ozone: Implement zero/one-copy texture for Ozone GBM.

ui/ozone/platform/drm/gpu/gbm_surface_factory.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/ozone/platform/drm/gpu/gbm_surface_factory.h"
 
 #include <gbm.h>
 
 #include "base/files/file_path.h"
+#include "base/posix/eintr_wrapper.h"
 #include "third_party/khronos/EGL/egl.h"
 #include "ui/ozone/common/egl_util.h"
 #include "ui/ozone/platform/drm/gpu/drm_device_manager.h"
 #include "ui/ozone/platform/drm/gpu/drm_window.h"
 #include "ui/ozone/platform/drm/gpu/gbm_buffer.h"
 #include "ui/ozone/platform/drm/gpu/gbm_device.h"
 #include "ui/ozone/platform/drm/gpu/gbm_surface.h"
 #include "ui/ozone/platform/drm/gpu/gbm_surfaceless.h"
 #include "ui/ozone/platform/drm/gpu/hardware_display_controller.h"
 #include "ui/ozone/platform/drm/gpu/screen_manager.h"
 #include "ui/ozone/public/native_pixmap.h"
 #include "ui/ozone/public/surface_ozone_canvas.h"
 #include "ui/ozone/public/surface_ozone_egl.h"
 
 namespace ui {
 
+namespace {
+
+bool ShareToRenderProcess(int fd, base::FileDescriptor* new_handle) {
+  int duped_handle = HANDLE_EINTR(dup(fd));
+  if (duped_handle < 0) {
+    DPLOG(ERROR) << "dup() failed.";
+    *new_handle = base::FileDescriptor();
+    return false;
+  }
+
+  *new_handle = base::FileDescriptor(duped_handle, true);
+  return true;
+}
+
+}  // namespace
+
 GbmSurfaceFactory::GbmSurfaceFactory(bool allow_surfaceless)
-    : DrmSurfaceFactory(NULL), allow_surfaceless_(allow_surfaceless) {
+    : DrmSurfaceFactory(NULL),
+      allow_surfaceless_(allow_surfaceless),
+      drm_device_manager_(nullptr) {
 }
 
 GbmSurfaceFactory::~GbmSurfaceFactory() {
   DCHECK(thread_checker_.CalledOnValidThread());
 }
 
 void GbmSurfaceFactory::InitializeGpu(DrmDeviceManager* drm_device_manager,
                                       ScreenManager* screen_manager) {
   drm_device_manager_ = drm_device_manager;
   screen_manager_ = screen_manager;
@@ skipping 63 matching lines @@
 
   return make_scoped_ptr(new GbmSurfaceless(screen_manager_->GetWindow(widget),
                                             drm_device_manager_));
 }
 
 scoped_refptr<ui::NativePixmap> GbmSurfaceFactory::CreateNativePixmap(
     gfx::AcceleratedWidget widget,
     gfx::Size size,
     BufferFormat format,
     BufferUsage usage) {
-  if (usage == MAP)
-    return nullptr;
-
   scoped_refptr<GbmDevice> gbm = GetGbmDevice(widget);
   DCHECK(gbm);
 
   scoped_refptr<GbmBuffer> buffer =
-      GbmBuffer::CreateBuffer(gbm, format, size, true);
+      GbmBuffer::CreateBuffer(gbm, format, size, usage == SCANOUT);
   if (!buffer.get())
     return nullptr;
 
   scoped_refptr<GbmPixmap> pixmap(new GbmPixmap(buffer, screen_manager_));
   if (!pixmap->Initialize())
     return nullptr;
 
   return pixmap;
 }
 
+base::FileDescriptor GbmSurfaceFactory::ExportDmaBuf(
+    gfx::AcceleratedWidget widget,
+    scoped_refptr<NativePixmap> pixmap) {
+  scoped_refptr<GbmDevice> gbm = GetGbmDevice(widget);
+  DCHECK(gbm);
+  DCHECK(pixmap->GetBufferUsage() == NativePixmap::MAP);
+
+  base::FileDescriptor dma_buf;
+  if (!ShareToRenderProcess(pixmap->GetDmaBufFd(), &dma_buf)) {
+    DLOG(ERROR) << "Fail to duplicate a DMA-BUF file descriptor";
+    return base::FileDescriptor();
+  }
+
+  return dma_buf;
+}
+
 bool GbmSurfaceFactory::CanShowPrimaryPlaneAsOverlay() {
   DCHECK(thread_checker_.CalledOnValidThread());
   return allow_surfaceless_;
 }
 
 scoped_refptr<GbmDevice> GbmSurfaceFactory::GetGbmDevice(
     gfx::AcceleratedWidget widget) {
   return static_cast<GbmDevice*>(
       drm_device_manager_->GetDrmDevice(widget).get());
 }
 
 }  // namespace ui