skge.c

linux-2.6.15.6

		
		/* Stop port */
		spin_lock_irqsave(&pAC->TxPort[pNet->PortNr]
			[TX_PRIO_LOW].TxDesRingLock, Flags);
		SkGeStopPort(pAC, pAC->IoBase, pNet->PortNr,
			SK_STOP_ALL, SK_HARD_RST);
		spin_unlock_irqrestore(&pAC->TxPort[pNet->PortNr]
			[TX_PRIO_LOW].TxDesRingLock, Flags);
	}

	if (pAC->RlmtNets == 1) {
		/* clear all descriptor rings */
		for (i=0; i<pAC->GIni.GIMacsFound; i++) {
			ReceiveIrq(pAC, &pAC->RxPort[i], SK_TRUE);
			ClearRxRing(pAC, &pAC->RxPort[i]);
			ClearTxRing(pAC, &pAC->TxPort[i][TX_PRIO_LOW]);
		}
	} else {
		/* clear port descriptor rings */
		ReceiveIrq(pAC, &pAC->RxPort[pNet->PortNr], SK_TRUE);
		ClearRxRing(pAC, &pAC->RxPort[pNet->PortNr]);
		ClearTxRing(pAC, &pAC->TxPort[pNet->PortNr][TX_PRIO_LOW]);
	}

	SK_DBG_MSG(NULL, SK_DBGMOD_DRV, SK_DBGCAT_DRV_ENTRY,
		("SkGeClose: done "));

	SK_MEMSET(&(pAC->PnmiBackup), 0, sizeof(SK_PNMI_STRUCT_DATA));
	SK_MEMCPY(&(pAC->PnmiBackup), &(pAC->PnmiStruct), 
			sizeof(SK_PNMI_STRUCT_DATA));

	pAC->MaxPorts--;
	pNet->Up = 0;

	return (0);
} /* SkGeClose */


/*****************************************************************************
 *
 * 	SkGeXmit - Linux frame transmit function
 *
 * Description:
 *	The system calls this function to send frames onto the wire.
 *	It puts the frame in the tx descriptor ring. If the ring is
 *	full then, the 'tbusy' flag is set.
 *
 * Returns:
 *	0, if everything is ok
 *	!=0, on error
 * WARNING: returning 1 in 'tbusy' case caused system crashes (double
 *	allocated skb's) !!!
 */
static int SkGeXmit(struct sk_buff *skb, struct SK_NET_DEVICE *dev)
{
DEV_NET		*pNet;
SK_AC		*pAC;
int			Rc;	/* return code of XmitFrame */

	pNet = netdev_priv(dev);
	pAC = pNet->pAC;

	if ((!skb_shinfo(skb)->nr_frags) ||
		(pAC->GIni.GIChipId == CHIP_ID_GENESIS)) {
		/* Don't activate scatter-gather and hardware checksum */

		if (pAC->RlmtNets == 2)
			Rc = XmitFrame(
				pAC,
				&pAC->TxPort[pNet->PortNr][TX_PRIO_LOW],
				skb);
		else
			Rc = XmitFrame(
				pAC,
				&pAC->TxPort[pAC->ActivePort][TX_PRIO_LOW],
				skb);
	} else {
		/* scatter-gather and hardware TCP checksumming anabled*/
		if (pAC->RlmtNets == 2)
			Rc = XmitFrameSG(
				pAC,
				&pAC->TxPort[pNet->PortNr][TX_PRIO_LOW],
				skb);
		else
			Rc = XmitFrameSG(
				pAC,
				&pAC->TxPort[pAC->ActivePort][TX_PRIO_LOW],
				skb);
	}

