// Copyright 2017 The Fuchsia 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 "platform-bus.h"

#include <assert.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <ddk/binding.h>
#include <ddk/debug.h>
#include <ddk/device.h>
#include <ddk/driver.h>
#include <ddk/metadata.h>
#include <ddk/platform-defs.h>
#include <fbl/algorithm.h>
#include <fbl/auto_lock.h>
#include <fbl/unique_ptr.h>
#include <fuchsia/sysinfo/c/fidl.h>
#include <zircon/boot/driver-config.h>
#include <zircon/boot/image.h>
#include <zircon/process.h>
#include <zircon/syscalls/iommu.h>

#include <utility>

#include "cpu-trace.h"

namespace platform_bus {

zx_status_t PlatformBus::IommuGetBti(uint32_t iommu_index, uint32_t bti_id,
                                     zx::bti* out_bti) {
    if (iommu_index != 0) {
        return ZX_ERR_OUT_OF_RANGE;
    }
    return zx::bti::create(iommu_handle_, 0, bti_id, out_bti);
}

zx_status_t PlatformBus::PBusRegisterProtocol(uint32_t proto_id, const void* protocol,
                                              size_t protocol_size) {
    if (!protocol || protocol_size < sizeof(ddk::AnyProtocol)) {
        return ZX_ERR_INVALID_ARGS;
    }

    switch (proto_id) {
    case ZX_PROTOCOL_GPIO_IMPL: {
        gpio_ = ddk::GpioImplProtocolClient(static_cast<const gpio_impl_protocol_t*>(protocol));
        break;
    }
    case ZX_PROTOCOL_I2C_IMPL: {
        auto proto = static_cast<const i2c_impl_protocol_t*>(protocol);
        auto status = I2cInit(proto);
        if (status != ZX_OK) {
            return status;
        }

        i2c_ = ddk::I2cImplProtocolClient(proto);
        break;
    }
    case ZX_PROTOCOL_CLOCK: {
        clk_ = ddk::ClockProtocolClient(static_cast<const clock_protocol_t*>(protocol));
        break;
    }
    case ZX_PROTOCOL_POWER_IMPL: {
        power_ = ddk::PowerImplProtocolClient(static_cast<const power_impl_protocol_t*>(protocol));
        break;
    }
    case ZX_PROTOCOL_IOMMU: {
        iommu_ = ddk::IommuProtocolClient(static_cast<const iommu_protocol_t*>(protocol));
        break;
    }
    case ZX_PROTOCOL_SYSMEM: {
        sysmem_ = ddk::SysmemProtocolClient(static_cast<const sysmem_protocol_t*>(protocol));
        break;
    }
    case ZX_PROTOCOL_AMLOGIC_CANVAS: {
        canvas_ = ddk::AmlogicCanvasProtocolClient(
                                        static_cast<const amlogic_canvas_protocol_t*>(protocol));
        break;
    }
    default:
        return ZX_ERR_NOT_SUPPORTED;
    }

    fbl::AutoLock lock(&proto_completion_mutex_);
    sync_completion_signal(&proto_completion_);
    return ZX_OK;
}

zx_status_t PlatformBus::PBusDeviceAdd(const pbus_dev_t* pdev) {
    if (!pdev->name) {
        return ZX_ERR_INVALID_ARGS;
    }

    zx_device_t* parent_dev;
    if (pdev->vid == PDEV_VID_GENERIC && pdev->pid == PDEV_PID_GENERIC &&
        pdev->did == PDEV_DID_KPCI) {
        // Add PCI root at top level.
        parent_dev = parent();
    } else {
        parent_dev = zxdev();
    }

    fbl::unique_ptr<platform_bus::PlatformDevice> dev;
    auto status = PlatformDevice::Create(pdev, parent_dev, this, &dev);
    if (status != ZX_OK) {
        return status;
    }

    status = dev->Start();
    if (status != ZX_OK) {
        return status;
    }

    // devmgr is now in charge of the device.
    __UNUSED auto* dummy = dev.release();
    return ZX_OK;
}

zx_status_t PlatformBus::PBusProtocolDeviceAdd(uint32_t proto_id, const pbus_dev_t* pdev) {
    if (!pdev->name) {
        return ZX_ERR_INVALID_ARGS;
    }

    fbl::unique_ptr<platform_bus::ProtocolDevice> dev;
    auto status = ProtocolDevice::Create(pdev, zxdev(), this, &dev);
    if (status != ZX_OK) {
        return status;
    }

