drivers/s390/net/qeth_eddp.c

   1 /*
   2  * linux/drivers/s390/net/qeth_eddp.c
   3  *
   4  * Enhanced Device Driver Packing (EDDP) support for the qeth driver.
   5  *
   6  * Copyright 2004 IBM Corporation
   7  *
   8  *    Author(s): Thomas Spatzier <tspat@de.ibm.com>
   9  *
  10  */
  11 #include <linux/errno.h>
  12 #include <linux/ip.h>
  13 #include <linux/inetdevice.h>
  14 #include <linux/netdevice.h>
  15 #include <linux/kernel.h>
  16 #include <linux/tcp.h>
  17 #include <net/tcp.h>
  18 #include <linux/skbuff.h>
  19
  20 #include <net/ip.h>
  21
  22 #include "qeth.h"
  23 #include "qeth_mpc.h"
  24 #include "qeth_eddp.h"
  25
  26 int
  27 qeth_eddp_check_buffers_for_context(struct qeth_qdio_out_q *queue,
  28                                     struct qeth_eddp_context *ctx)
  29 {
  30         int index = queue->next_buf_to_fill;
  31         int elements_needed = ctx->num_elements;
  32         int elements_in_buffer;
  33         int skbs_in_buffer;
  34         int buffers_needed = 0;
  35
  36         QETH_DBF_TEXT(trace, 5, "eddpcbfc");
  37         while(elements_needed > 0) {
  38                 buffers_needed++;
  39                 if (atomic_read(&queue->bufs[index].state) !=
  40                                 QETH_QDIO_BUF_EMPTY)
  41                         return -EBUSY;
  42
  43                 elements_in_buffer = QETH_MAX_BUFFER_ELEMENTS(queue->card) -
  44                                      queue->bufs[index].next_element_to_fill;
  45                 skbs_in_buffer = elements_in_buffer / ctx->elements_per_skb;
  46                 elements_needed -= skbs_in_buffer * ctx->elements_per_skb;
  47                 index = (index + 1) % QDIO_MAX_BUFFERS_PER_Q;
  48         }
  49         return buffers_needed;
  50 }
  51
  52 static void
  53 qeth_eddp_free_context(struct qeth_eddp_context *ctx)
  54 {
  55         int i;
  56
  57         QETH_DBF_TEXT(trace, 5, "eddpfctx");
  58         for (i = 0; i < ctx->num_pages; ++i)
  59                 free_page((unsigned long)ctx->pages[i]);
  60         kfree(ctx->pages);
  61         kfree(ctx->elements);
  62         kfree(ctx);
  63 }
  64
  65
  66 static inline void
  67 qeth_eddp_get_context(struct qeth_eddp_context *ctx)
  68 {
  69         atomic_inc(&ctx->refcnt);
  70 }
  71
  72 void
  73 qeth_eddp_put_context(struct qeth_eddp_context *ctx)
  74 {
  75         if (atomic_dec_return(&ctx->refcnt) == 0)
  76                 qeth_eddp_free_context(ctx);
  77 }
  78
  79 void
  80 qeth_eddp_buf_release_contexts(struct qeth_qdio_out_buffer *buf)
  81 {
  82         struct qeth_eddp_context_reference *ref;
  83
  84         QETH_DBF_TEXT(trace, 6, "eddprctx");
  85         while (!list_empty(&buf->ctx_list)){
  86                 ref = list_entry(buf->ctx_list.next,
  87                                  struct qeth_eddp_context_reference, list);
  88                 qeth_eddp_put_context(ref->ctx);
  89                 list_del(&ref->list);
  90                 kfree(ref);
  91         }
  92 }
  93
  94 static int
  95 qeth_eddp_buf_ref_context(struct qeth_qdio_out_buffer *buf,
  96                           struct qeth_eddp_context *ctx)
  97 {
  98         struct qeth_eddp_context_reference *ref;
  99
 100         QETH_DBF_TEXT(trace, 6, "eddprfcx");
 101         ref = kmalloc(sizeof(struct qeth_eddp_context_reference), GFP_ATOMIC);
 102         if (ref == NULL)
 103                 return -ENOMEM;
 104         qeth_eddp_get_context(ctx);
 105         ref->ctx = ctx;
 106         list_add_tail(&ref->list, &buf->ctx_list);
 107         return 0;
 108 }
 109
 110 int
 111 qeth_eddp_fill_buffer(struct qeth_qdio_out_q *queue,
 112                       struct qeth_eddp_context *ctx,
 113                       int index)
 114 {
 115         struct qeth_qdio_out_buffer *buf = NULL;
 116         struct qdio_buffer *buffer;
 117         int elements = ctx->num_elements;
 118         int element = 0;
 119         int flush_cnt = 0;
 120         int must_refcnt = 1;
 121         int i;
 122
