summaryrefslogtreecommitdiff
path: root/drivers/s390/net/qeth_eddp.c
blob: f94f1f25eec60a8e57ba9d311a90c47b2df58594 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
/*
 *
 * linux/drivers/s390/net/qeth_eddp.c ($Revision: 1.13 $)
 *
 * Enhanced Device Driver Packing (EDDP) support for the qeth driver.
 *
 * Copyright 2004 IBM Corporation
 *
 *    Author(s): Thomas Spatzier <tspat@de.ibm.com>
 *
 *    $Revision: 1.13 $	 $Date: 2005/05/04 20:19:18 $
 *
 */
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/ip.h>
#include <linux/inetdevice.h>
#include <linux/netdevice.h>
#include <linux/kernel.h>
#include <linux/tcp.h>
#include <net/tcp.h>
#include <linux/skbuff.h>

#include <net/ip.h>

#include "qeth.h"
#include "qeth_mpc.h"
#include "qeth_eddp.h"

int
qeth_eddp_check_buffers_for_context(struct qeth_qdio_out_q *queue,
				    struct qeth_eddp_context *ctx)
{
	int index = queue->next_buf_to_fill;
	int elements_needed = ctx->num_elements;
	int elements_in_buffer;
	int skbs_in_buffer;
	int buffers_needed = 0;

	QETH_DBF_TEXT(trace, 5, "eddpcbfc");
	while(elements_needed > 0) {
		buffers_needed++;
		if (atomic_read(&queue->bufs[index].state) !=
				QETH_QDIO_BUF_EMPTY)
			return -EBUSY;

		elements_in_buffer = QETH_MAX_BUFFER_ELEMENTS(queue->card) -
				     queue->bufs[index].next_element_to_fill;
		skbs_in_buffer = elements_in_buffer / ctx->elements_per_skb;
		elements_needed -= skbs_in_buffer * ctx->elements_per_skb;
		index = (index + 1) % QDIO_MAX_BUFFERS_PER_Q;
	}
	return buffers_needed;
}

static inline void
qeth_eddp_free_context(struct qeth_eddp_context *ctx)
{
	int i;

	QETH_DBF_TEXT(trace, 5, "eddpfctx");
	for (i = 0; i < ctx->num_pages; ++i)
		free_page((unsigned long)ctx->pages[i]);
	kfree(ctx->pages);
	if (ctx->elements != NULL)
		kfree(ctx->elements);
	kfree(ctx);
}


static inline void
qeth_eddp_get_context(struct qeth_eddp_context *ctx)
{
	atomic_inc(&ctx->refcnt);
}

void
qeth_eddp_put_context(struct qeth_eddp_context *ctx)
{
	if (atomic_dec_return(&ctx->refcnt) == 0)
		qeth_eddp_free_context(ctx);
}

void
qeth_eddp_buf_release_contexts(struct qeth_qdio_out_buffer *buf)
{
	struct qeth_eddp_context_reference *ref;
	
	QETH_DBF_TEXT(trace, 6, "eddprctx");
	while (!list_empty(&buf->ctx_list)){
		ref = list_entry(buf->ctx_list.next,
				 struct qeth_eddp_context_reference, list);
		qeth_eddp_put_context(ref->ctx);
		list_del(&ref->list);
		kfree(ref);
	}
}

static inline int
qeth_eddp_buf_ref_context(struct qeth_qdio_out_buffer *buf,
			  struct qeth_eddp_context *ctx)
{
	struct qeth_eddp_context_reference *ref;

	QETH_DBF_TEXT(trace, 6, "eddprfcx");
	ref = kmalloc(sizeof(struct qeth_eddp_context_reference), GFP_ATOMIC);
	if (ref == NULL)
		return -ENOMEM;
	qeth_eddp_get_context(ctx);
	ref->ctx = ctx;
	list_add_tail(&ref->list, &buf->ctx_list);
	return 0;
}

int
qeth_eddp_fill_buffer(struct qeth_qdio_out_q *queue,
		      struct qeth_eddp_context *ctx,
		      int index)
{
	struct qeth_qdio_out_buffer *buf = NULL;
	struct qdio_buffer *buffer;
	int elements = ctx->num_elements;
	int element = 0;
	int flush_cnt = 0;
	int must_refcnt = 1;
	int i;