    // Protocol devices run in our devhost.
    status = dev->Start();
    if (status != ZX_OK) {
        return status;
    }

    // devmgr is now in charge of the device.
    __UNUSED auto* dummy = dev.release();

    // Wait for protocol implementation driver to register its protocol.
    ddk::AnyProtocol dummy_proto;

    proto_completion_mutex_.Acquire();
    while (DdkGetProtocol(proto_id, &dummy_proto) == ZX_ERR_NOT_SUPPORTED) {
        sync_completion_reset(&proto_completion_);
        proto_completion_mutex_.Release();
        zx_status_t status = sync_completion_wait(&proto_completion_, ZX_SEC(10));
        if (status != ZX_OK) {
            zxlogf(ERROR, "%s sync_completion_wait(protocol %08x) failed: %d\n", __FUNCTION__,
                   proto_id, status);
            return status;
        }
        proto_completion_mutex_.Acquire();
    }
    proto_completion_mutex_.Release();
    return ZX_OK;
}

zx_status_t PlatformBus::PBusGetBoardInfo(pdev_board_info_t* out_info) {
    memcpy(out_info, &board_info_, sizeof(board_info_));
    return ZX_OK;
}

zx_status_t PlatformBus::PBusSetBoardInfo(const pbus_board_info_t* info) {
    board_info_.board_revision = info->board_revision;
    return ZX_OK;
}

zx_status_t PlatformBus::PBusRegisterSysSuspendCallback(const pbus_sys_suspend_t* suspend_cbin) {
    suspend_cb_ = *suspend_cbin;
    return ZX_OK;
}

zx_status_t PlatformBus::DdkGetProtocol(uint32_t proto_id, void* out) {
    switch (proto_id) {
    case ZX_PROTOCOL_PBUS: {
        auto proto = static_cast<pbus_protocol_t*>(out);
        proto->ctx = this;
        proto->ops = &pbus_protocol_ops_;
        return ZX_OK;
    }
    case ZX_PROTOCOL_GPIO_IMPL:
        if (gpio_) {
            gpio_->GetProto(static_cast<gpio_impl_protocol_t*>(out));
            return ZX_OK;
        }
        break;
    case ZX_PROTOCOL_I2C_IMPL:
        if (i2c_) {
            i2c_->GetProto(static_cast<i2c_impl_protocol_t*>(out));
            return ZX_OK;
        }
        break;
    case ZX_PROTOCOL_POWER_IMPL:
        if (power_) {
            power_->GetProto(static_cast<power_impl_protocol_t*>(out));
            return ZX_OK;
        }
        break;
    case ZX_PROTOCOL_CLOCK:
        if (clk_) {
            clk_->GetProto(static_cast<clock_protocol_t*>(out));
            return ZX_OK;
        }
        break;
    case ZX_PROTOCOL_SYSMEM:
        if (sysmem_) {
            sysmem_->GetProto(static_cast<sysmem_protocol_t*>(out));
            return ZX_OK;
        }
        break;
    case ZX_PROTOCOL_AMLOGIC_CANVAS:
        if (canvas_) {
            canvas_->GetProto(static_cast<amlogic_canvas_protocol_t*>(out));
            return ZX_OK;
        }
        break;
    case ZX_PROTOCOL_IOMMU:
        if (iommu_) {
            iommu_->GetProto(static_cast<iommu_protocol_t*>(out));
        } else {
            // return default implementation
            auto proto = static_cast<iommu_protocol_t*>(out);
            proto->ctx = this;
            proto->ops = &iommu_protocol_ops_;
            return ZX_OK;
        }
        break;
    }

