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u-boot 1.1.4
2024-01-07 23:57:24 +01:00
/******************************************************************************
*
* Author: Xilinx, Inc.
*
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
*
* XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS" AS A
* COURTESY TO YOU. 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 THIRD PARTY 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.
*
*
* Xilinx hardware products are not intended for use in life support
* appliances, devices, or systems. Use in such applications is
* expressly prohibited.
*
*
* (c) Copyright 2002-2004 Xilinx Inc.
* All rights reserved.
*
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
******************************************************************************/
/*****************************************************************************/
/**
*
* @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.
* </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 word-aligned.
*
* 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.
*
* The buffer attached to the descriptor must be word-aligned on the front end.
*
* 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;
u32 BdControl;
XASSERT_NONVOID(InstancePtr != NULL);
XASSERT_NONVOID(BdPtr != NULL);
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 | XEM_DFT_SEND_BD_MASK);
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);
}
}
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 word-aligned. This 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 word-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;
u32 BdControl;
XASSERT_NONVOID(InstancePtr != NULL);
XASSERT_NONVOID(BdPtr != NULL);
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 | XEM_DFT_RECV_BD_MASK);
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-
* gather DMA.
*
* Get the interrupt status from the IpIf to determine the source of the
* interrupt. The source can be: MAC, Recv Packet FIFO, Send Packet FIFO, Recv
* DMA channel, or Send DMA channel. The packet FIFOs only interrupt during
* "deadlock" conditions.
*
* @param InstancePtr is a pointer to the XEmac instance that just interrupted.
*
* @return
*
* None.
*
* @note
*
* None.
*
******************************************************************************/
void
XEmac_IntrHandlerDma(void *InstancePtr)
{
u32 IntrStatus;
XEmac *EmacPtr = (XEmac *) InstancePtr;
EmacPtr->Stats.TotalIntrs++;
/*
* Get the interrupt status from the IPIF. There is no clearing of
* interrupts in the IPIF. Interrupts must be cleared at the source.
*/
IntrStatus = XIIF_V123B_READ_DIPR(EmacPtr->BaseAddress);
/*
* See which type of interrupt is being requested, and service it
*/
if (IntrStatus & XEM_IPIF_RECV_DMA_MASK) { /* Receive DMA interrupt */
EmacPtr->Stats.RecvInterrupts++;
HandleDmaRecvIntr(EmacPtr);
}
if (IntrStatus & XEM_IPIF_SEND_DMA_MASK) { /* Send DMA interrupt */
EmacPtr->Stats.XmitInterrupts++;
HandleDmaSendIntr(EmacPtr);
}
if (IntrStatus & XEM_IPIF_EMAC_MASK) { /* MAC interrupt */
EmacPtr->Stats.EmacInterrupts++;
HandleEmacDmaIntr(EmacPtr);
}
if (IntrStatus & XEM_IPIF_RECV_FIFO_MASK) { /* Receive FIFO interrupt */
EmacPtr->Stats.RecvInterrupts++;
XEmac_CheckFifoRecvError(EmacPtr);
}
if (IntrStatus & XEM_IPIF_SEND_FIFO_MASK) { /* Send FIFO interrupt */
EmacPtr->Stats.XmitInterrupts++;
XEmac_CheckFifoSendError(EmacPtr);
}
if (IntrStatus & XIIF_V123B_ERROR_MASK) {
/*
* An error occurred internal to the IPIF. This is more of a debug and
* integration issue rather than a production error. Don't do anything
* other than clear it, which provides a spot for software to trap
* on the interrupt and begin debugging.
*/
XIIF_V123B_WRITE_DISR(EmacPtr->BaseAddress,
XIIF_V123B_ERROR_MASK);
}
}
/*****************************************************************************/
/**
*
* Set the packet count threshold for this device. The device must be stopped
* before setting the threshold. The packet count threshold is used for interrupt
* coalescing, which reduces the frequency of interrupts from the device to the
* processor. In this case, the scatter-gather DMA engine only interrupts when
* the packet count threshold is reached, instead of interrupting for each packet.
* A packet is a generic term used by the scatter-gather DMA engine, and is
* equivalent to an Ethernet frame in our case.
*
* @param InstancePtr is a pointer to the XEmac instance to be worked on.
* @param Direction indicates the channel, send or receive, from which the
* threshold register is read.
