skge.c

内核linux2.4.20,可跟rtlinux3.2打补丁 组成实时linux系统,编译内核

		/* StartTx(pAC, pTxPort->HwAddr); */
		SK_OUT8(pTxPort->HwAddr, TX_Q_CTRL, TX_Q_CTRL_START);
	}
	pTxPort->pTxdRingPrev = pTxd;
	
	
	BytesSend = pMessage->len;
	/* after releasing the lock, the skb may be immidiately freed */
	if (pTxPort->TxdRingFree != 0) {
		spin_unlock_irqrestore(&pTxPort->TxDesRingLock, Flags);
		return (BytesSend);
	}
	else {
		/* ring full: set tbusy on return */
		spin_unlock_irqrestore(&pTxPort->TxDesRingLock, Flags);
		return (0);
	}
} /* XmitFrame */


/*****************************************************************************
 *
 * 	FreeTxDescriptors - release descriptors from the descriptor ring
 *
 * Description:
 *	This function releases descriptors from a transmit ring if they
 *	have been sent by the BMU.
 *	If a descriptors is sent, it can be freed and the message can
 *	be freed, too.
 *	The SOFTWARE controllable bit is used to prevent running around a
 *	completely free ring for ever. If this bit is no set in the
 *	frame (by XmitFrame), this frame has never been sent or is
 *	already freed.
 *	The Tx descriptor ring lock must be held while calling this function !!!
 *
 * Returns:
 *	none
 */
static void FreeTxDescriptors(
SK_AC	*pAC,		/* pointer to the adapter context */
TX_PORT	*pTxPort)	/* pointer to destination port structure */
{
TXD	*pTxd;		/* pointer to the checked descriptor */
TXD	*pNewTail;	/* pointer to 'end' of the ring */
SK_U32	Control;	/* TBControl field of descriptor */
SK_U64	PhysAddr;	/* address of DMA mapping */

	pNewTail = pTxPort->pTxdRingTail;
	pTxd = pNewTail;
	
	/* 
	 * loop forever; exits if TX_CTRL_SOFTWARE bit not set in start frame
	 * or TX_CTRL_OWN_BMU bit set in any frame
	 */
	while (1) {
		Control = pTxd->TBControl;
		if ((Control & TX_CTRL_SOFTWARE) == 0) {
			/* 
			 * software controllable bit is set in first
			 * fragment when given to BMU. Not set means that
			 * this fragment was never sent or is already 
			 * freed ( -> ring completely free now).
			 */
			pTxPort->pTxdRingTail = pTxd;
			netif_start_queue(pAC->dev[pTxPort->PortIndex]);
			return;
		}
		if (Control & TX_CTRL_OWN_BMU) {
			pTxPort->pTxdRingTail = pTxd;
			if (pTxPort->TxdRingFree > 0) {
				netif_start_queue(pAC->dev[pTxPort->PortIndex]);
			}
			return;
		}
		
		/* release the DMA mapping */
		PhysAddr = ((SK_U64) pTxd->VDataHigh) << (SK_U64) 32;
		PhysAddr |= (SK_U64) pTxd->VDataLow;
		pci_unmap_page(&pAC->PciDev, PhysAddr,
			       pTxd->pMBuf->len,
			       PCI_DMA_TODEVICE);

		/* free message */
		DEV_KFREE_SKB_ANY(pTxd->pMBuf);
		pTxPort->TxdRingFree++;
		pTxd->TBControl &= ~TX_CTRL_SOFTWARE;
		pTxd = pTxd->pNextTxd; /* point behind fragment with EOF */
	} /* while(forever) */
} /* FreeTxDescriptors */


/*****************************************************************************
 *
 * 	FillRxRing - fill the receive ring with valid descriptors
 *
 * Description:
 *	This function fills the receive ring descriptors with data
 *	segments and makes them valid for the BMU.
 *	The active ring is filled completely, if possible.
 *	The non-active ring is filled only partial to save memory.
 *
 * Description of rx ring structure:
 *	head - points to the descriptor which will be used next by the BMU
 *	tail - points to the next descriptor to give to the BMU
 *	
 * Returns:	N/A
 */
static void FillRxRing(
SK_AC		*pAC,		/* pointer to the adapter context */
RX_PORT		*pRxPort)	/* ptr to port struct for which the ring
				   should be filled */
{
unsigned long	Flags;

	spin_lock_irqsave(&pRxPort->RxDesRingLock, Flags);
	while (pRxPort->RxdRingFree > pRxPort->RxFillLimit) {
		if(!FillRxDescriptor(pAC, pRxPort))
			break;
	}
	spin_unlock_irqrestore(&pRxPort->RxDesRingLock, Flags);
} /* FillRxRing */


