious vblank interrupts. We need to
+ * ignore those for accounting.
+ */
+ if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) {
+ /* Store new timestamp in ringbuffer. */
+ vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
+
+ /* Increment cooked vblank count. This also atomically commits
+ * the timestamp computed above.
+ */
+ smp_mb__before_atomic_inc();
+ atomic_inc(&dev->_vblank_count[crtc]);
+ smp_mb__after_atomic_inc();
+ } else {
+ DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
+ crtc, (int) diff_ns);
+ }
+
+ DRM_WAKEUP(&dev->vbl_queue[crtc]);
+ drm_handle_vblank_events(dev, crtc);
+
+ spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
+ return true;
+}
+EXPORT_SYMBOL(drm_handle_vblank);