* @param Threshold is the value of the packet threshold count used during
* interrupt coalescing. A value of 0 disables the use of packet threshold
* by the hardware.
*
* @return
*
* - XST_SUCCESS if the threshold was successfully set
* - XST_NOT_SGDMA if the MAC is not configured for scatter-gather DMA
* - XST_DEVICE_IS_STARTED if the device has not been stopped
* - XST_INVALID_PARAM if the Direction parameter is invalid. Turning on
* asserts would also catch this error.
*
* @note
*
* The packet threshold could be set to larger than the number of descriptors
* allocated to the DMA channel. In this case, the wait bound will take over
* and always indicate data arrival. There was a check in this function that
* returned an error if the treshold was larger than the number of descriptors,
* but that was removed because users would then have to set the threshold
* only after they set descriptor space, which is an order dependency that
* caused confustion.
*
******************************************************************************/
XStatus
XEmac_SetPktThreshold(XEmac * InstancePtr, u32 Direction, u8 Threshold)
{
XASSERT_NONVOID(InstancePtr != NULL);
XASSERT_NONVOID(Direction == XEM_SEND || Direction == XEM_RECV);
XASSERT_NONVOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);
/*
* Be sure device is configured for scatter-gather DMA and has been stopped
*/
if (!XEmac_mIsSgDma(InstancePtr)) {
return XST_NOT_SGDMA;
}
if (InstancePtr->IsStarted == XCOMPONENT_IS_STARTED) {
return XST_DEVICE_IS_STARTED;
}
/*
* Based on the direction, set the packet threshold in the
* corresponding DMA channel component. Default to the receive
* channel threshold register (if an invalid Direction is passed).
*/
switch (Direction) {
case XEM_SEND:
return XDmaChannel_SetPktThreshold(&InstancePtr->SendChannel,
Threshold);
case XEM_RECV:
return XDmaChannel_SetPktThreshold(&InstancePtr->RecvChannel,
Threshold);
default:
return XST_INVALID_PARAM;
}
}
/*****************************************************************************/
/**
*
* Get the value of the packet count threshold for this driver/device. The packet
* count threshold is used for interrupt coalescing, which reduces the frequency
* of interrupts from the device to the processor. In this case, the
* scatter-gather DMA engine only interrupts when the packet count threshold is
* reached, instead of interrupting for each packet. A packet is a generic term
* used by the scatter-gather DMA engine, and is equivalent to an Ethernet frame
* in our case.
*
* @param InstancePtr is a pointer to the XEmac instance to be worked on.
* @param Direction indicates the channel, send or receive, from which the
* threshold register is read.
* @param ThreshPtr is a pointer to the byte into which the current value of the
* packet threshold register will be copied. An output parameter. A value
* of 0 indicates the use of packet threshold by the hardware is disabled.
*
* @return
*
* - XST_SUCCESS if the packet threshold was retrieved successfully
* - XST_NOT_SGDMA if the MAC is not configured for scatter-gather DMA
* - XST_INVALID_PARAM if the Direction parameter is invalid. Turning on
* asserts would also catch this error.
*
* @note
*
* None.
*
******************************************************************************/
XStatus
XEmac_GetPktThreshold(XEmac * InstancePtr, u32 Direction, u8 * ThreshPtr)
{
XASSERT_NONVOID(InstancePtr != NULL);
XASSERT_NONVOID(Direction == XEM_SEND || Direction == XEM_RECV);
XASSERT_NONVOID(ThreshPtr != NULL);
XASSERT_NONVOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);
if (!XEmac_mIsSgDma(InstancePtr)) {
return XST_NOT_SGDMA;
}
/*
* Based on the direction, return the packet threshold set in the
* corresponding DMA channel component. Default to the value in
* the receive channel threshold register (if an invalid Direction
* is passed).
*/
switch (Direction) {
case XEM_SEND:
*ThreshPtr =
XDmaChannel_GetPktThreshold(&InstancePtr->SendChannel);
break;
case XEM_RECV:
*ThreshPtr =
XDmaChannel_GetPktThreshold(&InstancePtr->RecvChannel);
break;
default:
return XST_INVALID_PARAM;
}
return XST_SUCCESS;
}
/*****************************************************************************/
/**
*
* Set the packet wait bound timer for this driver/device. The device must be
* stopped before setting the timer value. The packet wait bound is used during
* interrupt coalescing to trigger an interrupt when not enough packets have been
* received to reach the packet count threshold. A packet is a generic term used
* by the scatter-gather DMA engine, and is equivalent to an Ethernet frame in
* our case. The timer is in milliseconds.
