1/*
2 * linux/drivers/s390/net/qeth_tso.h
3 *
4 * Header file for qeth TCP Segmentation Offload support.
5 *
6 * Copyright 2004 IBM Corporation
7 *
8 *    Author(s): Frank Pavlic <fpavlic@de.ibm.com>
9 *
10 */
11#ifndef __QETH_TSO_H__
12#define __QETH_TSO_H__
13
14#include <linux/skbuff.h>
15#include <linux/tcp.h>
16#include <linux/ip.h>
17#include <linux/ipv6.h>
18#include <net/ip6_checksum.h>
19#include "qeth.h"
20#include "qeth_mpc.h"
21
22
23static inline struct qeth_hdr_tso *
24qeth_tso_prepare_skb(struct qeth_card *card, struct sk_buff **skb)
25{
26	QETH_DBF_TEXT(trace, 5, "tsoprsk");
27	return qeth_push_skb(card, *skb, sizeof(struct qeth_hdr_tso));
28}
29
30/**
31 * fill header for a TSO packet
32 */
33static inline void
34qeth_tso_fill_header(struct qeth_card *card, struct sk_buff *skb)
35{
36	struct qeth_hdr_tso *hdr;
37	struct tcphdr *tcph;
38	struct iphdr *iph;
39
40	QETH_DBF_TEXT(trace, 5, "tsofhdr");
41
42	hdr  = (struct qeth_hdr_tso *) skb->data;
43	iph  = ip_hdr(skb);
44	tcph = tcp_hdr(skb);
45	/*fix header to TSO values ...*/
46	hdr->hdr.hdr.l3.id = QETH_HEADER_TYPE_TSO;
47	/*set values which are fix for the first approach ...*/
48	hdr->ext.hdr_tot_len = (__u16) sizeof(struct qeth_hdr_ext_tso);
49	hdr->ext.imb_hdr_no  = 1;
50	hdr->ext.hdr_type    = 1;
51	hdr->ext.hdr_version = 1;
52	hdr->ext.hdr_len     = 28;
53	/*insert non-fix values */
54	hdr->ext.mss = skb_shinfo(skb)->gso_size;
55	hdr->ext.dg_hdr_len = (__u16)(iph->ihl*4 + tcph->doff*4);
56	hdr->ext.payload_len = (__u16)(skb->len - hdr->ext.dg_hdr_len -
57				       sizeof(struct qeth_hdr_tso));
58}
59
60/**
61 * change some header values as requested by hardware
62 */
63static inline void
64qeth_tso_set_tcpip_header(struct qeth_card *card, struct sk_buff *skb)
65{
66	struct iphdr *iph    = ip_hdr(skb);
67	struct ipv6hdr *ip6h = ipv6_hdr(skb);
68	struct tcphdr *tcph  = tcp_hdr(skb);
69
70	tcph->check = 0;
71	if (skb->protocol == ETH_P_IPV6) {
72		ip6h->payload_len = 0;
73		tcph->check = ~csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
74					       0, IPPROTO_TCP, 0);
75		return;
76	}
77	/*OSA want us to set these values ...*/
78	tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
79					 0, IPPROTO_TCP, 0);
80	iph->tot_len = 0;
81	iph->check = 0;
82}
83
84static inline int
85qeth_tso_prepare_packet(struct qeth_card *card, struct sk_buff *skb,
86			int ipv, int cast_type)
87{
88	struct qeth_hdr_tso *hdr;
89
90	QETH_DBF_TEXT(trace, 5, "tsoprep");
91
92	hdr = (struct qeth_hdr_tso *) qeth_tso_prepare_skb(card, &skb);
93	if (hdr == NULL) {
94		QETH_DBF_TEXT(trace, 4, "tsoperr");
95		return -ENOMEM;
96	}
97	memset(hdr, 0, sizeof(struct qeth_hdr_tso));
98	qeth_fill_header(card, &hdr->hdr, skb, ipv, cast_type);
99	qeth_tso_fill_header(card, skb);
100	qeth_tso_set_tcpip_header(card, skb);
101	return 0;
102}
103
104static inline void
105__qeth_fill_buffer_frag(struct sk_buff *skb, struct qdio_buffer *buffer,
106			int is_tso, int *next_element_to_fill)
107{
108	struct skb_frag_struct *frag;
109	int fragno;
110	unsigned long addr;
111	int element, cnt, dlen;
112
113	fragno = skb_shinfo(skb)->nr_frags;
114	element = *next_element_to_fill;
115	dlen = 0;
116
117	if (is_tso)
118		buffer->element[element].flags =
119			SBAL_FLAGS_MIDDLE_FRAG;
120	else
121		buffer->element[element].flags =
122			SBAL_FLAGS_FIRST_FRAG;
123	if ( (dlen = (skb->len - skb->data_len)) ) {
124		buffer->element[element].addr = skb->data;
125		buffer->element[element].length = dlen;
126		element++;
127	}
128	for (cnt = 0; cnt < fragno; cnt++) {
129		frag = &skb_shinfo(skb)->frags[cnt];
130		addr = (page_to_pfn(frag->page) << PAGE_SHIFT) +
131			frag->page_offset;
132		buffer->element[element].addr = (char *)addr;
133		buffer->element[element].length = frag->size;
134		if (cnt < (fragno - 1))
135			buffer->element[element].flags =
136				SBAL_FLAGS_MIDDLE_FRAG;
137		else
138			buffer->element[element].flags =
139				SBAL_FLAGS_LAST_FRAG;
140		element++;
141	}
142	*next_element_to_fill = element;
143}
144#endif /* __QETH_TSO_H__ */
145