drivers/s390/net/qeth_eddp.c

   1 /*
   2  *
   3  * linux/drivers/s390/net/qeth_eddp.c ($Revision: 1.13 $)
   4  *
   5  * Enhanced Device Driver Packing (EDDP) support for the qeth driver.
   6  *
   7  * Copyright 2004 IBM Corporation
   8  *
   9  *    Author(s): Thomas Spatzier <tspat@de.ibm.com>
  10  *
  11  *    $Revision: 1.13 $  $Date: 2005/05/04 20:19:18 $
  12  *
  13  */
  14 #include <linux/config.h>
  15 #include <linux/errno.h>
  16 #include <linux/ip.h>
  17 #include <linux/inetdevice.h>
  18 #include <linux/netdevice.h>
  19 #include <linux/kernel.h>
  20 #include <linux/tcp.h>
  21 #include <net/tcp.h>
  22 #include <linux/skbuff.h>
  23
  24 #include <net/ip.h>
  25
  26 #include "qeth.h"
  27 #include "qeth_mpc.h"
  28 #include "qeth_eddp.h"
  29
  30 int
  31 qeth_eddp_check_buffers_for_context(struct qeth_qdio_out_q *queue,
  32                                     struct qeth_eddp_context *ctx)
  33 {
  34         int index = queue->next_buf_to_fill;
  35         int elements_needed = ctx->num_elements;
  36         int elements_in_buffer;
  37         int skbs_in_buffer;
  38         int buffers_needed = 0;
  39
  40         QETH_DBF_TEXT(trace, 5, "eddpcbfc");
  41         while(elements_needed > 0) {
  42                 buffers_needed++;
  43                 if (atomic_read(&queue->bufs[index].state) !=
  44                                 QETH_QDIO_BUF_EMPTY)
  45                         return -EBUSY;
  46
  47                 elements_in_buffer = QETH_MAX_BUFFER_ELEMENTS(queue->card) -
  48                                      queue->bufs[index].next_element_to_fill;
  49                 skbs_in_buffer = elements_in_buffer / ctx->elements_per_skb;
  50                 elements_needed -= skbs_in_buffer * ctx->elements_per_skb;
  51                 index = (index + 1) % QDIO_MAX_BUFFERS_PER_Q;
  52         }
  53         return buffers_needed;
  54 }
  55
  56 static inline void
  57 qeth_eddp_free_context(struct qeth_eddp_context *ctx)
  58 {
  59         int i;
  60
  61         QETH_DBF_TEXT(trace, 5, "eddpfctx");
  62         for (i = 0; i < ctx->num_pages; ++i)
  63                 free_page((unsigned long)ctx->pages[i]);
  64         kfree(ctx->pages);
  65         if (ctx->elements != NULL)
  66                 kfree(ctx->elements);
  67         kfree(ctx);
  68 }
  69
  70
  71 static inline void
  72 qeth_eddp_get_context(struct qeth_eddp_context *ctx)
  73 {
  74         atomic_inc(&ctx->refcnt);
  75 }
  76
  77 void
  78 qeth_eddp_put_context(struct qeth_eddp_context *ctx)
  79 {
  80         if (atomic_dec_return(&ctx->refcnt) == 0)
  81                 qeth_eddp_free_context(ctx);
  82 }
  83
  84 void
  85 qeth_eddp_buf_release_contexts(struct qeth_qdio_out_buffer *buf)
  86 {
  87         struct qeth_eddp_context_reference *ref;
  88
  89         QETH_DBF_TEXT(trace, 6, "eddprctx");
  90         while (!list_empty(&buf->ctx_list)){
  91                 ref = list_entry(buf->ctx_list.next,
  92                                  struct qeth_eddp_context_reference, list);
  93                 qeth_eddp_put_context(ref->ctx);
  94                 list_del(&ref->list);
  95                 kfree(ref);
  96         }
  97 }
  98
  99 static inline int
 100 qeth_eddp_buf_ref_context(struct qeth_qdio_out_buffer *buf,
 101                           struct qeth_eddp_context *ctx)
 102 {
 103         struct qeth_eddp_context_reference *ref;
 104
 105         QETH_DBF_TEXT(trace, 6, "eddprfcx");
 106         ref = kmalloc(sizeof(struct qeth_eddp_context_reference), GFP_ATOMIC);
 107         if (ref == NULL)
 108                 return -ENOMEM;
 109         qeth_eddp_get_context(ctx);
 110         ref->ctx = ctx;
 111         list_add_tail(&ref->list, &buf->ctx_list);
 112         return 0;
 113 }
 114
 115 int
 116 qeth_eddp_fill_buffer(struct qeth_qdio_out_q *queue,
 117                       struct qeth_eddp_context *ctx,
 118                       int index)
 119 {