*
* @param InstancePtr is a pointer to the XEmac instance to be worked on.
* @param Direction indicates the channel, send or receive, from which the
* threshold register is read.
* @param TimerValue is the value of the packet wait bound used during interrupt
* coalescing. It is in milliseconds in the range 0 - 1023. A value of 0
* disables the packet wait bound timer.
*
* @return
*
* - XST_SUCCESS if the packet wait bound was set successfully
* - XST_NOT_SGDMA if the MAC is not configured for scatter-gather DMA
* - XST_DEVICE_IS_STARTED if the device has not been stopped
* - XST_INVALID_PARAM if the Direction parameter is invalid. Turning on
* asserts would also catch this error.
*
* @note
*
* None.
*
******************************************************************************/
XStatus
XEmac_SetPktWaitBound(XEmac * InstancePtr, u32 Direction, u32 TimerValue)
{
XASSERT_NONVOID(InstancePtr != NULL);
XASSERT_NONVOID(Direction == XEM_SEND || Direction == XEM_RECV);
XASSERT_NONVOID(TimerValue <= XEM_SGDMA_MAX_WAITBOUND);
XASSERT_NONVOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);
/*
* Be sure device is configured for scatter-gather DMA and has been stopped
*/
if (!XEmac_mIsSgDma(InstancePtr)) {
return XST_NOT_SGDMA;
}
if (InstancePtr->IsStarted == XCOMPONENT_IS_STARTED) {
return XST_DEVICE_IS_STARTED;
}
/*
* Based on the direction, set the packet wait bound in the
* corresponding DMA channel component. Default to the receive
* channel wait bound register (if an invalid Direction is passed).
*/
switch (Direction) {
case XEM_SEND:
XDmaChannel_SetPktWaitBound(&InstancePtr->SendChannel,
TimerValue);
break;
case XEM_RECV:
XDmaChannel_SetPktWaitBound(&InstancePtr->RecvChannel,
TimerValue);
break;
default:
return XST_INVALID_PARAM;
}
return XST_SUCCESS;
}
/*****************************************************************************/
/**
*
* Get the packet wait bound timer for this driver/device. The packet wait bound
* is used during interrupt coalescing to trigger an interrupt when not enough
* packets have been received to reach the packet count threshold. A packet is a
* generic term used by the scatter-gather DMA engine, and is equivalent to an
* Ethernet frame in our case. The timer is in milliseconds.
*
* @param InstancePtr is a pointer to the XEmac instance to be worked on.
* @param Direction indicates the channel, send or receive, from which the
* threshold register is read.
* @param WaitPtr is a pointer to the byte into which the current value of the
* packet wait bound register will be copied. An output parameter. Units
* are in milliseconds in the range 0 - 1023. A value of 0 indicates the
* packet wait bound timer is disabled.
*
* @return
*
* - XST_SUCCESS if the packet wait bound was retrieved successfully
* - XST_NOT_SGDMA if the MAC is not configured for scatter-gather DMA
* - XST_INVALID_PARAM if the Direction parameter is invalid. Turning on
* asserts would also catch this error.
*
* @note
*
* None.
*
******************************************************************************/
XStatus
XEmac_GetPktWaitBound(XEmac * InstancePtr, u32 Direction, u32 * WaitPtr)
{
XASSERT_NONVOID(InstancePtr != NULL);
XASSERT_NONVOID(Direction == XEM_SEND || Direction == XEM_RECV);
XASSERT_NONVOID(WaitPtr != NULL);
XASSERT_NONVOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);
if (!XEmac_mIsSgDma(InstancePtr)) {
return XST_NOT_SGDMA;
}
/*
* Based on the direction, return the packet wait bound set in the
* corresponding DMA channel component. Default to the value in
* the receive channel wait bound register (if an invalid Direction
* is passed).
*/
switch (Direction) {
case XEM_SEND:
*WaitPtr =
XDmaChannel_GetPktWaitBound(&InstancePtr->SendChannel);
break;
case XEM_RECV:
*WaitPtr =
XDmaChannel_GetPktWaitBound(&InstancePtr->RecvChannel);
break;
default:
return XST_INVALID_PARAM;
}
return XST_SUCCESS;
}
/*****************************************************************************/
/**
*
* Give the driver the memory space to be used for the scatter-gather DMA
* receive descriptor list. This function should only be called once, during
* initialization of the Ethernet driver. The memory space must be big enough
* to hold some number of descriptors, depending on the needs of the system.