 123         QETH_DBF_TEXT(trace, 5, "eddpfibu");
 124         while (elements > 0) {
 125                 buf = &queue->bufs[index];
 126                 if (atomic_read(&buf->state) != QETH_QDIO_BUF_EMPTY){
 127                         /* normally this should not happen since we checked for
 128                          * available elements in qeth_check_elements_for_context
 129                          */
 130                         if (element == 0)
 131                                 return -EBUSY;
 132                         else {
 133                                 PRINT_WARN("could only partially fill eddp "
 134                                            "buffer!\n");
 135                                 goto out;
 136                         }
 137                 }
 138                 /* check if the whole next skb fits into current buffer */
 139                 if ((QETH_MAX_BUFFER_ELEMENTS(queue->card) -
 140                                         buf->next_element_to_fill)
 141                                 < ctx->elements_per_skb){
 142                         /* no -> go to next buffer */
 143                         atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
 144                         index = (index + 1) % QDIO_MAX_BUFFERS_PER_Q;
 145                         flush_cnt++;
 146                         /* new buffer, so we have to add ctx to buffer'ctx_list
 147                          * and increment ctx's refcnt */
 148                         must_refcnt = 1;
 149                         continue;
 150                 }
 151                 if (must_refcnt){
 152                         must_refcnt = 0;
 153                         if (qeth_eddp_buf_ref_context(buf, ctx)){
 154                                 PRINT_WARN("no memory to create eddp context "
 155                                            "reference\n");
 156                                 goto out_check;
 157                         }
 158                 }
 159                 buffer = buf->buffer;
 160                 /* fill one skb into buffer */
 161                 for (i = 0; i < ctx->elements_per_skb; ++i){
 162                         if (ctx->elements[element].length != 0) {
 163                                 buffer->element[buf->next_element_to_fill].
 164                                 addr = ctx->elements[element].addr;
 165                                 buffer->element[buf->next_element_to_fill].
 166                                 length = ctx->elements[element].length;
 167                                 buffer->element[buf->next_element_to_fill].
 168                                 flags = ctx->elements[element].flags;
 169                                 buf->next_element_to_fill++;
 170                         }
 171                         element++;
 172                         elements--;
 173                 }
 174         }
 175 out_check:
 176         if (!queue->do_pack) {
 177                 QETH_DBF_TEXT(trace, 6, "fillbfnp");
 178                 /* set state to PRIMED -> will be flushed */
 179                 if (buf->next_element_to_fill > 0){
 180                         atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
 181                         flush_cnt++;
 182                 }
 183         } else {
 184                 if (queue->card->options.performance_stats)
 185                         queue->card->perf_stats.skbs_sent_pack++;
 186                 QETH_DBF_TEXT(trace, 6, "fillbfpa");
 187                 if (buf->next_element_to_fill >=
 188                                 QETH_MAX_BUFFER_ELEMENTS(queue->card)) {
 189                         /*
 190                          * packed buffer if full -> set state PRIMED
 191                          * -> will be flushed
 192                          */
 193                         atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
 194                         flush_cnt++;
 195                 }
 196         }
 197 out:
 198         return flush_cnt;
 199 }
 200
 201 static void
