diff --git a/libs/ui/Gralloc4.cpp b/libs/ui/Gralloc4.cpp
new file mode 100644
index 0000000..dc105c0
--- /dev/null
+++ b/libs/ui/Gralloc4.cpp
@@ -0,0 +1,405 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "Gralloc4"
+
+#include <hidl/ServiceManagement.h>
+#include <hwbinder/IPCThreadState.h>
+#include <ui/Gralloc4.h>
+
+#include <inttypes.h>
+#include <log/log.h>
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wzero-length-array"
+#include <sync/sync.h>
+#pragma clang diagnostic pop
+
+using android::hardware::graphics::allocator::V4_0::IAllocator;
+using android::hardware::graphics::common::V1_2::BufferUsage;
+using android::hardware::graphics::mapper::V4_0::BufferDescriptor;
+using android::hardware::graphics::mapper::V4_0::Error;
+using android::hardware::graphics::mapper::V4_0::IMapper;
+using android::hardware::graphics::mapper::V4_0::YCbCrLayout;
+
+namespace android {
+
+namespace {
+
+static constexpr Error kTransactionError = Error::NO_RESOURCES;
+
+uint64_t getValidUsageBits() {
+    static const uint64_t validUsageBits = []() -> uint64_t {
+        uint64_t bits = 0;
+        for (const auto bit :
+             hardware::hidl_enum_range<hardware::graphics::common::V1_2::BufferUsage>()) {
+            bits = bits | bit;
+        }
+        return bits;
+    }();
+    return validUsageBits;
+}
+
+static inline IMapper::Rect sGralloc4Rect(const Rect& rect) {
+    IMapper::Rect outRect{};
+    outRect.left = rect.left;
+    outRect.top = rect.top;
+    outRect.width = rect.width();
+    outRect.height = rect.height();
+    return outRect;
+}
+static inline void sBufferDescriptorInfo(uint32_t width, uint32_t height,
+                                         android::PixelFormat format, uint32_t layerCount,
+                                         uint64_t usage,
+                                         IMapper::BufferDescriptorInfo* outDescriptorInfo) {
+    outDescriptorInfo->width = width;
+    outDescriptorInfo->height = height;
+    outDescriptorInfo->layerCount = layerCount;
+    outDescriptorInfo->format = static_cast<hardware::graphics::common::V1_2::PixelFormat>(format);
+    outDescriptorInfo->usage = usage;
+}
+
+} // anonymous namespace
+
+void Gralloc4Mapper::preload() {
+    android::hardware::preloadPassthroughService<IMapper>();
+}
+
+Gralloc4Mapper::Gralloc4Mapper() {
+    mMapper = IMapper::getService();
+    if (mMapper == nullptr) {
+        ALOGI("mapper 4.x is not supported");
+        return;
+    }
+    if (mMapper->isRemote()) {
+        LOG_ALWAYS_FATAL("gralloc-mapper must be in passthrough mode");
+    }
+}
+
+bool Gralloc4Mapper::isLoaded() const {
+    return mMapper != nullptr;
+}
+
+status_t Gralloc4Mapper::validateBufferDescriptorInfo(
+        IMapper::BufferDescriptorInfo* descriptorInfo) const {
+    uint64_t validUsageBits = getValidUsageBits();
+
+    if (descriptorInfo->usage & ~validUsageBits) {
+        ALOGE("buffer descriptor contains invalid usage bits 0x%" PRIx64,
+              descriptorInfo->usage & ~validUsageBits);
+        return BAD_VALUE;
+    }
+    return NO_ERROR;
+}
+
+status_t Gralloc4Mapper::createDescriptor(void* bufferDescriptorInfo,
+                                          void* outBufferDescriptor) const {
+    IMapper::BufferDescriptorInfo* descriptorInfo =
+            static_cast<IMapper::BufferDescriptorInfo*>(bufferDescriptorInfo);
+    BufferDescriptor* outDescriptor = static_cast<BufferDescriptor*>(outBufferDescriptor);
+
+    status_t status = validateBufferDescriptorInfo(descriptorInfo);
+    if (status != NO_ERROR) {
+        return status;
+    }
+
+    Error error;
+    auto hidl_cb = [&](const auto& tmpError, const auto& tmpDescriptor) {
+        error = tmpError;
+        if (error != Error::NONE) {
+            return;
+        }
+        *outDescriptor = tmpDescriptor;
+    };
+
