[PATCH] sk98lin: fix checksumming code

Remove code from sk98lin that does it's own checksum validation.
This code is incorrect when dealing with nested protocols like
VLAN's, and it is better to use regular receive code path to
handle hardware checksum.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

1 files changed, 36 insertions, 129 deletions

diff --git a/drivers/net/sk98lin/skge.c b/drivers/net/sk98lin/skge.c
index b18c92cb629..857ade44788 100644
--- a/drivers/net/sk98lin/skge.c
+++ b/drivers/net/sk98lin/skge.c
@@ -101,7 +101,6 @@
  *		"h/skgeinit.h"
  *		"h/skaddr.h"
  *		"h/skgesirq.h"
- *		"h/skcsum.h"
  *		"h/skrlmt.h"
  *
  ******************************************************************************/
@@ -113,6 +112,7 @@
 #include	<linux/init.h>
 #include 	<linux/proc_fs.h>
 #include	<linux/dma-mapping.h>
+#include	<linux/ip.h>
 
 #include	"h/skdrv1st.h"
 #include	"h/skdrv2nd.h"
@@ -601,11 +601,6 @@ SK_BOOL	DualNet;
        		return(-EAGAIN);
 	}
 
-	SkCsSetReceiveFlags(pAC,
-		SKCS_PROTO_IP | SKCS_PROTO_TCP | SKCS_PROTO_UDP,
-		&pAC->CsOfs1, &pAC->CsOfs2, 0);
-	pAC->CsOfs = (pAC->CsOfs2 << 16) | pAC->CsOfs1;
-
 	BoardInitMem(pAC);
 	/* tschilling: New common function with minimum size check. */
 	DualNet = SK_FALSE;
@@ -823,7 +818,7 @@ uintptr_t VNextDescr;	/* the virtual bus address of the next descriptor */
 		/* set the pointers right */
 		pDescr->VNextRxd = VNextDescr & 0xffffffffULL;
 		pDescr->pNextRxd = pNextDescr;
-		pDescr->TcpSumStarts = pAC->CsOfs;
+		pDescr->TcpSumStarts = 0;
 
 		/* advance one step */
 		pPrevDescr = pDescr;
@@ -1505,8 +1500,6 @@ struct sk_buff	*pMessage)	/* pointer to send-message              */
 	TXD		*pOldTxd;
 	unsigned long	 Flags;
 	SK_U64		 PhysAddr;
-	int	 	 Protocol;
-	int		 IpHeaderLength;
 	int		 BytesSend = pMessage->len;
 
 	SK_DBG_MSG(NULL, SK_DBGMOD_DRV, SK_DBGCAT_DRV_TX_PROGRESS, ("X"));
@@ -1579,8 +1572,10 @@ struct sk_buff	*pMessage)	/* pointer to send-message              */
 	pTxd->pMBuf     = pMessage;
 
 	if (pMessage->ip_summed == CHECKSUM_HW) {
-		Protocol = ((SK_U8)pMessage->data[C_OFFSET_IPPROTO] & 0xff);
-		if ((Protocol == C_PROTO_ID_UDP) && 
+		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;
@@ -1588,14 +1583,9 @@ struct sk_buff	*pMessage)	/* pointer to send-message              */
 			pTxd->TBControl = BMU_UDP_CHECK;
 		}
 
-		IpHeaderLength  = (SK_U8)pMessage->data[C_OFFSET_IPHEADER];
-		IpHeaderLength  = (IpHeaderLength & 0xf) * 4;
-		pTxd->TcpSumOfs = 0; /* PH-Checksum already calculated */
-		pTxd->TcpSumSt  = C_LEN_ETHERMAC_HEADER + IpHeaderLength + 
-							(Protocol == C_PROTO_ID_UDP ?
-							C_OFFSET_UDPHEADER_UDPCS : 
-							C_OFFSET_TCPHEADER_TCPCS);
-		pTxd->TcpSumWr  = C_LEN_ETHERMAC_HEADER + IpHeaderLength;
+		pTxd->TcpSumOfs = 0;
+		pTxd->TcpSumSt  = hdrlen;
+		pTxd->TcpSumWr  = offset;
 