    return ZX_ERR_NOT_SUPPORTED;
}

zx_status_t PlatformBus::ReadZbi(zx::vmo zbi) {
    zbi_header_t header;

    zx_status_t status = zbi.read(&header, 0, sizeof(header));
    if (status != ZX_OK) {
        return status;
    }
    if ((header.type != ZBI_TYPE_CONTAINER) || (header.extra != ZBI_CONTAINER_MAGIC)) {
        zxlogf(ERROR, "platform_bus: ZBI VMO not contain ZBI container\n");
        return ZX_ERR_INTERNAL;
    }

    size_t zbi_length = header.length;

    // compute size of ZBI records we need to save for metadata
    uint8_t* metadata = nullptr;
    size_t metadata_size = 0;
    size_t len = zbi_length;
    size_t off = sizeof(header);
    zbi_platform_id_t platform_id;

    while (len > sizeof(header)) {
        auto status = zbi.read(&header, off, sizeof(header));
        if (status < 0) {
            zxlogf(ERROR, "zbi.read() failed: %d\n", status);
            return status;
        }
        size_t itemlen = ZBI_ALIGN(
            static_cast<uint32_t>(sizeof(zbi_header_t)) + header.length);
        if (itemlen > len) {
            zxlogf(ERROR, "platform_bus: ZBI item too large (%zd > %zd)\n", itemlen, len);
            break;
        }
        if (ZBI_TYPE_DRV_METADATA(header.type)) {
            metadata_size += itemlen;
        }
        off += itemlen;
        len -= itemlen;
    }

    if (metadata_size) {
        fbl::AllocChecker ac;
        metadata_.reset(new (&ac) uint8_t[metadata_size], metadata_size);
        if (!ac.check()) {
            return ZX_ERR_NO_MEMORY;
        }
        metadata = metadata_.get();
    }

    bool got_platform_id = false;
    uint8_t interrupt_controller_type = fuchsia_sysinfo_InterruptControllerType_UNKNOWN;
    zx_off_t metadata_offset = 0;
    len = zbi_length;
    off = sizeof(header);

    // find platform ID record and copy metadata records
    while (len > sizeof(header)) {
        auto status = zbi.read(&header, off, sizeof(header));
        if (status < 0) {
            break;
        }
        const size_t itemlen = ZBI_ALIGN(
            static_cast<uint32_t>(sizeof(zbi_header_t)) + header.length);
        if (itemlen > len) {
            zxlogf(ERROR, "platform_bus: ZBI item too large (%zd > %zd)\n", itemlen, len);
            break;
        }
        if (header.type == ZBI_TYPE_PLATFORM_ID) {
            status = zbi.read(&platform_id, off + sizeof(zbi_header_t), sizeof(platform_id));
            if (status != ZX_OK) {
                zxlogf(ERROR, "zbi.read() failed: %d\n", status);
                return status;
            }
            board_info_.vid = platform_id.vid;
            board_info_.pid = platform_id.pid;
            memcpy(board_info_.board_name, platform_id.board_name, sizeof(board_info_.board_name));
            // This is optionally set later by the board driver.
            board_info_.board_revision = 0;
            got_platform_id = true;

            zxlogf(INFO, "platform bus: VID: %u PID: %u board: \"%s\"\n", platform_id.vid,
                   platform_id.pid, platform_id.board_name);