+    hardware::Return<void> ret = mMapper->createDescriptor(*descriptorInfo, hidl_cb);
+
+    return static_cast<status_t>((ret.isOk()) ? error : kTransactionError);
+}
+
+status_t Gralloc4Mapper::importBuffer(const hardware::hidl_handle& rawHandle,
+                                      buffer_handle_t* outBufferHandle) const {
+    Error error;
+    auto ret = mMapper->importBuffer(rawHandle, [&](const auto& tmpError, const auto& tmpBuffer) {
+        error = tmpError;
+        if (error != Error::NONE) {
+            return;
+        }
+        *outBufferHandle = static_cast<buffer_handle_t>(tmpBuffer);
+    });
+
+    return static_cast<status_t>((ret.isOk()) ? error : kTransactionError);
+}
+
+void Gralloc4Mapper::freeBuffer(buffer_handle_t bufferHandle) const {
+    auto buffer = const_cast<native_handle_t*>(bufferHandle);
+    auto ret = mMapper->freeBuffer(buffer);
+
+    auto error = (ret.isOk()) ? static_cast<Error>(ret) : kTransactionError;
+    ALOGE_IF(error != Error::NONE, "freeBuffer(%p) failed with %d", buffer, error);
+}
+
+status_t Gralloc4Mapper::validateBufferSize(buffer_handle_t bufferHandle, uint32_t width,
+                                            uint32_t height, android::PixelFormat format,
+                                            uint32_t layerCount, uint64_t usage,
+                                            uint32_t stride) const {
+    IMapper::BufferDescriptorInfo descriptorInfo;
+    sBufferDescriptorInfo(width, height, format, layerCount, usage, &descriptorInfo);
+
+    auto buffer = const_cast<native_handle_t*>(bufferHandle);
+    auto ret = mMapper->validateBufferSize(buffer, descriptorInfo, stride);
+
+    return static_cast<status_t>((ret.isOk()) ? static_cast<Error>(ret) : kTransactionError);
+}
+
+void Gralloc4Mapper::getTransportSize(buffer_handle_t bufferHandle, uint32_t* outNumFds,
+                                      uint32_t* outNumInts) const {
+    *outNumFds = uint32_t(bufferHandle->numFds);
+    *outNumInts = uint32_t(bufferHandle->numInts);
+
+    Error error;
+    auto buffer = const_cast<native_handle_t*>(bufferHandle);
+    auto ret = mMapper->getTransportSize(buffer,
+                                         [&](const auto& tmpError, const auto& tmpNumFds,
+                                             const auto& tmpNumInts) {
+                                             error = tmpError;
+                                             if (error != Error::NONE) {
+                                                 return;
+                                             }
+                                             *outNumFds = tmpNumFds;
+                                             *outNumInts = tmpNumInts;
+                                         });
+
+    error = (ret.isOk()) ? error : kTransactionError;
+
+    ALOGE_IF(error != Error::NONE, "getTransportSize(%p) failed with %d", buffer, error);
+}
+
+status_t Gralloc4Mapper::lock(buffer_handle_t bufferHandle, uint64_t usage, const Rect& bounds,
+                              int acquireFence, void** outData, int32_t* outBytesPerPixel,
+                              int32_t* outBytesPerStride) const {
+    auto buffer = const_cast<native_handle_t*>(bufferHandle);
+
+    IMapper::Rect accessRegion = sGralloc4Rect(bounds);
+
+    // put acquireFence in a hidl_handle
+    hardware::hidl_handle acquireFenceHandle;
+    NATIVE_HANDLE_DECLARE_STORAGE(acquireFenceStorage, 1, 0);
+    if (acquireFence >= 0) {
+        auto h = native_handle_init(acquireFenceStorage, 1, 0);
+        h->data[0] = acquireFence;
+        acquireFenceHandle = h;
+    }
+
+    Error error;
+    auto ret = mMapper->lock(buffer, usage, accessRegion, acquireFenceHandle,
+                             [&](const auto& tmpError, const auto& tmpData,
+                                 const auto& tmpBytesPerPixel, const auto& tmpBytesPerStride) {
+                                 error = tmpError;
