linux/drivers/s390/net/qeth_tso.h
Frank Pavlic f7b65d70a3 [PATCH] s390: qeth driver fixes [3/6]
[PATCH 6/9] s390: qeth driver fixes [3/6]

From: Frank Pavlic <fpavlic@de.ibm.com>
       	fixed kernel panic caused by qeth driver:
        Using a bonding device qeth driver will realloc
        headroom for every skb coming from the bond device.
        Once this happens qeth frees the original skb and
        set the skb pointer to the new realloced skb.
        Under heavy transmit workload (e.g.UDP streams) through bond
        network device the qdio output queue might get full.
        In this case we return with EBUSY from qeth_send_packet.
        Returning to qeth_hard_start_xmit routine
        the skb address on the stack still points to the old address,
        which has been freed before.
        Returning from qeth_hard_start_xmit with EBUSY results in
        requeuing the skb. In this case it corrupts the qdisc queue
        and results in kernel panic.

Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-17 01:03:07 -04:00

153 lines
3.8 KiB
C

/*
* linux/drivers/s390/net/qeth_tso.h
*
* Header file for qeth TCP Segmentation Offload support.
*
* Copyright 2004 IBM Corporation
*
* Author(s): Frank Pavlic <fpavlic@de.ibm.com>
*
*/
#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"
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;
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)->gso_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;
}
static inline int
qeth_tso_prepare_packet(struct qeth_card *card, struct sk_buff *skb,
int ipv, int cast_type)
{
struct qeth_hdr_tso *hdr;
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)
{
struct skb_frag_struct *frag;
int fragno;
unsigned long addr;
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++;
}
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__ */