/*++

Copyright (c) 1991 - 2002 Microsoft Corporation

Module Name:

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Abstract:

    This module contains the entire implementation of
    the virtual watchdog miniport driver.

@@BEGIN_DDKSPLIT
Author:

    Wesley Witt (wesw) 1-Oct-2001

@@END_DDKSPLIT
Environment:

    Kernel mode only.

Notes:


--*/

#include "mswd.h"


#ifdef ALLOC_PRAGMA
#pragma alloc_text(INIT,DriverEntry)
#endif



VOID
MsWdTimerReset(
    IN PDEVICE_EXTENSION DeviceExtension
    )
{
    LARGE_INTEGER DueTime;
    KeQuerySystemTime( &DeviceExtension->StartTime );
    DueTime.QuadPart = DeviceExtension->TimeoutValue.QuadPart;
    KeSetTimer( &DeviceExtension->Timer, DueTime, &DeviceExtension->TimerDpc );
}


VOID
MsWdShutdownWorker(
    IN PDEVICE_OBJECT DeviceObject,
    IN PVOID Context
    )
{
    PDEVICE_EXTENSION DeviceExtension = (PDEVICE_EXTENSION) Context;
    ULONG ExpireBehavior;


    ExAcquireFastMutex( &DeviceExtension->WdIoLock );
    ExpireBehavior = DeviceExtension->ExpireBehavior;
    ExReleaseFastMutex( &DeviceExtension->WdIoLock );

    SaPortShutdownSystem( ExpireBehavior == 1 );
}


VOID
MsWdTimerDpc(
    IN PKDPC Dpc,
    IN PVOID DeferredContext,
    IN PVOID SystemArgument1,
    IN PVOID SystemArgument2
    )
{
    PDEVICE_EXTENSION DeviceExtension = (PDEVICE_EXTENSION)DeferredContext;
    PIO_WORKITEM WorkItem;


    WorkItem = IoAllocateWorkItem( DeviceExtension->DeviceObject );
    if (WorkItem) {
        IoQueueWorkItem( WorkItem, MsWdShutdownWorker, DelayedWorkQueue, DeviceExtension );
    }
}


NTSTATUS
MsWdDeviceIoctl(
    IN PVOID DeviceExtensionIn,
    IN PIRP Irp,
    IN PVOID FsContext,
    IN ULONG FunctionCode,
    IN PVOID InputBuffer,
    IN ULONG InputBufferLength,
    IN PVOID OutputBuffer,
    IN ULONG OutputBufferLength
    )

/*++

Routine Description:

    This function is called by the SAPORT driver so that
    the mini-port driver can service an IOCTL call.

Arguments:

    DeviceExtension     - A pointer to the mini-port's device extension
    FunctionCode        - The IOCTL function code
    InputBuffer         - Pointer to the input buffer, contains the data sent down by the I/O
    InputBufferLength   - Length in bytes of the InputBuffer
    OutputBuffer        - Pointer to the output buffer, contains the data generated by this call
    OutputBufferLength  - Length in bytes of the OutputBuffer

Context:

    IRQL: IRQL PASSIVE_LEVEL, arbitrary thread context

Return Value:

    If the function succeeds, it must return STATUS_SUCCESS.
    Otherwise, it must return one of the error status values defined in ntstatus.h.

--*/

{
    PDEVICE_EXTENSION DeviceExtension = (PDEVICE_EXTENSION)DeviceExtensionIn;
    NTSTATUS Status = STATUS_SUCCESS;
    PSA_WD_CAPS WdCaps = NULL;
    LARGE_INTEGER CurrentTime;


    switch (FunctionCode) {
        case FUNC_SA_GET_VERSION:
            *((PULONG)OutputBuffer) = SA_INTERFACE_VERSION;
            break;

        case FUNC_SA_GET_CAPABILITIES:
            WdCaps = (PSA_WD_CAPS)OutputBuffer;
            WdCaps->SizeOfStruct = sizeof(SA_WD_CAPS);
            WdCaps->Minimum = 1;
            WdCaps->Maximum = 512;
            break;

        case FUNC_SAWD_DISABLE:
            ExAcquireFastMutex( &DeviceExtension->WdIoLock );
            if (*((PULONG)InputBuffer) == 1) {
                DeviceExtension->Enabled = 1;
                MsWdTimerReset( DeviceExtension );
            } else if (*((PULONG)InputBuffer) == 0) {
                DeviceExtension->Enabled = 0;
                KeCancelTimer( &DeviceExtension->Timer );
            } else {
                Status = STATUS_INVALID_PARAMETER_1;
            }
            ExReleaseFastMutex( &DeviceExtension->WdIoLock );
            break;

        case FUNC_SAWD_QUERY_EXPIRE_BEHAVIOR:
            ExAcquireFastMutex( &DeviceExtension->WdIoLock );
            *((PULONG)OutputBuffer) = DeviceExtension->ExpireBehavior;
            ExReleaseFastMutex( &DeviceExtension->WdIoLock );
            break;

