// Copyright (C) 2019 The Android Open Source Project
// Copyright (C) 2019 Google Inc.
//
// 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.

#include "android/emulation/hostdevices/HostAddressSpace.h"

#include <memory>

#if PLATFORM_SDK_VERSION < 26
#include <cutils/log.h>
#else
#include <log/log.h>
#endif

#include <errno.h>
#include "goldfish_address_space.h"

namespace {

const int HOST_MEMORY_ALLOCATOR_COMMAND_ALLOCATE_ID = 1;
const int HOST_MEMORY_ALLOCATOR_COMMAND_UNALLOCATE_ID = 2;

}  // namsepace

using android::HostAddressSpaceDevice;
using android::emulation::AddressSpaceDevicePingInfo;

GoldfishAddressSpaceBlockProvider::GoldfishAddressSpaceBlockProvider(GoldfishAddressSpaceSubdeviceType subdevice)
    : m_handle(HostAddressSpaceDevice::get()->open())
{
    if ((subdevice != GoldfishAddressSpaceSubdeviceType::NoSubdevice) && is_opened()) {
        AddressSpaceDevicePingInfo request;
        ::memset(&request, 0, sizeof(request));
        request.metadata = subdevice;

        HostAddressSpaceDevice::get()->ping(m_handle, &request);
    }
}

GoldfishAddressSpaceBlockProvider::~GoldfishAddressSpaceBlockProvider()
{
    if (is_opened()) {
        HostAddressSpaceDevice::get()->close(m_handle);
    }
}

bool GoldfishAddressSpaceBlockProvider::is_opened() const
{
    return m_handle > 0;
}

void GoldfishAddressSpaceBlockProvider::close()
{
    if (is_opened()) {
        HostAddressSpaceDevice::get()->close(m_handle);
        m_handle = 0;
    }
}

address_space_handle_t GoldfishAddressSpaceBlockProvider::release()
{
    address_space_handle_t handle = m_handle;
    m_handle = 0;
    return handle;
}

void GoldfishAddressSpaceBlockProvider::closeHandle(address_space_handle_t handle)
{
    HostAddressSpaceDevice::get()->close(handle);
}

GoldfishAddressSpaceBlock::GoldfishAddressSpaceBlock()
    : m_handle(0)
    , m_mmaped_ptr(NULL)
    , m_phys_addr(0)
    , m_host_addr(0)
    , m_offset(0)
    , m_size(0)
    , m_is_shared_mapping(false) {}

GoldfishAddressSpaceBlock::~GoldfishAddressSpaceBlock()
{
    destroy();
}

GoldfishAddressSpaceBlock &GoldfishAddressSpaceBlock::operator=(const GoldfishAddressSpaceBlock &rhs)
{
    m_mmaped_ptr = rhs.m_mmaped_ptr;
    m_phys_addr = rhs.m_phys_addr;
    m_host_addr = rhs.m_host_addr;
    m_offset = rhs.m_offset;
    m_size = rhs.m_size;
    m_is_shared_mapping = rhs.m_is_shared_mapping;
    m_handle = rhs.m_handle;
    return *this;
}

bool GoldfishAddressSpaceBlock::allocate(GoldfishAddressSpaceBlockProvider *provider, size_t size)
{
    ALOGD("%s: Ask for block of size 0x%llx\n", __func__,
         (unsigned long long)size);

    destroy();

    if (!provider->is_opened()) {
        return false;
    }

    m_size = size;
    m_offset =
        HostAddressSpaceDevice::get()->allocBlock(
            provider->m_handle, size, &m_phys_addr);
    m_handle = provider->m_handle;
    m_is_shared_mapping = false;

    return true;
}

bool GoldfishAddressSpaceBlock::claimShared(GoldfishAddressSpaceBlockProvider *provider, uint64_t offset, uint64_t size)
{
    ALOGD("%s: Ask to claim region [0x%llx 0x%llx]\n", __func__,
         (unsigned long long)offset,
         (unsigned long long)offset + size);

    destroy();

    if (!provider->is_opened()) {
        return false;
    }

    int claimRes = HostAddressSpaceDevice::get()->claimShared(
            provider->m_handle, offset, size);