/*****************************************************************************
 *
 * 	FillRxDescriptor - fill one buffer into the receive ring
 *
 * Description:
 *	The function allocates a new receive buffer and
 *	puts it into the next descriptor.
 *
 * Returns:
 *	SK_TRUE - a buffer was added to the ring
 *	SK_FALSE - a buffer could not be added
 */
static SK_BOOL FillRxDescriptor(
SK_AC		*pAC,		/* pointer to the adapter context struct */
RX_PORT		*pRxPort)	/* ptr to port struct of ring to fill */
{
struct sk_buff	*pMsgBlock;	/* pointer to a new message block */
RXD		*pRxd;		/* the rxd to fill */
SK_U16		Length;		/* data fragment length */
SK_U64		PhysAddr;	/* physical address of a rx buffer */

	pMsgBlock = alloc_skb(pAC->RxBufSize, GFP_ATOMIC);
	if (pMsgBlock == NULL) {
		SK_DBG_MSG(NULL, SK_DBGMOD_DRV,
			SK_DBGCAT_DRV_ENTRY,
			("%s: Allocation of rx buffer failed !\n",
			pAC->dev[pRxPort->PortIndex]->name));
		SK_PNMI_CNT_NO_RX_BUF(pAC, pRxPort->PortIndex);
		return(SK_FALSE);
	}
	skb_reserve(pMsgBlock, 2); /* to align IP frames */
	/* skb allocated ok, so add buffer */
	pRxd = pRxPort->pRxdRingTail;
	pRxPort->pRxdRingTail = pRxd->pNextRxd;
	pRxPort->RxdRingFree--;
	Length = pAC->RxBufSize;
	PhysAddr = (SK_U64) pci_map_page(&pAC->PciDev,
					 virt_to_page(pMsgBlock->data),
					 ((unsigned long) pMsgBlock->data &
					  ~PAGE_MASK),
					 pAC->RxBufSize - 2,
					 PCI_DMA_FROMDEVICE);
	pRxd->VDataLow = (SK_U32) (PhysAddr & 0xffffffff);
	pRxd->VDataHigh = (SK_U32) (PhysAddr >> 32);
	pRxd->pMBuf = pMsgBlock;
	pRxd->RBControl = RX_CTRL_OWN_BMU | RX_CTRL_STF |
		RX_CTRL_EOF_IRQ | RX_CTRL_CHECK_CSUM | Length;
	return (SK_TRUE);

} /* FillRxDescriptor */


/*****************************************************************************
 *
 * 	ReQueueRxBuffer - fill one buffer back into the receive ring
 *
 * Description:
 *	Fill a given buffer back into the rx ring. The buffer
 *	has been previously allocated and aligned, and its phys.
 *	address calculated, so this is no more necessary.
 *
 * Returns: N/A
 */
static void ReQueueRxBuffer(
SK_AC		*pAC,		/* pointer to the adapter context struct */
RX_PORT		*pRxPort,	/* ptr to port struct of ring to fill */
struct sk_buff	*pMsg,		/* pointer to the buffer */
SK_U32		PhysHigh,	/* phys address high dword */
SK_U32		PhysLow)	/* phys address low dword */
{
RXD		*pRxd;		/* the rxd to fill */
SK_U16		Length;		/* data fragment length */

	pRxd = pRxPort->pRxdRingTail;
	pRxPort->pRxdRingTail = pRxd->pNextRxd;
	pRxPort->RxdRingFree--;
	Length = pAC->RxBufSize;
	pRxd->VDataLow = PhysLow;
	pRxd->VDataHigh = PhysHigh;
	pRxd->pMBuf = pMsg;
	pRxd->RBControl = RX_CTRL_OWN_BMU | RX_CTRL_STF |
		RX_CTRL_EOF_IRQ | RX_CTRL_CHECK_CSUM | Length;
	return;
} /* ReQueueRxBuffer */


/*****************************************************************************
 *
 * 	ReceiveIrq - handle a receive IRQ
 *
 * Description:
 *	This function is called when a receive IRQ is set.
 *	It walks the receive descriptor ring and sends up all
 *	frames that are complete.
 *
 * Returns:	N/A
 */
static void ReceiveIrq(
SK_AC		*pAC,		/* pointer to adapter context */
RX_PORT		*pRxPort)	/* pointer to receive port struct */
{
RXD		*pRxd;		/* pointer to receive descriptors */
SK_U32		Control;	/* control field of descriptor */
struct sk_buff	*pMsg;		/* pointer to message holding frame */
struct sk_buff	*pNewMsg;	/* pointer to a new message for copying frame */
int		FrameLength;	/* total length of received frame */
SK_MBUF		*pRlmtMbuf;	/* ptr to a buffer for giving a frame to rlmt */
SK_EVPARA	EvPara;		/* an event parameter union */	
int		PortIndex = pRxPort->PortIndex;
unsigned int	Offset;
unsigned int	NumBytes;
unsigned int	ForRlmt;
SK_BOOL		IsBc;
SK_BOOL		IsMc;
SK_U32		FrameStat;
unsigned short	Csum1;
unsigned short	Csum2;
unsigned short	Type;
int		Result;
SK_U64		PhysAddr;

