xemac_intr_dma.c

powerpc405开发板的linux网口驱动程序

/* $Id: xemac_intr_dma.c,v 1.6 2006/12/05 13:23:01 mta Exp $ */
/******************************************************************************
*
*       XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS"
*       AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND
*       SOLUTIONS FOR XILINX DEVICES.  BY PROVIDING THIS DESIGN, CODE,
*       OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE,
*       APPLICATION OR STANDARD, XILINX IS MAKING NO REPRESENTATION
*       THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT,
*       AND YOU ARE RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE
*       FOR YOUR IMPLEMENTATION.  XILINX EXPRESSLY DISCLAIMS ANY
*       WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE
*       IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR
*       REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF
*       INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
*       FOR A PARTICULAR PURPOSE.
*
*       (c) Copyright 2003 Xilinx Inc.
*       All rights reserved.
*
******************************************************************************/
/*****************************************************************************/
/**
*
* @file xemac_intr_dma.c
*
* Contains functions used in interrupt mode when configured with scatter-gather
* DMA.
*
* The interrupt handler, XEmac_IntrHandlerDma(), must be connected by the user
* to the interrupt controller.
*
* <pre>
* MODIFICATION HISTORY:
*
* Ver   Who  Date     Changes
* ----- ---- -------- ---------------------------------------------------------
* 1.00a rpm  07/31/01 First release
* 1.00b rpm  02/20/02 Repartitioned files and functions
* 1.00c rpm  12/05/02 New version includes support for simple DMA and the delay
*                     argument to SgSend
* 1.00c rpm  02/03/03 The XST_DMA_SG_COUNT_EXCEEDED return code was removed
*                     from SetPktThreshold in the internal DMA driver. Also
*                     avoided compiler warnings by initializing Result in the
*                     interrupt service routines.
* 1.00c rpm  03/26/03 Fixed a problem in the interrupt service routines where
*                     the interrupt status was toggled clear after a call to
*                     ErrorHandler, but if ErrorHandler reset the device the
*                     toggle actually asserted the interrupt because the
*                     reset had cleared it.
* 1.00d rpm  09/26/03 New version includes support PLB Ethernet and v2.00a of
*                     the packet fifo driver.
* 1.00e rmm  04/06/04 Instead of invoking once for each packet received,
*                     send/recv callbacks are invoked once for all packets.
*                     Added functions XEmac_GetSgRecvFreeDesc() and XEmac_Get-
*                     SgSendFreeDesc().
* 1.01a ecm  09/01/05 Added DRE and Checksum Offload support through Control
*                     words in instance which are set at initialization.
* 1.01a xd   03/22/06 Fixed a multi-descriptor packet related bug that tx sgdma
*                     engine is restarted in case no scatter gather disabled
*                     bit is set yet
* </pre>
*
******************************************************************************/

/***************************** Include Files *********************************/

#include "xbasic_types.h"
#include "xemac_i.h"
#include "xio.h"
#include "xbuf_descriptor.h"
#include "xdma_channel.h"
#include "xipif_v1_23_b.h"      /* Uses v1.23b of the IPIF */

/************************** Constant Definitions *****************************/


/**************************** Type Definitions *******************************/


/***************** Macros (Inline Functions) Definitions *********************/


/************************** Variable Definitions *****************************/


/************************** Function Prototypes ******************************/

static void HandleDmaRecvIntr(XEmac *InstancePtr);
static void HandleDmaSendIntr(XEmac *InstancePtr);
static void HandleEmacDmaIntr(XEmac *InstancePtr);

