zero copy - NOT FOR REVIEW

content/common/gpu/client/gpu_memory_buffer_impl_foobar.cc

+// Copyright 2013 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 "base/debug/trace_event.h"
+
+#include "content/common/gpu/client/gpu_memory_buffer_impl_foobar.h"
+
+#include "ui/gl/gl_bindings.h"
+
+extern "C" {
+#include <libdrm/intel_bufmgr.h>
+}
+
+char GetZCopy() {
+  // 0 off, 't' tiled, 'u' untiled
+  static char mode;
+  static char done = 0;
+  if (!done) {
+    done = 1;
+    mode = 0;
+    char *e = getenv("ZCOPY");
+    if (e) {
+      if (e[0] == 't') {
+        mode = 't';
+        TRACE_EVENT_INSTANT0("zcopy", "zero copy enabled - tiled mode",
+                             TRACE_EVENT_SCOPE_THREAD);
+      } else if (e[0] == 'u') {
+        mode = 'u';
+        TRACE_EVENT_INSTANT0("zcopy", "zero copy enabled - untiled mode",
+                             TRACE_EVENT_SCOPE_THREAD);
+      }
+    }
+    if (!mode) {
+      TRACE_EVENT_INSTANT0("zcopy", "zero copy disabled",
+                           TRACE_EVENT_SCOPE_THREAD);
+    }
+  }
+  return mode;
+}
+
+namespace content {
+
+GpuMemoryBufferImplFoobar::GpuMemoryBufferImplFoobar(
+    gfx::Size size, unsigned internalformat)
+    : GpuMemoryBufferImpl(size, internalformat), _prime_fd(-1) {
+}
+
+GpuMemoryBufferImplFoobar::~GpuMemoryBufferImplFoobar() {
+  if (_prime_fd >= 0) {
+    close(_prime_fd);
+  }
+  drm_intel_bo_unreference(foobar_object);
+}
+
+int GpuMemoryBufferImplFoobar::prime_fd() const {
+  if (_prime_fd < 0) {
+    TRACE_EVENT0("zcopy", "export");
+    DCHECK(foobar_object);
+    drm_intel_bo_gem_export_to_prime(foobar_object, &_prime_fd);
+  }
+  return _prime_fd;
+}
+
+// static
+bool GpuMemoryBufferImplFoobar::IsFormatSupported(unsigned internalformat) {
+  return GetZCopy() && internalformat == GL_BGRA8_EXT;
+}
+
+bool GpuMemoryBufferImplFoobar::InitializeFromFoobarObject(
+    void *foobar_object) {
+  this->foobar_object = (drm_intel_bo *) foobar_object;
+  return true;
+}
+
+void GpuMemoryBufferImplFoobar::Map(AccessMode mode, void** vaddr) {
+  DCHECK(!mapped_);
+  TRACE_EVENT0("zcopy", "map");
+  if (GetZCopy() == 'u')
+    drm_intel_bo_map(foobar_object, 1);
+  else
+    drm_intel_gem_bo_map_gtt(foobar_object);
+  *vaddr = foobar_object->virt;
+  mapped_ = true;
+}
+
+void GpuMemoryBufferImplFoobar::Unmap() {
+  DCHECK(mapped_);
+  drm_intel_bo_unmap(foobar_object);
+  mapped_ = false;
+}
+
+gfx::GpuMemoryBufferHandle GpuMemoryBufferImplFoobar::GetHandle() const {
+  gfx::GpuMemoryBufferHandle handle;
+  handle.type = gfx::FOOBAR_BUFFER;
+  handle.handle.fd = prime_fd();
+  return handle;
+}
+
+}  // namespace content