drivers/s390/net/qeth_eddp.c - kernel/msm-4.19 - Gitiles

 /*
  * linux/drivers/s390/net/qeth_eddp.c
  *
  * Enhanced Device Driver Packing (EDDP) support for the qeth driver.
  *
  * Copyright 2004 IBM Corporation
  *
  *    Author(s): Thomas Spatzier <tspat@de.ibm.com>
  *
  */
 #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);
 	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;
        if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2) {
                eddp->skb_offset += sizeof(struct ethhdr);
 #ifdef CONFIG_QETH_VLAN
                if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
                        eddp->skb_offset += VLAN_HLEN;
 #endif /* CONFIG_QETH_VLAN */
        }
 	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) {
 		skb->mac.raw = (skb->data) + sizeof(struct qeth_hdr);
 		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;
 }
	/*
	* linux/drivers/s390/net/qeth_eddp.c
	*
	* Enhanced Device Driver Packing (EDDP) support for the qeth driver.
	*
	* Copyright 2004 IBM Corporation
	*
	* Author(s): Thomas Spatzier <tspat@de.ibm.com>
	*
	*/
	#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);
	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;
	if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2) {
	eddp->skb_offset += sizeof(struct ethhdr);
	#ifdef CONFIG_QETH_VLAN
	if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
	eddp->skb_offset += VLAN_HLEN;
	#endif /* CONFIG_QETH_VLAN */
	}
	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->doff4);
	else
	eddp = qeth_eddp_create_eddp_data(qhdr, (u8 *)skb->nh.ipv6h,
	sizeof(struct ipv6hdr),
	(u8 )skb->h.th, skb->h.th->doff4);

	if (eddp == NULL) {
	QETH_DBF_TEXT(trace, 2, "eddpfcnm");
	return -ENOMEM;
	}
	if (qhdr->hdr.l2.id == QETH_HEADER_TYPE_LAYER2) {
	skb->mac.raw = (skb->data) + sizeof(struct qeth_hdr);
	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;
	}