    if (claimRes) {
        ALOGE("%s: failed to claim shared region. Error: %d\n", __func__, claimRes);
        return false;
    }

    m_size = size;
    m_offset = offset;
    m_handle = provider->m_handle;
    m_is_shared_mapping = true;
    m_phys_addr = HostAddressSpaceDevice::get()->offsetToPhysAddr(m_offset);

    return true;
}

uint64_t GoldfishAddressSpaceBlock::physAddr() const
{
    return m_phys_addr;
}

uint64_t GoldfishAddressSpaceBlock::hostAddr() const
{
    return m_host_addr;
}

// In the host implementation:
// mmap: is done by interpreting |host_addr| as the actual host address.
void *GoldfishAddressSpaceBlock::mmap(uint64_t host_addr)
{
    if (m_size == 0) {
        ALOGE("%s: called with zero size\n", __func__);
        return NULL;
    }

    if (m_mmaped_ptr != nullptr) {
        ALOGE("'mmap' called for an already mmaped address block 0x%llx %d", (unsigned long long)m_mmaped_ptr, nullptr == m_mmaped_ptr);
        ::abort();
    }

    m_mmaped_ptr = (void*)(uintptr_t)(host_addr & (~(PAGE_SIZE - 1)));
    m_host_addr = host_addr;

    return guestPtr();
}

void *GoldfishAddressSpaceBlock::guestPtr() const
{
    return reinterpret_cast<char *>(m_mmaped_ptr) + (m_host_addr & (PAGE_SIZE - 1));
}

void GoldfishAddressSpaceBlock::destroy()
{
    if (m_mmaped_ptr && m_size) {
        m_mmaped_ptr = NULL;
    }

    if (m_size) {
        if (m_is_shared_mapping) {
            HostAddressSpaceDevice::get()->unclaimShared(m_handle, m_offset);
        } else {
            HostAddressSpaceDevice::get()->freeBlock(m_handle, m_offset);
        }
        m_phys_addr = 0;
        m_host_addr = 0;
        m_offset = 0;
        m_size = 0;
    }
}

void GoldfishAddressSpaceBlock::release()
{
    m_handle = 0;
    m_mmaped_ptr = NULL;
    m_phys_addr = 0;
    m_host_addr = 0;
    m_offset = 0;
    m_size = 0;
}

int GoldfishAddressSpaceBlock::memoryMap(void *addr,
                                         size_t,
                                         address_space_handle_t,
                                         uint64_t,
                                         void** dst) {
    *dst = addr;
    return 0;
}

void GoldfishAddressSpaceBlock::memoryUnmap(void *ptr, size_t size) {}

GoldfishAddressSpaceHostMemoryAllocator::GoldfishAddressSpaceHostMemoryAllocator(bool useSharedSlots)
  : m_provider(useSharedSlots
        ? GoldfishAddressSpaceSubdeviceType::SharedSlotsHostMemoryAllocator
        : GoldfishAddressSpaceSubdeviceType::HostMemoryAllocator),
    m_useSharedSlots(useSharedSlots)
{}

bool GoldfishAddressSpaceHostMemoryAllocator::is_opened() const { return m_provider.is_opened(); }

long GoldfishAddressSpaceHostMemoryAllocator::hostMalloc(GoldfishAddressSpaceBlock *block, size_t size)
{
    if (size == 0) {
        return -EINVAL;
    }
    if (block->size() > 0) {
        return -EINVAL;
    }
    if (!m_provider.is_opened()) {
        return -ENODEV;
    }

    AddressSpaceDevicePingInfo request;
    if (m_useSharedSlots) {
        ::memset(&request, 0, sizeof(request));
        request.size = block->size();
        request.metadata = HOST_MEMORY_ALLOCATOR_COMMAND_ALLOCATE_ID;

        HostAddressSpaceDevice::get()->ping(m_provider.m_handle, &request);

        block->claimShared(&m_provider, request.phys_addr, request.size);

        void *hostPtr = HostAddressSpaceDevice::get()->getHostAddr(block->physAddr());
        block->mmap(static_cast<uint64_t>(reinterpret_cast<uintptr_t>(hostPtr)));
    } else {
        if (!block->allocate(&m_provider, size)) {
            return -ENOMEM;
        }