	QETH_DBF_TEXT(trace, 5, "eddpfibu");
	while (elements > 0) {
		buf = &queue->bufs[index];
		if (atomic_read(&buf->state) != QETH_QDIO_BUF_EMPTY){
			/* normally this should not happen since we checked for
			 * available elements in qeth_check_elements_for_context
			 */
			if (element == 0)
				return -EBUSY;
			else {
				PRINT_WARN("could only partially fill eddp "
					   "buffer!\n");
				goto out;
			}
		}		
		/* check if the whole next skb fits into current buffer */
		if ((QETH_MAX_BUFFER_ELEMENTS(queue->card) -
					buf->next_element_to_fill)
				< ctx->elements_per_skb){
			/* no -> go to next buffer */
			atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
			index = (index + 1) % QDIO_MAX_BUFFERS_PER_Q;
			flush_cnt++;
			/* new buffer, so we have to add ctx to buffer'ctx_list
			 * and increment ctx's refcnt */
			must_refcnt = 1;
			continue;
		}	
		if (must_refcnt){
			must_refcnt = 0;
			if (qeth_eddp_buf_ref_context(buf, ctx)){
				PRINT_WARN("no memory to create eddp context "
					   "reference\n");
				goto out_check;
			}
		}
		buffer = buf->buffer;
		/* fill one skb into buffer */
		for (i = 0; i < ctx->elements_per_skb; ++i){
			buffer->element[buf->next_element_to_fill].addr =
				ctx->elements[element].addr;
			buffer->element[buf->next_element_to_fill].length =
				ctx->elements[element].length;
			buffer->element[buf->next_element_to_fill].flags =
				ctx->elements[element].flags;
			buf->next_element_to_fill++;
			element++;
			elements--;
		}
	}
out_check:
	if (!queue->do_pack) {
		QETH_DBF_TEXT(trace, 6, "fillbfnp");
		/* set state to PRIMED -> will be flushed */
		if (buf->next_element_to_fill > 0){
			atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
			flush_cnt++;
		}
	} else {
#ifdef CONFIG_QETH_PERF_STATS
		queue->card->perf_stats.skbs_sent_pack++;
#endif
		QETH_DBF_TEXT(trace, 6, "fillbfpa");
		if (buf->next_element_to_fill >=
				QETH_MAX_BUFFER_ELEMENTS(queue->card)) {
			/*
			 * packed buffer if full -> set state PRIMED
			 * -> will be flushed
			 */
			atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
			flush_cnt++;
		}
	}
out:
	return flush_cnt;
}

static inline void
qeth_eddp_create_segment_hdrs(struct qeth_eddp_context *ctx,
			      struct qeth_eddp_data *eddp, int data_len)
{
	u8 *page;
	int page_remainder;
	int page_offset;
	int pkt_len;
	struct qeth_eddp_element *element;

	QETH_DBF_TEXT(trace, 5, "eddpcrsh");
	page = ctx->pages[ctx->offset >> PAGE_SHIFT];
	page_offset = ctx->offset % PAGE_SIZE;
	element = &ctx->elements[ctx->num_elements];
	pkt_len = eddp->nhl + eddp->thl + data_len;
	/* FIXME: layer2 and VLAN !!! */
	if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2)
		pkt_len += ETH_HLEN;
	if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
		pkt_len += VLAN_HLEN;
	/* does complete packet fit in current page ? */
	page_remainder = PAGE_SIZE - page_offset;
	if (page_remainder < (sizeof(struct qeth_hdr) + pkt_len)){
		/* no -> go to start of next page */
		ctx->offset += page_remainder;
		page = ctx->pages[ctx->offset >> PAGE_SHIFT];
		page_offset = 0;
	}
	memcpy(page + page_offset, &eddp->qh, sizeof(struct qeth_hdr));
	element->addr = page + page_offset;
	element->length = sizeof(struct qeth_hdr);
	ctx->offset += sizeof(struct qeth_hdr);
	page_offset += sizeof(struct qeth_hdr);
	/* add mac header (?) */
	if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2){
		memcpy(page + page_offset, &eddp->mac, ETH_HLEN);
		element->length += ETH_HLEN;
		ctx->offset += ETH_HLEN;
		page_offset += ETH_HLEN;
	}
	/* add VLAN tag */
	if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q)){
		memcpy(page + page_offset, &eddp->vlan, VLAN_HLEN);
		element->length += VLAN_HLEN;
		ctx->offset += VLAN_HLEN;
		page_offset += VLAN_HLEN;
	}
	/* add network header */
	memcpy(page + page_offset, (u8 *)&eddp->nh, eddp->nhl);
	element->length += eddp->nhl;
	eddp->nh_in_ctx = page + page_offset;
	ctx->offset += eddp->nhl;
	page_offset += eddp->nhl;
	/* add transport header */
	memcpy(page + page_offset, (u8 *)&eddp->th, eddp->thl);
	element->length += eddp->thl;
	eddp->th_in_ctx = page + page_offset;
	ctx->offset += eddp->thl;
}

