[PATCH] s390: qeth bug fixes

[patch 10/10] s390: qeth bug fixes.

From: Frank Pavlic <pavlic@de.ibm.com>

qeth network driver related changes:
 - due to OSA hardware changes in TCP Segmentation Offload
   support we are able now to pack TSO packets too.
   This fits perfectly in design of qeth buffer handling and
   sending data respectively.
 - remove skb_realloc_headroom from the sending path since
   hard_header_len value provides enough headroom now.
 - device recovery behaviour improvement
 - bug fixed in Enhanced Device Driver Packing functionality

Signed-off-by: Frank Pavlic <pavlic@de.ibm.com>

1 files changed, 122 insertions, 71 deletions

diff --git a/drivers/s390/net/qeth_tso.h b/drivers/s390/net/qeth_tso.h
index ff585ae49b6c..ad33e6f466f1 100644
--- a/drivers/s390/net/qeth_tso.h
+++ b/drivers/s390/net/qeth_tso.h
@@ -1,5 +1,5 @@
 /*
- * linux/drivers/s390/net/qeth_tso.h ($Revision: 1.5 $)
+ * linux/drivers/s390/net/qeth_tso.h ($Revision: 1.7 $)
  *
  * Header file for qeth TCP Segmentation Offload support.
  *
@@ -7,97 +7,148 @@
  *
  *    Author(s): Frank Pavlic <pavlic@de.ibm.com>
  *
- *    $Revision: 1.5 $	 $Date: 2005/04/01 21:40:41 $
+ *    $Revision: 1.7 $	 $Date: 2005/05/04 20:19:18 $
  *
  */
 #ifndef __QETH_TSO_H__
 #define __QETH_TSO_H__
 
+#include <linux/skbuff.h>
+#include <linux/tcp.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <net/ip6_checksum.h>
+#include "qeth.h"
+#include "qeth_mpc.h"
 
-extern int
-qeth_tso_send_packet(struct qeth_card *, struct sk_buff *,
-		     struct qeth_qdio_out_q *, int , int);
 
-struct qeth_hdr_ext_tso {
-        __u16 hdr_tot_len;
-        __u8  imb_hdr_no;
-        __u8  reserved;
-        __u8  hdr_type;
-        __u8  hdr_version;
-        __u16 hdr_len;
-        __u32 payload_len;
-        __u16 mss;
-        __u16 dg_hdr_len;
-        __u8  padding[16];
-} __attribute__ ((packed));
+static inline struct qeth_hdr_tso *
+qeth_tso_prepare_skb(struct qeth_card *card, struct sk_buff **skb)
+{
+	QETH_DBF_TEXT(trace, 5, "tsoprsk");
+	return qeth_push_skb(card, skb, sizeof(struct qeth_hdr_tso));
+}
+
+/**
+ * fill header for a TSO packet
+ */
+static inline void
+qeth_tso_fill_header(struct qeth_card *card, struct sk_buff *skb)
+{
+	struct qeth_hdr_tso *hdr;
+	struct tcphdr *tcph;
+	struct iphdr *iph;
 
-struct qeth_hdr_tso {
-        struct qeth_hdr hdr; 	/*hdr->hdr.l3.xxx*/
-	struct qeth_hdr_ext_tso ext;
-} __attribute__ ((packed));
+	QETH_DBF_TEXT(trace, 5, "tsofhdr");
+
+	hdr  = (struct qeth_hdr_tso *) skb->data;
+	iph  = skb->nh.iph;
+	tcph = skb->h.th;
+	/*fix header to TSO values ...*/
+	hdr->hdr.hdr.l3.id = QETH_HEADER_TYPE_TSO;
+	/*set values which are fix for the first approach ...*/
+	hdr->ext.hdr_tot_len = (__u16) sizeof(struct qeth_hdr_ext_tso);
+	hdr->ext.imb_hdr_no  = 1;
+	hdr->ext.hdr_type    = 1;
+	hdr->ext.hdr_version = 1;
+	hdr->ext.hdr_len     = 28;
+	/*insert non-fix values */
+	hdr->ext.mss = skb_shinfo(skb)->tso_size;
+	hdr->ext.dg_hdr_len = (__u16)(iph->ihl*4 + tcph->doff*4);
+	hdr->ext.payload_len = (__u16)(skb->len - hdr->ext.dg_hdr_len -
+				       sizeof(struct qeth_hdr_tso));
+}
+
+/**
+ * change some header values as requested by hardware
+ */
+static inline void
+qeth_tso_set_tcpip_header(struct qeth_card *card, struct sk_buff *skb)
+{
+	struct iphdr *iph;
+	struct ipv6hdr *ip6h;
+	struct tcphdr *tcph;
+
+	iph  = skb->nh.iph;
+	ip6h = skb->nh.ipv6h;
+	tcph = skb->h.th;
+
+	tcph->check = 0;
+	if (skb->protocol == ETH_P_IPV6) {
+		ip6h->payload_len = 0;
+		tcph->check = ~csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
+					       0, IPPROTO_TCP, 0);
+		return;
+	}
+	/*OSA want us to set these values ...*/
+	tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
+					 0, IPPROTO_TCP, 0);
+	iph->tot_len = 0;
+	iph->check = 0;
+}
 