            // Publish board name to sysinfo driver
            status = device_publish_metadata(parent(), "/dev/misc/sysinfo",
                                             DEVICE_METADATA_BOARD_NAME, platform_id.board_name,
                                             sizeof(platform_id.board_name));
            if (status != ZX_OK) {
                zxlogf(ERROR, "device_publish_metadata(board_name) failed: %d\n", status);
                return status;
            }
        } else if (header.type == ZBI_TYPE_KERNEL_DRIVER) {
            if (header.extra == KDRV_ARM_GIC_V2) {
                interrupt_controller_type = fuchsia_sysinfo_InterruptControllerType_GIC_V2;
            } else if (header.extra == KDRV_ARM_GIC_V3) {
                interrupt_controller_type = fuchsia_sysinfo_InterruptControllerType_GIC_V3;
            }
        } else if (ZBI_TYPE_DRV_METADATA(header.type)) {
            status = zbi.read(metadata + metadata_offset, off, itemlen);
            if (status != ZX_OK) {
                zxlogf(ERROR, "zbi.read() failed: %d\n", status);
                return status;
            }
            metadata_offset += itemlen;
        }
        off += itemlen;
        len -= itemlen;
    }

    // Publish interrupt controller type to sysinfo driver
    status = device_publish_metadata(parent(), "/dev/misc/sysinfo",
                                     DEVICE_METADATA_INTERRUPT_CONTROLLER_TYPE,
                                     &interrupt_controller_type, sizeof(interrupt_controller_type));
    if (status != ZX_OK) {
        zxlogf(ERROR, "device_publish_metadata(interrupt_controller_type) failed: %d\n", status);
        return status;
    }

    if (!got_platform_id) {
#if __x86_64__
        /*
         * For x86_64, we might not find the ZBI_TYPE_PLATFORM_ID, old bootloaders
         * won't support this, for example. If this is the case, cons up the VID/PID here
         * to allow the acpi board driver to load and bind.
         */
        board_info_.vid = PDEV_VID_INTEL;
        board_info_.pid = PDEV_PID_X86;
        strncpy(board_info_.board_name, "x86_64", sizeof(board_info_.board_name));
        // This is optionally set later by the board driver.
        board_info_.board_revision = 0;

        // Publish board name to sysinfo driver
        status = device_publish_metadata(parent(), "/dev/misc/sysinfo",
                                         DEVICE_METADATA_BOARD_NAME, "x86_64",
                                         strlen("x86_64") + 1);
        if (status != ZX_OK) {
            zxlogf(ERROR, "device_publish_metadata(board_name) failed: %d\n", status);
            return status;
        }
#else
        zxlogf(ERROR, "platform_bus: ZBI_TYPE_PLATFORM_ID not found\n");
        return ZX_ERR_INTERNAL;
#endif
    }

    return ZX_OK;
}

zx_status_t PlatformBus::GetZbiMetadata(uint32_t type, uint32_t extra, const void** out_metadata,
                                        uint32_t* out_size) {
    const uint8_t* metadata = metadata_.get();
    const size_t metadata_size = metadata_.size();
    size_t offset = 0;

    while (offset + sizeof(zbi_header_t) < metadata_size) {
        const auto header = reinterpret_cast<const zbi_header_t*>(metadata);
        const size_t length = ZBI_ALIGN(
            static_cast<uint32_t>(sizeof(zbi_header_t)) + header->length);
        if (offset + length > metadata_size) {
            break;
        }

        if (header->type == type && header->extra == extra) {
            *out_metadata = header + 1;
            *out_size = static_cast<uint32_t>(length - sizeof(zbi_header_t));
            return ZX_OK;
        }
        metadata += length;
        offset += length;
    }
    zxlogf(ERROR, "%s metadata not found for type %08x, extra %u\n", __FUNCTION__, type, extra);
    return ZX_ERR_NOT_FOUND;
}

zx_status_t PlatformBus::I2cInit(const i2c_impl_protocol_t* i2c) {
    if (!i2c_buses_.is_empty()) {
        // already initialized
        return ZX_ERR_BAD_STATE;
    }

    uint32_t bus_count = i2c_impl_get_bus_count(i2c);
    if (!bus_count) {
        return ZX_ERR_NOT_SUPPORTED;
    }

