drm/vbl rework: rework how the drm deals with vblank.
Other Authors: Michel Dänzer <michel@tungstengraphics.com>
mga: Ian Romanick <idr@us.ibm.com>
via: Thomas Hellstrom <thomas-at-tungstengraphics-dot-com>
This re-works the DRM internals to provide a better interface for drivers
to expose vblank on multiple crtcs.
It also includes work done by Michel on making i915 triple buffering and pageflipping work properly.
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/char/drm/drm_irq.c b/drivers/char/drm/drm_irq.c
index 089c015..286f9d6 100644
--- a/drivers/char/drm/drm_irq.c
+++ b/drivers/char/drm/drm_irq.c
@@ -71,6 +71,117 @@
return 0;
}
+static void vblank_disable_fn(unsigned long arg)
+{
+ struct drm_device *dev = (struct drm_device *)arg;
+ unsigned long irqflags;
+ int i;
+
+ 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]) {
+ dev->driver->disable_vblank(dev, i);
+ dev->vblank_enabled[i] = 0;
+ }
+ spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+ }
+}
+
+static 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);
+
+ drm_free(dev->vbl_queue, sizeof(*dev->vbl_queue) * dev->num_crtcs,
+ DRM_MEM_DRIVER);
+ drm_free(dev->vbl_sigs, sizeof(*dev->vbl_sigs) * dev->num_crtcs,
+ DRM_MEM_DRIVER);
+ drm_free(dev->_vblank_count, sizeof(*dev->_vblank_count) *
+ dev->num_crtcs, DRM_MEM_DRIVER);
+ drm_free(dev->vblank_refcount, sizeof(*dev->vblank_refcount) *
+ dev->num_crtcs, DRM_MEM_DRIVER);
+ drm_free(dev->vblank_enabled, sizeof(*dev->vblank_enabled) *
+ dev->num_crtcs, DRM_MEM_DRIVER);
+ drm_free(dev->last_vblank, sizeof(*dev->last_vblank) * dev->num_crtcs,
+ DRM_MEM_DRIVER);
+ drm_free(dev->vblank_premodeset, sizeof(*dev->vblank_premodeset) *
+ dev->num_crtcs, DRM_MEM_DRIVER);
+ drm_free(dev->vblank_offset, sizeof(*dev->vblank_offset) * dev->num_crtcs,
+ DRM_MEM_DRIVER);
+
+ dev->num_crtcs = 0;
+}
+
+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);
+ atomic_set(&dev->vbl_signal_pending, 0);
+ dev->num_crtcs = num_crtcs;
+
+ dev->vbl_queue = drm_alloc(sizeof(wait_queue_head_t) * num_crtcs,
+ DRM_MEM_DRIVER);
+ if (!dev->vbl_queue)
+ goto err;
+
+ dev->vbl_sigs = drm_alloc(sizeof(struct list_head) * num_crtcs,
+ DRM_MEM_DRIVER);
+ if (!dev->vbl_sigs)
+ goto err;
+
+ dev->_vblank_count = drm_alloc(sizeof(atomic_t) * num_crtcs,
+ DRM_MEM_DRIVER);
+ if (!dev->_vblank_count)
+ goto err;
+
+ dev->vblank_refcount = drm_alloc(sizeof(atomic_t) * num_crtcs,
+ DRM_MEM_DRIVER);
+ if (!dev->vblank_refcount)
+ goto err;
+
+ dev->vblank_enabled = drm_calloc(num_crtcs, sizeof(int),
+ DRM_MEM_DRIVER);
+ if (!dev->vblank_enabled)
+ goto err;
+
+ dev->last_vblank = drm_calloc(num_crtcs, sizeof(u32), DRM_MEM_DRIVER);
+ if (!dev->last_vblank)
+ goto err;
+
+ dev->vblank_premodeset = drm_calloc(num_crtcs, sizeof(u32),
+ DRM_MEM_DRIVER);
+ if (!dev->vblank_premodeset)
+ goto err;
+
+ dev->vblank_offset = drm_calloc(num_crtcs, sizeof(u32), DRM_MEM_DRIVER);
+ if (!dev->vblank_offset)
+ goto err;
+
+ /* Zero per-crtc vblank stuff */
+ for (i = 0; i < num_crtcs; i++) {
+ init_waitqueue_head(&dev->vbl_queue[i]);
+ INIT_LIST_HEAD(&dev->vbl_sigs[i]);
+ atomic_set(&dev->_vblank_count[i], 0);
+ atomic_set(&dev->vblank_refcount[i], 0);
+ }
+
+ return 0;
+
+err:
+ drm_vblank_cleanup(dev);
+ return ret;
+}
+EXPORT_SYMBOL(drm_vblank_init);
+
/**
* Install IRQ handler.
