/*
* linux/drivers/s390/net/qeth_tso.c ($Revision: 1.7 $)
*
* Header file for qeth TCP Segmentation Offload support.
*
* Copyright 2004 IBM Corporation
*
* Author(s): Frank Pavlic <pavlic@de.ibm.com>
*
* $Revision: 1.7 $ $Date: 2005/04/01 21:40:41 $
*
*/
#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"
#include "qeth_tso.h"
/**
* skb already partially prepared
* classic qdio header in skb->data
* */
static inline struct qeth_hdr_tso *
qeth_tso_prepare_skb(struct qeth_card *card, struct sk_buff **skb)
{
int rc = 0;
QETH_DBF_TEXT(trace, 5, "tsoprsk");
rc = qeth_realloc_headroom(card, skb,sizeof(struct qeth_hdr_ext_tso));
if (rc)
return NULL;
return qeth_push_skb(card, skb, sizeof(struct qeth_hdr_ext_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)->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;
}
static inline struct qeth_hdr_tso *
qeth_tso_prepare_packet(struct qeth_card *card, struct sk_buff *skb,
int ipv, int cast_type)
{
struct qeth_hdr_tso *hdr;
int rc = 0;
QETH_DBF_TEXT(trace, 5, "tsoprep");
/*get headroom for tso qdio header */
hdr = (struct qeth_hdr_tso *) qeth_tso_prepare_skb(card, &skb);
if (hdr == NULL) {
QETH_DBF_TEXT_(trace, 4, "2err%d", rc);
return NULL;
}
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 hdr;
}
static inline int
qeth_tso_get_queue_buffer(struct qeth_qdio_out_q *queue)
{
struct qeth_qdio_out_buffer *buffer;
int flush_cnt = 0;
QETH_DBF_TEXT(trace, 5, "tsobuf");
/* force to non-packing*/
if (queue->do_pack)
queue->do_pack = 0;
buffer = &queue->bufs[queue->next_buf_to_fill];
/* get a new buffer if current is already in use*/
if ((atomic_read(&buffer->state) == QETH_QDIO_BUF_EMPTY) &&
(buffer->next_element_to_fill > 0)) {
atomic_set(&buffer->state, QETH_QDIO_BUF_PRIMED);
queue->next_buf_to_fill = (queue->next_buf_to_fill + 1) %
QDIO_MAX_BUFFERS_PER_Q;
flush_cnt++;
}
return flush_cnt;
}
static inline int
qeth_tso_fill_buffer(struct qeth_qdio_out_buffer *buf,
struct sk_buff *skb)
{
int length, length_here, element;
int hdr_len;
struct qdio_buffer *buffer;
struct qeth_hdr_tso *hdr;
char *data;
QETH_DBF_TEXT(trace, 3, "tsfilbuf");
/*increment user count and queue skb ...*/
atomic_inc(&skb->users);
skb_queue_tail(&buf->skb_list, skb);
/*initialize all variables...*/
buffer = buf->buffer;
hdr = (struct qeth_hdr_tso *)skb->data;
hdr_len = sizeof(struct qeth_hdr_tso) + hdr->ext.dg_hdr_len;
data = skb->data + hdr_len;
length = skb->len - hdr_len;
element = buf->next_element_to_fill;
/*fill first buffer entry only with header information */
buffer->element[element].addr = skb->data;
buffer->element[element].length = hdr_len;
buffer->element[element].flags = SBAL_FLAGS_FIRST_FRAG;
buf->next_element_to_fill++;
/*check if we have frags ...*/
if (skb_shinfo(skb)->nr_frags > 0) {
skb->len = length;
skb->data = data;
__qeth_fill_buffer_frag(skb, buffer,1,
(int *)&buf->next_element_to_fill);
goto out;
}
/*... if not, use this */
element++;
while (length > 0) {
/* length_here is the remaining amount of data in this page */
length_here = PAGE_SIZE - ((unsigned long) data % PAGE_SIZE);
if (length < length_here)
length_here = length;
buffer->element[element].addr = data;
buffer->element[element].length = length_here;
length -= length_here;
if (!length)
buffer->element[element].flags =
SBAL_FLAGS_LAST_FRAG;
else
buffer->element[element].flags =
SBAL_FLAGS_MIDDLE_FRAG;
data += length_here;
element++;
}
buf->next_element_to_fill = element;
out:
/*prime buffer now ...*/
atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
return 1;
}
int
qeth_tso_send_packet(struct qeth_card *card, struct sk_buff *skb,
struct qeth_qdio_out_q *queue, int ipv, int cast_type)
{
int flush_cnt = 0;
struct qeth_hdr_tso *hdr;
struct qeth_qdio_out_buffer *buffer;
int start_index;
QETH_DBF_TEXT(trace, 3, "tsosend");
if (!(hdr = qeth_tso_prepare_packet(card, skb, ipv, cast_type)))
return -ENOMEM;
/*check if skb fits in one SBAL ...*/
if (!(qeth_get_elements_no(card, (void*)hdr, skb)))
return -EINVAL;
/*lock queue, force switching to non-packing and send it ...*/
while (atomic_compare_and_swap(QETH_OUT_Q_UNLOCKED,
QETH_OUT_Q_LOCKED,
&queue->state));
start_index = queue->next_buf_to_fill;
buffer = &queue->bufs[queue->next_buf_to_fill];
/*check if card is too busy ...*/
if (atomic_read(&buffer->state) != QETH_QDIO_BUF_EMPTY){
card->stats.tx_dropped++;
goto out;
}
/*let's force to non-packing and get a new SBAL*/
flush_cnt += qeth_tso_get_queue_buffer(queue);
buffer = &queue->bufs[queue->next_buf_to_fill];
if (atomic_read(&buffer->state) != QETH_QDIO_BUF_EMPTY) {
card->stats.tx_dropped++;
goto out;
}
flush_cnt += qeth_tso_fill_buffer(buffer, skb);
queue->next_buf_to_fill = (queue->next_buf_to_fill + 1) %
QDIO_MAX_BUFFERS_PER_Q;
out:
atomic_set(&queue->state, QETH_OUT_Q_UNLOCKED);
if (flush_cnt)
qeth_flush_buffers(queue, 0, start_index, flush_cnt);
/*do some statistics */
card->stats.tx_packets++;
card->stats.tx_bytes += skb->len;
return 0;
}
