diff --git a/libs/ui/Gralloc2.cpp b/libs/ui/Gralloc2.cpp
index 0eb08e5..1f746a2 100644
--- a/libs/ui/Gralloc2.cpp
+++ b/libs/ui/Gralloc2.cpp
@@ -39,9 +39,15 @@
 Mapper::Mapper()
 {
     mMapper = IMapper::getService();
-    if (mMapper == nullptr || mMapper->isRemote()) {
+    if (mMapper == nullptr) {
+        LOG_ALWAYS_FATAL("gralloc-mapper is missing");
+    }
+    if (mMapper->isRemote()) {
         LOG_ALWAYS_FATAL("gralloc-mapper must be in passthrough mode");
     }
+
+    // IMapper 2.1 is optional
+    mMapperV2_1 = hardware::graphics::mapper::V2_1::IMapper::castFrom(mMapper);
 }
 
 Error Mapper::createDescriptor(
@@ -91,6 +97,50 @@
             buffer, error);
 }
 
+Error Mapper::validateBufferSize(buffer_handle_t bufferHandle,
+        const IMapper::BufferDescriptorInfo& descriptorInfo,
+        uint32_t stride) const
+{
+    if (mMapperV2_1 == nullptr) {
+        return Error::NONE;
+    }
+
+    auto buffer = const_cast<native_handle_t*>(bufferHandle);
+    auto ret = mMapperV2_1->validateBufferSize(buffer, descriptorInfo, stride);
+
+    return (ret.isOk()) ? static_cast<Error>(ret) : kTransactionError;
+}
+
+void Mapper::getTransportSize(buffer_handle_t bufferHandle,
+        uint32_t* outNumFds, uint32_t* outNumInts) const
+{
+    *outNumFds = uint32_t(bufferHandle->numFds);
+    *outNumInts = uint32_t(bufferHandle->numInts);
+
+    if (mMapperV2_1 == nullptr) {
+        return;
+    }
+
+    Error error;
+    auto buffer = const_cast<native_handle_t*>(bufferHandle);
+    auto ret = mMapperV2_1->getTransportSize(buffer,
+            [&](const auto& tmpError, const auto& tmpNumFds, const auto& tmpNumInts) {
+                error = tmpError;
+                if (error != Error::NONE) {
+                    return;
+                }
+
+                *outNumFds = tmpNumFds;
+                *outNumInts = tmpNumInts;
+            });
+
+    if (!ret.isOk()) {
+        error = kTransactionError;
+    }
+    ALOGE_IF(error != Error::NONE, "getTransportSize(%p) failed with %d",
+            buffer, error);
+}
+
 Error Mapper::lock(buffer_handle_t bufferHandle, uint64_t usage,
         const IMapper::Rect& accessRegion,
         int acquireFence, void** outData) const