* The xemac.h file defines minimum and default numbers of descriptors
* which can be used to allocate this memory space.
*
* The memory space must be word-aligned. An assert will occur if asserts are
* turned on and the memory is not word-aligned.
*
* @param InstancePtr is a pointer to the XEmac instance to be worked on.
* @param MemoryPtr is a pointer to the word-aligned memory.
* @param ByteCount is the length, in bytes, of the memory space.
*
* @return
*
* - XST_SUCCESS if the space was initialized successfully
* - XST_NOT_SGDMA if the MAC is not configured for scatter-gather DMA
* - XST_DMA_SG_LIST_EXISTS if this list space has already been created
*
* @note
*
* If the device is configured for scatter-gather DMA, this function must be
* called AFTER the XEmac_Initialize() function because the DMA channel
* components must be initialized before the memory space is set.
*
******************************************************************************/
XStatus
XEmac_SetSgRecvSpace(XEmac * InstancePtr, u32 * MemoryPtr, u32 ByteCount)
{
XASSERT_NONVOID(InstancePtr != NULL);
XASSERT_NONVOID(MemoryPtr != NULL);
XASSERT_NONVOID(ByteCount != 0);
XASSERT_NONVOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);
if (!XEmac_mIsSgDma(InstancePtr)) {
return XST_NOT_SGDMA;
}
return XDmaChannel_CreateSgList(&InstancePtr->RecvChannel, MemoryPtr,
ByteCount);
}
/*****************************************************************************/
/**
*
* Give the driver the memory space to be used for the scatter-gather DMA
* transmit descriptor list. This function should only be called once, during
* initialization of the Ethernet driver. The memory space must be big enough
* to hold some number of descriptors, depending on the needs of the system.
* The xemac.h file defines minimum and default numbers of descriptors
* which can be used to allocate this memory space.
*
* The memory space must be word-aligned. An assert will occur if asserts are
* turned on and the memory is not word-aligned.
*
* @param InstancePtr is a pointer to the XEmac instance to be worked on.
* @param MemoryPtr is a pointer to the word-aligned memory.
* @param ByteCount is the length, in bytes, of the memory space.
*
* @return
*
* - XST_SUCCESS if the space was initialized successfully
* - XST_NOT_SGDMA if the MAC is not configured for scatter-gather DMA
* - XST_DMA_SG_LIST_EXISTS if this list space has already been created
*
* @note
*
* If the device is configured for scatter-gather DMA, this function must be
* called AFTER the XEmac_Initialize() function because the DMA channel
* components must be initialized before the memory space is set.
*
******************************************************************************/
XStatus
XEmac_SetSgSendSpace(XEmac * InstancePtr, u32 * MemoryPtr, u32 ByteCount)
{
XASSERT_NONVOID(InstancePtr != NULL);
XASSERT_NONVOID(MemoryPtr != NULL);
XASSERT_NONVOID(ByteCount != 0);
XASSERT_NONVOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);
if (!XEmac_mIsSgDma(InstancePtr)) {
return XST_NOT_SGDMA;
}
return XDmaChannel_CreateSgList(&InstancePtr->SendChannel, MemoryPtr,
ByteCount);
}
/*****************************************************************************/
/**
*
* Set the callback function for handling received frames in scatter-gather DMA
* mode. The upper layer software should call this function during
* initialization. The callback is called once per frame received. The head of
* a descriptor list is passed in along with the number of descriptors in the
* list. Before leaving the callback, the upper layer software should attach a
* new buffer to each descriptor in the list.
*
* The callback is invoked by the driver within interrupt context, so it needs
* to do its job quickly. Sending the received frame up the protocol stack
* should be done at task-level. If there are other potentially slow operations
* within the callback, these too should be done at task-level.
*
* @param InstancePtr is a pointer to the XEmac instance to be worked on.
* @param CallBackRef is a reference pointer to be passed back to the adapter in
* the callback. This helps the adapter correlate the callback to a
* particular driver.
* @param FuncPtr is the pointer to the callback function.
*
* @return
*
* None.
*
* @note
*
* None.