*
@@ -109,17 +220,6 @@
DRM_DEBUG("irq=%d\n", dev->irq);
- if (drm_core_check_feature(dev, DRIVER_IRQ_VBL)) {
- init_waitqueue_head(&dev->vbl_queue);
-
- spin_lock_init(&dev->vbl_lock);
-
- INIT_LIST_HEAD(&dev->vbl_sigs);
- INIT_LIST_HEAD(&dev->vbl_sigs2);
-
- dev->vbl_pending = 0;
- }
-
/* Before installing handler */
dev->driver->irq_preinstall(dev);
@@ -137,9 +237,14 @@
}
/* After installing handler */
- dev->driver->irq_postinstall(dev);
+ ret = dev->driver->irq_postinstall(dev);
+ if (ret < 0) {
+ mutex_lock(&dev->struct_mutex);
+ dev->irq_enabled = 0;
+ mutex_unlock(&dev->struct_mutex);
+ }
- return 0;
+ return ret;
}
/**
@@ -170,6 +275,8 @@
free_irq(dev->irq, dev);
+ drm_vblank_cleanup(dev);
+
dev->locked_tasklet_func = NULL;
return 0;
@@ -214,6 +321,148 @@
}
/**
+ * 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]) +
+ dev->vblank_offset[crtc];
+}
+EXPORT_SYMBOL(drm_vblank_count);
+
+/**
+ * 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.
+ */
+void drm_update_vblank_count(struct drm_device *dev, int crtc)
+{
+ unsigned long irqflags;
+ u32 cur_vblank, diff;
+
+ /*
+ * 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.
+ */
+ cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
+ spin_lock_irqsave(&dev->vbl_lock, irqflags);
+ if (cur_vblank < dev->last_vblank[crtc]) {
+ diff = dev->max_vblank_count -
+ dev->last_vblank[crtc];
+ diff += cur_vblank;
+ } else {
+ diff = cur_vblank - dev->last_vblank[crtc];
+ }
+ dev->last_vblank[crtc] = cur_vblank;
+ spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+
+ atomic_add(diff, &dev->_vblank_count[crtc]);
+}
+EXPORT_SYMBOL(drm_update_vblank_count);
+
+/**
+ * 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. Note callers will probably want to update the master counter
+ * using drm_update_vblank_count() above before calling this routine so that
+ * wakeups occur on the right vblank event.
+ *
+ * RETURNS
+ * Zero on success, nonzero on failure.
+ */
+int drm_vblank_get(struct drm_device *dev, int crtc)
+{
+ unsigned long irqflags;
+ 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 &&
+ !dev->vblank_enabled[crtc]) {
+ ret = dev->driver->enable_vblank(dev, crtc);
+ if (ret)
+ atomic_dec(&dev->vblank_refcount[crtc]);
+ else
+ dev->vblank_enabled[crtc] = 1;
+ }
+ 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.