rx_start:	
	/* do forever; exit if RX_CTRL_OWN_BMU found */
	for ( pRxd = pRxPort->pRxdRingHead ;
		  pRxPort->RxdRingFree < pAC->RxDescrPerRing ;
		  pRxd = pRxd->pNextRxd,
		  pRxPort->pRxdRingHead = pRxd,
		  pRxPort->RxdRingFree ++) {

		/*
		 * For a better understanding of this loop 
		 * Go through every descriptor beginning at the head 
		 * Please note: the ring might be completely received so the OWN bit
		 * set is not a good crirteria to leave that loop.
		 * Therefore the RingFree counter is used.
		 * On entry of this loop pRxd is a pointer to the Rxd that needs
		 * to be checked next.
		 */

		Control = pRxd->RBControl;
	
		/* check if this descriptor is ready */
		if ((Control & RX_CTRL_OWN_BMU) != 0) {
			/* this descriptor is not yet ready */
			/* This is the usual end of the loop */
			/* We don't need to start the ring again */
			FillRxRing(pAC, pRxPort);
			return;
		}

		/* get length of frame and check it */
		FrameLength = Control & RX_CTRL_LEN_MASK;
		if (FrameLength > pAC->RxBufSize) {
			goto rx_failed;
		}

		/* check for STF and EOF */
		if ((Control & (RX_CTRL_STF | RX_CTRL_EOF)) !=
			(RX_CTRL_STF | RX_CTRL_EOF)) {
			goto rx_failed;
		}
		
		/* here we have a complete frame in the ring */
		pMsg = pRxd->pMBuf;

		FrameStat = pRxd->FrameStat;
		SK_DBG_MSG(NULL, SK_DBGMOD_DRV, 0,
			("Received frame of length %d on port %d\n",
			FrameLength, PortIndex));
		SK_DBG_MSG(NULL, SK_DBGMOD_DRV, 0,
			("Number of free rx descriptors: %d\n",
			pRxPort->RxdRingFree));
		/*DumpMsg(pMsg, "Rx");	*/	
		
		if ((Control & RX_CTRL_STAT_VALID) != RX_CTRL_STAT_VALID ||
			(FrameStat & (XMR_FS_ANY_ERR | XMR_FS_2L_VLAN)) != 0) {
			/* there is a receive error in this frame */
			SK_DBG_MSG(NULL, SK_DBGMOD_DRV,
				SK_DBGCAT_DRV_RX_PROGRESS,
				("skge: Error in received frame, dropped!\n"
				"Control: %x\nRxStat: %x\n",
				Control, FrameStat));
			PhysAddr = ((SK_U64) pRxd->VDataHigh) << (SK_U64)32;
			PhysAddr |= (SK_U64) pRxd->VDataLow;
			pci_dma_sync_single(&pAC->PciDev,
					    (dma_addr_t) PhysAddr,
					    FrameLength,
					    PCI_DMA_FROMDEVICE);
			ReQueueRxBuffer(pAC, pRxPort, pMsg,
				pRxd->VDataHigh, pRxd->VDataLow);

			continue;
		}

		/*
		 * if short frame then copy data to reduce memory waste
		 */
		if ((FrameLength < SK_COPY_THRESHOLD) &&
			((pNewMsg = alloc_skb(FrameLength+2, GFP_ATOMIC)) != NULL)) {
			/*
			 * Short frame detected and allocation successfull
			 */
			PhysAddr = ((SK_U64) pRxd->VDataHigh) << (SK_U64)32;
			PhysAddr |= (SK_U64) pRxd->VDataLow;

			/* use new skb and copy data */
			skb_reserve(pNewMsg, 2);
			skb_put(pNewMsg, FrameLength);
			pci_dma_sync_single(&pAC->PciDev,
					    (dma_addr_t) PhysAddr,
					    FrameLength,
					    PCI_DMA_FROMDEVICE);
			eth_copy_and_sum(pNewMsg, pMsg->data,
				FrameLength, 0);
			ReQueueRxBuffer(pAC, pRxPort, pMsg,
				pRxd->VDataHigh, pRxd->VDataLow);
			pMsg = pNewMsg;