*
******************************************************************************/
void
XEmac_SetSgRecvHandler(XEmac * InstancePtr, void *CallBackRef,
XEmac_SgHandler FuncPtr)
{
/*
* Asserted IsDmaSg here instead of run-time check because there is really
* no ill-effects of setting these when not configured for scatter-gather.
*/
XASSERT_VOID(InstancePtr != NULL);
XASSERT_VOID(FuncPtr != NULL);
XASSERT_VOID(XEmac_mIsSgDma(InstancePtr));
XASSERT_VOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);
InstancePtr->SgRecvHandler = FuncPtr;
InstancePtr->SgRecvRef = CallBackRef;
}
/*****************************************************************************/
/**
*
* Set the callback function for handling confirmation of transmitted frames in
* scatter-gather DMA mode. The upper layer software should call this function
* during initialization. The callback is called once per frame sent. The head
* of a descriptor list is passed in along with the number of descriptors in
* the list. The callback is responsible for freeing buffers attached to these
* descriptors.
*
* The callback is invoked by the driver within interrupt context, so it needs
* to do its job quickly. If there are potentially slow operations within the
* callback, these should be done at task-level.
*
* @param InstancePtr is a pointer to the XEmac instance to be worked on.
* @param CallBackRef is a reference pointer to be passed back to the adapter in
* the callback. This helps the adapter correlate the callback to a
* particular driver.
* @param FuncPtr is the pointer to the callback function.
*
* @return
*
* None.
*
* @note
*
* None.
*
******************************************************************************/
void
XEmac_SetSgSendHandler(XEmac * InstancePtr, void *CallBackRef,
XEmac_SgHandler FuncPtr)
{
/*
* Asserted IsDmaSg here instead of run-time check because there is really
* no ill-effects of setting these when not configured for scatter-gather.
*/
XASSERT_VOID(InstancePtr != NULL);
XASSERT_VOID(FuncPtr != NULL);
XASSERT_VOID(XEmac_mIsSgDma(InstancePtr));
XASSERT_VOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);
InstancePtr->SgSendHandler = FuncPtr;
InstancePtr->SgSendRef = CallBackRef;
}
/*****************************************************************************/
/*
*
* Handle an interrupt from the DMA receive channel. DMA interrupts are:
*
* - DMA error. DMA encountered a bus error or timeout. This is a fatal error
* that requires reset of the channel. The driver calls the error handler
* of the upper layer software with an error code indicating the device should
* be reset.
* - Packet count threshold reached. For scatter-gather operations, indicates
* the threshold for the number of packets not serviced by software has been
* reached. The driver behaves as follows:
* - Get the value of the packet counter, which tells us how many packets
* are ready to be serviced
* - For each packet
* - For each descriptor, remove it from the scatter-gather list
* - Check for the last descriptor in the frame, and if set
* - Bump frame statistics
* - Call the scatter-gather receive callback function
* - Decrement the packet counter by one
* Note that there are no receive errors reported in the status word of
* the buffer descriptor. If receive errors occur, the MAC drops the
* packet, and we only find out about the errors through various error
* count registers.
* - Packet wait bound reached. For scatter-gather, indicates the time to wait
* for the next packet has expired. The driver follows the same logic as when
* the packet count threshold interrupt is received.
* - Scatter-gather end acknowledge. Hardware has reached the end of the
* descriptor list. The driver follows the same logic as when the packet count
* threshold interrupt is received. In addition, the driver restarts the DMA
* scatter-gather channel in case there are newly inserted descriptors.
*
* @param InstancePtr is a pointer to the XEmac instance to be worked on.
*
* @return
*
* Although the function returns void, there are asynchronous errors that can
* be generated (by calling the ErrorHandler) from this function. These are:
* - XST_DMA_SG_LIST_EMPTY indicates we tried to get a buffer descriptor from the
* DMA channel, but there was not one ready for software.
* - XST_DMA_ERROR indicates a DMA bus error or timeout occurred. This is a fatal
* error that requires reset.
*
* @note
*
* None.
*
******************************************************************************/
static void
HandleDmaRecvIntr(XEmac * InstancePtr)
{
u32 IntrStatus;
/*
* Read the interrupt status
*/
IntrStatus = XDmaChannel_GetIntrStatus(&InstancePtr->RecvChannel);
/*
* For packet threshold or wait bound interrupts, process desciptors. Also
* process descriptors on a SG end acknowledgement, which means the end of
* the descriptor list has been reached by the hardware. For receive, this
* is potentially trouble since it means the descriptor list is full,
* unless software can process enough packets quickly enough so the
* hardware has room to put new packets.
