/*
 * Copyright (C) 2019 Red Hat, Inc.
 *
 * Written By: Gal Hammer <ghammer@redhat.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met :
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and / or other materials provided with the distribution.
 * 3. Neither the names of the copyright holders nor the names of their contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "viofs.h"
#include "viofs.tmh"

#ifdef ALLOC_PRAGMA
#pragma alloc_text(INIT, DriverEntry)
#pragma alloc_text(PAGE, VirtFsEvtDeviceAdd)
#pragma alloc_text(PAGE, VirtFsEvtDriverContextCleanup)
#endif

NTSTATUS DriverEntry(IN PDRIVER_OBJECT DriverObject,
                     IN PUNICODE_STRING RegistryPath)
{
    NTSTATUS status;
    WDF_DRIVER_CONFIG config;
    WDF_OBJECT_ATTRIBUTES attributes;

    ExInitializeDriverRuntime(DrvRtPoolNxOptIn);
    
    // Initialize the WPP tracing.
    WPP_INIT_TRACING(DriverObject, RegistryPath);

    TraceEvents(TRACE_LEVEL_VERBOSE, DBG_INIT, "--> %!FUNC!");

    // Register a cleanup callback so that we can call WPP_CLEANUP when
    // the framework driver object is deleted during driver unload.
    WDF_OBJECT_ATTRIBUTES_INIT(&attributes);
    attributes.EvtCleanupCallback = VirtFsEvtDriverContextCleanup;

    WDF_DRIVER_CONFIG_INIT(&config, VirtFsEvtDeviceAdd);

    status = WdfDriverCreate(DriverObject, RegistryPath, &attributes,
        &config, WDF_NO_HANDLE);

    if (!NT_SUCCESS(status))
    {
        TraceEvents(TRACE_LEVEL_ERROR, DBG_INIT,
            "WdfDriverCreate failed: %!STATUS!", status);
        WPP_CLEANUP(DriverObject);
    }

    TraceEvents(TRACE_LEVEL_VERBOSE, DBG_INIT, "<-- %!FUNC!");

    return status;
}

NTSTATUS VirtFsEvtDeviceAdd(IN WDFDRIVER Driver,
                            IN PWDFDEVICE_INIT DeviceInit)
{
    NTSTATUS status;
    WDFDEVICE device;
    WDF_PNPPOWER_EVENT_CALLBACKS pnpPowerCallbacks;
    WDF_OBJECT_ATTRIBUTES attributes;
    WDFQUEUE queue;
    WDF_IO_QUEUE_CONFIG queueConfig;
    WDF_INTERRUPT_CONFIG interruptConfig;
    PDEVICE_CONTEXT context;

    UNREFERENCED_PARAMETER(Driver);

    TraceEvents(TRACE_LEVEL_VERBOSE, DBG_INIT, "--> %!FUNC!");

    PAGED_CODE();

    WDF_PNPPOWER_EVENT_CALLBACKS_INIT(&pnpPowerCallbacks);

    pnpPowerCallbacks.EvtDevicePrepareHardware = VirtFsEvtDevicePrepareHardware;
    pnpPowerCallbacks.EvtDeviceReleaseHardware = VirtFsEvtDeviceReleaseHardware;
    pnpPowerCallbacks.EvtDeviceD0Entry = VirtFsEvtDeviceD0Entry;
    pnpPowerCallbacks.EvtDeviceD0Exit = VirtFsEvtDeviceD0Exit;

    WdfDeviceInitSetPnpPowerEventCallbacks(DeviceInit, &pnpPowerCallbacks);
    WdfDeviceInitSetIoType(DeviceInit, WdfDeviceIoDirect);

    WDF_OBJECT_ATTRIBUTES_INIT_CONTEXT_TYPE(&attributes, DEVICE_CONTEXT);
    attributes.EvtCleanupCallback = VirtFsEvtDeviceContextCleanup;

    status = WdfDeviceCreate(&DeviceInit, &attributes, &device);
    if (!NT_SUCCESS(status))
    {
        TraceEvents(TRACE_LEVEL_ERROR, DBG_INIT,
            "WdfDeviceCreate failed: %!STATUS!", status);
        return status;
    }

    context = GetDeviceContext(device);

    WDF_INTERRUPT_CONFIG_INIT(&interruptConfig,
        VirtFsEvtInterruptIsr, VirtFsEvtInterruptDpc);

    interruptConfig.EvtInterruptEnable = VirtFsEvtInterruptEnable;
    interruptConfig.EvtInterruptDisable = VirtFsEvtInterruptDisable;

    for (ULONG idx = 0; idx < ARRAYSIZE(context->WdfInterrupt); idx++)
    {
        status = WdfInterruptCreate(device, &interruptConfig,
            WDF_NO_OBJECT_ATTRIBUTES, &context->WdfInterrupt[idx]);

        if (!NT_SUCCESS(status))
        {
            TraceEvents(TRACE_LEVEL_ERROR, DBG_INIT,
                "WdfInterruptCreate #%ul failed: %!STATUS!", idx, status);
            return status;
        }
    }