        case FUNC_SAWD_SET_EXPIRE_BEHAVIOR:
            ExAcquireFastMutex( &DeviceExtension->WdIoLock );
            if (*((PULONG)InputBuffer) == 1) {
                DeviceExtension->ExpireBehavior = 1;
            } else {
                DeviceExtension->ExpireBehavior = 0;
            }
            ExReleaseFastMutex( &DeviceExtension->WdIoLock );
            break;

        case FUNC_SAWD_PING:
            ExAcquireFastMutex( &DeviceExtension->WdIoLock );
            MsWdTimerReset( DeviceExtension );
            ExReleaseFastMutex( &DeviceExtension->WdIoLock );
            break;

        case FUNC_SAWD_QUERY_TIMER:
            ExAcquireFastMutex( &DeviceExtension->WdIoLock );
            KeQuerySystemTime( &CurrentTime );
            CurrentTime.QuadPart = DeviceExtension->TimeoutValue.QuadPart - (CurrentTime.QuadPart - DeviceExtension->StartTime.QuadPart);
            *((PULONG)OutputBuffer) = (ULONG)NanoToSec( CurrentTime.QuadPart );
            ExReleaseFastMutex( &DeviceExtension->WdIoLock );
            break;

        case FUNC_SAWD_SET_TIMER:
            ExAcquireFastMutex( &DeviceExtension->WdIoLock );
            DeviceExtension->TimeoutValue.QuadPart = (ULONGLONG)-SecToNano( *((PLONG)InputBuffer) );
            MsWdTimerReset( DeviceExtension );
            ExReleaseFastMutex( &DeviceExtension->WdIoLock );
            break;

        default:
            Status = STATUS_NOT_SUPPORTED;
            REPORT_ERROR( SA_DEVICE_WATCHDOG, "Unsupported device control", Status );
            break;
    }

    return Status;
}


NTSTATUS
MsWdHwInitialize(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp,
    IN PVOID DeviceExtensionIn,
    IN PCM_PARTIAL_RESOURCE_DESCRIPTOR PartialResources,
    IN ULONG PartialResourceCount
    )

/*++

Routine Description:

    This function is called by the SAPORT driver so that
    the mini-port driver can initialize it's hardware
    resources.

Arguments:

    DeviceObject            - Pointer to the target device object.
    Irp                     - Pointer to an IRP structure that describes the requested I/O operation.
    DeviceExtension         - A pointer to the mini-port's device extension.
    PartialResources        - Pointer to the translated resources alloacted by the system.
    PartialResourceCount    - The number of resources in the PartialResources array.

Context:

    IRQL: IRQL PASSIVE_LEVEL, system thread context

Return Value:

    If the function succeeds, it must return STATUS_SUCCESS.
    Otherwise, it must return one of the error status values defined in ntstatus.h.

--*/

{
    PDEVICE_EXTENSION DeviceExtension = (PDEVICE_EXTENSION) DeviceExtensionIn;


    DeviceExtension->DeviceObject = DeviceObject;
    ExInitializeFastMutex( &DeviceExtension->WdIoLock );
    KeInitializeTimer( &DeviceExtension->Timer );
    KeInitializeDpc( &DeviceExtension->TimerDpc, MsWdTimerDpc, DeviceExtension );
    DeviceExtension->TimeoutValue.QuadPart = -SecToNano(DEFAULT_WD_TIMEOUT_SECS);
    DeviceExtension->Enabled = 1;
    DeviceExtension->ExpireBehavior = 0;
    MsWdTimerReset( DeviceExtension );
    return STATUS_SUCCESS;
}


NTSTATUS
DriverEntry(
    IN PDRIVER_OBJECT DriverObject,
    IN PUNICODE_STRING RegistryPath
    )

/*++

Routine Description:

    This routine is the driver's entry point, called by the I/O system
    to load the driver.  The driver's entry points are initialized and
    a mutex to control paging is initialized.

    In DBG mode, this routine also examines the registry for special
    debug parameters.

Arguments:

    DriverObject - a pointer to the object that represents this device driver.
    RegistryPath - a pointer to this driver's key in the Services tree.

Return Value:

    STATUS_SUCCESS

--*/

{
    NTSTATUS Status;
    SAPORT_INITIALIZATION_DATA SaPortInitData;


    RtlZeroMemory( &SaPortInitData, sizeof(SAPORT_INITIALIZATION_DATA) );

    SaPortInitData.StructSize = sizeof(SAPORT_INITIALIZATION_DATA);
    SaPortInitData.DeviceType = SA_DEVICE_WATCHDOG;
    SaPortInitData.HwInitialize = MsWdHwInitialize;
    SaPortInitData.DeviceIoctl = MsWdDeviceIoctl;

    SaPortInitData.DeviceExtensionSize = sizeof(DEVICE_EXTENSION);

    Status = SaPortInitialize( DriverObject, RegistryPath, &SaPortInitData );
    if (!NT_SUCCESS(Status)) {
        REPORT_ERROR( SA_DEVICE_WATCHDOG, "SaPortInitialize failed\n", Status );
        return Status;
    }

    return STATUS_SUCCESS;
}