-/*some helper functions*/
 static inline int
-qeth_get_elements_no(struct qeth_card *card, void *hdr, struct sk_buff *skb)
+qeth_tso_prepare_packet(struct qeth_card *card, struct sk_buff *skb,
+			int ipv, int cast_type)
 {
-	int elements_needed = 0;
+	struct qeth_hdr_tso *hdr;
 
-        if (skb_shinfo(skb)->nr_frags > 0)
-                elements_needed = (skb_shinfo(skb)->nr_frags + 1);
-        if (elements_needed == 0 )
-                elements_needed = 1 + (((((unsigned long) hdr) % PAGE_SIZE)
-                                        + skb->len) >> PAGE_SHIFT);
-        if (elements_needed > QETH_MAX_BUFFER_ELEMENTS(card)){
-                PRINT_ERR("qeth_do_send_packet: invalid size of "
-                          "IP packet. Discarded.");
-                return 0;
-        }
-        return elements_needed;
+	QETH_DBF_TEXT(trace, 5, "tsoprep");
+
+	hdr = (struct qeth_hdr_tso *) qeth_tso_prepare_skb(card, &skb);
+	if (hdr == NULL) {
+		QETH_DBF_TEXT(trace, 4, "tsoperr");
+		return -ENOMEM;
+	}
+	memset(hdr, 0, sizeof(struct qeth_hdr_tso));
+	/*fill first 32 bytes of  qdio header as used
+	 *FIXME: TSO has two struct members
+	 * with different names but same size
+	 * */
+	qeth_fill_header(card, &hdr->hdr, skb, ipv, cast_type);
+	qeth_tso_fill_header(card, skb);
+	qeth_tso_set_tcpip_header(card, skb);
+	return 0;
 }
 
 static inline void
 __qeth_fill_buffer_frag(struct sk_buff *skb, struct qdio_buffer *buffer,
 			int is_tso, int *next_element_to_fill)
 {
-	int length = skb->len;
 	struct skb_frag_struct *frag;
 	int fragno;
 	unsigned long addr;
-	int element;
-	int first_lap = 1;
-
-	fragno = skb_shinfo(skb)->nr_frags; /* start with last frag */
-	element = *next_element_to_fill + fragno;
-	while (length > 0) {
-		if (fragno > 0) {
-			frag = &skb_shinfo(skb)->frags[fragno - 1];
-			addr = (page_to_pfn(frag->page) << PAGE_SHIFT) +
-				frag->page_offset;
-			buffer->element[element].addr = (char *)addr;
-			buffer->element[element].length = frag->size;
-			length -= frag->size;
-			if (first_lap)
-				buffer->element[element].flags =
-				    SBAL_FLAGS_LAST_FRAG;
-			else
-				buffer->element[element].flags =
-				    SBAL_FLAGS_MIDDLE_FRAG;
-		} else {
-			buffer->element[element].addr = skb->data;
-			buffer->element[element].length = length;
-			length = 0;
-			if (is_tso)
-				buffer->element[element].flags =
-					SBAL_FLAGS_MIDDLE_FRAG;
-			else
-				buffer->element[element].flags =
-					SBAL_FLAGS_FIRST_FRAG;
-		}
-		element--;
-		fragno--;
-		first_lap = 0;
+	int element, cnt, dlen;
+	
+	fragno = skb_shinfo(skb)->nr_frags;
+	element = *next_element_to_fill;
+	dlen = 0;
+	
+	if (is_tso)
+		buffer->element[element].flags =
+			SBAL_FLAGS_MIDDLE_FRAG;
+	else
+		buffer->element[element].flags =
+			SBAL_FLAGS_FIRST_FRAG;
+	if ( (dlen = (skb->len - skb->data_len)) ) {
+		buffer->element[element].addr = skb->data;
+		buffer->element[element].length = dlen;
+		element++;
 	}
-	*next_element_to_fill += skb_shinfo(skb)->nr_frags + 1;
+	for (cnt = 0; cnt < fragno; cnt++) {
+		frag = &skb_shinfo(skb)->frags[cnt];
+		addr = (page_to_pfn(frag->page) << PAGE_SHIFT) +
+			frag->page_offset;
+		buffer->element[element].addr = (char *)addr;
+		buffer->element[element].length = frag->size;
+		if (cnt < (fragno - 1))
+			buffer->element[element].flags =
+				SBAL_FLAGS_MIDDLE_FRAG;
+		else
+			buffer->element[element].flags =
+				SBAL_FLAGS_LAST_FRAG;
+		element++;
+	}
+	*next_element_to_fill = element;
 }
-
 #endif /* __QETH_TSO_H__ */