drm_hwcomposer: Rework HWC frontends buffer management

Change summary:

- Use BufferInfo instead of native_buffer to configure the HwcLayer.
- Extend buffer properties with slot info.
- Provide fence and active slot ID separate from the buffer.
- Move swapchain tracking into HWC2. HWC3 doesn't need that.

Why:

- Support more flexible resource management control from the frontend
  side,  which is required by HWC3 API.
- Move more Android-specific data types to the frontend module.

Change-Id: Idaa4c552f600f78d6f0ad21997cfa7f3a6c6cbd8
Signed-off-by: Roman Stratiienko <r.stratiienko@gmail.com>
diff --git a/hwc3/ComposerClient.cpp b/hwc3/ComposerClient.cpp
index 52c0e4a..c58e6e4 100644
--- a/hwc3/ComposerClient.cpp
+++ b/hwc3/ComposerClient.cpp
@@ -40,6 +40,7 @@
 #include <cutils/native_handle.h>
 #include <hardware/hwcomposer2.h>
 #include <hardware/hwcomposer_defs.h>
+#include <ui/GraphicBufferMapper.h>
 
 #include "bufferinfo/BufferInfo.h"
 #include "compositor/DisplayInfo.h"
@@ -351,6 +352,92 @@
 
 }  // namespace
 
+class Hwc3BufferHandle : public PrimeFdsSharedBase {
+ public:
+  static auto Create(buffer_handle_t handle)
+      -> std::shared_ptr<Hwc3BufferHandle> {
+    auto hwc3 = std::shared_ptr<Hwc3BufferHandle>(new Hwc3BufferHandle());
+
+    ::android::GraphicBufferMapper::get()
+        .importBufferNoValidate(handle, &hwc3->imported_handle_);
+
+    return hwc3;
+  }
+
+  auto GetHandle() const -> buffer_handle_t {
+    return imported_handle_;
+  }
+
+  ~Hwc3BufferHandle() override {
+    ::android::GraphicBufferMapper::get().freeBuffer(imported_handle_);
+  }
+
+ private:
+  Hwc3BufferHandle() = default;
+  buffer_handle_t imported_handle_{};
+};
+
+class Hwc3Layer : public ::android::FrontendLayerBase {
+ public:
+  auto HandleNextBuffer(std::optional<buffer_handle_t> raw_handle,
+                        ::android::SharedFd fence_fd, int32_t slot_id)
+      -> std::optional<HwcLayer::LayerProperties> {
+    HwcLayer::LayerProperties lp;
+    if (!raw_handle && slots_.count(slot_id) != 0) {
+      lp.active_slot = {
+          .slot_id = slot_id,
+          .fence = std::move(fence_fd),
+      };
+
+      return lp;
+    }
+
+    if (!raw_handle) {
+      ALOGE("Buffer handle is nullopt but slot was not cached.");
+      return std::nullopt;
+    }
+
+    auto hwc3 = Hwc3BufferHandle::Create(*raw_handle);
+    if (!hwc3) {
+      return std::nullopt;
+    }
+
+    auto bi = ::android::BufferInfoGetter::GetInstance()->GetBoInfo(
+        hwc3->GetHandle());
+    if (!bi) {
+      return std::nullopt;
+    }
+
+    bi->fds_shared = hwc3;
+
+    lp.slot_buffer = {
+        .slot_id = slot_id,
+        .bi = bi,
+    };
+
+    lp.active_slot = {
+        .slot_id = slot_id,
+        .fence = std::move(fence_fd),
+    };
+
+    slots_[slot_id] = hwc3;
+
+    return lp;
+  }
+
+ private:
+  std::map<int32_t /*slot*/, std::shared_ptr<Hwc3BufferHandle>> slots_;
+};
+
+static auto GetHwc3Layer(HwcLayer& layer) -> std::shared_ptr<Hwc3Layer> {
+  auto frontend_private_data = layer.GetFrontendPrivateData();
+  if (!frontend_private_data) {
+    frontend_private_data = std::make_shared<Hwc3Layer>();
+    layer.SetFrontendPrivateData(frontend_private_data);
+  }
+  return std::static_pointer_cast<Hwc3Layer>(frontend_private_data);
+}
+
 ComposerClient::ComposerClient() {
   DEBUG_FUNC();
 }
@@ -491,14 +578,26 @@
 
   HwcLayer::LayerProperties properties;
   if (command.buffer) {
-    HwcLayer::Buffer buffer;
-    auto err = ImportLayerBuffer(display_id, command.layer, *command.buffer,
-                                 &buffer);
-    if (err != hwc3::Error::kNone) {
-      cmd_result_writer_->AddError(err);
+    auto hwc3_layer = GetHwc3Layer(*layer);
+    std::optional<buffer_handle_t> buffer_handle = std::nullopt;
+    if (command.buffer->handle) {
+      buffer_handle = ::android::makeFromAidl(*command.buffer->handle);
+    }
+
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-const-cast)
+    auto fence = const_cast<::ndk::ScopedFileDescriptor&>(command.buffer->fence)
+                     .release();
+
+    auto lp = hwc3_layer->HandleNextBuffer(buffer_handle,
+                                           ::android::MakeSharedFd(fence),
+                                           command.buffer->slot);
+
+    if (!lp) {
+      cmd_result_writer_->AddError(hwc3::Error::kBadLayer);
       return;
     }
-    properties.buffer.emplace(buffer);
+
+    properties = lp.value();
   }
 
   properties.blend_mode = AidlToBlendMode(command.blendMode);
@@ -1297,7 +1396,8 @@
 }
 
 ndk::ScopedAStatus ComposerClient::notifyExpectedPresent(
-    int64_t /*display*/, const ClockMonotonicTimestamp& /*expected_present_time*/,
+    int64_t /*display*/,
+    const ClockMonotonicTimestamp& /*expected_present_time*/,
     int32_t /*frame_interval_ns*/) {
   return ToBinderStatus(hwc3::Error::kUnsupported);
 }
@@ -1319,19 +1419,6 @@
   return binder;
 }
 
