/*++

Copyright (c) 1990  Microsoft Corporation
Copyright (c) 1992, 1993  Digital Equipment Corporation

Module Name:

    lxintsup.c

Abstract:

    The module provides the interrupt support for LX3

Author:

    Eric Rehm (DEC) 29-December-1993

Revision History:

    Rewritten from ebintsup.c to lx3intsup.


--*/


#include "halp.h"
#include "eisa.h"
#include "ebsgdma.h"
#include "lx3.h"
#include "pcrtc.h"


extern BOOLEAN SioCStep;

#ifdef IDLE_PROCESSOR
ULONG HalpInterruptReceived;
BOOLEAN
PreHalpSioDispatch(
    VOID
    );
#endif

//
// Declare the interrupt handler for the PCI and ISA bus.
//
  
BOOLEAN
HalpSioDispatch(
    VOID
    );

//
// The following is the interrupt object used for DMA controller interrupts.
// DMA controller interrupts occur when a memory parity error occurs or a
// programming error occurs to the DMA controller.
//

KINTERRUPT HalpEisaNmiInterrupt;

//
// The following function initializes NMI handling.
//

VOID
HalpInitializeNMI( 
    VOID 
    );

//
// The following function is called when an ISA NMI occurs.
//

BOOLEAN
HalHandleNMI(
    IN PKINTERRUPT Interrupt,
    IN PVOID ServiceContext
    );


BOOLEAN
HalpInitializePCIInterrupts (
    VOID
    )

/*++

Routine Description:

    This routine initializes the structures necessary for ISA & PCI operations
    and connects the intermediate interrupt dispatcher. 

Arguments:

    None.

Return Value:

    If the second level interrupt dispatcher is connected, then a value of
    TRUE is returned. Otherwise, a value of FALSE is returned.

--*/

{

    KIRQL oldIrql;


    //
    // Initialize the EISA NMI interrupt.
    //

    HalpInitializeNMI();


    //
    // Directly connect the ISA interrupt dispatcher to the level for
    // ISA bus interrupt.
    //
    // N.B. This vector is reserved for exclusive use by the HAL (see
    //      interrupt initialization.
    //

#ifdef IDLE_PROCESSOR
    PCR->InterruptRoutine[PIC_VECTOR] = PreHalpSioDispatch;
#else
    PCR->InterruptRoutine[PIC_VECTOR] = HalpSioDispatch;
#endif
    HalEnableSystemInterrupt(PIC_VECTOR, ISA_DEVICE_LEVEL, LevelSensitive);


    //
    // Intitialize interrupt controller
    //

    KeRaiseIrql(ISA_DEVICE_LEVEL, &oldIrql);


    //
    // Initialize the PCI-ISA bridge interrupt controller
    //

    HalpInitializeSioInterrupts();

    //
    // Restore IRQL level.
    //

    KeLowerIrql(oldIrql);

    //
    // Initialize the DMA mode registers to a default value.
    // Disable all of the DMA channels except channel 4 which is the
    // cascade of channels 0-3.
    //

    WRITE_PORT_UCHAR(
        &((PEISA_CONTROL) HalpEisaControlBase)->Dma1BasePort.AllMask,
        0x0F
        );

    WRITE_PORT_UCHAR(
        &((PEISA_CONTROL) HalpEisaControlBase)->Dma2BasePort.AllMask,
        0x0E
        );

    return(TRUE);
}

VOID
HalpInitializeNMI( 
    VOID 
    )
/*++

Routine Description:

   This function is called to intialize SIO NMI interrupts.

Arguments:

    None.

Return Value:

    None.
--*/
{
    UCHAR DataByte;

    //
    // Initialize the SIO NMI interrupt.
    //

    KeInitializeInterrupt( &HalpEisaNmiInterrupt,
                           HalHandleNMI,
                           NULL,
                           NULL,
                           EISA_NMI_VECTOR,
                           EISA_NMI_LEVEL,
                           EISA_NMI_LEVEL,
                           LevelSensitive,
                           FALSE,
                           0,
                           FALSE
                         );

    //
    // Don't fail if the interrupt cannot be connected.
    //

    KeConnectInterrupt( &HalpEisaNmiInterrupt );

    //
    // Clear the Eisa NMI disable bit.  This bit is the high order of the
    // NMI enable register.
    //

    DataByte = 0;

    WRITE_PORT_UCHAR(
      &((PEISA_CONTROL) HalpEisaControlBase)->NmiEnable,
      DataByte
      );

}

BOOLEAN
HalHandleNMI(
    IN PKINTERRUPT Interrupt,
    IN PVOID ServiceContext
    )
/*++

Routine Description:

   This function is called when an EISA NMI occurs.  It print the appropriate
   status information and bugchecks.

Arguments:

   Interrupt - Supplies a pointer to the interrupt object

   ServiceContext - Bug number to call bugcheck with.

Return Value:

   Returns TRUE.

--*/
{
    UCHAR   StatusByte;
    
#ifdef IDLE_PROCESSOR
    //
    // Clear interrupt flag
    //

    HalpInterruptReceived = 0;
#endif

    StatusByte =
        READ_PORT_UCHAR(&((PEISA_CONTROL) HalpEisaControlBase)->NmiStatus);

    if (StatusByte & 0x80) {
        HalDisplayString ("NMI: Parity Check / Parity Error\n");
    }

    if (StatusByte & 0x40) {
        HalDisplayString ("NMI: Channel Check / IOCHK\n");
    }

     //
     // This is an Sio machine, no extnded nmi information, so just do it.
     //


    KeBugCheck(NMI_HARDWARE_FAILURE);
    return(TRUE);
}

UCHAR
HalpAcknowledgeEisaInterrupt(
    PVOID ServiceContext
    )
/*++

Routine Description:

    Acknowledge the EISA interrupt from the programmable interrupt controller.
    Return the vector number of the highest priority pending interrupt.

Arguments:

    ServiceContext - Service context of the interrupt service supplies
                     a pointer to the EISA interrupt acknowledge register.

Return Value:

    Return the value of the highest priority pending interrupt.

--*/
{
    UCHAR InterruptVector;

#ifdef IDLE_PROCESSOR
    //
    // Clear interrupt flag
    //

    HalpInterruptReceived = 0;
#endif

    //
    // Read the interrupt vector from the PIC.
    //

    InterruptVector = READ_PORT_UCHAR(ServiceContext);

    return( InterruptVector );

}

VOID
HalpAcknowledgeClockInterrupt(
    VOID
    )
/*++

Routine Description:

    Acknowledge the clock interrupt from the interval timer.  The interval
    timer for EB66 comes from the Dallas real-time clock.

Arguments:

    None.

Return Value:

    None.

--*/
{

#ifdef IDLE_PROCESSOR
    //
    // Clear interrupt flag
    //

    HalpInterruptReceived = 0;
#endif

    //
    // Acknowledge the clock interrupt by reading the control register C of
    // the Real Time Clock.
    //

    HalpReadClockRegister( RTC_CONTROL_REGISTERC );

    return;
}

#ifdef IDLE_PROCESSOR
BOOLEAN
PreHalpSioDispatch(
    VOID
    )
/*++

Routine Description:

    Acknowledge the PCI interrupt by clearing the interrupt flag, then
    dispatch to the real PCI/SIO interrupt handler

Arguments:

    None.

Return Value:

    None.

--*/
{

    //
    // Clear interrupt flag
    //

    HalpInterruptReceived = 0;

    return HalpSioDispatch();

}
#endif