frameworks/native: Add support for Secure Display

- Add secure UI layers to primary and remove other layers from
  internal and external list for Secure Display usecase.
- Dont let secure UI layers to be captured on screen

Change-Id: Iebdad5c56247308604ee90928f6d6460a1f69279

services/surfaceflinger/Layer.cpp

@@ -1283,6 +1283,18 @@ bool Layer::isIntOnly() const
     }
     return false;
 }
+
+bool Layer::isSecureDisplay() const
+{
+    const sp<GraphicBuffer>& activeBuffer(mActiveBuffer);
+    if (activeBuffer != 0) {
+        uint32_t usage = activeBuffer->getUsage();
+        if(usage & GRALLOC_USAGE_PRIVATE_SECURE_DISPLAY)
+            return true;
+    }
+    return false;
+}
+
 #endif
 // ---------------------------------------------------------------------------
 }; // namespace android

services/surfaceflinger/Layer.h

@@ -261,6 +261,7 @@ class Layer : public SurfaceFlingerConsumer::FrameAvailableListener {
 #ifdef QCOM_BSP
     virtual bool isExtOnly() const;
     virtual bool isIntOnly() const;
+    virtual bool isSecureDisplay() const;
 #endif
 
     /*

services/surfaceflinger/SurfaceFlinger.cpp

@@ -1592,18 +1592,25 @@ void SurfaceFlinger::computeVisibleRegions(size_t dpy,
 
     outDirtyRegion.clear();
     bool bIgnoreLayers = false;
-    int extOnlyLayerIndex = -1;
+    int indexLOI = -1;
     size_t i = currentLayers.size();
 #ifdef QCOM_BSP
     while (i--) {
         const sp<Layer>& layer = currentLayers[i];
         // iterate through the layer list to find ext_only layers and store
         // the index
-        if ((dpy && layer->isExtOnly())) {
+        if (layer->isSecureDisplay()) {
             bIgnoreLayers = true;
-            extOnlyLayerIndex = i;
+            indexLOI = -1;
+            if(!dpy)
+                indexLOI = i;
             break;
         }
+
+        if (dpy && layer->isExtOnly()) {
+            bIgnoreLayers = true;
+            indexLOI = i;
+        }
     }
     i = currentLayers.size();
 #endif
@@ -1617,7 +1624,9 @@ void SurfaceFlinger::computeVisibleRegions(size_t dpy,
         // Only add the layer marked as "external_only" to external list and
         // only remove the layer marked as "external_only" from primary list
         // and do not add the layer marked as "internal_only" to external list
-        if((bIgnoreLayers && extOnlyLayerIndex != (int)i) ||
+        // Add secure UI layers to primary and remove other layers from internal
+        //and external list
+        if((bIgnoreLayers && indexLOI != (int)i) ||
            (!dpy && layer->isExtOnly()) ||
            (dpy && layer->isIntOnly())) {
             // Ignore all other layers except the layers marked as ext_only
@@ -3088,6 +3097,12 @@ void SurfaceFlinger::renderScreenImplLocked(
         const Layer::State& state(layer->getDrawingState());
         if (state.layerStack == hw->getLayerStack()) {
             if (state.z >= minLayerZ && state.z <= maxLayerZ) {
+#ifdef QCOM_BSP
+                // dont render the secure Display Layer
+                if(layer->isSecureDisplay()) {
+                    continue;
+                }
+#endif
                 if (layer->isVisible()) {
                     if (filtering) layer->setFiltering(true);
                     layer->draw(hw);