 202 qeth_eddp_create_segment_hdrs(struct qeth_eddp_context *ctx,
 203                               struct qeth_eddp_data *eddp, int data_len)
 204 {
 205         u8 *page;
 206         int page_remainder;
 207         int page_offset;
 208         int pkt_len;
 209         struct qeth_eddp_element *element;
 210
 211         QETH_DBF_TEXT(trace, 5, "eddpcrsh");
 212         page = ctx->pages[ctx->offset >> PAGE_SHIFT];
 213         page_offset = ctx->offset % PAGE_SIZE;
 214         element = &ctx->elements[ctx->num_elements];
 215         pkt_len = eddp->nhl + eddp->thl + data_len;
 216         /* FIXME: layer2 and VLAN !!! */
 217         if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2)
 218                 pkt_len += ETH_HLEN;
 219         if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
 220                 pkt_len += VLAN_HLEN;
 221         /* does complete packet fit in current page ? */
 222         page_remainder = PAGE_SIZE - page_offset;
 223         if (page_remainder < (sizeof(struct qeth_hdr) + pkt_len)){
 224                 /* no -> go to start of next page */
 225                 ctx->offset += page_remainder;
 226                 page = ctx->pages[ctx->offset >> PAGE_SHIFT];
 227                 page_offset = 0;
 228         }
 229         memcpy(page + page_offset, &eddp->qh, sizeof(struct qeth_hdr));
 230         element->addr = page + page_offset;
 231         element->length = sizeof(struct qeth_hdr);
 232         ctx->offset += sizeof(struct qeth_hdr);
 233         page_offset += sizeof(struct qeth_hdr);
 234         /* add mac header (?) */
 235         if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2){
 236                 memcpy(page + page_offset, &eddp->mac, ETH_HLEN);
 237                 element->length += ETH_HLEN;
 238                 ctx->offset += ETH_HLEN;
 239                 page_offset += ETH_HLEN;
 240         }
 241         /* add VLAN tag */
 242         if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q)){
 243                 memcpy(page + page_offset, &eddp->vlan, VLAN_HLEN);
 244                 element->length += VLAN_HLEN;
 245                 ctx->offset += VLAN_HLEN;
 246                 page_offset += VLAN_HLEN;
 247         }
 248         /* add network header */
 249         memcpy(page + page_offset, (u8 *)&eddp->nh, eddp->nhl);
 250         element->length += eddp->nhl;
 251         eddp->nh_in_ctx = page + page_offset;
 252         ctx->offset += eddp->nhl;
 253         page_offset += eddp->nhl;
 254         /* add transport header */
 255         memcpy(page + page_offset, (u8 *)&eddp->th, eddp->thl);
 256         element->length += eddp->thl;
 257         eddp->th_in_ctx = page + page_offset;
 258         ctx->offset += eddp->thl;
 259 }
 260
 261 static void
 262 qeth_eddp_copy_data_tcp(char *dst, struct qeth_eddp_data *eddp, int len,
 263                         __wsum *hcsum)
 264 {
 265         struct skb_frag_struct *frag;
 266         int left_in_frag;
 267         int copy_len;
 268         u8 *src;
 269
 270         QETH_DBF_TEXT(trace, 5, "eddpcdtc");
 271         if (skb_shinfo(eddp->skb)->nr_frags == 0) {
 272                 skb_copy_from_linear_data_offset(eddp->skb, eddp->skb_offset,
 273                                                  dst, len);
 274                 *hcsum = csum_partial(eddp->skb->data + eddp->skb_offset, len,
 275                                       *hcsum);
 276                 eddp->skb_offset += len;
 277         } else {
 278                 while (len > 0) {
 279                         if (eddp->frag < 0) {
 280                                 /* we're in skb->data */
 281                                 left_in_frag = (eddp->skb->len - eddp->skb->data_len)
 282                                                 - eddp->skb_offset;
 283                                 src = eddp->skb->data + eddp->skb_offset;
 284                         } else {
 285                                 frag = &skb_shinfo(eddp->skb)->
 286                                         frags[eddp->frag];