 120         struct qeth_qdio_out_buffer *buf = NULL;
 121         struct qdio_buffer *buffer;
 122         int elements = ctx->num_elements;
 123         int element = 0;
 124         int flush_cnt = 0;
 125         int must_refcnt = 1;
 126         int i;
 127
 128         QETH_DBF_TEXT(trace, 5, "eddpfibu");
 129         while (elements > 0) {
 130                 buf = &queue->bufs[index];
 131                 if (atomic_read(&buf->state) != QETH_QDIO_BUF_EMPTY){
 132                         /* normally this should not happen since we checked for
 133                          * available elements in qeth_check_elements_for_context
 134                          */
 135                         if (element == 0)
 136                                 return -EBUSY;
 137                         else {
 138                                 PRINT_WARN("could only partially fill eddp "
 139                                            "buffer!\n");
 140                                 goto out;
 141                         }
 142                 }
 143                 /* check if the whole next skb fits into current buffer */
 144                 if ((QETH_MAX_BUFFER_ELEMENTS(queue->card) -
 145                                         buf->next_element_to_fill)
 146                                 < ctx->elements_per_skb){
 147                         /* no -> go to next buffer */
 148                         atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
 149                         index = (index + 1) % QDIO_MAX_BUFFERS_PER_Q;
 150                         flush_cnt++;
 151                         /* new buffer, so we have to add ctx to buffer'ctx_list
 152                          * and increment ctx's refcnt */
 153                         must_refcnt = 1;
 154                         continue;
 155                 }
 156                 if (must_refcnt){
 157                         must_refcnt = 0;
 158                         if (qeth_eddp_buf_ref_context(buf, ctx)){
 159                                 PRINT_WARN("no memory to create eddp context "
 160                                            "reference\n");
 161                                 goto out_check;
 162                         }
 163                 }
 164                 buffer = buf->buffer;
 165                 /* fill one skb into buffer */
 166                 for (i = 0; i < ctx->elements_per_skb; ++i){
 167                         buffer->element[buf->next_element_to_fill].addr =
 168                                 ctx->elements[element].addr;
 169                         buffer->element[buf->next_element_to_fill].length =
 170                                 ctx->elements[element].length;
 171                         buffer->element[buf->next_element_to_fill].flags =
 172                                 ctx->elements[element].flags;
 173                         buf->next_element_to_fill++;
 174                         element++;
 175                         elements--;
 176                 }
 177         }
 178 out_check:
 179         if (!queue->do_pack) {
 180                 QETH_DBF_TEXT(trace, 6, "fillbfnp");
 181                 /* set state to PRIMED -> will be flushed */
 182                 if (buf->next_element_to_fill > 0){
 183                         atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
 184                         flush_cnt++;
 185                 }
 186         } else {
 187 #ifdef CONFIG_QETH_PERF_STATS
 188                 queue->card->perf_stats.skbs_sent_pack++;
 189 #endif
 190                 QETH_DBF_TEXT(trace, 6, "fillbfpa");
 191                 if (buf->next_element_to_fill >=
 192                                 QETH_MAX_BUFFER_ELEMENTS(queue->card)) {
 193                         /*
 194                          * packed buffer if full -> set state PRIMED
 195                          * -> will be flushed
 196                          */
 197                         atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