*/
if (IntrStatus & (XDC_IXR_PKT_THRESHOLD_MASK |
XDC_IXR_PKT_WAIT_BOUND_MASK | XDC_IXR_SG_END_MASK)) {
XStatus Result = XST_SUCCESS;
u32 NumFrames;
u32 NumProcessed;
u32 NumBuffers;
u32 NumBytes;
u32 IsLast;
XBufDescriptor *FirstBdPtr;
XBufDescriptor *BdPtr;
/*
* Get the number of unserviced packets
*/
NumFrames = XDmaChannel_GetPktCount(&InstancePtr->RecvChannel);
for (NumProcessed = 0; NumProcessed < NumFrames; NumProcessed++) {
IsLast = FALSE;
FirstBdPtr = NULL;
NumBuffers = 0;
NumBytes = 0;
/*
* For each packet, get the descriptor from the list. On the
* last one in the frame, make the callback to the upper layer.
*/
while (!IsLast) {
Result =
XDmaChannel_GetDescriptor(&InstancePtr->
RecvChannel,
&BdPtr);
if (Result != XST_SUCCESS) {
/*
* An error getting a buffer descriptor from the list.
* This should not happen, but if it does, report it to
* the error callback and break out of the loops to service
* other interrupts.
*/
InstancePtr->ErrorHandler(InstancePtr->
ErrorRef,
Result);
break;
}
/*
* Keep a pointer to the first descriptor in the list, as it
* will be passed to the upper layers in a bit. By the fact
* that we received this packet means no errors occurred, so
* no need to check the device status word for errors.
*/
if (FirstBdPtr == NULL) {
FirstBdPtr = BdPtr;
}
NumBytes += XBufDescriptor_GetLength(BdPtr);
/*
* Check to see if this is the last descriptor in the frame,
* and if so, set the IsLast flag to get out of the loop.
*/
if (XBufDescriptor_IsLastStatus(BdPtr)) {
IsLast = TRUE;
}
/*
* Bump the number of buffers in this packet
*/
NumBuffers++;
} /* end while loop */
/*
* Check for error that occurred inside the while loop, and break
* out of the for loop if there was one so other interrupts can
* be serviced.
*/
if (Result != XST_SUCCESS) {
break;
}
InstancePtr->Stats.RecvFrames++;
InstancePtr->Stats.RecvBytes += NumBytes;
/*
* Make the callback to the upper layers, passing it the first
* descriptor in the packet and the number of descriptors in the
* packet.
*/
InstancePtr->SgRecvHandler(InstancePtr->SgRecvRef,
FirstBdPtr, NumBuffers);
/*
* Decrement the packet count register to reflect the fact we
* just processed a packet
*/
XDmaChannel_DecrementPktCount(&InstancePtr->
RecvChannel);
} /* end for loop */
/*
* If the interrupt was an end-ack, check the descriptor list again to
* see if it is empty. If not, go ahead and restart the scatter-gather
* channel. This is to fix a possible race condition where, on receive,
* the driver attempted to start a scatter-gather channel that was
* already started, which resulted in no action from the XDmaChannel
* component. But, just after the XDmaChannel component saw that the
* hardware was already started, the hardware stopped because it
* reached the end of the list. In that case, this interrupt is
* generated and we can restart the hardware here.
*/
if (IntrStatus & XDC_IXR_SG_END_MASK) {
/*
* Ignore the return status since we know the list exists and we
* don't care if the list is empty or the channel is already started.
*/
(void) XDmaChannel_SgStart(&InstancePtr->RecvChannel);
}
}
/*
* All interrupts are handled (except the error below) so acknowledge
* (clear) the interrupts by writing the value read above back to the status
* register. The packet count interrupt must be acknowledged after the
* decrement, otherwise it will come right back. We clear the interrupts
* before we handle the error interrupt because the ErrorHandler should
* result in a reset, which clears the interrupt status register. So we
* don't want to toggle the interrupt back on by writing the interrupt
* status register with an old value after a reset.
*/
XDmaChannel_SetIntrStatus(&InstancePtr->RecvChannel, IntrStatus);
/*
* Check for DMA errors and call the error callback function if an error
* occurred (DMA bus or timeout error), which should result in a reset of
* the device by the upper layer software.
