Initial import

1 files changed, 268 insertions, 0 deletions

diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c
new file mode 100644
index 000000000..5b192128c
--- /dev/null
+++ b/drivers/gpu/drm/msm/msm_atomic.c
@@ -0,0 +1,268 @@
+/*
+ * Copyright (C) 2014 Red Hat
+ * Author: Rob Clark <robdclark@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "msm_drv.h"
+#include "msm_kms.h"
+#include "msm_gem.h"
+
+struct msm_commit {
+	struct drm_device *dev;
+	struct drm_atomic_state *state;
+	uint32_t fence;
+	struct msm_fence_cb fence_cb;
+	uint32_t crtc_mask;
+};
+
+static void fence_cb(struct msm_fence_cb *cb);
+
+/* block until specified crtcs are no longer pending update, and
+ * atomically mark them as pending update
+ */
+static int start_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
+{
+	int ret;
+
+	spin_lock(&priv->pending_crtcs_event.lock);
+	ret = wait_event_interruptible_locked(priv->pending_crtcs_event,
+			!(priv->pending_crtcs & crtc_mask));
+	if (ret == 0) {
+		DBG("start: %08x", crtc_mask);
+		priv->pending_crtcs |= crtc_mask;
+	}
+	spin_unlock(&priv->pending_crtcs_event.lock);
+
+	return ret;
+}
+
+/* clear specified crtcs (no longer pending update)
+ */
+static void end_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
+{
+	spin_lock(&priv->pending_crtcs_event.lock);
+	DBG("end: %08x", crtc_mask);
+	priv->pending_crtcs &= ~crtc_mask;
+	wake_up_all_locked(&priv->pending_crtcs_event);
+	spin_unlock(&priv->pending_crtcs_event.lock);
+}
+
+static struct msm_commit *commit_init(struct drm_atomic_state *state)
+{
+	struct msm_commit *c = kzalloc(sizeof(*c), GFP_KERNEL);
+
+	if (!c)
+		return NULL;
+
+	c->dev = state->dev;
+	c->state = state;
+
+	/* TODO we might need a way to indicate to run the cb on a
+	 * different wq so wait_for_vblanks() doesn't block retiring
+	 * bo's..
+	 */
+	INIT_FENCE_CB(&c->fence_cb, fence_cb);
+
+	return c;
+}
+
+static void commit_destroy(struct msm_commit *c)
+{
+	end_atomic(c->dev->dev_private, c->crtc_mask);
+	kfree(c);
+}
+
+/* The (potentially) asynchronous part of the commit.  At this point
+ * nothing can fail short of armageddon.
+ */
+static void complete_commit(struct msm_commit *c)
+{
+	struct drm_atomic_state *state = c->state;
+	struct drm_device *dev = state->dev;
+	struct msm_drm_private *priv = dev->dev_private;
+	struct msm_kms *kms = priv->kms;
+
+	kms->funcs->prepare_commit(kms, state);
+
+	drm_atomic_helper_commit_modeset_disables(dev, state);
+
+	drm_atomic_helper_commit_planes(dev, state);
+
+	drm_atomic_helper_commit_modeset_enables(dev, state);
+
+	/* NOTE: _wait_for_vblanks() only waits for vblank on
+	 * enabled CRTCs.  So we end up faulting when disabling
+	 * due to (potentially) unref'ing the outgoing fb's
+	 * before the vblank when the disable has latched.
+	 *
+	 * But if it did wait on disabled (or newly disabled)
+	 * CRTCs, that would be racy (ie. we could have missed
+	 * the irq.  We need some way to poll for pipe shut
+	 * down.  Or just live with occasionally hitting the
+	 * timeout in the CRTC disable path (which really should
+	 * not be critical path)
+	 */
+
+	drm_atomic_helper_wait_for_vblanks(dev, state);
+
+	drm_atomic_helper_cleanup_planes(dev, state);
+
+	kms->funcs->complete_commit(kms, state);
+
+	drm_atomic_state_free(state);
+
+	commit_destroy(c);
+}
+
+static void fence_cb(struct msm_fence_cb *cb)
+{
+	struct msm_commit *c =
+			container_of(cb, struct msm_commit, fence_cb);
+	complete_commit(c);
+}
+
+static void add_fb(struct msm_commit *c, struct drm_framebuffer *fb)
+{
+	struct drm_gem_object *obj = msm_framebuffer_bo(fb, 0);
+	c->fence = max(c->fence, msm_gem_fence(to_msm_bo(obj), MSM_PREP_READ));
+}
+
+
+int msm_atomic_check(struct drm_device *dev,
+		     struct drm_atomic_state *state)
+{
+	int ret;
+
+	/*
+	 * msm ->atomic_check can update ->mode_changed for pixel format
+	 * changes, hence must be run before we check the modeset changes.