 198                         flush_cnt++;
 199                 }
 200         }
 201 out:
 202         return flush_cnt;
 203 }
 204
 205 static inline void
 206 qeth_eddp_create_segment_hdrs(struct qeth_eddp_context *ctx,
 207                               struct qeth_eddp_data *eddp, int data_len)
 208 {
 209         u8 *page;
 210         int page_remainder;
 211         int page_offset;
 212         int pkt_len;
 213         struct qeth_eddp_element *element;
 214
 215         QETH_DBF_TEXT(trace, 5, "eddpcrsh");
 216         page = ctx->pages[ctx->offset >> PAGE_SHIFT];
 217         page_offset = ctx->offset % PAGE_SIZE;
 218         element = &ctx->elements[ctx->num_elements];
 219         pkt_len = eddp->nhl + eddp->thl + data_len;
 220         /* FIXME: layer2 and VLAN !!! */
 221         if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2)
 222                 pkt_len += ETH_HLEN;
 223         if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
 224                 pkt_len += VLAN_HLEN;
 225         /* does complete packet fit in current page ? */
 226         page_remainder = PAGE_SIZE - page_offset;
 227         if (page_remainder < (sizeof(struct qeth_hdr) + pkt_len)){
 228                 /* no -> go to start of next page */
 229                 ctx->offset += page_remainder;
 230                 page = ctx->pages[ctx->offset >> PAGE_SHIFT];
 231                 page_offset = 0;
 232         }
 233         memcpy(page + page_offset, &eddp->qh, sizeof(struct qeth_hdr));
 234         element->addr = page + page_offset;
 235         element->length = sizeof(struct qeth_hdr);
 236         ctx->offset += sizeof(struct qeth_hdr);
 237         page_offset += sizeof(struct qeth_hdr);
 238         /* add mac header (?) */
 239         if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2){
 240                 memcpy(page + page_offset, &eddp->mac, ETH_HLEN);
 241                 element->length += ETH_HLEN;
 242                 ctx->offset += ETH_HLEN;
 243                 page_offset += ETH_HLEN;
 244         }
 245         /* add VLAN tag */
 246         if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q)){
 247                 memcpy(page + page_offset, &eddp->vlan, VLAN_HLEN);
 248                 element->length += VLAN_HLEN;
 249                 ctx->offset += VLAN_HLEN;
 250                 page_offset += VLAN_HLEN;
 251         }
 252         /* add network header */
 253         memcpy(page + page_offset, (u8 *)&eddp->nh, eddp->nhl);
 254         element->length += eddp->nhl;
 255         eddp->nh_in_ctx = page + page_offset;
 256         ctx->offset += eddp->nhl;
 257         page_offset += eddp->nhl;
 258         /* add transport header */
 259         memcpy(page + page_offset, (u8 *)&eddp->th, eddp->thl);
 260         element->length += eddp->thl;
 261         eddp->th_in_ctx = page + page_offset;
 262         ctx->offset += eddp->thl;
 263 }
 264
 265 static inline void
 266 qeth_eddp_copy_data_tcp(char *dst, struct qeth_eddp_data *eddp, int len,
 267                         u32 *hcsum)
 268 {
 269         struct skb_frag_struct *frag;
 270         int left_in_frag;
 271         int copy_len;
 272         u8 *src;
 273
 274         QETH_DBF_TEXT(trace, 5, "eddpcdtc");
 275         if (skb_shinfo(eddp->skb)->nr_frags == 0) {
 276                 memcpy(dst, eddp->skb->data + eddp->skb_offset, len);
 277                 *hcsum = csum_partial(eddp->skb->data + eddp->skb_offset, len,
 278                                       *hcsum);
 279                 eddp->skb_offset += len;
 280         } else {
 281                 while (len > 0) {
 282                         if (eddp->frag < 0) {
 283                                 /* we're in skb->data */
 284                                 left_in_frag = (eddp->skb->len - eddp->skb->data_len)
 285                                                 - eddp->skb_offset;
 286                                 src = eddp->skb->data + eddp->skb_offset;