    fbl::AllocChecker ac;
    i2c_buses_.reserve(bus_count, &ac);
    if (!ac.check()) {
        return ZX_ERR_NO_MEMORY;
    }

    for (uint32_t i = 0; i < bus_count; i++) {
        fbl::unique_ptr<PlatformI2cBus> i2c_bus(new (&ac) PlatformI2cBus(i2c, i));
        if (!ac.check()) {
            return ZX_ERR_NO_MEMORY;
        }

        auto status = i2c_bus->Start();
        if (status != ZX_OK) {
            return status;
        }

        i2c_buses_.push_back(std::move(i2c_bus));
    }

    return ZX_OK;
}

zx_status_t PlatformBus::I2cTransact(uint32_t txid, rpc_i2c_req_t* req,
                                     const pbus_i2c_channel_t* channel,
                                     zx_handle_t channel_handle) {
    if (channel->bus_id >= i2c_buses_.size()) {
        return ZX_ERR_OUT_OF_RANGE;
    }
    auto i2c_bus = i2c_buses_[channel->bus_id].get();
    return i2c_bus->Transact(txid, req, channel->address, channel_handle);
}

void PlatformBus::DdkRelease() {
    delete this;
}

typedef struct {
    void *pbus_instance;
} sysdev_suspend_t;

static zx_status_t sys_device_suspend(void* ctx, uint32_t flags) {
    auto* p = reinterpret_cast<sysdev_suspend_t *>(ctx);
    auto* pbus = reinterpret_cast<class PlatformBus *>(p->pbus_instance);

    if (pbus != nullptr) {
        pbus_sys_suspend_t suspend_cb = pbus->suspend_cb();
        if (suspend_cb.callback != nullptr) {
            return suspend_cb.callback(suspend_cb.ctx, flags);
        }
    }
    return ZX_ERR_NOT_SUPPORTED;
}

static void sys_device_release(void* ctx) {
    auto* p = reinterpret_cast<sysdev_suspend_t *>(ctx);
    delete p;
}

// cpu-trace provides access to the cpu's tracing and performance counters.
// As such the "device" is the cpu itself.
static zx_status_t InitCpuTrace(zx_device_t* parent, zx_handle_t dummy_iommu_handle) {
    zx_handle_t cpu_trace_bti;
    zx_status_t status = zx_bti_create(dummy_iommu_handle, 0, CPU_TRACE_BTI_ID, &cpu_trace_bti);
    if (status != ZX_OK) {
        zxlogf(ERROR, "platform-bus: error %d in bti_create(cpu_trace_bti)\n", status);
        return status;
    }

    status = publish_cpu_trace(cpu_trace_bti, parent);
    if (status != ZX_OK) {
        // This is not fatal.
        zxlogf(INFO, "publish_cpu_trace returned %d\n", status);
    }
    return status;
}

static zx_protocol_device_t sys_device_proto = []() {
    zx_protocol_device_t result;

    result.version = DEVICE_OPS_VERSION;
    result.suspend = sys_device_suspend;
    result.release = sys_device_release;
    return result;
}();

zx_status_t PlatformBus::Create(zx_device_t* parent, const char* name, zx::vmo zbi) {
    // This creates the "sys" device.
    sys_device_proto.version = DEVICE_OPS_VERSION;

    // The suspend op needs to get access to the PBus instance, to be able to
    // callback the ACPI suspend hook. Introducing a level of indirection here
    // to allow us to update the PBus instance in the device context after creating
    // the device.
    fbl::AllocChecker ac;
    fbl::unique_ptr<uint8_t[]> ptr(new (&ac) uint8_t[sizeof(sysdev_suspend_t)]);
    if (!ac.check()) {
        return ZX_ERR_NO_MEMORY;
    }
    auto* suspend_buf = reinterpret_cast<sysdev_suspend_t *>(ptr.get());
    suspend_buf->pbus_instance = nullptr;

    device_add_args_t args = {};
    args.version = DEVICE_ADD_ARGS_VERSION;
    args.name = "sys";
    args.ops = &sys_device_proto;
    args.flags = DEVICE_ADD_NON_BINDABLE;
    args.ctx = suspend_buf;