/*****************************************************************************/
/**
*
* Send an Ethernet frame using scatter-gather DMA. The caller attaches the
* frame to one or more buffer descriptors, then calls this function once for
* each descriptor. The caller is responsible for allocating and setting up the
* descriptor. An entire Ethernet frame may or may not be contained within one
* descriptor.  This function simply inserts the descriptor into the scatter-
* gather engine's transmit list. The caller is responsible for providing mutual
* exclusion to guarantee that a frame is contiguous in the transmit list. The
* buffer attached to the descriptor must be 32-bit aligned if using the OPB
* Ethernet core and 64-bit aligned if using the PLB Ethernet core.
*
* The driver updates the descriptor with the device control register before
* being inserted into the transmit list.  If this is the last descriptor in
* the frame, the inserts are committed, which means the descriptors for this
* frame are now available for transmission.
*
* It is assumed that the upper layer software supplies a correctly formatted
* Ethernet frame, including the destination and source addresses, the
* type/length field, and the data field.  It is also assumed that upper layer
* software does not append FCS at the end of the frame.
*
* This call is non-blocking.  Notification of error or successful transmission
* is done asynchronously through the send or error callback function.
*
* @param InstancePtr is a pointer to the XEmac instance to be worked on.
* @param BdPtr is the address of a descriptor to be inserted into the transmit
*        ring.
* @param Delay indicates whether to start the scatter-gather DMA channel
*        immediately, or whether to wait. This allows the user to build up a
*        list of more than one descriptor before starting the transmission of
*        the packets, which allows the application to keep up with DMA and have
*        a constant stream of frames being transmitted. Use XEM_SGDMA_NODELAY or
*        XEM_SGDMA_DELAY, defined in xemac.h, as the value of this argument. If
*        the user chooses to delay and build a list, the user must call this
*        function with the XEM_SGDMA_NODELAY option or call XEmac_Start() to
*        kick off the tranmissions.
*
* @return
*
* - XST_SUCCESS if the buffer was successfull sent
* - XST_DEVICE_IS_STOPPED if the Ethernet MAC has not been started yet
* - XST_NOT_SGDMA if the device is not in scatter-gather DMA mode
* - XST_DMA_SG_LIST_FULL if the descriptor list for the DMA channel is full
* - XST_DMA_SG_BD_LOCKED if the DMA channel cannot insert the descriptor into
*   the list because a locked descriptor exists at the insert point
* - XST_DMA_SG_NOTHING_TO_COMMIT if even after inserting a descriptor into the
*   list, the DMA channel believes there are no new descriptors to commit. If
*   this is ever encountered, there is likely a thread mutual exclusion problem
*   on transmit.
*
* @note
*
* This function is not thread-safe. The user must provide mutually exclusive
* access to this function if there are to be multiple threads that can call it.
*
* @internal
*
* A status that should never be returned from this function, although
* the code is set up to handle it, is XST_DMA_SG_NO_LIST. Starting the device
* requires a list to be created, and this function requires the device to be
* started.
*
******************************************************************************/
XStatus XEmac_SgSend(XEmac *InstancePtr, XBufDescriptor *BdPtr, int Delay)
{
    XStatus Result;
    Xuint32 BdControl;

    XASSERT_NONVOID(InstancePtr != XNULL);
    XASSERT_NONVOID(BdPtr != XNULL);
    XASSERT_NONVOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);

    /*
     * Be sure the device is configured for scatter-gather DMA, then be sure
     * it is started.
     */
    if (!XEmac_mIsSgDma(InstancePtr))
    {
        return XST_NOT_SGDMA;
    }

    /*
     * Set some descriptor control word defaults (source address increment
     * and local destination address) and the destination address
     * (the FIFO).  These are the same for every transmit descriptor.
     */
    BdControl = XBufDescriptor_GetControl(BdPtr);
    XBufDescriptor_SetControl(BdPtr, BdControl | (InstancePtr->TxDmaControlWord));

    /*
     * If the TX channel has Checksum offload enabled, do not overwrite
     * the Data in the destination address location, it is offload related
     * not the actual address for the data to be written to
     */
    if ((InstancePtr->TxDmaControlWord & XDC_DMACR_CS_OFFLOAD_MASK) == 0)
    {
        XBufDescriptor_SetDestAddress(BdPtr,
                    InstancePtr->BaseAddress + XEM_PFIFO_TXDATA_OFFSET);
    }

    /*
     * Put the descriptor in the send list. The DMA component accesses data
     * here that can also be modified in interrupt context, so a critical
     * section is required.
     */
    XIIF_V123B_GINTR_DISABLE(InstancePtr->BaseAddress);

    Result = XDmaChannel_PutDescriptor(&InstancePtr->SendChannel, BdPtr);
    if (Result != XST_SUCCESS)
    {
        XIIF_V123B_GINTR_ENABLE(InstancePtr->BaseAddress);
        return Result;
    }

    /*
     * If this is the last buffer in the frame, commit the inserts and start
     * the DMA engine if necessary
     */
    if (XBufDescriptor_IsLastControl(BdPtr))
    {
        Result = XDmaChannel_CommitPuts(&InstancePtr->SendChannel);
        if (Result != XST_SUCCESS)
        {
            XIIF_V123B_GINTR_ENABLE(InstancePtr->BaseAddress);
            return Result;
        }

        if (Delay == XEM_SGDMA_NODELAY)
        {
            /*
             * Start the DMA channel. Ignore the return status since we know the
             * list exists and has at least one entry and we don't care if the
             * channel is already started.  The DMA component accesses data here
             * that can be modified at interrupt or task levels, so a critical
             * section is required.
             */
            (void)XDmaChannel_SgStart(&InstancePtr->SendChannel);