 287                         } else {
 288                                 frag = &skb_shinfo(eddp->skb)->
 289                                         frags[eddp->frag];
 290                                 left_in_frag = frag->size - eddp->frag_offset;
 291                                 src = (u8 *)(
 292                                         (page_to_pfn(frag->page) << PAGE_SHIFT)+
 293                                         frag->page_offset + eddp->frag_offset);
 294                         }
 295                         if (left_in_frag <= 0) {
 296                                 eddp->frag++;
 297                                 eddp->frag_offset = 0;
 298                                 continue;
 299                         }
 300                         copy_len = min(left_in_frag, len);
 301                         memcpy(dst, src, copy_len);
 302                         *hcsum = csum_partial(src, copy_len, *hcsum);
 303                         dst += copy_len;
 304                         eddp->frag_offset += copy_len;
 305                         eddp->skb_offset += copy_len;
 306                         len -= copy_len;
 307                 }
 308         }
 309 }
 310
 311 static inline void
 312 qeth_eddp_create_segment_data_tcp(struct qeth_eddp_context *ctx,
 313                                   struct qeth_eddp_data *eddp, int data_len,
 314                                   u32 hcsum)
 315 {
 316         u8 *page;
 317         int page_remainder;
 318         int page_offset;
 319         struct qeth_eddp_element *element;
 320         int first_lap = 1;
 321
 322         QETH_DBF_TEXT(trace, 5, "eddpcsdt");
 323         page = ctx->pages[ctx->offset >> PAGE_SHIFT];
 324         page_offset = ctx->offset % PAGE_SIZE;
 325         element = &ctx->elements[ctx->num_elements];
 326         while (data_len){
 327                 page_remainder = PAGE_SIZE - page_offset;
 328                 if (page_remainder < data_len){
 329                         qeth_eddp_copy_data_tcp(page + page_offset, eddp,
 330                                                 page_remainder, &hcsum);
 331                         element->length += page_remainder;
 332                         if (first_lap)
 333                                 element->flags = SBAL_FLAGS_FIRST_FRAG;
 334                         else
 335                                 element->flags = SBAL_FLAGS_MIDDLE_FRAG;
 336                         ctx->num_elements++;
 337                         element++;
 338                         data_len -= page_remainder;
 339                         ctx->offset += page_remainder;
 340                         page = ctx->pages[ctx->offset >> PAGE_SHIFT];
 341                         page_offset = 0;
 342                         element->addr = page + page_offset;
 343                 } else {
 344                         qeth_eddp_copy_data_tcp(page + page_offset, eddp,
 345                                                 data_len, &hcsum);
 346                         element->length += data_len;
 347                         if (!first_lap)
 348                                 element->flags = SBAL_FLAGS_LAST_FRAG;
 349                         ctx->num_elements++;
 350                         ctx->offset += data_len;
 351                         data_len = 0;
 352                 }
 353                 first_lap = 0;
 354         }
 355         ((struct tcphdr *)eddp->th_in_ctx)->check = csum_fold(hcsum);
 356 }
 357
 358 static inline u32
 359 qeth_eddp_check_tcp4_hdr(struct qeth_eddp_data *eddp, int data_len)
 360 {
 361         u32 phcsum; /* pseudo header checksum */
 362
 363         QETH_DBF_TEXT(trace, 5, "eddpckt4");
 364         eddp->th.tcp.h.check = 0;
 365         /* compute pseudo header checksum */
 366         phcsum = csum_tcpudp_nofold(eddp->nh.ip4.h.saddr, eddp->nh.ip4.h.daddr,
 367                                     eddp->thl + data_len, IPPROTO_TCP, 0);