+ */
+void drm_vblank_put(struct drm_device *dev, int crtc)
+{
+ /* Last user schedules interrupt disable */
+ if (atomic_dec_and_test(&dev->vblank_refcount[crtc]))
+ mod_timer(&dev->vblank_disable_timer, jiffies + 5*DRM_HZ);
+}
+EXPORT_SYMBOL(drm_vblank_put);
+
+/**
+ * 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.
+ */
+int drm_modeset_ctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
+{
+ struct drm_modeset_ctl *modeset = data;
+ int crtc, ret = 0;
+ u32 new;
+
+ crtc = modeset->arg;
+ if (crtc >= dev->num_crtcs) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ switch (modeset->cmd) {
+ case _DRM_PRE_MODESET:
+ dev->vblank_premodeset[crtc] =
+ dev->driver->get_vblank_counter(dev, crtc);
+ break;
+ case _DRM_POST_MODESET:
+ new = dev->driver->get_vblank_counter(dev, crtc);
+ dev->vblank_offset[crtc] = dev->vblank_premodeset[crtc] - new;
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+out:
+ return ret;
+}
+
+/**
* Wait for VBLANK.
*
* \param inode device inode.
@@ -232,12 +481,13 @@
*
* If a signal is not requested, then calls vblank_wait().
*/
-int drm_wait_vblank(struct drm_device *dev, void *data, struct drm_file *file_priv)
+int drm_wait_vblank(struct drm_device *dev, void *data,
+ struct drm_file *file_priv)
{
union drm_wait_vblank *vblwait = data;
struct timeval now;
int ret = 0;
- unsigned int flags, seq;
+ unsigned int flags, seq, crtc;
if ((!dev->irq) || (!dev->irq_enabled))
return -EINVAL;
@@ -251,13 +501,13 @@
}
flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
+ crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
- if (!drm_core_check_feature(dev, (flags & _DRM_VBLANK_SECONDARY) ?
- DRIVER_IRQ_VBL2 : DRIVER_IRQ_VBL))
+ if (crtc >= dev->num_crtcs)
return -EINVAL;
- seq = atomic_read((flags & _DRM_VBLANK_SECONDARY) ? &dev->vbl_received2
- : &dev->vbl_received);
+ drm_update_vblank_count(dev, crtc);
+ seq = drm_vblank_count(dev, crtc);
switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
case _DRM_VBLANK_RELATIVE:
@@ -276,8 +526,7 @@
if (flags & _DRM_VBLANK_SIGNAL) {
unsigned long irqflags;
- struct list_head *vbl_sigs = (flags & _DRM_VBLANK_SECONDARY)
- ? &dev->vbl_sigs2 : &dev->vbl_sigs;
+ struct list_head *vbl_sigs = &dev->vbl_sigs[crtc];
struct drm_vbl_sig *vbl_sig;
spin_lock_irqsave(&dev->vbl_lock, irqflags);
@@ -298,22 +547,26 @@
}
}
- if (dev->vbl_pending >= 100) {
+ if (atomic_read(&dev->vbl_signal_pending) >= 100) {
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
return -EBUSY;
}
- dev->vbl_pending++;
-
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
- if (!