 287                                 left_in_frag = frag->size - eddp->frag_offset;
 288                                 src = (u8 *)(
 289                                         (page_to_pfn(frag->page) << PAGE_SHIFT)+
 290                                         frag->page_offset + eddp->frag_offset);
 291                         }
 292                         if (left_in_frag <= 0) {
 293                                 eddp->frag++;
 294                                 eddp->frag_offset = 0;
 295                                 continue;
 296                         }
 297                         copy_len = min(left_in_frag, len);
 298                         memcpy(dst, src, copy_len);
 299                         *hcsum = csum_partial(src, copy_len, *hcsum);
 300                         dst += copy_len;
 301                         eddp->frag_offset += copy_len;
 302                         eddp->skb_offset += copy_len;
 303                         len -= copy_len;
 304                 }
 305         }
 306 }
 307
 308 static void
 309 qeth_eddp_create_segment_data_tcp(struct qeth_eddp_context *ctx,
 310                                   struct qeth_eddp_data *eddp, int data_len,
 311                                   __wsum hcsum)
 312 {
 313         u8 *page;
 314         int page_remainder;
 315         int page_offset;
 316         struct qeth_eddp_element *element;
 317         int first_lap = 1;
 318
 319         QETH_DBF_TEXT(trace, 5, "eddpcsdt");
 320         page = ctx->pages[ctx->offset >> PAGE_SHIFT];
 321         page_offset = ctx->offset % PAGE_SIZE;
 322         element = &ctx->elements[ctx->num_elements];
 323         while (data_len){
 324                 page_remainder = PAGE_SIZE - page_offset;
 325                 if (page_remainder < data_len){
 326                         qeth_eddp_copy_data_tcp(page + page_offset, eddp,
 327                                                 page_remainder, &hcsum);
 328                         element->length += page_remainder;
 329                         if (first_lap)
 330                                 element->flags = SBAL_FLAGS_FIRST_FRAG;
 331                         else
 332                                 element->flags = SBAL_FLAGS_MIDDLE_FRAG;
 333                         ctx->num_elements++;
 334                         element++;
 335                         data_len -= page_remainder;
 336                         ctx->offset += page_remainder;
 337                         page = ctx->pages[ctx->offset >> PAGE_SHIFT];
 338                         page_offset = 0;
 339                         element->addr = page + page_offset;
 340                 } else {
 341                         qeth_eddp_copy_data_tcp(page + page_offset, eddp,
 342                                                 data_len, &hcsum);
 343                         element->length += data_len;
 344                         if (!first_lap)
 345                                 element->flags = SBAL_FLAGS_LAST_FRAG;
 346                         ctx->num_elements++;
 347                         ctx->offset += data_len;
 348                         data_len = 0;
 349                 }
 350                 first_lap = 0;
 351         }
 352         ((struct tcphdr *)eddp->th_in_ctx)->check = csum_fold(hcsum);
 353 }
 354
 355 static __wsum
 356 qeth_eddp_check_tcp4_hdr(struct qeth_eddp_data *eddp, int data_len)
 357 {
 358         __wsum phcsum; /* pseudo header checksum */
 359
 360         QETH_DBF_TEXT(trace, 5, "eddpckt4");
 361         eddp->th.tcp.h.check = 0;
 362         /* compute pseudo header checksum */
 363         phcsum = csum_tcpudp_nofold(eddp->nh.ip4.h.saddr, eddp->nh.ip4.h.daddr,
 364                                     eddp->thl + data_len, IPPROTO_TCP, 0);
 365         /* compute checksum of tcp header */
 366         return csum_partial((u8 *)&eddp->th, eddp->thl, phcsum);
 367 }
 368
 369 static __wsum
 370 qeth_eddp_check_tcp6_hdr(struct qeth_eddp_data *eddp, int data_len)
 371 {
 372         __be32 proto;
 373         __wsum phcsum; /* pseudo header checksum */