+	 */
+	ret = drm_atomic_helper_check_planes(dev, state);
+	if (ret)
+		return ret;
+
+	ret = drm_atomic_helper_check_modeset(dev, state);
+	if (ret)
+		return ret;
+
+	return ret;
+}
+
+/**
+ * drm_atomic_helper_commit - commit validated state object
+ * @dev: DRM device
+ * @state: the driver state object
+ * @async: asynchronous commit
+ *
+ * This function commits a with drm_atomic_helper_check() pre-validated state
+ * object. This can still fail when e.g. the framebuffer reservation fails. For
+ * now this doesn't implement asynchronous commits.
+ *
+ * RETURNS
+ * Zero for success or -errno.
+ */
+int msm_atomic_commit(struct drm_device *dev,
+		struct drm_atomic_state *state, bool async)
+{
+	int nplanes = dev->mode_config.num_total_plane;
+	int ncrtcs = dev->mode_config.num_crtc;
+	struct timespec timeout;
+	struct msm_commit *c;
+	int i, ret;
+
+	ret = drm_atomic_helper_prepare_planes(dev, state);
+	if (ret)
+		return ret;
+
+	c = commit_init(state);
+	if (!c)
+		return -ENOMEM;
+
+	/*
+	 * Figure out what crtcs we have:
+	 */
+	for (i = 0; i < ncrtcs; i++) {
+		struct drm_crtc *crtc = state->crtcs[i];
+		if (!crtc)
+			continue;
+		c->crtc_mask |= (1 << drm_crtc_index(crtc));
+	}
+
+	/*
+	 * Figure out what fence to wait for:
+	 */
+	for (i = 0; i < nplanes; i++) {
+		struct drm_plane *plane = state->planes[i];
+		struct drm_plane_state *new_state = state->plane_states[i];
+
+		if (!plane)
+			continue;
+
+		if ((plane->state->fb != new_state->fb) && new_state->fb)
+			add_fb(c, new_state->fb);
+	}
+
+	/*
+	 * Wait for pending updates on any of the same crtc's and then
+	 * mark our set of crtc's as busy:
+	 */
+	ret = start_atomic(dev->dev_private, c->crtc_mask);
+	if (ret) {
+		kfree(c);
+		return ret;
+	}
+
+	/*
+	 * This is the point of no return - everything below never fails except
+	 * when the hw goes bonghits. Which means we can commit the new state on
+	 * the software side now.
+	 */
+
+	drm_atomic_helper_swap_state(dev, state);
+
+	/*
+	 * Everything below can be run asynchronously without the need to grab
+	 * any modeset locks at all under one conditions: It must be guaranteed
+	 * that the asynchronous work has either been cancelled (if the driver
+	 * supports it, which at least requires that the framebuffers get
+	 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
+	 * before the new state gets committed on the software side with
+	 * drm_atomic_helper_swap_state().
+	 *
+	 * This scheme allows new atomic state updates to be prepared and
+	 * checked in parallel to the asynchronous completion of the previous
+	 * update. Which is important since compositors need to figure out the
+	 * composition of the next frame right after having submitted the
+	 * current layout.
+	 */
+
+	if (async) {
+		msm_queue_fence_cb(dev, &c->fence_cb, c->fence);
+		return 0;
+	}
+
+	jiffies_to_timespec(jiffies + msecs_to_jiffies(1000), &timeout);
+
+	ret = msm_wait_fence_interruptable(dev, c->fence, &timeout);
+	if (ret) {
+		WARN_ON(ret);  // TODO unswap state back?  or??
+		commit_destroy(c);
+		return ret;
+	}
+
+	complete_commit(c);
+
+	return 0;
+}