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   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
  23 static inline struct qeth_hdr_tso *
  24 qeth_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  */
  33 static inline void
  34 qeth_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  */
  63 static inline void
  64 qeth_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
  84 static inline int
  85 qeth_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         /*fill first 32 bytes of  qdio header as used
  99          *FIXME: TSO has two struct members
 100          * with different names but same size
 101          * */
 102         qeth_fill_header(card, &hdr->hdr, skb, ipv, cast_type);
 103         qeth_tso_fill_header(card, skb);
 104         qeth_tso_set_tcpip_header(card, skb);
 105         return 0;
 106 }
 107
 108 static inline void
 109 __qeth_fill_buffer_frag(struct sk_buff *skb, struct qdio_buffer *buffer,
 110                         int is_tso, int *next_element_to_fill)
 111 {
 112         struct skb_frag_struct *frag;
 113         int fragno;
 114         unsigned long addr;
 115         int element, cnt, dlen;
 116
 117         fragno = skb_shinfo(skb)->nr_frags;
 118         element = *next_element_to_fill;
 119         dlen = 0;
 120
 121         if (is_tso)
 122                 buffer->element[element].flags =
 123                         SBAL_FLAGS_MIDDLE_FRAG;
 124         else
 125                 buffer->element[element].flags =
 126                         SBAL_FLAGS_FIRST_FRAG;
 127         if ( (dlen = (skb->len - skb->data_len)) ) {
 128                 buffer->element[element].addr = skb->data;
 129                 buffer->element[element].length = dlen;
 130                 element++;
 131         }
 132         for (cnt = 0; cnt < fragno; cnt++) {
 133                 frag = &skb_shinfo(skb)->frags[cnt];
 134                 addr = (page_to_pfn(frag->page) << PAGE_SHIFT) +
 135                         frag->page_offset;
 136                 buffer->element[element].addr = (char *)addr;
 137                 buffer->element[element].length = frag->size;
 138                 if (cnt < (fragno - 1))
 139                         buffer->element[element].flags =
 140                                 SBAL_FLAGS_MIDDLE_FRAG;
 141                 else
 142                         buffer->element[element].flags =
 143                                 SBAL_FLAGS_LAST_FRAG;
 144                 element++;
 145         }
 146         *next_element_to_fill = element;
 147 }
 148 #endif /* __QETH_TSO_H__ */