 368         /* compute checksum of tcp header */
 369         return csum_partial((u8 *)&eddp->th, eddp->thl, phcsum);
 370 }
 371
 372 static inline u32
 373 qeth_eddp_check_tcp6_hdr(struct qeth_eddp_data *eddp, int data_len)
 374 {
 375         u32 proto;
 376         u32 phcsum; /* pseudo header checksum */
 377
 378         QETH_DBF_TEXT(trace, 5, "eddpckt6");
 379         eddp->th.tcp.h.check = 0;
 380         /* compute pseudo header checksum */
 381         phcsum = csum_partial((u8 *)&eddp->nh.ip6.h.saddr,
 382                               sizeof(struct in6_addr), 0);
 383         phcsum = csum_partial((u8 *)&eddp->nh.ip6.h.daddr,
 384                               sizeof(struct in6_addr), phcsum);
 385         proto = htonl(IPPROTO_TCP);
 386         phcsum = csum_partial((u8 *)&proto, sizeof(u32), phcsum);
 387         return phcsum;
 388 }
 389
 390 static inline struct qeth_eddp_data *
 391 qeth_eddp_create_eddp_data(struct qeth_hdr *qh, u8 *nh, u8 nhl, u8 *th, u8 thl)
 392 {
 393         struct qeth_eddp_data *eddp;
 394
 395         QETH_DBF_TEXT(trace, 5, "eddpcrda");
 396         eddp = kmalloc(sizeof(struct qeth_eddp_data), GFP_ATOMIC);
 397         if (eddp){
 398                 memset(eddp, 0, sizeof(struct qeth_eddp_data));
 399                 eddp->nhl = nhl;
 400                 eddp->thl = thl;
 401                 memcpy(&eddp->qh, qh, sizeof(struct qeth_hdr));
 402                 memcpy(&eddp->nh, nh, nhl);
 403                 memcpy(&eddp->th, th, thl);
 404                 eddp->frag = -1; /* initially we're in skb->data */
 405         }
 406         return eddp;
 407 }
 408
 409 static inline void
 410 __qeth_eddp_fill_context_tcp(struct qeth_eddp_context *ctx,
 411                              struct qeth_eddp_data *eddp)
 412 {
 413         struct tcphdr *tcph;
 414         int data_len;
 415         u32 hcsum;
 416
 417         QETH_DBF_TEXT(trace, 5, "eddpftcp");
 418         eddp->skb_offset = sizeof(struct qeth_hdr) + eddp->nhl + eddp->thl;
 419         tcph = eddp->skb->h.th;
 420         while (eddp->skb_offset < eddp->skb->len) {
 421                 data_len = min((int)skb_shinfo(eddp->skb)->tso_size,
 422                                (int)(eddp->skb->len - eddp->skb_offset));
 423                 /* prepare qdio hdr */
 424                 if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2){
 425                         eddp->qh.hdr.l2.pkt_length = data_len + ETH_HLEN +
 426                                                      eddp->nhl + eddp->thl -
 427                                                      sizeof(struct qeth_hdr);
 428 #ifdef CONFIG_QETH_VLAN
 429                         if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
 430                                 eddp->qh.hdr.l2.pkt_length += VLAN_HLEN;
 431 #endif /* CONFIG_QETH_VLAN */
 432                 } else
 433                         eddp->qh.hdr.l3.length = data_len + eddp->nhl +
 434                                                  eddp->thl;
 435                 /* prepare ip hdr */
 436                 if (eddp->skb->protocol == ETH_P_IP){
 437                         eddp->nh.ip4.h.tot_len = data_len + eddp->nhl +
 438                                                  eddp->thl;
 439                         eddp->nh.ip4.h.check = 0;
 440                         eddp->nh.ip4.h.check =
 441                                 ip_fast_csum((u8 *)&eddp->nh.ip4.h,
 442                                                 eddp->nh.ip4.h.ihl);
 443                 } else
 444                         eddp->nh.ip6.h.payload_len = data_len + eddp->thl;
 445                 /* prepare tcp hdr */
 446                 if (data_len == (eddp->skb->len - eddp->skb_offset)){
 447                         /* last segment -> set FIN and PSH flags */
 448                         eddp->th.tcp.h.fin = tcph->fin;
 449                         eddp->th.tcp.h.psh = tcph->psh;
 450                 }