        ::memset(&request, 0, sizeof(request));
        request.phys_addr = block->physAddr();
        request.size = block->size();
        request.metadata = HOST_MEMORY_ALLOCATOR_COMMAND_ALLOCATE_ID;

        HostAddressSpaceDevice::get()->ping(m_provider.m_handle, &request);

        void *hostPtr = HostAddressSpaceDevice::get()->getHostAddr(block->physAddr());
        block->mmap(static_cast<uint64_t>(reinterpret_cast<uintptr_t>(hostPtr)));
    }

    return 0;
}

void GoldfishAddressSpaceHostMemoryAllocator::hostFree(GoldfishAddressSpaceBlock *block)
{
    if (block->size() == 0) {
        return;
    }

    if (!m_provider.is_opened()) {
        ALOGE("%s: device is not available", __func__);
        ::abort();
    }

    if (block->guestPtr()) {
        AddressSpaceDevicePingInfo request;
        ::memset(&request, 0, sizeof(request));
        request.phys_addr = block->physAddr();
        request.metadata = HOST_MEMORY_ALLOCATOR_COMMAND_UNALLOCATE_ID;

        HostAddressSpaceDevice::get()->ping(m_provider.m_handle, &request);
    }

    block->replace(NULL);
}

address_space_handle_t goldfish_address_space_open() {
    return HostAddressSpaceDevice::get()->open();
}

void goldfish_address_space_close(address_space_handle_t handle) {
    HostAddressSpaceDevice::get()->close(handle);
}

bool goldfish_address_space_allocate(
    address_space_handle_t handle,
    size_t size, uint64_t* phys_addr, uint64_t* offset) {

    *offset =
        HostAddressSpaceDevice::get()->allocBlock(
            handle, size, phys_addr);

    return true;
}

bool goldfish_address_space_free(
    address_space_handle_t handle, uint64_t offset) {
    HostAddressSpaceDevice::get()->freeBlock(handle, offset);
    return true;
}

bool goldfish_address_space_claim_shared(
    address_space_handle_t handle, uint64_t offset, uint64_t size) {

    int claimRes = HostAddressSpaceDevice::get()->claimShared(
        handle, offset, size);

    if (claimRes) {
        ALOGE("%s: failed to claim shared region. Error: %d\n", __func__, claimRes);
        return false;
    }

    return true;
}

bool goldfish_address_space_unclaim_shared(
        address_space_handle_t handle, uint64_t offset) {
    HostAddressSpaceDevice::get()->unclaimShared(handle, offset);
    return true;
}

// pgoff is the offset into the page to return in the result
void* goldfish_address_space_map(
    address_space_handle_t handle,
    uint64_t offset, uint64_t size,
    uint64_t pgoff) {

    (void)size;

    void* res = HostAddressSpaceDevice::get()->
        getHostAddr(
            HostAddressSpaceDevice::get()->offsetToPhysAddr(offset));

    if (!res) {
        ALOGE("%s: failed to map. errno: %d\n", __func__, errno);
        return nullptr;
    }

    return (void*)(((char*)res) + (uintptr_t)(pgoff & (PAGE_SIZE - 1)));
}

// same address space
void goldfish_address_space_unmap(void*, uint64_t) { }

bool goldfish_address_space_set_subdevice_type(
    address_space_handle_t handle, GoldfishAddressSpaceSubdeviceType type,
    address_space_handle_t* handle_out) {
    struct address_space_ping request;
    request.metadata = (uint64_t)type;
    *handle_out = handle;
    return goldfish_address_space_ping(handle, &request);
}

bool goldfish_address_space_ping(
    address_space_handle_t handle,
    struct address_space_ping* ping) {

    AddressSpaceDevicePingInfo* asHostPingInfo =
        reinterpret_cast<AddressSpaceDevicePingInfo*>(ping);

    HostAddressSpaceDevice::get()->ping(handle, asHostPingInfo);

    return true;
}