/*
 * Copyright (c) 1995 FirePower Systems, Inc.
 * DO NOT DISTRIBUTE without permission
 *
 * $RCSfile: pxflshio.c $
 * $Revision: 1.11 $
 * $Date: 1996/05/14 02:34:19 $
 * $Locker:  $
 */

/*++

Copyright (c) 1991-1993  Microsoft Corporation
        Copyright 1994 MOTOROLA, INC.  All Rights Reserved.  This file
        contains copyrighted material.  Use of this file is restricted
        by the provisions of a Motorola Software License Agreement.

Module Name:

    psflshio.c

Abstract:

    This module implements miscellaneous PowerPC HAL functions.

Author:

    Jim Wooldridge  (jimw@austin.ibm.com)

Environment:

    Kernel mode

Revision History:

--*/

#include "halp.h"
#include "arccodes.h"



ULONG
HalGetDmaAlignmentRequirement (
    VOID
    )

/*++

Routine Description:

    This function returns the alignment requirements for DMA transfers on
    host system.

Arguments:

    None.

Return Value:

    The DMA alignment requirement is returned as the fucntion value.

--*/

{

    return 1;
}

VOID
HalFlushIoBuffers (
    IN PMDL Mdl,
    IN BOOLEAN ReadOperation,
    IN BOOLEAN DmaOperation
    )

/*++

Routine Description:

    This function flushes the I/O buffer specified by the memory descriptor
    list from the data cache on the current processor.

Arguments:

    Mdl - Supplies a pointer to a memory descriptor list that describes the
        I/O buffer location.

    ReadOperation - Supplies a boolean value that determines whether the I/O
        operation is a read into memory.

    DmaOperation - Supplies a boolean value that determines whether the I/O
        operation is a DMA operation.

Return Value:

    None.

--*/

{

    ULONG Length;
    ULONG PartialLength;
    ULONG Offset;
    PULONG Page;
    BOOLEAN DoDcache = FALSE;

    //
    // check for 601, it has a combined I and D cache that bus snoops
    //
    //

    if ((HalpGetProcessorVersion() >> 16) != 1) {

        Length = Mdl->ByteCount;

        if ( !Length ) {
            return;
        }
        //
        // If the I/O operation is not a DMA operation,
        // and the  I/O operation is a page read operation,
        // then sweep (index/writeback/invalidate) the data cache.
        //
        if (((DmaOperation == FALSE) &&
	     (ReadOperation != FALSE) &&
	     ((Mdl->MdlFlags & MDL_IO_PAGE_READ) != 0))) {
	    DoDcache = TRUE;
        }
	
        //
        // If the I/O operation is a page read, then sweep (index/invalidate)
        // the range from the cache.  Note it is not reasonable to sweep
        // the entire cache on an MP system as "Flash Invalidate" doesn't
        // broadcast the invalidate to other processors.
        //
        if ((ReadOperation != FALSE) &&
            ((Mdl->MdlFlags & MDL_IO_PAGE_READ) != 0)) {
	
            Offset = Mdl->ByteOffset;
            PartialLength = PAGE_SIZE - Offset;
            if (PartialLength > Length) {
                PartialLength = Length;
            }
	
            Page = (PULONG)(Mdl + 1);
	
            if (DoDcache == TRUE) {
                HalpSweepPhysicalRangeInBothCaches(
						   *Page++,
						   Offset,
						   PartialLength
						   );
                Length -= PartialLength;
                if (Length) {
                    PartialLength = PAGE_SIZE;
                    do {
                        if (PartialLength > Length) {
                            PartialLength = Length;
                        }
                        HalpSweepPhysicalRangeInBothCaches(
							   *Page++,
							   0,
							   PartialLength
							   );
                        Length -= PartialLength;
                    } while (Length != 0);
                }
            } else {
                HalpSweepPhysicalIcacheRange(
					     *Page++,
					     Offset,
					     PartialLength
					     );
                Length -= PartialLength;
                if (Length) {
                    PartialLength = PAGE_SIZE;
                    do {
                        if (PartialLength > Length) {
                            PartialLength = Length;
                        }
                        HalpSweepPhysicalIcacheRange(
						     *Page++,
						     0,
						     PartialLength
						     );
                        Length -= PartialLength;
                    } while (Length != 0);
                }
            }
        }
    }
    return;
}