static inline void
qeth_eddp_copy_data_tcp(char *dst, struct qeth_eddp_data *eddp, int len,
			u32 *hcsum)
{
	struct skb_frag_struct *frag;
	int left_in_frag;
	int copy_len;
	u8 *src;
	
	QETH_DBF_TEXT(trace, 5, "eddpcdtc");
	if (skb_shinfo(eddp->skb)->nr_frags == 0) {
		memcpy(dst, eddp->skb->data + eddp->skb_offset, len);
		*hcsum = csum_partial(eddp->skb->data + eddp->skb_offset, len,
				      *hcsum);
		eddp->skb_offset += len;
	} else {
		while (len > 0) {
			if (eddp->frag < 0) {
				/* we're in skb->data */
				left_in_frag = (eddp->skb->len - eddp->skb->data_len)
						- eddp->skb_offset;
				src = eddp->skb->data + eddp->skb_offset;
			} else {
				frag = &skb_shinfo(eddp->skb)->
					frags[eddp->frag];
				left_in_frag = frag->size - eddp->frag_offset;
				src = (u8 *)(
					(page_to_pfn(frag->page) << PAGE_SHIFT)+
					frag->page_offset + eddp->frag_offset);
			}
			if (left_in_frag <= 0) {
				eddp->frag++;
				eddp->frag_offset = 0;
				continue;
			}
			copy_len = min(left_in_frag, len);
			memcpy(dst, src, copy_len);
			*hcsum = csum_partial(src, copy_len, *hcsum);
			dst += copy_len;
			eddp->frag_offset += copy_len;
			eddp->skb_offset += copy_len;
			len -= copy_len;
		}
	}
}

static inline void
qeth_eddp_create_segment_data_tcp(struct qeth_eddp_context *ctx,
				  struct qeth_eddp_data *eddp, int data_len,
				  u32 hcsum)
{
	u8 *page;
	int page_remainder;
	int page_offset;
	struct qeth_eddp_element *element;
	int first_lap = 1;

	QETH_DBF_TEXT(trace, 5, "eddpcsdt");
	page = ctx->pages[ctx->offset >> PAGE_SHIFT];
	page_offset = ctx->offset % PAGE_SIZE;
	element = &ctx->elements[ctx->num_elements];
	while (data_len){
		page_remainder = PAGE_SIZE - page_offset;
		if (page_remainder < data_len){
			qeth_eddp_copy_data_tcp(page + page_offset, eddp,
						page_remainder, &hcsum);
			element->length += page_remainder;
			if (first_lap)
				element->flags = SBAL_FLAGS_FIRST_FRAG;
			else
				element->flags = SBAL_FLAGS_MIDDLE_FRAG;
			ctx->num_elements++;
			element++;
			data_len -= page_remainder;
			ctx->offset += page_remainder;
			page = ctx->pages[ctx->offset >> PAGE_SHIFT];
			page_offset = 0;
			element->addr = page + page_offset;
		} else {
			qeth_eddp_copy_data_tcp(page + page_offset, eddp,
						data_len, &hcsum);
			element->length += data_len;
			if (!first_lap)
				element->flags = SBAL_FLAGS_LAST_FRAG;
			ctx->num_elements++;
			ctx->offset += data_len;
			data_len = 0;
		}
		first_lap = 0;
	}
	((struct tcphdr *)eddp->th_in_ctx)->check = csum_fold(hcsum);
}

static inline u32
qeth_eddp_check_tcp4_hdr(struct qeth_eddp_data *eddp, int data_len)
{
	u32 phcsum; /* pseudo header checksum */