- (vbl_sig =
- drm_alloc(sizeof(struct drm_vbl_sig), DRM_MEM_DRIVER))) {
+ vbl_sig = drm_calloc(1, sizeof(struct drm_vbl_sig),
+ DRM_MEM_DRIVER);
+ if (!vbl_sig)
return -ENOMEM;
+
+ ret = drm_vblank_get(dev, crtc);
+ if (ret) {
+ drm_free(vbl_sig, sizeof(struct drm_vbl_sig),
+ DRM_MEM_DRIVER);
+ return ret;
}
- memset((void *)vbl_sig, 0, sizeof(*vbl_sig));
+ atomic_inc(&dev->vbl_signal_pending);
vbl_sig->sequence = vblwait->request.sequence;
vbl_sig->info.si_signo = vblwait->request.signal;
@@ -327,17 +580,20 @@
vblwait->reply.sequence = seq;
} else {
- if (flags & _DRM_VBLANK_SECONDARY) {
- if (dev->driver->vblank_wait2)
- ret = dev->driver->vblank_wait2(dev, &vblwait->request.sequence);
- } else if (dev->driver->vblank_wait)
- ret =
- dev->driver->vblank_wait(dev,
- &vblwait->request.sequence);
+ unsigned long cur_vblank;
+ ret = drm_vblank_get(dev, crtc);
+ if (ret)
+ return ret;
+ DRM_WAIT_ON(ret, dev->vbl_queue[crtc], 3 * DRM_HZ,
+ (((cur_vblank = drm_vblank_count(dev, crtc))
+ - vblwait->request.sequence) <= (1 << 23)));
+ drm_vblank_put(dev, crtc);
do_gettimeofday(&now);
+
vblwait->reply.tval_sec = now.tv_sec;
vblwait->reply.tval_usec = now.tv_usec;
+ vblwait->reply.sequence = cur_vblank;
}
done:
@@ -348,44 +604,57 @@
* Send the VBLANK signals.
*
* \param dev DRM device.
+ * \param crtc CRTC where the vblank event occurred
*
* Sends a signal for each task in drm_device::vbl_sigs and empties the list.
*
* If a signal is not requested, then calls vblank_wait().
*/
-void drm_vbl_send_signals(struct drm_device * dev)
+static void drm_vbl_send_signals(struct drm_device * dev, int crtc)
{
+ struct drm_vbl_sig *vbl_sig, *tmp;
+ struct list_head *vbl_sigs;
+ unsigned int vbl_seq;
unsigned long flags;
- int i;
spin_lock_irqsave(&dev->vbl_lock, flags);
- for (i = 0; i < 2; i++) {
- struct drm_vbl_sig *vbl_sig, *tmp;
- struct list_head *vbl_sigs = i ? &dev->vbl_sigs2 : &dev->vbl_sigs;
- unsigned int vbl_seq = atomic_read(i ? &dev->vbl_received2 :
- &dev->vbl_received);
+ vbl_sigs = &dev->vbl_sigs[crtc];
+ vbl_seq = drm_vblank_count(dev, crtc);
- list_for_each_entry_safe(vbl_sig, tmp, vbl_sigs, head) {
- if ((vbl_seq - vbl_sig->sequence) <= (1 << 23)) {
- vbl_sig->info.si_code = vbl_seq;
- send_sig_info(vbl_sig->info.si_signo,
- &vbl_sig->info, vbl_sig->task);
+ list_for_each_entry_safe(vbl_sig, tmp, vbl_sigs, head) {
+ if ((vbl_seq - vbl_sig->sequence) <= (1 << 23)) {
+ vbl_sig->info.si_code = vbl_seq;
+ send_sig_info(vbl_sig->info.si_signo,
+ &vbl_sig->info, vbl_sig->task);
- list_del(&vbl_sig->head);
+ list_del(&vbl_sig->head);
- drm_free(vbl_sig, sizeof(*vbl_sig),
- DRM_MEM_DRIVER);
-
- dev->vbl_pending--;
- }
- }
+ drm_free(vbl_sig, sizeof(*vbl_sig),
+ DRM_MEM_DRIVER);
+ atomic_dec(&dev->vbl_signal_pending);
+ drm_vblank_put(dev, crtc);
+ }
}
spin_unlock_irqrestore(&dev->vbl_lock, flags);
}
-EXPORT_SYMBOL(drm_vbl_send_signals);
+/**
+ * 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.
+ */
+void drm_handle_vblank(struct drm_device *dev, int crtc)
+{
+ drm_update_vblank_count(dev, crtc);
+ DRM_WAKEUP(&dev->vbl_queue[crtc]);
+ drm_vbl_send_signals(dev, crtc);
+}
+EXPORT_SYMBOL(drm_handle_vblank);
/**
* Tasklet wrapper function.