    WDF_OBJECT_ATTRIBUTES_INIT(&attributes);
    attributes.ParentObject = device;
    status = WdfSpinLockCreate(&attributes,
        &context->RequestsLock);

    if (!NT_SUCCESS(status))
    {
        TraceEvents(TRACE_LEVEL_ERROR, DBG_INIT,
            "WdfSpinLockCreate failed: %!STATUS!", status);
        return status;
    }

    status = WdfDeviceCreateDeviceInterface(device,
        &GUID_DEVINTERFACE_VIRT_FS, NULL);

    if (!NT_SUCCESS(status))
    {
        TraceEvents(TRACE_LEVEL_ERROR, DBG_INIT,
            "WdfDeviceCreateDeviceInterface failed: %!STATUS!", status);
        return status;
    }

    WDF_IO_QUEUE_CONFIG_INIT(&queueConfig, WdfIoQueueDispatchSequential);
    queueConfig.EvtIoDeviceControl = VirtFsEvtIoDeviceControl;
    queueConfig.EvtIoStop = VirtFsEvtIoStop;
    queueConfig.AllowZeroLengthRequests = FALSE;

    status = WdfIoQueueCreate(device, &queueConfig, WDF_NO_OBJECT_ATTRIBUTES,
        &queue);

    if (!NT_SUCCESS(status))
    {
        TraceEvents(TRACE_LEVEL_ERROR, DBG_INIT,
            "WdfIoQueueCreate failed: %!STATUS!", status);
        return status;
    }

    status = WdfDeviceConfigureRequestDispatching(device, queue,
        WdfRequestTypeDeviceControl);

    if (!NT_SUCCESS(status))
    {
        TraceEvents(TRACE_LEVEL_ERROR, DBG_INIT,
            "WdfDeviceConfigureRequestDispatching failed: %!STATUS!", status);
        return status;
    }

    WDF_OBJECT_ATTRIBUTES_INIT(&attributes);
    attributes.ParentObject = device;

    status = WdfLookasideListCreate(&attributes, sizeof(VIRTIO_FS_REQUEST),
        NonPagedPool, WDF_NO_OBJECT_ATTRIBUTES, VIRT_FS_MEMORY_TAG,
        &context->RequestsLookaside);

    if (!NT_SUCCESS(status))
    {
        TraceEvents(TRACE_LEVEL_ERROR, DBG_INIT,
            "WdfLookasideListCreate failed: %!STATUS!", status);
        return status;
    }

    TraceEvents(TRACE_LEVEL_VERBOSE, DBG_INIT, "<-- %!FUNC!");

    return status;
}

VOID VirtFsEvtDeviceContextCleanup(IN WDFOBJECT DeviceObject)
{
    PDEVICE_CONTEXT context = GetDeviceContext(DeviceObject);
    PSINGLE_LIST_ENTRY iter;

    TraceEvents(TRACE_LEVEL_VERBOSE, DBG_INIT, "--> %!FUNC!");

    WdfSpinLockAcquire(context->RequestsLock);
    iter = PopEntryList(&context->RequestsList);
    while (iter != NULL)
    {
        PVIRTIO_FS_REQUEST fs_req = CONTAINING_RECORD(iter,
            VIRTIO_FS_REQUEST, ListEntry);

        FreeVirtFsRequest(fs_req);

        iter = PopEntryList(&context->RequestsList);
    };
    WdfSpinLockRelease(context->RequestsLock);

    TraceEvents(TRACE_LEVEL_VERBOSE, DBG_INIT, "<-- %!FUNC!");
}

VOID VirtFsEvtDriverContextCleanup(IN WDFOBJECT DriverObject)
{
    UNREFERENCED_PARAMETER(DriverObject);

    TraceEvents(TRACE_LEVEL_VERBOSE, DBG_INIT, "<-> %!FUNC!");

    PAGED_CODE();

    // Stop the WPP tracing.
    WPP_CLEANUP(WdfDriverWdmGetDriverObject(DriverObject));
}

void FreeVirtFsRequest(IN PVIRTIO_FS_REQUEST Request)
{
    if (Request->InputBuffer != NULL)
    {
        MmFreePagesFromMdl(Request->InputBuffer);
        Request->InputBuffer = NULL;
        Request->InputBufferLength = 0;
    }
    
    if (Request->OutputBuffer != NULL)
    {
        MmFreePagesFromMdl(Request->OutputBuffer);
        Request->OutputBuffer = NULL;
        Request->OutputBufferLength = 0;
    }

    if (Request->Handle != NULL)
    {
        WdfObjectDelete(Request->Handle);
        Request->Handle = NULL;
    }
}