+                                 if (error != Error::NONE) {
+                                     return;
+                                 }
+                                 *outData = tmpData;
+                                 if (outBytesPerPixel) {
+                                     *outBytesPerPixel = tmpBytesPerPixel;
+                                 }
+                                 if (outBytesPerStride) {
+                                     *outBytesPerStride = tmpBytesPerStride;
+                                 }
+                             });
+
+    // we own acquireFence even on errors
+    if (acquireFence >= 0) {
+        close(acquireFence);
+    }
+
+    error = (ret.isOk()) ? error : kTransactionError;
+
+    ALOGW_IF(error != Error::NONE, "lock(%p, ...) failed: %d", bufferHandle, error);
+
+    return static_cast<status_t>(error);
+}
+
+status_t Gralloc4Mapper::lock(buffer_handle_t bufferHandle, uint64_t usage, const Rect& bounds,
+                              int acquireFence, android_ycbcr* ycbcr) const {
+    auto buffer = const_cast<native_handle_t*>(bufferHandle);
+
+    IMapper::Rect accessRegion = sGralloc4Rect(bounds);
+
+    // put acquireFence in a hidl_handle
+    hardware::hidl_handle acquireFenceHandle;
+    NATIVE_HANDLE_DECLARE_STORAGE(acquireFenceStorage, 1, 0);
+    if (acquireFence >= 0) {
+        auto h = native_handle_init(acquireFenceStorage, 1, 0);
+        h->data[0] = acquireFence;
+        acquireFenceHandle = h;
+    }
+
+    YCbCrLayout layout;
+    Error error;
+    auto ret = mMapper->lockYCbCr(buffer, usage, accessRegion, acquireFenceHandle,
+                                  [&](const auto& tmpError, const auto& tmpLayout) {
+                                      error = tmpError;
+                                      if (error != Error::NONE) {
+                                          return;
+                                      }
+
+                                      layout = tmpLayout;
+                                  });
+
+    if (error == Error::NONE) {
+        ycbcr->y = layout.y;
+        ycbcr->cb = layout.cb;
+        ycbcr->cr = layout.cr;
+        ycbcr->ystride = static_cast<size_t>(layout.yStride);
+        ycbcr->cstride = static_cast<size_t>(layout.cStride);
+        ycbcr->chroma_step = static_cast<size_t>(layout.chromaStep);
+    }
+
+    // we own acquireFence even on errors
+    if (acquireFence >= 0) {
+        close(acquireFence);
+    }
+
+    return static_cast<status_t>((ret.isOk()) ? error : kTransactionError);
+}
+
+int Gralloc4Mapper::unlock(buffer_handle_t bufferHandle) const {
+    auto buffer = const_cast<native_handle_t*>(bufferHandle);
+
+    int releaseFence = -1;
+    Error error;
+    auto ret = mMapper->unlock(buffer, [&](const auto& tmpError, const auto& tmpReleaseFence) {
+        error = tmpError;
+        if (error != Error::NONE) {
+            return;
+        }
+
+        auto fenceHandle = tmpReleaseFence.getNativeHandle();
+        if (fenceHandle && fenceHandle->numFds == 1) {
+            int fd = dup(fenceHandle->data[0]);
+            if (fd >= 0) {
+                releaseFence = fd;
+            } else {
+                ALOGD("failed to dup unlock release fence");
+                sync_wait(fenceHandle->data[0], -1);
+            }
+        }
+    });
+
+    if (!ret.isOk()) {
+        error = kTransactionError;
+    }
+
+    if (error != Error::NONE) {
+        ALOGE("unlock(%p) failed with %d", buffer, error);
+    }
+
+    return releaseFence;
+}
+
+status_t Gralloc4Mapper::isSupported(uint32_t width, uint32_t height, android::PixelFormat format,
+                                     uint32_t layerCount, uint64_t usage,
+                                     bool* outSupported) const {
+    IMapper::BufferDescriptorInfo descriptorInfo;