 374
 375         QETH_DBF_TEXT(trace, 5, "eddpckt6");
 376         eddp->th.tcp.h.check = 0;
 377         /* compute pseudo header checksum */
 378         phcsum = csum_partial((u8 *)&eddp->nh.ip6.h.saddr,
 379                               sizeof(struct in6_addr), 0);
 380         phcsum = csum_partial((u8 *)&eddp->nh.ip6.h.daddr,
 381                               sizeof(struct in6_addr), phcsum);
 382         proto = htonl(IPPROTO_TCP);
 383         phcsum = csum_partial((u8 *)&proto, sizeof(u32), phcsum);
 384         return phcsum;
 385 }
 386
 387 static struct qeth_eddp_data *
 388 qeth_eddp_create_eddp_data(struct qeth_hdr *qh, u8 *nh, u8 nhl, u8 *th, u8 thl)
 389 {
 390         struct qeth_eddp_data *eddp;
 391
 392         QETH_DBF_TEXT(trace, 5, "eddpcrda");
 393         eddp = kzalloc(sizeof(struct qeth_eddp_data), GFP_ATOMIC);
 394         if (eddp){
 395                 eddp->nhl = nhl;
 396                 eddp->thl = thl;
 397                 memcpy(&eddp->qh, qh, sizeof(struct qeth_hdr));
 398                 memcpy(&eddp->nh, nh, nhl);
 399                 memcpy(&eddp->th, th, thl);
 400                 eddp->frag = -1; /* initially we're in skb->data */
 401         }
 402         return eddp;
 403 }
 404
 405 static void
 406 __qeth_eddp_fill_context_tcp(struct qeth_eddp_context *ctx,
 407                              struct qeth_eddp_data *eddp)
 408 {
 409         struct tcphdr *tcph;
 410         int data_len;
 411         __wsum hcsum;
 412
 413         QETH_DBF_TEXT(trace, 5, "eddpftcp");
 414         eddp->skb_offset = sizeof(struct qeth_hdr) + eddp->nhl + eddp->thl;
 415        if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2) {
 416                eddp->skb_offset += sizeof(struct ethhdr);
 417 #ifdef CONFIG_QETH_VLAN
 418                if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
 419                        eddp->skb_offset += VLAN_HLEN;
 420 #endif /* CONFIG_QETH_VLAN */
 421        }
 422         tcph = tcp_hdr(eddp->skb);
 423         while (eddp->skb_offset < eddp->skb->len) {
 424                 data_len = min((int)skb_shinfo(eddp->skb)->gso_size,
 425                                (int)(eddp->skb->len - eddp->skb_offset));
 426                 /* prepare qdio hdr */
 427                 if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2){
 428                         eddp->qh.hdr.l2.pkt_length = data_len + ETH_HLEN +
 429                                                      eddp->nhl + eddp->thl;
 430 #ifdef CONFIG_QETH_VLAN
 431                         if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
 432                                 eddp->qh.hdr.l2.pkt_length += VLAN_HLEN;
 433 #endif /* CONFIG_QETH_VLAN */
 434                 } else
 435                         eddp->qh.hdr.l3.length = data_len + eddp->nhl +
 436                                                  eddp->thl;
 437                 /* prepare ip hdr */
 438                 if (eddp->skb->protocol == htons(ETH_P_IP)){
 439                         eddp->nh.ip4.h.tot_len = htons(data_len + eddp->nhl +
 440                                                  eddp->thl);
 441                         eddp->nh.ip4.h.check = 0;
 442                         eddp->nh.ip4.h.check =
 443                                 ip_fast_csum((u8 *)&eddp->nh.ip4.h,
 444                                                 eddp->nh.ip4.h.ihl);
 445                 } else
 446                         eddp->nh.ip6.h.payload_len = htons(data_len + eddp->thl);
 447                 /* prepare tcp hdr */
 448                 if (data_len == (eddp->skb->len - eddp->skb_offset)){
 449                         /* last segment -> set FIN and PSH flags */
 450                         eddp->th.tcp.h.fin = tcph->fin;
 451                         eddp->th.tcp.h.psh = tcph->psh;
 452                 }
 453                 if (eddp->skb->protocol == htons(ETH_P_IP))
 454                         hcsum = qeth_eddp_check_tcp4_hdr(eddp, data_len);
 455                 else