 451                 if (eddp->skb->protocol == ETH_P_IP)
 452                         hcsum = qeth_eddp_check_tcp4_hdr(eddp, data_len);
 453                 else
 454                         hcsum = qeth_eddp_check_tcp6_hdr(eddp, data_len);
 455                 /* fill the next segment into the context */
 456                 qeth_eddp_create_segment_hdrs(ctx, eddp, data_len);
 457                 qeth_eddp_create_segment_data_tcp(ctx, eddp, data_len, hcsum);
 458                 if (eddp->skb_offset >= eddp->skb->len)
 459                         break;
 460                 /* prepare headers for next round */
 461                 if (eddp->skb->protocol == ETH_P_IP)
 462                         eddp->nh.ip4.h.id++;
 463                 eddp->th.tcp.h.seq += data_len;
 464         }
 465 }
 466
 467 static inline int
 468 qeth_eddp_fill_context_tcp(struct qeth_eddp_context *ctx,
 469                            struct sk_buff *skb, struct qeth_hdr *qhdr)
 470 {
 471         struct qeth_eddp_data *eddp = NULL;
 472
 473         QETH_DBF_TEXT(trace, 5, "eddpficx");
 474         /* create our segmentation headers and copy original headers */
 475         if (skb->protocol == ETH_P_IP)
 476                 eddp = qeth_eddp_create_eddp_data(qhdr, (u8 *)skb->nh.iph,
 477                                 skb->nh.iph->ihl*4,
 478                                 (u8 *)skb->h.th, skb->h.th->doff*4);
 479         else
 480                 eddp = qeth_eddp_create_eddp_data(qhdr, (u8 *)skb->nh.ipv6h,
 481                                 sizeof(struct ipv6hdr),
 482                                 (u8 *)skb->h.th, skb->h.th->doff*4);
 483
 484         if (eddp == NULL) {
 485                 QETH_DBF_TEXT(trace, 2, "eddpfcnm");
 486                 return -ENOMEM;
 487         }
 488         if (qhdr->hdr.l2.id == QETH_HEADER_TYPE_LAYER2) {
 489                 memcpy(&eddp->mac, eth_hdr(skb), ETH_HLEN);
 490 #ifdef CONFIG_QETH_VLAN
 491                 if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q)) {
 492                         eddp->vlan[0] = __constant_htons(skb->protocol);
 493                         eddp->vlan[1] = htons(vlan_tx_tag_get(skb));
 494                 }
 495 #endif /* CONFIG_QETH_VLAN */
 496         }
 497         /* the next flags will only be set on the last segment */
 498         eddp->th.tcp.h.fin = 0;
 499         eddp->th.tcp.h.psh = 0;
 500         eddp->skb = skb;
 501         /* begin segmentation and fill context */
 502         __qeth_eddp_fill_context_tcp(ctx, eddp);
 503         kfree(eddp);
 504         return 0;
 505 }
 506
 507 static inline void
 508 qeth_eddp_calc_num_pages(struct qeth_eddp_context *ctx, struct sk_buff *skb,
 509                          int hdr_len)
 510 {
 511         int skbs_per_page;
 512
 513         QETH_DBF_TEXT(trace, 5, "eddpcanp");
 514         /* can we put multiple skbs in one page? */
 515         skbs_per_page = PAGE_SIZE / (skb_shinfo(skb)->tso_size + hdr_len);
 516         if (skbs_per_page > 1){
 517                 ctx->num_pages = (skb_shinfo(skb)->tso_segs + 1) /
 518                                  skbs_per_page + 1;
 519                 ctx->elements_per_skb = 1;
 520         } else {
 521                 /* no -> how many elements per skb? */
 522                 ctx->elements_per_skb = (skb_shinfo(skb)->tso_size + hdr_len +
 523                                      PAGE_SIZE) >> PAGE_SHIFT;
 524                 ctx->num_pages = ctx->elements_per_skb *
 525                                  (skb_shinfo(skb)->tso_segs + 1);
 526         }
 527         ctx->num_elements = ctx->elements_per_skb *
 528                             (skb_shinfo(skb)->tso_segs + 1);
 529 }
 530
 531 static inline struct qeth_eddp_context *
 532 qeth_eddp_create_context_generic(struct qeth_card *card, struct sk_buff *skb,
 533                                  int hdr_len)
 534 {
 535         struct qeth_eddp_context *ctx = NULL;
 536         u8 *addr;
 537         int i;
 538