*/
if (IntrStatus & XDC_IXR_DMA_ERROR_MASK) {
InstancePtr->Stats.DmaErrors++;
InstancePtr->ErrorHandler(InstancePtr->ErrorRef, XST_DMA_ERROR);
}
}
/*****************************************************************************/
/*
*
* Handle an interrupt from the DMA send channel. DMA interrupts are:
*
* - DMA error. DMA encountered a bus error or timeout. This is a fatal error
* that requires reset of the channel. The driver calls the error handler
* of the upper layer software with an error code indicating the device should
* be reset.
* - Packet count threshold reached. For scatter-gather operations, indicates
* the threshold for the number of packets not serviced by software has been
* reached. The driver behaves as follows:
* - Get the value of the packet counter, which tells us how many packets
* are ready to be serviced
* - For each packet
* - For each descriptor, remove it from the scatter-gather list
* - Check for the last descriptor in the frame, and if set
* - Bump frame statistics
* - Call the scatter-gather receive callback function
* - Decrement the packet counter by one
* Note that there are no receive errors reported in the status word of
* the buffer descriptor. If receive errors occur, the MAC drops the
* packet, and we only find out about the errors through various error
* count registers.
* - Packet wait bound reached. For scatter-gather, indicates the time to wait
* for the next packet has expired. The driver follows the same logic as when
* the packet count threshold interrupt is received.
* - Scatter-gather end acknowledge. Hardware has reached the end of the
* descriptor list. The driver follows the same logic as when the packet count
* threshold interrupt is received. In addition, the driver restarts the DMA
* scatter-gather channel in case there are newly inserted descriptors.
*
* @param InstancePtr is a pointer to the XEmac instance to be worked on.
*
* @return
*
* Although the function returns void, there are asynchronous errors
* that can be generated from this function. These are:
* - XST_DMA_SG_LIST_EMPTY indicates we tried to get a buffer descriptor from
* the DMA channel, but there was not one ready for software.
* - XST_DMA_ERROR indicates a DMA bus error or timeout occurred. This is a
* fatal error that requires reset.
*
* @note
*
* None.
*
******************************************************************************/
static void
HandleDmaSendIntr(XEmac * InstancePtr)
{
u32 IntrStatus;
/*
* Read the interrupt status
*/
IntrStatus = XDmaChannel_GetIntrStatus(&InstancePtr->SendChannel);
/*
* For packet threshold or wait bound interrupt, process descriptors. Also
* process descriptors on a SG end acknowledgement, which means the end of
* the descriptor list has been reached by the hardware. For transmit,
* this is a normal condition during times of light traffic. In fact, the
* wait bound interrupt may be masked for transmit since the end-ack would
* always occur before the wait bound expires.
*/
if (IntrStatus & (XDC_IXR_PKT_THRESHOLD_MASK |
XDC_IXR_PKT_WAIT_BOUND_MASK | XDC_IXR_SG_END_MASK)) {
XStatus Result = XST_SUCCESS;
u32 NumFrames;
u32 NumProcessed;
u32 NumBuffers;
u32 NumBytes;
u32 IsLast;
XBufDescriptor *FirstBdPtr;
XBufDescriptor *BdPtr;
/*
* Get the number of unserviced packets
*/
NumFrames = XDmaChannel_GetPktCount(&InstancePtr->SendChannel);
for (NumProcessed = 0; NumProcessed < NumFrames; NumProcessed++) {
IsLast = FALSE;
FirstBdPtr = NULL;
NumBuffers = 0;
NumBytes = 0;
/*
* For each frame, traverse the descriptor list and look for
* errors. On the last one in the frame, make the callback.
*/
while (!IsLast) {
Result =
XDmaChannel_GetDescriptor(&InstancePtr->
SendChannel,
&BdPtr);
if (Result != XST_SUCCESS) {
/*
* An error getting a buffer descriptor from the list.
* This should not happen, but if it does, report it to
* the error callback and break out of the loops to service
* other interrupts
*/
InstancePtr->ErrorHandler(InstancePtr->
ErrorRef,
Result);
break;
}
/*
* Keep a pointer to the first descriptor in the list and
* check the device status for errors. The device status is
* only available in the first descriptor of a packet.