    // Create /dev/sys.
    zx_device_t* sys_root;
    auto status = device_add(parent, &args, &sys_root);
    if (status != ZX_OK) {
        return status;
    } else {
        __UNUSED auto* dummy = ptr.release();
    }

    // Add child of sys for the board driver to bind to.
    fbl::unique_ptr<platform_bus::PlatformBus> bus(new (&ac) platform_bus::PlatformBus(sys_root));
    if (!ac.check()) {
        return ZX_ERR_NO_MEMORY;
    }
    suspend_buf->pbus_instance = bus.get();

    status = bus->Init(std::move(zbi));
    if (status != ZX_OK) {
        return status;
    }

    // Create /dev/sys/cpu-trace.
    // But only do so if we have an iommu handle. Normally we do, but tests
    // may create us without a root resource, and thus without the iommu
    // handle.
    if (bus->iommu_handle_.is_valid()) {
        status = InitCpuTrace(sys_root, bus->iommu_handle_.get());
        if (status != ZX_OK) {
            // This is not fatal. Error message already printed.
        }
    }

    // devmgr is now in charge of the device.
    __UNUSED auto* dummy = bus.release();
    return ZX_OK;
}

PlatformBus::PlatformBus(zx_device_t* parent)
    : PlatformBusType(parent) {
    sync_completion_reset(&proto_completion_);
}

zx_status_t PlatformBus::Init(zx::vmo zbi) {
    auto status = ReadZbi(std::move(zbi));
    if (status != ZX_OK) {
        return status;
    }

    // Set up a dummy IOMMU protocol to use in the case where our board driver does not
    // set a real one.
    zx_iommu_desc_dummy_t desc;
    zx::unowned_resource root_resource(get_root_resource());
    if (root_resource->is_valid()) {
      status = zx::iommu::create(*root_resource, ZX_IOMMU_TYPE_DUMMY, &desc, sizeof(desc),
                                 &iommu_handle_);
      if (status != ZX_OK) {
          return status;
      }
    }

    // Add board driver metadata if available.
    const void* data;
    uint32_t length;
    status = GetZbiMetadata(DEVICE_METADATA_BOARD_PRIVATE, 0, &data, &length);
    if (status != ZX_OK) {
        length = 0;
    }

    // Then we attach the platform-bus device below it.
    zx_device_prop_t props[] = {
        {BIND_PLATFORM_DEV_VID, 0, board_info_.vid},
        {BIND_PLATFORM_DEV_PID, 0, board_info_.pid},
    };

    status = DdkAdd("platform", DEVICE_ADD_INVISIBLE, props, fbl::count_of(props));
    if (status == ZX_OK && length != 0) {
        if (DdkAddMetadata(DEVICE_METADATA_BOARD_PRIVATE, data, length) != ZX_OK) {
            zxlogf(WARN, "%s failed to add metadata for board driver\n", __func__);
        }
    }
    DdkMakeVisible();
    return status;
}

zx_status_t platform_bus_create(void* ctx, zx_device_t* parent, const char* name,
                                const char* args, zx_handle_t zbi_vmo_handle) {
    zx::vmo zbi(zbi_vmo_handle);
    return platform_bus::PlatformBus::Create(parent, name, std::move(zbi));
}

static zx_driver_ops_t driver_ops = [](){
    zx_driver_ops_t ops;
    ops.version = DRIVER_OPS_VERSION;
    ops.create = platform_bus_create;
    return ops;
}();

} // namespace platform_bus

ZIRCON_DRIVER_BEGIN(platform_bus, platform_bus::driver_ops, "zircon", "0.1", 1)
    // devmgr loads us directly, so we need no binding information here
    BI_ABORT_IF_AUTOBIND,
ZIRCON_DRIVER_END(platform_bus)