 456                         hcsum = qeth_eddp_check_tcp6_hdr(eddp, data_len);
 457                 /* fill the next segment into the context */
 458                 qeth_eddp_create_segment_hdrs(ctx, eddp, data_len);
 459                 qeth_eddp_create_segment_data_tcp(ctx, eddp, data_len, hcsum);
 460                 if (eddp->skb_offset >= eddp->skb->len)
 461                         break;
 462                 /* prepare headers for next round */
 463                 if (eddp->skb->protocol == htons(ETH_P_IP))
 464                         eddp->nh.ip4.h.id = htons(ntohs(eddp->nh.ip4.h.id) + 1);
 465                 eddp->th.tcp.h.seq = htonl(ntohl(eddp->th.tcp.h.seq) + data_len);
 466         }
 467 }
 468
 469 static int
 470 qeth_eddp_fill_context_tcp(struct qeth_eddp_context *ctx,
 471                            struct sk_buff *skb, struct qeth_hdr *qhdr)
 472 {
 473         struct qeth_eddp_data *eddp = NULL;
 474
 475         QETH_DBF_TEXT(trace, 5, "eddpficx");
 476         /* create our segmentation headers and copy original headers */
 477         if (skb->protocol == htons(ETH_P_IP))
 478                 eddp = qeth_eddp_create_eddp_data(qhdr,
 479                                                   skb_network_header(skb),
 480                                                   ip_hdrlen(skb),
 481                                                   skb_transport_header(skb),
 482                                                   tcp_hdrlen(skb));
 483         else
 484                 eddp = qeth_eddp_create_eddp_data(qhdr,
 485                                                   skb_network_header(skb),
 486                                                   sizeof(struct ipv6hdr),
 487                                                   skb_transport_header(skb),
 488                                                   tcp_hdrlen(skb));
 489
 490         if (eddp == NULL) {
 491                 QETH_DBF_TEXT(trace, 2, "eddpfcnm");
 492                 return -ENOMEM;
 493         }
 494         if (qhdr->hdr.l2.id == QETH_HEADER_TYPE_LAYER2) {
 495                 skb_set_mac_header(skb, sizeof(struct qeth_hdr));
 496                 memcpy(&eddp->mac, eth_hdr(skb), ETH_HLEN);
 497 #ifdef CONFIG_QETH_VLAN
 498                 if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q)) {
 499                         eddp->vlan[0] = skb->protocol;
 500                         eddp->vlan[1] = htons(vlan_tx_tag_get(skb));
 501                 }
 502 #endif /* CONFIG_QETH_VLAN */
 503         }
 504         /* the next flags will only be set on the last segment */
 505         eddp->th.tcp.h.fin = 0;
 506         eddp->th.tcp.h.psh = 0;
 507         eddp->skb = skb;
 508         /* begin segmentation and fill context */
 509         __qeth_eddp_fill_context_tcp(ctx, eddp);
 510         kfree(eddp);
 511         return 0;
 512 }
 513
 514 static void
 515 qeth_eddp_calc_num_pages(struct qeth_eddp_context *ctx, struct sk_buff *skb,
 516                          int hdr_len)
 517 {
 518         int skbs_per_page;
 519
 520         QETH_DBF_TEXT(trace, 5, "eddpcanp");
 521         /* can we put multiple skbs in one page? */
 522         skbs_per_page = PAGE_SIZE / (skb_shinfo(skb)->gso_size + hdr_len);
 523         if (skbs_per_page > 1){
 524                 ctx->num_pages = (skb_shinfo(skb)->gso_segs + 1) /
 525                                  skbs_per_page + 1;
 526                 ctx->elements_per_skb = 1;
 527         } else {
 528                 /* no -> how many elements per skb? */
 529                 ctx->elements_per_skb = (skb_shinfo(skb)->gso_size + hdr_len +
 530                                      PAGE_SIZE) >> PAGE_SHIFT;
 531                 ctx->num_pages = ctx->elements_per_skb *
 532                                  (skb_shinfo(skb)->gso_segs + 1);
 533         }
 534         ctx->num_elements = ctx->elements_per_skb *
 535                             (skb_shinfo(skb)->gso_segs + 1);
 536 }
 537
 538 static struct qeth_eddp_context *
 539 qeth_eddp_create_context_generic(struct qeth_card *card, struct sk_buff *skb,
