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

ui/ozone/platform/drm/common/client_native_pixmap_factory_gbm.cc

 // Copyright 2015 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/common/client_native_pixmap_factory_gbm.h"
 
+#include <fcntl.h>
+
 #include "base/file_descriptor_posix.h"
 #include "ui/ozone/public/client_native_pixmap_factory.h"
 
+#if defined(OZONE_USE_VGEM_MAP)
+#include "ui/ozone/platform/drm/gpu/client_native_pixmap_vgem.h"
+#endif
+
 namespace ui {
 
 namespace {
 
 class ClientNativePixmapFactoryGbm : public ClientNativePixmapFactory {
  public:
-  ClientNativePixmapFactoryGbm() {}
+  ClientNativePixmapFactoryGbm() {
+#if defined(OZONE_USE_VGEM_MAP)
+    // TODO(dshwang): remove ad-hoc file open. crrev.com/1248713002
+    static const char kVgemPath[] = "/dev/dri/renderD129";
+    int vgem_fd = open(kVgemPath, O_RDWR | O_CLOEXEC);
+    if (vgem_fd < 0) {
+      PLOG(ERROR) << "Failed to open: " << kVgemPath;
+      return;
+    }
+    vgem_fd_.reset(vgem_fd);
+#endif
+  }
   ~ClientNativePixmapFactoryGbm() override {}
 
   // ClientNativePixmapFactory:
   std::vector<Configuration> GetSupportedConfigurations() const override {
     const Configuration kConfiguratioins[] = {
         {gfx::BufferFormat::BGRA_8888, gfx::BufferUsage::SCANOUT},
         {gfx::BufferFormat::RGBX_8888, gfx::BufferUsage::SCANOUT}};
     std::vector<Configuration> configurations(
         kConfiguratioins, kConfiguratioins + arraysize(kConfiguratioins));
+#if defined(OZONE_USE_VGEM_MAP)
+    // Map requires VGEM supports.
+    if (vgem_fd_.get() >= 0) {
+      configurations.push_back(
+          {gfx::BufferFormat::BGRA_8888, gfx::BufferUsage::MAP});
+    }
+#endif
     return configurations;
   }
   scoped_ptr<ClientNativePixmap> ImportFromHandle(
       const gfx::NativePixmapHandle& handle,
       const gfx::Size& size,
       gfx::BufferFormat format,
       gfx::BufferUsage usage) override {
-    NOTIMPLEMENTED();
+    if (usage == gfx::BufferUsage::SCANOUT)

[reveman, 2015/08/07 14:35:16]

would it hurt to still create the client pixmap?

[dshwang, 2015/08/07 15:36:46]

Upstream linux cannot create vgem pixmap because vgem is not upstream. SCANOUT
should work with upstream linux.

+      return nullptr;
+#if defined(OZONE_USE_VGEM_MAP)
+    DCHECK_GE(vgem_fd_.get(), 0);
+    return ClientNativePixmapVgem::Create(
+        handle, base::FileDescriptor(vgem_fd_.get(), false), size, format,
+        usage);
+#else
     return nullptr;
+#endif
   }
 
  private:
+  base::ScopedFD vgem_fd_;
+
   DISALLOW_COPY_AND_ASSIGN(ClientNativePixmapFactoryGbm);
 };
 
 }  // namespace
 
 ClientNativePixmapFactory* CreateClientNativePixmapFactoryGbm() {
   return new ClientNativePixmapFactoryGbm();
 }
 
 }  // namespace ui