	QETH_DBF_TEXT(trace, 5, "eddpckt4");
	eddp->th.tcp.h.check = 0;
	/* compute pseudo header checksum */
	phcsum = csum_tcpudp_nofold(eddp->nh.ip4.h.saddr, eddp->nh.ip4.h.daddr,
				    eddp->thl + data_len, IPPROTO_TCP, 0);
	/* compute checksum of tcp header */
	return csum_partial((u8 *)&eddp->th, eddp->thl, phcsum);
}

static inline u32
qeth_eddp_check_tcp6_hdr(struct qeth_eddp_data *eddp, int data_len)
{
	u32 proto;
	u32 phcsum; /* pseudo header checksum */

	QETH_DBF_TEXT(trace, 5, "eddpckt6");
	eddp->th.tcp.h.check = 0;
	/* compute pseudo header checksum */
	phcsum = csum_partial((u8 *)&eddp->nh.ip6.h.saddr,
			      sizeof(struct in6_addr), 0);
	phcsum = csum_partial((u8 *)&eddp->nh.ip6.h.daddr,
			      sizeof(struct in6_addr), phcsum);
	proto = htonl(IPPROTO_TCP);
	phcsum = csum_partial((u8 *)&proto, sizeof(u32), phcsum);
	return phcsum;
}

static inline struct qeth_eddp_data *
qeth_eddp_create_eddp_data(struct qeth_hdr *qh, u8 *nh, u8 nhl, u8 *th, u8 thl)
{
	struct qeth_eddp_data *eddp;

	QETH_DBF_TEXT(trace, 5, "eddpcrda");
	eddp = kmalloc(sizeof(struct qeth_eddp_data), GFP_ATOMIC);
	if (eddp){
		memset(eddp, 0, sizeof(struct qeth_eddp_data));
		eddp->nhl = nhl;
		eddp->thl = thl;
		memcpy(&eddp->qh, qh, sizeof(struct qeth_hdr));
		memcpy(&eddp->nh, nh, nhl);
		memcpy(&eddp->th, th, thl);
		eddp->frag = -1; /* initially we're in skb->data */
	}
	return eddp;
}

static inline void
__qeth_eddp_fill_context_tcp(struct qeth_eddp_context *ctx,
			     struct qeth_eddp_data *eddp)
{
	struct tcphdr *tcph;
	int data_len;
	u32 hcsum;
	
	QETH_DBF_TEXT(trace, 5, "eddpftcp");
	eddp->skb_offset = sizeof(struct qeth_hdr) + eddp->nhl + eddp->thl;
	tcph = eddp->skb->h.th;
	while (eddp->skb_offset < eddp->skb->len) {
		data_len = min((int)skb_shinfo(eddp->skb)->tso_size,
			       (int)(eddp->skb->len - eddp->skb_offset));
		/* prepare qdio hdr */
		if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2){
			eddp->qh.hdr.l2.pkt_length = data_len + ETH_HLEN +
						     eddp->nhl + eddp->thl -
						     sizeof(struct qeth_hdr);
#ifdef CONFIG_QETH_VLAN
			if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
				eddp->qh.hdr.l2.pkt_length += VLAN_HLEN;
#endif /* CONFIG_QETH_VLAN */
		} else
			eddp->qh.hdr.l3.length = data_len + eddp->nhl +
						 eddp->thl;
		/* prepare ip hdr */
		if (eddp->skb->protocol == ETH_P_IP){
			eddp->nh.ip4.h.tot_len = data_len + eddp->nhl +
						 eddp->thl;
			eddp->nh.ip4.h.check = 0;
			eddp->nh.ip4.h.check =
				ip_fast_csum((u8 *)&eddp->nh.ip4.h,
						eddp->nh.ip4.h.ihl);
		} else
			eddp->nh.ip6.h.payload_len = data_len + eddp->thl;
		/* prepare tcp hdr */
		if (data_len == (eddp->skb->len - eddp->skb_offset)){
			/* last segment -> set FIN and PSH flags */
			eddp->th.tcp.h.fin = tcph->fin;
			eddp->th.tcp.h.psh = tcph->psh;
		}
		if (eddp->skb->protocol == ETH_P_IP)
			hcsum = qeth_eddp_check_tcp4_hdr(eddp, data_len);
		else
			hcsum = qeth_eddp_check_tcp6_hdr(eddp, data_len);
		/* fill the next segment into the context */
		qeth_eddp_create_segment_hdrs(ctx, eddp, data_len);
		qeth_eddp_create_segment_data_tcp(ctx, eddp, data_len, hcsum);
		if (eddp->skb_offset >= eddp->skb->len)
			break;
		/* prepare headers for next round */
		if (eddp->skb->protocol == ETH_P_IP)
			eddp->nh.ip4.h.id++;
		eddp->th.tcp.h.seq += data_len;
	}
}
			   
