drm_hwcomposer: Introduce Planner interface

This patch introduces a new Planner interface to the platform specific
code. This new interface will allow for platform-specific plane provisioning
decisions to cover various hardware quirks.

Each platform must provide a Planner with one or more PlanStage steps. These
stages are run in order and are used to move the given layers onto composition
planes.

There are two generic stages provided by the platform:
- Protected: Places layers on dedicated planes
- Greedy: Provisions as many layers to planes and sticks the rest in precomp

There is also one platform-specific stage included:
- ProtectedRotated: Places any protected & rotated layer on the primary plane

BUG=b/28117135
TEST=Tested on ryu with a variety of window layouts

Signed-off-by: Sean Paul <seanpaul@chromium.org>
Change-Id: Ib6062ab4779166753afaf122450bb63126bf9161

1 files changed, 167 insertions, 0 deletions

diff --git a/platform.cpp b/platform.cpp
new file mode 100644
index 0000000..105d8f7
--- /dev/null
+++ b/platform.cpp
@@ -0,0 +1,167 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "hwc-platform"
+
+#include "drmresources.h"
+#include "platform.h"
+
+#include <cutils/log.h>
+
+namespace android {
+
+std::vector<DrmPlane *> Planner::GetUsablePlanes(
+    DrmCrtc *crtc, std::vector<DrmPlane *> *primary_planes,
+    std::vector<DrmPlane *> *overlay_planes) {
+  std::vector<DrmPlane *> usable_planes;
+  std::copy_if(primary_planes->begin(), primary_planes->end(),
+               std::back_inserter(usable_planes),
+               [=](DrmPlane *plane) { return plane->GetCrtcSupported(*crtc); });
+  std::copy_if(overlay_planes->begin(), overlay_planes->end(),
+               std::back_inserter(usable_planes),
+               [=](DrmPlane *plane) { return plane->GetCrtcSupported(*crtc); });
+  return usable_planes;
+}
+
+std::tuple<int, std::vector<DrmCompositionPlane>> Planner::ProvisionPlanes(
+    std::map<size_t, DrmHwcLayer *> &layers, bool use_squash_fb, DrmCrtc *crtc,
+    std::vector<DrmPlane *> *primary_planes,
+    std::vector<DrmPlane *> *overlay_planes) {
+  std::vector<DrmCompositionPlane> composition;
+  std::vector<DrmPlane *> planes =
+      GetUsablePlanes(crtc, primary_planes, overlay_planes);
+  if (planes.empty()) {
+    ALOGE("Display %d has no usable planes", crtc->display());
+    return std::make_tuple(-ENODEV, std::vector<DrmCompositionPlane>());
+  }
+
+  // If needed, reserve the squash plane at the highest z-order
+  DrmPlane *squash_plane = NULL;
+  if (use_squash_fb) {
+    if (!planes.empty()) {
+      squash_plane = planes.back();
+      planes.pop_back();
+    } else {
+      ALOGI("Not enough planes to reserve for squash fb");
+    }
+  }
+
+  // If needed, reserve the precomp plane at the next highest z-order
+  DrmPlane *precomp_plane = NULL;
+  if (layers.size() > planes.size()) {
+    if (!planes.empty()) {
+      precomp_plane = planes.back();
+      planes.pop_back();
+      composition.emplace_back(DrmCompositionPlane::Type::kPrecomp,
+                               precomp_plane, crtc);
+    } else {
+      ALOGE("Not enough planes to reserve for precomp fb");
+    }
+  }
+
+  // Go through the provisioning stages and provision planes
+  for (auto &i : stages_) {
+    int ret = i->ProvisionPlanes(&composition, layers, crtc, &planes);
+    if (ret) {
+      ALOGE("Failed provision stage with ret %d", ret);
+      return std::make_tuple(ret, std::vector<DrmCompositionPlane>());
+    }
+  }
+
+  if (squash_plane)
+    composition.emplace_back(DrmCompositionPlane::Type::kSquash, squash_plane,
+                             crtc);
+
+  return std::make_tuple(0, std::move(composition));
+}
+
+int PlanStageProtected::ProvisionPlanes(
+    std::vector<DrmCompositionPlane> *composition,
+    std::map<size_t, DrmHwcLayer *> &layers, DrmCrtc *crtc,
+    std::vector<DrmPlane *> *planes) {
+  int ret;
+  int protected_zorder = -1;
+  for (auto i = layers.begin(); i != layers.end();) {
+    if (!i->second->protected_usage()) {
+      ++i;
+      continue;
+    }
+
+    ret = Emplace(composition, planes, DrmCompositionPlane::Type::kLayer, crtc,
+                  i->first);
+    if (ret)
+      ALOGE("Failed to dedicate protected layer! Dropping it.");
+
+    protected_zorder = i->first;
+    i = layers.erase(i);
+  }
+
+  if (protected_zorder == -1)
+    return 0;
+
+  // Add any layers below the protected content to the precomposition since we
+  // need to punch a hole through them.
+  for (auto i = layers.begin(); i != layers.end();) {
+    // Skip layers above the z-order of the protected content
+    if (i->first > static_cast<size_t>(protected_zorder)) {
+      ++i;
+      continue;
+    }
+
+    // If there's no precomp layer already queued, queue one now.
+    DrmCompositionPlane *precomp = GetPrecomp(composition);
+    if (precomp) {
+      precomp->source_layers().emplace_back(i->first);
+    } else {
+      if (!planes->empty()) {
+        DrmPlane *precomp_plane = planes->back();
+        planes->pop_back();
+        composition->emplace_back(DrmCompositionPlane::Type::kPrecomp,
+                                  precomp_plane, crtc, i->first);
+      } else {
+        ALOGE("Not enough planes to reserve for precomp fb");
+      }
+    }
+    i = layers.erase(i);
+  }
+  return 0;
+}
+
+int PlanStageGreedy::ProvisionPlanes(
+    std::vector<DrmCompositionPlane> *composition,
+    std::map<size_t, DrmHwcLayer *> &layers, DrmCrtc *crtc,
+    std::vector<DrmPlane *> *planes) {
+  // Fill up the remaining planes
+  for (auto i = layers.begin(); i != layers.end(); i = layers.erase(i)) {
+    int ret = Emplace(composition, planes, DrmCompositionPlane::Type::kLayer,
+                      crtc, i->first);
+    // We don't have any planes left
+    if (ret == -ENOENT)
+      break;
+    else if (ret)
+      ALOGE("Failed to emplace layer %zu, dropping it", i->first);
+  }
+
+  // Put the rest of the layers in the precomp plane
+  DrmCompositionPlane *precomp = GetPrecomp(composition);
+  if (precomp) {
+    for (auto i = layers.begin(); i != layers.end(); i = layers.erase(i))
+      precomp->source_layers().emplace_back(i->first);
+  }
+
+  return 0;
+}
+}