	/* Transmitter out of resources? */
	if (Rc <= 0) {
		netif_stop_queue(dev);
	}

	/* If not taken, give buffer ownership back to the
	 * queueing layer.
	 */
	if (Rc < 0)
		return (1);

	dev->trans_start = jiffies;
	return (0);
} /* SkGeXmit */


/*****************************************************************************
 *
 * 	XmitFrame - fill one socket buffer into the transmit ring
 *
 * Description:
 *	This function puts a message into the transmit descriptor ring
 *	if there is a descriptors left.
 *	Linux skb's consist of only one continuous buffer.
 *	The first step locks the ring. It is held locked
 *	all time to avoid problems with SWITCH_../PORT_RESET.
 *	Then the descriptoris allocated.
 *	The second part is linking the buffer to the descriptor.
 *	At the very last, the Control field of the descriptor
 *	is made valid for the BMU and a start TX command is given
 *	if necessary.
 *
 * Returns:
 *	> 0 - on succes: the number of bytes in the message
 *	= 0 - on resource shortage: this frame sent or dropped, now
 *		the ring is full ( -> set tbusy)
 *	< 0 - on failure: other problems ( -> return failure to upper layers)
 */
static int XmitFrame(
SK_AC 		*pAC,		/* pointer to adapter context           */
TX_PORT		*pTxPort,	/* pointer to struct of port to send to */
struct sk_buff	*pMessage)	/* pointer to send-message              */
{
	TXD		*pTxd;		/* the rxd to fill */
	TXD		*pOldTxd;
	unsigned long	 Flags;
	SK_U64		 PhysAddr;
	int		 BytesSend = pMessage->len;

	SK_DBG_MSG(NULL, SK_DBGMOD_DRV, SK_DBGCAT_DRV_TX_PROGRESS, ("X"));

	spin_lock_irqsave(&pTxPort->TxDesRingLock, Flags);
#ifndef USE_TX_COMPLETE
	FreeTxDescriptors(pAC, pTxPort);
#endif
	if (pTxPort->TxdRingFree == 0) {
		/* 
		** no enough free descriptors in ring at the moment.
		** Maybe free'ing some old one help?
		*/
		FreeTxDescriptors(pAC, pTxPort);
		if (pTxPort->TxdRingFree == 0) {
			spin_unlock_irqrestore(&pTxPort->TxDesRingLock, Flags);
			SK_PNMI_CNT_NO_TX_BUF(pAC, pTxPort->PortIndex);
			SK_DBG_MSG(NULL, SK_DBGMOD_DRV,
				SK_DBGCAT_DRV_TX_PROGRESS,
				("XmitFrame failed\n"));
			/* 
			** the desired message can not be sent
			** Because tbusy seems to be set, the message 
			** should not be freed here. It will be used 
			** by the scheduler of the ethernet handler 
			*/
			return (-1);
		}
	}

	/*
	** If the passed socket buffer is of smaller MTU-size than 60,
	** copy everything into new buffer and fill all bytes between
	** the original packet end and the new packet end of 60 with 0x00.
	** This is to resolve faulty padding by the HW with 0xaa bytes.
	*/
	if (BytesSend < C_LEN_ETHERNET_MINSIZE) {
		if ((pMessage = skb_padto(pMessage, C_LEN_ETHERNET_MINSIZE)) == NULL) {
			spin_unlock_irqrestore(&pTxPort->TxDesRingLock, Flags);
			return 0;
		}
		pMessage->len = C_LEN_ETHERNET_MINSIZE;
	}

	/* 
	** advance head counter behind descriptor needed for this frame, 
	** so that needed descriptor is reserved from that on. The next
	** action will be to add the passed buffer to the TX-descriptor
	*/
	pTxd = pTxPort->pTxdRingHead;
	pTxPort->pTxdRingHead = pTxd->pNextTxd;
	pTxPort->TxdRingFree--;

#ifdef SK_DUMP_TX
	DumpMsg(pMessage, "XmitFrame");
#endif

	/* 
	** First step is to map the data to be sent via the adapter onto
	** the DMA memory. Kernel 2.2 uses virt_to_bus(), but kernels 2.4
	** and 2.6 need to use pci_map_page() for that mapping.
	*/
	PhysAddr = (SK_U64) pci_map_page(pAC->PciDev,
					virt_to_page(pMessage->data),
					((unsigned long) pMessage->data & ~PAGE_MASK),
					pMessage->len,
					PCI_DMA_TODEVICE);
	pTxd->VDataLow  = (SK_U32) (PhysAddr & 0xffffffff);
	pTxd->VDataHigh = (SK_U32) (PhysAddr >> 32);
	pTxd->pMBuf     = pMessage;