static inline int
qeth_eddp_fill_context_tcp(struct qeth_eddp_context *ctx,
			   struct sk_buff *skb, struct qeth_hdr *qhdr)
{
	struct qeth_eddp_data *eddp = NULL;
	
	QETH_DBF_TEXT(trace, 5, "eddpficx");
	/* create our segmentation headers and copy original headers */
	if (skb->protocol == ETH_P_IP)
		eddp = qeth_eddp_create_eddp_data(qhdr, (u8 *)skb->nh.iph,
				skb->nh.iph->ihl*4,
				(u8 *)skb->h.th, skb->h.th->doff*4);
	else
		eddp = qeth_eddp_create_eddp_data(qhdr, (u8 *)skb->nh.ipv6h,
				sizeof(struct ipv6hdr),
				(u8 *)skb->h.th, skb->h.th->doff*4);

	if (eddp == NULL) {
		QETH_DBF_TEXT(trace, 2, "eddpfcnm");
		return -ENOMEM;
	}
	if (qhdr->hdr.l2.id == QETH_HEADER_TYPE_LAYER2) {
		memcpy(&eddp->mac, eth_hdr(skb), ETH_HLEN);
#ifdef CONFIG_QETH_VLAN
		if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q)) {
			eddp->vlan[0] = __constant_htons(skb->protocol);
			eddp->vlan[1] = htons(vlan_tx_tag_get(skb));
		}
#endif /* CONFIG_QETH_VLAN */
	}
	/* the next flags will only be set on the last segment */
	eddp->th.tcp.h.fin = 0;
	eddp->th.tcp.h.psh = 0;
	eddp->skb = skb;
	/* begin segmentation and fill context */
	__qeth_eddp_fill_context_tcp(ctx, eddp);
	kfree(eddp);
	return 0;
}

static inline void
qeth_eddp_calc_num_pages(struct qeth_eddp_context *ctx, struct sk_buff *skb,
			 int hdr_len)
{
	int skbs_per_page;
	
	QETH_DBF_TEXT(trace, 5, "eddpcanp");
	/* can we put multiple skbs in one page? */
	skbs_per_page = PAGE_SIZE / (skb_shinfo(skb)->tso_size + hdr_len);
	if (skbs_per_page > 1){
		ctx->num_pages = (skb_shinfo(skb)->tso_segs + 1) /
				 skbs_per_page + 1;
		ctx->elements_per_skb = 1;
	} else {
		/* no -> how many elements per skb? */
		ctx->elements_per_skb = (skb_shinfo(skb)->tso_size + hdr_len +
				     PAGE_SIZE) >> PAGE_SHIFT;
		ctx->num_pages = ctx->elements_per_skb *
				 (skb_shinfo(skb)->tso_segs + 1);
	}
	ctx->num_elements = ctx->elements_per_skb *
			    (skb_shinfo(skb)->tso_segs + 1);
}

static inline struct qeth_eddp_context *
qeth_eddp_create_context_generic(struct qeth_card *card, struct sk_buff *skb,
				 int hdr_len)
{
	struct qeth_eddp_context *ctx = NULL;
	u8 *addr;
	int i;