            (InstancePtr->SendChannel).Committed = XFALSE;

        }
    }

    XIIF_V123B_GINTR_ENABLE(InstancePtr->BaseAddress);

    return XST_SUCCESS;
}

/*****************************************************************************/
/**
*
* Add a descriptor, with an attached empty buffer, into the receive descriptor
* list. The buffer attached to the descriptor must be 32-bit aligned if using
* the OPB Ethernet core and 64-bit aligned if using the PLB Ethernet core.
* This function is used by the upper layer software during initialization when
* first setting up the receive descriptors, and also during reception of frames
* to replace filled buffers with empty buffers. This function can be called
* when the device is started or stopped. Note that it does start the scatter-
* gather DMA engine.  Although this is not necessary during initialization, it
* is not a problem during initialization because the MAC receiver is not yet
* started.
*
* The buffer attached to the descriptor must be aligned on both the front end
* and the back end.
*
* Notification of received frames are done asynchronously through the receive
* callback function.
*
* @param InstancePtr is a pointer to the XEmac instance to be worked on.
* @param BdPtr is a pointer to the buffer descriptor that will be added to the
*        descriptor list.
*
* @return
*
* - XST_SUCCESS if a descriptor was successfully returned to the driver
* - XST_NOT_SGDMA if the device is not in scatter-gather DMA mode
* - XST_DMA_SG_LIST_FULL if the receive descriptor list is full
* - XST_DMA_SG_BD_LOCKED if the DMA channel cannot insert the descriptor into
*   the list because a locked descriptor exists at the insert point.
* - XST_DMA_SG_NOTHING_TO_COMMIT if even after inserting a descriptor into the
*   list, the DMA channel believes there are no new descriptors to commit.
*
* @internal
*
* A status that should never be returned from this function, although
* the code is set up to handle it, is XST_DMA_SG_NO_LIST. Starting the device
* requires a list to be created, and this function requires the device to be
* started.
*
******************************************************************************/
XStatus XEmac_SgRecv(XEmac *InstancePtr, XBufDescriptor *BdPtr)
{
    XStatus Result;
    Xuint32 BdControl;

    XASSERT_NONVOID(InstancePtr != XNULL);
    XASSERT_NONVOID(BdPtr != XNULL);
    XASSERT_NONVOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);

    /*
     * Be sure the device is configured for scatter-gather DMA
     */
    if (!XEmac_mIsSgDma(InstancePtr))
    {
        return XST_NOT_SGDMA;
    }

    /*
     * Set some descriptor control word defaults (destination address increment
     * and local source address) and the source address (the FIFO). These are
     * the same for every receive descriptor.
     */
    BdControl = XBufDescriptor_GetControl(BdPtr);
    XBufDescriptor_SetControl(BdPtr, BdControl | (InstancePtr->RxDmaControlWord));
    XBufDescriptor_SetSrcAddress(BdPtr,
                      InstancePtr->BaseAddress + XEM_PFIFO_RXDATA_OFFSET);

    /*
     * Put the descriptor into the channel's descriptor list and commit.
     * Although this function is likely called within interrupt context, there
     * is the possibility that the upper layer software queues it to a task.
     * In this case, a critical section is needed here to protect shared data
     * in the DMA component.
     */
    XIIF_V123B_GINTR_DISABLE(InstancePtr->BaseAddress);

    Result = XDmaChannel_PutDescriptor(&InstancePtr->RecvChannel, BdPtr);
    if (Result != XST_SUCCESS)
    {
        XIIF_V123B_GINTR_ENABLE(InstancePtr->BaseAddress);
        return Result;
    }

    Result = XDmaChannel_CommitPuts(&InstancePtr->RecvChannel);
    if (Result != XST_SUCCESS)
    {
        XIIF_V123B_GINTR_ENABLE(InstancePtr->BaseAddress);
        return Result;
    }

    /*
     * Start the DMA channel. Ignore the return status since we know the list
     * exists and has at least one entry and we don't care if the channel is
     * already started. The DMA component accesses data here that can be
     * modified at interrupt or task levels, so a critical section is required.
     */
    (void)XDmaChannel_SgStart(&InstancePtr->RecvChannel);

    XIIF_V123B_GINTR_ENABLE(InstancePtr->BaseAddress);

    return XST_SUCCESS;
}


/*****************************************************************************/
/**
*
* The interrupt handler for the Ethernet driver when configured with scatter-