 		pTxd->TBControl |= BMU_OWN | BMU_STF | 
 				   BMU_SW  | BMU_EOF |
@@ -1658,11 +1648,10 @@ struct sk_buff	*pMessage)	/* pointer to send-message              */
 	TXD		*pTxdLst;
 	int 	 	 CurrFrag;
 	int		 BytesSend;
-	int		 IpHeaderLength; 
-	int		 Protocol;
 	skb_frag_t	*sk_frag;
 	SK_U64		 PhysAddr;
 	unsigned long	 Flags;
+	SK_U32		 Control;
 
 	spin_lock_irqsave(&pTxPort->TxDesRingLock, Flags);
 #ifndef USE_TX_COMPLETE
@@ -1685,7 +1674,6 @@ struct sk_buff	*pMessage)	/* pointer to send-message              */
 	pTxdFst   = pTxd;
 	pTxdLst   = pTxd;
 	BytesSend = 0;
-	Protocol  = 0;
 
 	/* 
 	** Map the first fragment (header) into the DMA-space
@@ -1703,32 +1691,31 @@ struct sk_buff	*pMessage)	/* pointer to send-message              */
 	** Does the HW need to evaluate checksum for TCP or UDP packets? 
 	*/
 	if (pMessage->ip_summed == CHECKSUM_HW) {
-		pTxd->TBControl = BMU_STF | BMU_STFWD | skb_headlen(pMessage);
+		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)
 		*/
-		Protocol = ((SK_U8)pMessage->data[C_OFFSET_IPPROTO] & 0xff);
-		if ((Protocol == C_PROTO_ID_UDP) && 
+		if ((pMessage->h.ipiph->protocol == IPPROTO_UDP ) &&
 			(pAC->GIni.GIChipRev == 0) &&
 			(pAC->GIni.GIChipId == CHIP_ID_YUKON)) {
-			pTxd->TBControl |= BMU_TCP_CHECK;
+			Control |= BMU_TCP_CHECK;
 		} else {
-			pTxd->TBControl |= BMU_UDP_CHECK;
+			Control |= BMU_UDP_CHECK;
 		}
 
-		IpHeaderLength  = ((SK_U8)pMessage->data[C_OFFSET_IPHEADER] & 0xf)*4;
-		pTxd->TcpSumOfs = 0; /* PH-Checksum already claculated */
-		pTxd->TcpSumSt  = C_LEN_ETHERMAC_HEADER + IpHeaderLength +
-						(Protocol == C_PROTO_ID_UDP ?
-						C_OFFSET_UDPHEADER_UDPCS :
-						C_OFFSET_TCPHEADER_TCPCS);
-		pTxd->TcpSumWr  = C_LEN_ETHERMAC_HEADER + IpHeaderLength;
-	} else {
-		pTxd->TBControl = BMU_CHECK | BMU_SW | BMU_STF |
-					skb_headlen(pMessage);
-	}
+		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--;
@@ -1752,40 +1739,18 @@ struct sk_buff	*pMessage)	/* pointer to send-message              */
 		pTxd->VDataHigh = (SK_U32) (PhysAddr >> 32);
 		pTxd->pMBuf     = pMessage;
 		
-		/* 
-		** Does the HW need to evaluate checksum for TCP or UDP packets? 
-		*/
-		if (pMessage->ip_summed == CHECKSUM_HW) {
-			pTxd->TBControl = BMU_OWN | BMU_SW | 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 ((Protocol == C_PROTO_ID_UDP) && 
-				(pAC->GIni.GIChipRev == 0) &&
-				(pAC->GIni.GIChipId == CHIP_ID_YUKON)) {
-				pTxd->TBControl |= BMU_TCP_CHECK;
-			} else {
-				pTxd->TBControl |= BMU_UDP_CHECK;
-			}
-		} else {
-			pTxd->TBControl = BMU_CHECK | BMU_SW | BMU_OWN;
-		}
+		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 | sk_frag->size;
+			pTxd->TBControl |= BMU_EOF | BMU_IRQ_EOF;
 #else
-			pTxd->TBControl |= BMU_EOF | sk_frag->size;
+			pTxd->TBControl |= BMU_EOF;
 #endif
 			pTxdFst->TBControl |= BMU_OWN | BMU_SW;
-
-		} else {
-			pTxd->TBControl |= sk_frag->size;
 		}
 		pTxdLst = pTxd;
 		pTxd    = pTxd->pNextTxd;
@@ -2032,7 +1997,6 @@ 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 */
-int				IpFrameLength;
 SK_MBUF			*pRlmtMbuf;		/* ptr to a buffer for giving a frame to rlmt */
 SK_EVPARA		EvPara;			/* an event parameter union */	
 unsigned long	Flags;			/* for spin lock */
@@ -2045,10 +2009,6 @@ SK_BOOL			IsMc;
 SK_BOOL  IsBadFrame; 			/* Bad frame */
 