	QETH_DBF_TEXT(trace, 5, "creddpcg");
	/* create the context and allocate pages */
	ctx = kmalloc(sizeof(struct qeth_eddp_context), GFP_ATOMIC);
	if (ctx == NULL){
		QETH_DBF_TEXT(trace, 2, "ceddpcn1");
		return NULL;
	}
	memset(ctx, 0, sizeof(struct qeth_eddp_context));
	ctx->type = QETH_LARGE_SEND_EDDP;
	qeth_eddp_calc_num_pages(ctx, skb, hdr_len);
	if (ctx->elements_per_skb > QETH_MAX_BUFFER_ELEMENTS(card)){
		QETH_DBF_TEXT(trace, 2, "ceddpcis");
		kfree(ctx);
		return NULL;
	}
	ctx->pages = kmalloc(ctx->num_pages * sizeof(u8 *), GFP_ATOMIC);
	if (ctx->pages == NULL){
		QETH_DBF_TEXT(trace, 2, "ceddpcn2");
		kfree(ctx);
		return NULL;
	}
	memset(ctx->pages, 0, ctx->num_pages * sizeof(u8 *));
	for (i = 0; i < ctx->num_pages; ++i){
		addr = (u8 *)__get_free_page(GFP_ATOMIC);
		if (addr == NULL){
			QETH_DBF_TEXT(trace, 2, "ceddpcn3");
			ctx->num_pages = i;
			qeth_eddp_free_context(ctx);
			return NULL;
		}
		memset(addr, 0, PAGE_SIZE);
		ctx->pages[i] = addr;
	}
	ctx->elements = kmalloc(ctx->num_elements *
				sizeof(struct qeth_eddp_element), GFP_ATOMIC);
	if (ctx->elements == NULL){
		QETH_DBF_TEXT(trace, 2, "ceddpcn4");
		qeth_eddp_free_context(ctx);
		return NULL;
	}
	memset(ctx->elements, 0,
	       ctx->num_elements * sizeof(struct qeth_eddp_element));
	/* reset num_elements; will be incremented again in fill_buffer to
	 * reflect number of actually used elements */
	ctx->num_elements = 0;
	return ctx;
}

static inline struct qeth_eddp_context *
qeth_eddp_create_context_tcp(struct qeth_card *card, struct sk_buff *skb,
			     struct qeth_hdr *qhdr)
{
	struct qeth_eddp_context *ctx = NULL;
	
	QETH_DBF_TEXT(trace, 5, "creddpct");
	if (skb->protocol == ETH_P_IP)
		ctx = qeth_eddp_create_context_generic(card, skb,
			sizeof(struct qeth_hdr) + skb->nh.iph->ihl*4 +
			skb->h.th->doff*4);
	else if (skb->protocol == ETH_P_IPV6)
		ctx = qeth_eddp_create_context_generic(card, skb,
			sizeof(struct qeth_hdr) + sizeof(struct ipv6hdr) +
			skb->h.th->doff*4);
	else
		QETH_DBF_TEXT(trace, 2, "cetcpinv");

	if (ctx == NULL) {
		QETH_DBF_TEXT(trace, 2, "creddpnl");
		return NULL;
	}
	if (qeth_eddp_fill_context_tcp(ctx, skb, qhdr)){
		QETH_DBF_TEXT(trace, 2, "ceddptfe");
		qeth_eddp_free_context(ctx);
		return NULL;
	}
	atomic_set(&ctx->refcnt, 1);
	return ctx;
}

struct qeth_eddp_context *
qeth_eddp_create_context(struct qeth_card *card, struct sk_buff *skb,
			 struct qeth_hdr *qhdr)
{
	QETH_DBF_TEXT(trace, 5, "creddpc");
	switch (skb->sk->sk_protocol){
	case IPPROTO_TCP:
		return qeth_eddp_create_context_tcp(card, skb, qhdr);
	default:
		QETH_DBF_TEXT(trace, 2, "eddpinvp");
	}
	return NULL;
}