drivers/s390/net/qeth_tso.h

   1 /*
   2  * linux/drivers/s390/net/qeth_tso.h ($Revision: 1.5 $)
   3  *
   4  * Header file for qeth TCP Segmentation Offload support.
   5  *
   6  * Copyright 2004 IBM Corporation
   7  *
   8  *    Author(s): Frank Pavlic <pavlic@de.ibm.com>
   9  *
  10  *    $Revision: 1.5 $   $Date: 2005/04/01 21:40:41 $
  11  *
  12  */
  13 #ifndef __QETH_TSO_H__
  14 #define __QETH_TSO_H__
  15
  16
  17 extern int
  18 qeth_tso_send_packet(struct qeth_card *, struct sk_buff *,
  19                      struct qeth_qdio_out_q *, int , int);
  20
  21 struct qeth_hdr_ext_tso {
  22         __u16 hdr_tot_len;
  23         __u8  imb_hdr_no;
  24         __u8  reserved;
  25         __u8  hdr_type;
  26         __u8  hdr_version;
  27         __u16 hdr_len;
  28         __u32 payload_len;
  29         __u16 mss;
  30         __u16 dg_hdr_len;
  31         __u8  padding[16];
  32 } __attribute__ ((packed));
  33
  34 struct qeth_hdr_tso {
  35         struct qeth_hdr hdr;    /*hdr->hdr.l3.xxx*/
  36         struct qeth_hdr_ext_tso ext;
  37 } __attribute__ ((packed));
  38
  39 /*some helper functions*/
  40 static inline int
  41 qeth_get_elements_no(struct qeth_card *card, void *hdr, struct sk_buff *skb)
  42 {
  43         int elements_needed = 0;
  44
  45         if (skb_shinfo(skb)->nr_frags > 0)
  46                 elements_needed = (skb_shinfo(skb)->nr_frags + 1);
  47         if (elements_needed == 0 )
  48                 elements_needed = 1 + (((((unsigned long) hdr) % PAGE_SIZE)
  49                                         + skb->len) >> PAGE_SHIFT);
  50         if (elements_needed > QETH_MAX_BUFFER_ELEMENTS(card)){
  51                 PRINT_ERR("qeth_do_send_packet: invalid size of "
  52                           "IP packet. Discarded.");
  53                 return 0;
  54         }
  55         return elements_needed;
  56 }
  57
  58 static inline void
  59 __qeth_fill_buffer_frag(struct sk_buff *skb, struct qdio_buffer *buffer,
  60                         int is_tso, int *next_element_to_fill)
  61 {
  62         int length = skb->len;
  63         struct skb_frag_struct *frag;
  64         int fragno;
  65         unsigned long addr;
  66         int element;
  67         int first_lap = 1;
  68
  69         fragno = skb_shinfo(skb)->nr_frags; /* start with last frag */
  70         element = *next_element_to_fill + fragno;
  71         while (length > 0) {
  72                 if (fragno > 0) {
  73                         frag = &skb_shinfo(skb)->frags[fragno - 1];
  74                         addr = (page_to_pfn(frag->page) << PAGE_SHIFT) +
  75                                 frag->page_offset;
  76                         buffer->element[element].addr = (char *)addr;
  77                         buffer->element[element].length = frag->size;
  78                         length -= frag->size;
  79                         if (first_lap)
  80                                 buffer->element[element].flags =
  81                                     SBAL_FLAGS_LAST_FRAG;
  82                         else
  83                                 buffer->element[element].flags =
  84                                     SBAL_FLAGS_MIDDLE_FRAG;
  85                 } else {
  86                         buffer->element[element].addr = skb->data;
  87                         buffer->element[element].length = length;
  88                         length = 0;
  89                         if (is_tso)
  90                                 buffer->element[element].flags =
  91                                         SBAL_FLAGS_MIDDLE_FRAG;
  92                         else
  93                                 buffer->element[element].flags =
  94                                         SBAL_FLAGS_FIRST_FRAG;
  95                 }
  96                 element--;
  97                 fragno--;
  98                 first_lap = 0;
  99         }
 100         *next_element_to_fill += skb_shinfo(skb)->nr_frags + 1;
 101 }
 102
 103 #endif /* __QETH_TSO_H__ */