 SK_U32			FrameStat;
-unsigned short	Csum1;
-unsigned short	Csum2;
-unsigned short	Type;
-int				Result;
 SK_U64			PhysAddr;
 
 rx_start:	
@@ -2177,8 +2137,8 @@ rx_start:
 						    (dma_addr_t) PhysAddr,
 						    FrameLength,
 						    PCI_DMA_FROMDEVICE);
-			eth_copy_and_sum(pNewMsg, pMsg->data,
-				FrameLength, 0);
+			memcpy(pNewMsg->data, pMsg, FrameLength);
+
 			pci_dma_sync_single_for_device(pAC->PciDev,
 						       (dma_addr_t) PhysAddr,
 						       FrameLength,
@@ -2206,69 +2166,16 @@ rx_start:
 
 			/* set length in message */
 			skb_put(pMsg, FrameLength);
-			/* hardware checksum */
-			Type = ntohs(*((short*)&pMsg->data[12]));
+		} /* frame > SK_COPY_TRESHOLD */
 
 #ifdef USE_SK_RX_CHECKSUM
-			if (Type == 0x800) {
-				Csum1=le16_to_cpu(pRxd->TcpSums & 0xffff);
-				Csum2=le16_to_cpu((pRxd->TcpSums >> 16) & 0xffff);
-				IpFrameLength = (int) ntohs((unsigned short)
-								((unsigned short *) pMsg->data)[8]);
-
-				/*
-				 * Test: If frame is padded, a check is not possible!
-				 * Frame not padded? Length difference must be 14 (0xe)!
-				 */
-				if ((FrameLength - IpFrameLength) != 0xe) {
-				/* Frame padded => TCP offload not possible! */
-					pMsg->ip_summed = CHECKSUM_NONE;
-				} else {
-				/* Frame not padded => TCP offload! */
-					if ((((Csum1 & 0xfffe) && (Csum2 & 0xfffe)) &&
-						(pAC->GIni.GIChipId == CHIP_ID_GENESIS)) ||
-						(pAC->ChipsetType)) {
-						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;
-						}
-						else if (Result ==
-							SKCS_STATUS_TCP_CSUM_ERROR ||
-							Result ==
-							SKCS_STATUS_UDP_CSUM_ERROR ||
-							Result ==
-							SKCS_STATUS_IP_CSUM_ERROR_UDP ||
-							Result ==
-							SKCS_STATUS_IP_CSUM_ERROR_TCP ||
-							Result ==
-							SKCS_STATUS_IP_CSUM_ERROR ) {
-							/* HW Checksum error */
-							SK_DBG_MSG(NULL, SK_DBGMOD_DRV,
-							SK_DBGCAT_DRV_RX_PROGRESS,
-							("skge: CRC error. Frame dropped!\n"));
-							goto rx_failed;
-						} else {
-								pMsg->ip_summed =
-								CHECKSUM_NONE;
-						}
-					}/* checksumControl calculation valid */
-				} /* Frame length check */
-			} /* IP frame */
+		pMsg->csum = pRxd->TcpSums;
+		pMsg->ip_summed = CHECKSUM_HW;
 #else
-			pMsg->ip_summed = CHECKSUM_NONE;	
+		pMsg->ip_summed = CHECKSUM_NONE;
 #endif
-		} /* frame > SK_COPY_TRESHOLD */
-		
+
+
 		SK_DBG_MSG(NULL, SK_DBGMOD_DRV,	1,("V"));
 		ForRlmt = SK_RLMT_RX_PROTOCOL;
 #if 0