 540                                  int hdr_len)
 541 {
 542         struct qeth_eddp_context *ctx = NULL;
 543         u8 *addr;
 544         int i;
 545
 546         QETH_DBF_TEXT(trace, 5, "creddpcg");
 547         /* create the context and allocate pages */
 548         ctx = kzalloc(sizeof(struct qeth_eddp_context), GFP_ATOMIC);
 549         if (ctx == NULL){
 550                 QETH_DBF_TEXT(trace, 2, "ceddpcn1");
 551                 return NULL;
 552         }
 553         ctx->type = QETH_LARGE_SEND_EDDP;
 554         qeth_eddp_calc_num_pages(ctx, skb, hdr_len);
 555         if (ctx->elements_per_skb > QETH_MAX_BUFFER_ELEMENTS(card)){
 556                 QETH_DBF_TEXT(trace, 2, "ceddpcis");
 557                 kfree(ctx);
 558                 return NULL;
 559         }
 560         ctx->pages = kcalloc(ctx->num_pages, sizeof(u8 *), GFP_ATOMIC);
 561         if (ctx->pages == NULL){
 562                 QETH_DBF_TEXT(trace, 2, "ceddpcn2");
 563                 kfree(ctx);
 564                 return NULL;
 565         }
 566         for (i = 0; i < ctx->num_pages; ++i){
 567                 addr = (u8 *)__get_free_page(GFP_ATOMIC);
 568                 if (addr == NULL){
 569                         QETH_DBF_TEXT(trace, 2, "ceddpcn3");
 570                         ctx->num_pages = i;
 571                         qeth_eddp_free_context(ctx);
 572                         return NULL;
 573                 }
 574                 memset(addr, 0, PAGE_SIZE);
 575                 ctx->pages[i] = addr;
 576         }
 577         ctx->elements = kcalloc(ctx->num_elements,
 578                                 sizeof(struct qeth_eddp_element), GFP_ATOMIC);
 579         if (ctx->elements == NULL){
 580                 QETH_DBF_TEXT(trace, 2, "ceddpcn4");
 581                 qeth_eddp_free_context(ctx);
 582                 return NULL;
 583         }
 584         /* reset num_elements; will be incremented again in fill_buffer to
 585          * reflect number of actually used elements */
 586         ctx->num_elements = 0;
 587         return ctx;
 588 }
 589
 590 static struct qeth_eddp_context *
 591 qeth_eddp_create_context_tcp(struct qeth_card *card, struct sk_buff *skb,
 592                              struct qeth_hdr *qhdr)
 593 {
 594         struct qeth_eddp_context *ctx = NULL;
 595
 596         QETH_DBF_TEXT(trace, 5, "creddpct");
 597         if (skb->protocol == htons(ETH_P_IP))
 598                 ctx = qeth_eddp_create_context_generic(card, skb,
 599                                                        (sizeof(struct qeth_hdr) +
 600                                                         ip_hdrlen(skb) +
 601                                                         tcp_hdrlen(skb)));
 602         else if (skb->protocol == htons(ETH_P_IPV6))
 603                 ctx = qeth_eddp_create_context_generic(card, skb,
 604                         sizeof(struct qeth_hdr) + sizeof(struct ipv6hdr) +
 605                         tcp_hdrlen(skb));
 606         else
 607                 QETH_DBF_TEXT(trace, 2, "cetcpinv");
 608
 609         if (ctx == NULL) {
 610                 QETH_DBF_TEXT(trace, 2, "creddpnl");
 611                 return NULL;
 612         }
 613         if (qeth_eddp_fill_context_tcp(ctx, skb, qhdr)){
 614                 QETH_DBF_TEXT(trace, 2, "ceddptfe");
 615                 qeth_eddp_free_context(ctx);
 616                 return NULL;
 617         }
 618         atomic_set(&ctx->refcnt, 1);
 619         return ctx;
 620 }
 621
 622 struct qeth_eddp_context *
 623 qeth_eddp_create_context(struct qeth_card *card, struct sk_buff *skb,
 624                          struct qeth_hdr *qhdr, unsigned char sk_protocol)
 625 {
 626         QETH_DBF_TEXT(trace, 5, "creddpc");
 627         switch (sk_protocol) {
 628         case IPPROTO_TCP:
 629                 return qeth_eddp_create_context_tcp(card, skb, qhdr);
 630         default:
 631                 QETH_DBF_TEXT(trace, 2, "eddpinvp");
 632         }
 633         return NULL;
 634 }