drm: GPU process manages VGEM fd.

ui/ozone/platform/drm/gpu/drm_device_manager.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/gpu/drm_device_manager.h"
 
 #include "base/file_descriptor_posix.h"
 #include "base/single_thread_task_runner.h"
 #include "ui/ozone/platform/drm/gpu/drm_device.h"
 #include "ui/ozone/platform/drm/gpu/drm_device_generator.h"
@@ skipping 20 matching lines @@
     scoped_ptr<DrmDeviceGenerator> drm_device_generator)
     : drm_device_generator_(drm_device_generator.Pass()) {
 }
 
 DrmDeviceManager::~DrmDeviceManager() {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(drm_device_map_.empty());
 }
 
 bool DrmDeviceManager::AddDrmDevice(const base::FilePath& path,
-                                    const base::FileDescriptor& fd) {
+                                    const base::FileDescriptor& fd,
+                                    bool is_vgem) {
   DCHECK(thread_checker_.CalledOnValidThread());
+
+  if (is_vgem) {
+    vgem_device_.reset(fd.fd);
+    vgem_path_ = path;
+    return true;
+  }
+
   base::File file(fd.fd);
   auto it =
       std::find_if(devices_.begin(), devices_.end(), FindByDevicePath(path));
   if (it != devices_.end()) {
     VLOG(2) << "Got request to add existing device: " << path.value();
     return false;
   }
 
   scoped_refptr<DrmDevice> device =
       drm_device_generator_->CreateDevice(path, file.Pass());
   if (!device) {
     LOG(ERROR) << "Could not initialize DRM device for " << path.value();
     return false;
   }
 
   if (io_task_runner_)
     device->InitializeTaskRunner(io_task_runner_);
 
   if (!primary_device_)
     primary_device_ = device;
 
   devices_.push_back(device);
   return true;
 }
 
 void DrmDeviceManager::RemoveDrmDevice(const base::FilePath& path) {
   DCHECK(thread_checker_.CalledOnValidThread());
+  if (vgem_path_ == path) {

[dnicoara, 2015/05/12 15:41:22]

Should it be possible to remove the VGEM device? If yes, maybe we shouldn't
cache the path of the VGEM device in DrmDisplayHostManager.

[dshwang, 2015/05/12 16:18:57]

What's mean? IMO it's impossible for chromium to drop vgem kernel module. vgem
path is immutable since chromebook booting.

+    vgem_device_.reset();
+    vgem_path_ = base::FilePath();
+    return;
+  }
+
   auto it =
       std::find_if(devices_.begin(), devices_.end(), FindByDevicePath(path));
   if (it == devices_.end()) {
     VLOG(2) << "Got request to remove non-existent device: " << path.value();
     return;
   }
 
   DCHECK_NE(primary_device_, *it);
   devices_.erase(it);
 }
@@ skipping 36 matching lines @@
     return primary_device_;
 
   return it->second;
 }
 
 const DrmDeviceVector& DrmDeviceManager::GetDrmDevices() const {
   DCHECK(thread_checker_.CalledOnValidThread());
   return devices_;
 }
 
+int DrmDeviceManager::GetVgemDevice() const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  return vgem_device_.get();
+}
+
 }  // namespace ui