	if (pMessage->ip_summed == CHECKSUM_HW) {
		u16 hdrlen = pMessage->h.raw - pMessage->data;
		u16 offset = hdrlen + pMessage->csum;

		if ((pMessage->h.ipiph->protocol == IPPROTO_UDP ) &&
			(pAC->GIni.GIChipRev == 0) &&
			(pAC->GIni.GIChipId == CHIP_ID_YUKON)) {
			pTxd->TBControl = BMU_TCP_CHECK;
		} else {
			pTxd->TBControl = BMU_UDP_CHECK;
		}

		pTxd->TcpSumOfs = 0;
		pTxd->TcpSumSt  = hdrlen;
		pTxd->TcpSumWr  = offset;

		pTxd->TBControl |= BMU_OWN | BMU_STF | 
				   BMU_SW  | BMU_EOF |
#ifdef USE_TX_COMPLETE
				   BMU_IRQ_EOF |
#endif
				   pMessage->len;
        } else {
		pTxd->TBControl = BMU_OWN | BMU_STF | BMU_CHECK | 
				  BMU_SW  | BMU_EOF |
#ifdef USE_TX_COMPLETE
				   BMU_IRQ_EOF |
#endif
			pMessage->len;
	}

	/* 
	** If previous descriptor already done, give TX start cmd 
	*/
	pOldTxd = xchg(&pTxPort->pTxdRingPrev, pTxd);
	if ((pOldTxd->TBControl & BMU_OWN) == 0) {
		SK_OUT8(pTxPort->HwAddr, Q_CSR, CSR_START);
	}	

	/* 
	** after releasing the lock, the skb may immediately be free'd 
	*/
	spin_unlock_irqrestore(&pTxPort->TxDesRingLock, Flags);
	if (pTxPort->TxdRingFree != 0) {
		return (BytesSend);
	} else {
		return (0);
	}

} /* XmitFrame */

/*****************************************************************************
 *
 * 	XmitFrameSG - fill one socket buffer into the transmit ring
 *                (use SG and TCP/UDP hardware checksumming)
 *
 * Description:
 *	This function puts a message into the transmit descriptor ring
 *	if there is a descriptors left.
 *
 * Returns:
 *	> 0 - on succes: the number of bytes in the message
 *	= 0 - on resource shortage: this frame sent or dropped, now
 *		the ring is full ( -> set tbusy)
 *	< 0 - on failure: other problems ( -> return failure to upper layers)
 */
static int XmitFrameSG(
SK_AC 		*pAC,		/* pointer to adapter context           */
TX_PORT		*pTxPort,	/* pointer to struct of port to send to */
struct sk_buff	*pMessage)	/* pointer to send-message              */
{

	TXD		*pTxd;
	TXD		*pTxdFst;
	TXD		*pTxdLst;
	int 	 	 CurrFrag;
	int		 BytesSend;
	skb_frag_t	*sk_frag;
	SK_U64		 PhysAddr;
	unsigned long	 Flags;
	SK_U32		 Control;

	spin_lock_irqsave(&pTxPort->TxDesRingLock, Flags);
#ifndef USE_TX_COMPLETE
	FreeTxDescriptors(pAC, pTxPort);
#endif
	if ((skb_shinfo(pMessage)->nr_frags +1) > pTxPort->TxdRingFree) {
		FreeTxDescriptors(pAC, pTxPort);
		if ((skb_shinfo(pMessage)->nr_frags + 1) > pTxPort->TxdRingFree) {
			spin_unlock_irqrestore(&pTxPort->TxDesRingLock, Flags);
			SK_PNMI_CNT_NO_TX_BUF(pAC, pTxPort->PortIndex);
			SK_DBG_MSG(NULL, SK_DBGMOD_DRV,
				SK_DBGCAT_DRV_TX_PROGRESS,
				("XmitFrameSG failed - Ring full\n"));
				/* this message can not be sent now */
			return(-1);
		}
	}

	pTxd      = pTxPort->pTxdRingHead;
	pTxdFst   = pTxd;
	pTxdLst   = pTxd;
	BytesSend = 0;

