drm/msm: atomic core bits
The core parts for async commit.
Signed-off-by: Rob Clark <robdclark@gmail.com>
diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c
new file mode 100644
index 0000000..8cf3361
--- /dev/null
+++ b/drivers/gpu/drm/msm/msm_atomic.c
@@ -0,0 +1,163 @@
+/*
+ * 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_atomic_state *state;
+ uint32_t fence;
+ struct msm_fence_cb fence_cb;
+};
+
+static void fence_cb(struct msm_fence_cb *cb);
+
+static struct msm_commit *new_commit(struct drm_atomic_state *state)
+{
+ struct msm_commit *c = kzalloc(sizeof(*c), GFP_KERNEL);
+
+ if (!c)
+ return NULL;
+
+ 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;
+}
+
+/* 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;
+
+ drm_atomic_helper_commit_pre_planes(dev, state);
+
+ drm_atomic_helper_commit_planes(dev, state);
+
+ drm_atomic_helper_commit_post_planes(dev, state);
+
+ drm_atomic_helper_wait_for_vblanks(dev, state);
+
+ drm_atomic_helper_cleanup_planes(dev, state);
+
+ drm_atomic_state_free(state);
+
+ kfree(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));
+}
+
+
+/**
+ * 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)
+{
+ struct msm_commit *c;
+ int nplanes = dev->mode_config.num_total_plane;
+ int i, ret;
+
+ ret = drm_atomic_helper_prepare_planes(dev, state);
+ if (ret)
+ return ret;
+
+ c = new_commit(state);
+
+ /*
+ * 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)
+ add_fb(c, new_state->fb);
+ }
+
+ /*
+ * 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;
+ }
+
+ ret = msm_wait_fence_interruptable(dev, c->fence, NULL);
+ if (ret) {
+ WARN_ON(ret); // TODO unswap state back? or??
+ kfree(c);
+ return ret;
+ }
+
+ complete_commit(c);
+
+ return 0;
+}