		}
		else {
			/*
			 * if large frame, or SKB allocation failed, pass
			 * the SKB directly to the networking
			 */

			PhysAddr = ((SK_U64) pRxd->VDataHigh) << (SK_U64)32;
			PhysAddr |= (SK_U64) pRxd->VDataLow;

			/* release the DMA mapping */
			pci_unmap_page(&pAC->PciDev,
				       PhysAddr,
				       pAC->RxBufSize - 2,
				       PCI_DMA_FROMDEVICE);

			/* set length in message */
			skb_put(pMsg, FrameLength);
			/* hardware checksum */
			Type = ntohs(*((short*)&pMsg->data[12]));
			if (Type == 0x800) {
				Csum1=le16_to_cpu(pRxd->TcpSums & 0xffff);
				Csum2=le16_to_cpu((pRxd->TcpSums >> 16) & 0xffff);
				if ((Csum1 & 0xfffe) && (Csum2 & 0xfffe)) {
					Result = SkCsGetReceiveInfo(pAC,
						&pMsg->data[14], 
						Csum1, Csum2, pRxPort->PortIndex);
					if (Result == 
						SKCS_STATUS_IP_FRAGMENT ||
						Result ==
						SKCS_STATUS_IP_CSUM_OK ||
						Result ==
						SKCS_STATUS_TCP_CSUM_OK ||
						Result ==
						SKCS_STATUS_UDP_CSUM_OK) {
						pMsg->ip_summed =
						CHECKSUM_UNNECESSARY;
					}
				} /* checksum calculation valid */
			} /* IP frame */
		} /* frame > SK_COPY_TRESHOLD */
		
		SK_DBG_MSG(NULL, SK_DBGMOD_DRV,	1,("V"));
		ForRlmt = SK_RLMT_RX_PROTOCOL;
		IsBc = (FrameStat & XMR_FS_BC)==XMR_FS_BC;
		SK_RLMT_PRE_LOOKAHEAD(pAC, PortIndex, FrameLength,
			IsBc, &Offset, &NumBytes);
		if (NumBytes != 0) {
			IsMc = (FrameStat & XMR_FS_MC)==XMR_FS_MC;
			SK_RLMT_LOOKAHEAD(pAC, PortIndex, 
				&pMsg->data[Offset],
				IsBc, IsMc, &ForRlmt);
		}
		if (ForRlmt == SK_RLMT_RX_PROTOCOL) {
					SK_DBG_MSG(NULL, SK_DBGMOD_DRV,	1,("W"));
			/* send up only frames from active port */
			if ((PortIndex == pAC->ActivePort) ||
				(pAC->RlmtNets == 2)) {
				/* frame for upper layer */
				SK_DBG_MSG(NULL, SK_DBGMOD_DRV, 1,("U"));
#ifdef xDEBUG
				DumpMsg(pMsg, "Rx");
#endif
				SK_PNMI_CNT_RX_OCTETS_DELIVERED(pAC,
					FrameLength, pRxPort->PortIndex);

				pMsg->dev = pAC->dev[pRxPort->PortIndex];
				pMsg->protocol = eth_type_trans(pMsg,
					pAC->dev[pRxPort->PortIndex]);
				netif_rx(pMsg);
				pAC->dev[pRxPort->PortIndex]->last_rx = jiffies;
			}
			else {
				/* drop frame */
				SK_DBG_MSG(NULL, SK_DBGMOD_DRV, 
					SK_DBGCAT_DRV_RX_PROGRESS,
					("D"));
				DEV_KFREE_SKB(pMsg);
			}
			
		} /* if not for rlmt */
		else {
			/* packet for rlmt */
			SK_DBG_MSG(NULL, SK_DBGMOD_DRV, 
				SK_DBGCAT_DRV_RX_PROGRESS, ("R"));
			pRlmtMbuf = SkDrvAllocRlmtMbuf(pAC,
				pAC->IoBase, FrameLength);
			if (pRlmtMbuf != NULL) {
				pRlmtMbuf->pNext = NULL;
				pRlmtMbuf->Length = FrameLength;
				pRlmtMbuf->PortIdx = PortIndex;
				EvPara.pParaPtr = pRlmtMbuf;
				memcpy((char*)(pRlmtMbuf->pData),
					   (char*)(pMsg->data),
					   FrameLength);
				SkEventQueue(pAC, SKGE_RLMT,
					SK_RLMT_PACKET_RECEIVED,
					EvPara);
				pAC->CheckQueue = SK_TRUE;
				SK_DBG_MSG(NULL, SK_DBGMOD_DRV, 
					SK_DBGCAT_DRV_RX_PROGRESS,
					("Q"));
			}
			if ((pAC->dev[pRxPort->PortIndex]->flags &