*/
if (FirstBdPtr == NULL) {
u32 XmitStatus;
FirstBdPtr = BdPtr;
XmitStatus =
XBufDescriptor_GetDeviceStatus
(BdPtr);
if (XmitStatus &
XEM_TSR_EXCESS_DEFERRAL_MASK) {
InstancePtr->Stats.
XmitExcessDeferral++;
}
if (XmitStatus &
XEM_TSR_LATE_COLLISION_MASK) {
InstancePtr->Stats.
XmitLateCollisionErrors++;
}
}
NumBytes += XBufDescriptor_GetLength(BdPtr);
/*
* Check to see if this is the last descriptor in the frame,
* and if so, set the IsLast flag to get out of the loop. The
* transmit channel must check the last bit in the control
* word, not the status word (the DMA engine does not update
* the last bit in the status word for the transmit direction).
*/
if (XBufDescriptor_IsLastControl(BdPtr)) {
IsLast = TRUE;
}
/*
* Bump the number of buffers in this packet
*/
NumBuffers++;
} /* end while loop */
/*
* Check for error that occurred inside the while loop, and break
* out of the for loop if there was one so other interrupts can
* be serviced.
*/
if (Result != XST_SUCCESS) {
break;
}
InstancePtr->Stats.XmitFrames++;
InstancePtr->Stats.XmitBytes += NumBytes;
/*
* Make the callback to the upper layers, passing it the first
* descriptor in the packet and the number of descriptors in the
* packet.
*/
InstancePtr->SgSendHandler(InstancePtr->SgSendRef,
FirstBdPtr, NumBuffers);
/*
* Decrement the packet count register to reflect the fact we
* just processed a packet
*/
XDmaChannel_DecrementPktCount(&InstancePtr->
SendChannel);
} /* end for loop */
/*
* If the interrupt was an end-ack, check the descriptor list again to
* see if it is empty. If not, go ahead and restart the scatter-gather
* channel. This is to fix a possible race condition where, on transmit,
* the driver attempted to start a scatter-gather channel that was
* already started, which resulted in no action from the XDmaChannel
* component. But, just after the XDmaChannel component saw that the
* hardware was already started, the hardware stopped because it
* reached the end of the list. In that case, this interrupt is
* generated and we can restart the hardware here.
*/
if (IntrStatus & XDC_IXR_SG_END_MASK) {
/*
* Ignore the return status since we know the list exists and we
* don't care if the list is empty or the channel is already started.
*/
(void) XDmaChannel_SgStart(&InstancePtr->SendChannel);
}
}
/*
* All interrupts are handled (except the error below) so acknowledge
* (clear) the interrupts by writing the value read above back to the status
* register. The packet count interrupt must be acknowledged after the
* decrement, otherwise it will come right back. We clear the interrupts
* before we handle the error interrupt because the ErrorHandler should
* result in a reset, which clears the interrupt status register. So we
* don't want to toggle the interrupt back on by writing the interrupt
* status register with an old value after a reset.
*/
XDmaChannel_SetIntrStatus(&InstancePtr->SendChannel, IntrStatus);
/*
* Check for DMA errors and call the error callback function if an error
* occurred (DMA bus or timeout error), which should result in a reset of
* the device by the upper layer software.
*/
if (IntrStatus & XDC_IXR_DMA_ERROR_MASK) {
InstancePtr->Stats.DmaErrors++;
InstancePtr->ErrorHandler(InstancePtr->ErrorRef, XST_DMA_ERROR);
}
}
/*****************************************************************************/
/*
*
* Handle an interrupt from the Ethernet MAC when configured with scatter-gather
* DMA. The only interrupts handled in this case are errors.
*
* @param InstancePtr is a pointer to the XEmac instance to be worked on.
*
* @return
*
* None.
*
* @note
*
* None.
*
******************************************************************************/
static void
HandleEmacDmaIntr(XEmac * InstancePtr)
{
u32 IntrStatus;
/*
* When configured with DMA, the EMAC generates interrupts only when errors
* occur. We clear the interrupts immediately so that any latched status
* interrupt bits will reflect the true status of the device, and so any
* pulsed interrupts (non-status) generated during the Isr will not be lost.
*/
IntrStatus = XIIF_V123B_READ_IISR(InstancePtr->BaseAddress);
XIIF_V123B_WRITE_IISR(InstancePtr->BaseAddress, IntrStatus);
/*
* Check the MAC for errors
*/
XEmac_CheckEmacError(InstancePtr, IntrStatus);
}
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