 539         QETH_DBF_TEXT(trace, 5, "creddpcg");
 540         /* create the context and allocate pages */
 541         ctx = kmalloc(sizeof(struct qeth_eddp_context), GFP_ATOMIC);
 542         if (ctx == NULL){
 543                 QETH_DBF_TEXT(trace, 2, "ceddpcn1");
 544                 return NULL;
 545         }
 546         memset(ctx, 0, sizeof(struct qeth_eddp_context));
 547         ctx->type = QETH_LARGE_SEND_EDDP;
 548         qeth_eddp_calc_num_pages(ctx, skb, hdr_len);
 549         if (ctx->elements_per_skb > QETH_MAX_BUFFER_ELEMENTS(card)){
 550                 QETH_DBF_TEXT(trace, 2, "ceddpcis");
 551                 kfree(ctx);
 552                 return NULL;
 553         }
 554         ctx->pages = kmalloc(ctx->num_pages * sizeof(u8 *), GFP_ATOMIC);
 555         if (ctx->pages == NULL){
 556                 QETH_DBF_TEXT(trace, 2, "ceddpcn2");
 557                 kfree(ctx);
 558                 return NULL;
 559         }
 560         memset(ctx->pages, 0, ctx->num_pages * sizeof(u8 *));
 561         for (i = 0; i < ctx->num_pages; ++i){
 562                 addr = (u8 *)__get_free_page(GFP_ATOMIC);
 563                 if (addr == NULL){
 564                         QETH_DBF_TEXT(trace, 2, "ceddpcn3");
 565                         ctx->num_pages = i;
 566                         qeth_eddp_free_context(ctx);
 567                         return NULL;
 568                 }
 569                 memset(addr, 0, PAGE_SIZE);
 570                 ctx->pages[i] = addr;
 571         }
 572         ctx->elements = kmalloc(ctx->num_elements *
 573                                 sizeof(struct qeth_eddp_element), GFP_ATOMIC);
 574         if (ctx->elements == NULL){
 575                 QETH_DBF_TEXT(trace, 2, "ceddpcn4");
 576                 qeth_eddp_free_context(ctx);
 577                 return NULL;
 578         }
 579         memset(ctx->elements, 0,
 580                ctx->num_elements * sizeof(struct qeth_eddp_element));
 581         /* reset num_elements; will be incremented again in fill_buffer to
 582          * reflect number of actually used elements */
 583         ctx->num_elements = 0;
 584         return ctx;
 585 }
 586
 587 static inline struct qeth_eddp_context *
 588 qeth_eddp_create_context_tcp(struct qeth_card *card, struct sk_buff *skb,
 589                              struct qeth_hdr *qhdr)
 590 {
 591         struct qeth_eddp_context *ctx = NULL;
 592
 593         QETH_DBF_TEXT(trace, 5, "creddpct");
 594         if (skb->protocol == ETH_P_IP)
 595                 ctx = qeth_eddp_create_context_generic(card, skb,
 596                         sizeof(struct qeth_hdr) + skb->nh.iph->ihl*4 +
 597                         skb->h.th->doff*4);
 598         else if (skb->protocol == ETH_P_IPV6)
 599                 ctx = qeth_eddp_create_context_generic(card, skb,
 600                         sizeof(struct qeth_hdr) + sizeof(struct ipv6hdr) +
 601                         skb->h.th->doff*4);
 602         else
 603                 QETH_DBF_TEXT(trace, 2, "cetcpinv");
 604
 605         if (ctx == NULL) {
 606                 QETH_DBF_TEXT(trace, 2, "creddpnl");
 607                 return NULL;
 608         }
 609         if (qeth_eddp_fill_context_tcp(ctx, skb, qhdr)){
 610                 QETH_DBF_TEXT(trace, 2, "ceddptfe");
 611                 qeth_eddp_free_context(ctx);
 612                 return NULL;
 613         }
 614         atomic_set(&ctx->refcnt, 1);
 615         return ctx;
 616 }
 617
 618 struct qeth_eddp_context *
 619 qeth_eddp_create_context(struct qeth_card *card, struct sk_buff *skb,
 620                          struct qeth_hdr *qhdr)
 621 {
 622         QETH_DBF_TEXT(trace, 5, "creddpc");
 623         switch (skb->sk->sk_protocol){
 624         case IPPROTO_TCP:
 625                 return qeth_eddp_create_context_tcp(card, skb, qhdr);
 626         default:
 627                 QETH_DBF_TEXT(trace, 2, "eddpinvp");
 628         }
 629         return NULL;
 630 }
 631
 632