atmoc3txcp.c

摩托罗拉Motolola公司网络处理器C3的示范代码.实现了ATM的AAL2层交换功能.想了解网络处理器的可以

/*
 *  atmTx.c
 *
 *  Transmit side of the ATM cell switch
 */

/*
 *  Copyright (c) 1998,1999,2000,2001,2002 C-Port Corporation
 *  All Rights Reserved
 *
 *  The information contained in this file is C-Port Corporation confidential and proprietary.
 *  Any reproduction, use or disclosure, in whole or in part, of this
 *  program, including any attempt to obtain a human-readable version of this
 *  program, without the express, prior written consent of C-Port
 *  Corporation or Motorola Incorporated is strictly prohibited.
 */

#include <dcpPduSvcs.h>
#include <dcpQueueSvcs.h>
#include <dcpKernelSvcs.h>
#include <dcpTableSvcs.h>
#include <dcpRegisterDefs.h>
#include <dcpDiagSvcs.h>

#include "atm.h"
#include "atmStatus.h"
#include "atmPrivate.h"
#include "atmCellDesc.h"
#include "atmVcTable.h"
#include "rcSdpAtmApiIf.h"
#include "errorHandling.h"
#include "atmIf.h"

QsMessage ALIGNED64 atmTxCellDescMsg;

extern KsContext atmTxNextContext;
/*
 * Pending transmit buffer storage - used for double
 * buffering on transmit and double buffer index
 */
BsBufHandle txPendingBuf[MAX_SCOPES];
int bufferId;

/* static TsEntry txEntry = {0, 8, NULL, REQ_IDX(1), 4}; */

/*
 *  atmTx() - dequeue a cell from the Queue Controller and transmit
 *
 */
int32u
atmTx(void* arg)
{
    MergeSpc*        mergeSpc;
    AtmMergeSpc*     atmMerge;
    CellDescriptor*  atmTxCellDesc;
    PduHandle        pduHandle;
    CellHeader       egressHdr;
    QsQueueId        myQueue;
    int32u           numQs; 
    TsKey            key;
    int32u           keyData;
    BsBufHandle      bufHandle = NULL;
    /* VpiVci*          vpiVci; */

    /* init key */
    key.keyData = (int32u*)&keyData;
    key.maskLenBits =0;

    atmTxCellDesc = qsMessageGetData(&atmTxCellDescMsg);
    memset(atmTxCellDesc,0,sizeof(CellDescriptor));

    /*
     * Allocate the pending buffers txPendingBuf[0]
     * and txPendingBuf[1].
     */
    
    while(bsError(txPendingBuf[0] = bsBufferAllocate(poolId)));
    while(bsError(txPendingBuf[1] = bsBufferAllocate(poolId)));

    qsQueueGet(ksProcIdCreate(ProcCP,0,ksCpGetId()),&myQueue,&numQs);

    while (1) {

        MSG_EVENT("CPRC: ATMTX wait for message");
        /*
         *  While the cell descriptor queue is empty, yield to another thread
         *  The queue number is derived from the CP id.  Each CP has 16 queues
         *  allocated to it, so the first queue is cpId*16, but we use cpId<<4
         *  since we don't have a multiply instruction.
         */
        while (!qsQueueGetLength(myQueue)) 
	{
            ksContextSwitch(atmTxNextContext);
        }

        /*
         *  There is a cell descriptor in the queue,
         *  dequeue the head of the queue
         */
        qsMessageReceiveStart(myQueue, &atmTxCellDescMsg); 

        while (!qsMessageReceiveComplete(myQueue, &atmTxCellDescMsg)) {
            ksContextSwitch(atmTxNextContext);
        }
        MSG_EVENT("CPRC: ATMTX got message");

        if (atmTxCellDesc->MulticastFlag == 0) {
            egressHdr   = atmTxCellDesc->CellHeader;
        }else {
            bsBufferFreeReference(atmTxCellDesc->Bh);
            ksPrintf ("ATM Multi-cast support not provided in aal2Switch app");
            continue;

            /*
            txEntry.offset = ksCpId<<2;
            keyData = atmTxCellDesc->VcIndex;
            tsEntryLookup(TABLE_ID_EGRESS, &key, &txEntry);

            while (!tsLookupResponseValid(4)) {
                ksContextSwitch(atmTxNextContext);
            }

            vpiVci = (VpiVci*)tsLookupGetResponse(4);
            vpiVci += (ksCpId&0x01);

            egressHdr.word   = *vpiVci << 4;

            tsLookupRelease(4);
            */

        }
        MSG_EVENT("CPRC: ATMTX wait for payload done");
        /*
         *  Wait for an opportunity to transmit the cell header
         */
        while ((pduHandle = pduTxAllocate()) == NULL) {
            ksContextSwitch(atmTxNextContext);
        }
        MSG_EVENT("CPRC: ATMTX payload done");

        /*
         *  Put the cell header fields into merge register space
         */
        mergeSpc = (MergeSpc*)pduTxHeaderGet(pduHandle);
        atmMerge = &mergeSpc->atmMergeSpc;
        atmMerge->cellHeader.word  = (egressHdr.word) | getPtiClp(atmTxCellDesc->CellHeader.word);
	atmMerge->txType = atmTxCellDesc->payloadType;

        if (atmMerge->txType == atmPayloadTypeSwitched) {
            atmStatsBuffer.txCells++;
        } else {
            atmStatsBuffer.txOamCells++;
        }

        MSG_EVENT("CPRC: ATMTX release scope");
        /*
         *  Setup the transmit of cell payload on the wire
         */
        pduTxBufHandleSet(pduHandle, atmTxCellDesc->Bh);
        pduTxLengthSet(pduHandle, 48, 0);


        /*
         *  Give the header and cell to the DCP SDP for transmit
         */
        pduTxFree(pduHandle);
        MSG_EVENT("CPRC: ATMTX scope released");

        /*
         * Free the last transmit pending buffer from this scope,
         * store the current bufHandle and adjust the double buffer
         * index.
         */
        bufHandle = txPendingBuf[bufferId];
        txPendingBuf[bufferId] = atmTxCellDesc->Bh;
        bufferId ^= (MAX_SCOPES - 1);
        bsBufferFreeReference(bufHandle);

	/*
         *  Switch to the Rx thread to prevent starvation under load
         */
         ksContextSwitch(atmTxNextContext);

    } /* while (1) */

}