	/* 
	** Map the first fragment (header) into the DMA-space
	*/
	PhysAddr = (SK_U64) pci_map_page(pAC->PciDev,
			virt_to_page(pMessage->data),
			((unsigned long) pMessage->data & ~PAGE_MASK),
			skb_headlen(pMessage),
			PCI_DMA_TODEVICE);

	pTxd->VDataLow  = (SK_U32) (PhysAddr & 0xffffffff);
	pTxd->VDataHigh = (SK_U32) (PhysAddr >> 32);

	/* 
	** Does the HW need to evaluate checksum for TCP or UDP packets? 
	*/
	if (pMessage->ip_summed == CHECKSUM_HW) {
		u16 hdrlen = pMessage->h.raw - pMessage->data;
		u16 offset = hdrlen + pMessage->csum;

		Control = BMU_STFWD;

		/* 
		** We have to use the opcode for tcp here,  because the
		** opcode for udp is not working in the hardware yet 
		** (Revision 2.0)
		*/
		if ((pMessage->h.ipiph->protocol == IPPROTO_UDP ) &&
			(pAC->GIni.GIChipRev == 0) &&
			(pAC->GIni.GIChipId == CHIP_ID_YUKON)) {
			Control |= BMU_TCP_CHECK;
		} else {
			Control |= BMU_UDP_CHECK;
		}

		pTxd->TcpSumOfs = 0;
		pTxd->TcpSumSt  = hdrlen;
		pTxd->TcpSumWr  = offset;
	} else
		Control = BMU_CHECK | BMU_SW;

	pTxd->TBControl = BMU_STF | Control | skb_headlen(pMessage);

	pTxd = pTxd->pNextTxd;
	pTxPort->TxdRingFree--;
	BytesSend += skb_headlen(pMessage);

	/* 
	** Browse over all SG fragments and map each of them into the DMA space
	*/
	for (CurrFrag = 0; CurrFrag < skb_shinfo(pMessage)->nr_frags; CurrFrag++) {
		sk_frag = &skb_shinfo(pMessage)->frags[CurrFrag];
		/* 
		** we already have the proper value in entry
		*/
		PhysAddr = (SK_U64) pci_map_page(pAC->PciDev,
						 sk_frag->page,
						 sk_frag->page_offset,
						 sk_frag->size,
						 PCI_DMA_TODEVICE);

		pTxd->VDataLow  = (SK_U32) (PhysAddr & 0xffffffff);
		pTxd->VDataHigh = (SK_U32) (PhysAddr >> 32);
		pTxd->pMBuf     = pMessage;
		
		pTxd->TBControl = Control | BMU_OWN | sk_frag->size;;

		/* 
		** Do we have the last fragment? 
		*/
		if( (CurrFrag+1) == skb_shinfo(pMessage)->nr_frags )  {
#ifdef USE_TX_COMPLETE
			pTxd->TBControl |= BMU_EOF | BMU_IRQ_EOF;
#else
			pTxd->TBControl |= BMU_EOF;
#endif
			pTxdFst->TBControl |= BMU_OWN | BMU_SW;
		}
		pTxdLst = pTxd;
		pTxd    = pTxd->pNextTxd;
		pTxPort->TxdRingFree--;
		BytesSend += sk_frag->size;
	}

	/* 
	** If previous descriptor already done, give TX start cmd 
	*/
	if ((pTxPort->pTxdRingPrev->TBControl & BMU_OWN) == 0) {
		SK_OUT8(pTxPort->HwAddr, Q_CSR, CSR_START);
	}

	pTxPort->pTxdRingPrev = pTxdLst;
	pTxPort->pTxdRingHead = pTxd;

	spin_unlock_irqrestore(&pTxPort->TxDesRingLock, Flags);

	if (pTxPort->TxdRingFree > 0) {
		return (BytesSend);
	} else {
		return (0);
	}
}

/*****************************************************************************
 *
 * 	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 BMU_SW bit not set in start frame
	** or BMU_OWN bit set in any frame
	*/
	while (1) {
		Control = pTxd->TBControl;
		if ((Control & BMU_SW) == 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).