-hwc3::Error ComposerClient::ImportLayerBuffer(int64_t display_id,
-                                              int64_t layer_id,
-                                              const Buffer& buffer,
-                                              HwcLayer::Buffer* out_buffer) {
-  auto releaser = ComposerResources::CreateResourceReleaser(true);
-  auto err = composer_resources_->GetLayerBuffer(display_id, layer_id, buffer,
-                                                 &out_buffer->buffer_handle,
-                                                 releaser.get());
-  out_buffer->acquire_fence = ::android::MakeSharedFd(
-      buffer.fence.dup().release());
-  return err;
-}
-
 void ComposerClient::ExecuteSetDisplayClientTarget(
     uint64_t display_id, const ClientTarget& command) {
   auto* display = GetDisplay(display_id);
@@ -1340,31 +1427,35 @@
     return;
   }
 
-  buffer_handle_t imported_buffer = nullptr;
-  auto buf_releaser = ComposerResources::CreateResourceReleaser(true);
+  auto& client_layer = display->GetClientLayer();
+  auto hwc3layer = GetHwc3Layer(client_layer);
 
-  auto error = composer_resources_->GetDisplayClientTarget(display_id,
-                                                           command.buffer,
-                                                           &imported_buffer,
-                                                           buf_releaser.get());
-  if (error != hwc3::Error::kNone) {
-    cmd_result_writer_->AddError(error);
-    return;
+  std::optional<buffer_handle_t> raw_buffer = std::nullopt;
+  if (command.buffer.handle) {
+    raw_buffer = ::android::makeFromAidl(*command.buffer.handle);
   }
 
   // NOLINTNEXTLINE(cppcoreguidelines-pro-type-const-cast)
   auto fence = const_cast<::ndk::ScopedFileDescriptor&>(command.buffer.fence)
                    .release();
-  auto& client_layer = display->GetClientLayer();
-  HwcLayer::LayerProperties properties;
-  properties.buffer = {
-      .buffer_handle = imported_buffer,
-      .acquire_fence = ::android::MakeSharedFd(fence),
-  };
-  properties.color_space = AidlToColorSpace(command.dataspace);
-  properties.sample_range = AidlToSampleRange(command.dataspace);
 
-  client_layer.SetLayerProperties(properties);
+  auto properties = hwc3layer->HandleNextBuffer(raw_buffer,
+                                                ::android::MakeSharedFd(fence),
+                                                command.buffer.slot);
+
+  if (!properties) {
+    ALOGE("Failed to import client target buffer.");
+    /* Here, sending an error would be the natural way to do the thing.
+     * But VTS checks for no error. Is it the VTS issue?
+     * https://cs.android.com/android/platform/superproject/main/+/main:hardware/interfaces/graphics/composer/aidl/vts/VtsHalGraphicsComposer3_TargetTest.cpp;l=1892;drc=2647200f4c535ca6567b452695b7d13f2aaf3f2a
+     */
+    return;
+  }
+
+  properties->color_space = AidlToColorSpace(command.dataspace);
+  properties->sample_range = AidlToSampleRange(command.dataspace);
+
+  client_layer.SetLayerProperties(properties.value());
 }
 
 void ComposerClient::ExecuteSetDisplayOutputBuffer(uint64_t display_id,
@@ -1375,33 +1466,32 @@
     return;
   }
 
-  buffer_handle_t imported_buffer = nullptr;
-  auto buf_releaser = ComposerResources::CreateResourceReleaser(true);
-
-  auto error = composer_resources_->GetDisplayOutputBuffer(display_id, buffer,
-                                                           &imported_buffer,
-                                                           buf_releaser.get());
-  if (error != hwc3::Error::kNone) {
-    cmd_result_writer_->AddError(error);
-    return;
-  }
-
-  // NOLINTNEXTLINE(cppcoreguidelines-pro-type-const-cast)
-  auto fence = const_cast<::ndk::ScopedFileDescriptor&>(buffer.fence).release();
-
   auto& writeback_layer = display->GetWritebackLayer();
   if (!writeback_layer) {
     cmd_result_writer_->AddError(hwc3::Error::kBadLayer);
     return;
   }
 
-  HwcLayer::LayerProperties properties;
-  properties.buffer = {
-      .buffer_handle = imported_buffer,
-      .acquire_fence = ::android::MakeSharedFd(fence),
-  };
+  auto hwc3layer = GetHwc3Layer(*writeback_layer);
 
-  writeback_layer->SetLayerProperties(properties);
+  std::optional<buffer_handle_t> raw_buffer = std::nullopt;
+  if (buffer.handle) {
+    raw_buffer = ::android::makeFromAidl(*buffer.handle);
+  }
+
+  // NOLINTNEXTLINE(cppcoreguidelines-pro-type-const-cast)
+  auto fence = const_cast<::ndk::ScopedFileDescriptor&>(buffer.fence).release();
+
+  auto properties = hwc3layer->HandleNextBuffer(raw_buffer,
+                                                ::android::MakeSharedFd(fence),
+                                                buffer.slot);
+
+  if (!properties) {
+    cmd_result_writer_->AddError(hwc3::Error::kBadLayer);
+    return;
+  }
+
+  writeback_layer->SetLayerProperties(properties.value());
 }
 
 }  // namespace aidl::android::hardware::graphics::composer3::impl