+    sBufferDescriptorInfo(width, height, format, layerCount, usage, &descriptorInfo);
+
+    Error error;
+    auto ret = mMapper->isSupported(descriptorInfo,
+                                    [&](const auto& tmpError, const auto& tmpSupported) {
+                                        error = tmpError;
+                                        if (error != Error::NONE) {
+                                            return;
+                                        }
+                                        if (outSupported) {
+                                            *outSupported = tmpSupported;
+                                        }
+                                    });
+
+    if (!ret.isOk()) {
+        error = kTransactionError;
+    }
+
+    if (error != Error::NONE) {
+        ALOGE("isSupported(%u, %u, %d, %u, ...) failed with %d", width, height, format, layerCount,
+              error);
+    }
+
+    return static_cast<status_t>(error);
+}
+
+Gralloc4Allocator::Gralloc4Allocator(const Gralloc4Mapper& mapper) : mMapper(mapper) {
+    mAllocator = IAllocator::getService();
+    if (mAllocator == nullptr) {
+        ALOGW("allocator 3.x is not supported");
+        return;
+    }
+}
+
+bool Gralloc4Allocator::isLoaded() const {
+    return mAllocator != nullptr;
+}
+
+std::string Gralloc4Allocator::dumpDebugInfo() const {
+    std::string debugInfo;
+
+    mAllocator->dumpDebugInfo([&](const auto& tmpDebugInfo) { debugInfo = tmpDebugInfo.c_str(); });
+
+    return debugInfo;
+}
+
+status_t Gralloc4Allocator::allocate(uint32_t width, uint32_t height, android::PixelFormat format,
+                                     uint32_t layerCount, uint64_t usage, uint32_t bufferCount,
+                                     uint32_t* outStride, buffer_handle_t* outBufferHandles) const {
+    IMapper::BufferDescriptorInfo descriptorInfo;
+    sBufferDescriptorInfo(width, height, format, layerCount, usage, &descriptorInfo);
+
+    BufferDescriptor descriptor;
+    status_t error = mMapper.createDescriptor(static_cast<void*>(&descriptorInfo),
+                                              static_cast<void*>(&descriptor));
+    if (error != NO_ERROR) {
+        return error;
+    }
+
+    auto ret = mAllocator->allocate(descriptor, bufferCount,
+                                    [&](const auto& tmpError, const auto& tmpStride,
+                                        const auto& tmpBuffers) {
+                                        error = static_cast<status_t>(tmpError);
+                                        if (tmpError != Error::NONE) {
+                                            return;
+                                        }
+
+                                        // import buffers
+                                        for (uint32_t i = 0; i < bufferCount; i++) {
+                                            error = mMapper.importBuffer(tmpBuffers[i],
+                                                                         &outBufferHandles[i]);
+                                            if (error != NO_ERROR) {
+                                                for (uint32_t j = 0; j < i; j++) {
+                                                    mMapper.freeBuffer(outBufferHandles[j]);
+                                                    outBufferHandles[j] = nullptr;
+                                                }
+                                                return;
+                                            }
+                                        }
+                                        *outStride = tmpStride;
+                                    });
+
+    // make sure the kernel driver sees BC_FREE_BUFFER and closes the fds now
+    hardware::IPCThreadState::self()->flushCommands();
+
+    return (ret.isOk()) ? error : static_cast<status_t>(kTransactionError);
+}
+
+} // namespace android