[deliverable/linux.git] / drivers / s390 / net / qeth_eddp.c

/*
 *
 * 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);
	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;
}
Commit	Line	Data
1da177e4 LT	1	/*
1da177e4 LT	2	*
05e08a2a	3	* linux/drivers/s390/net/qeth_eddp.c ($Revision: 1.13 $)
1da177e4 LT	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	*
05e08a2a	11	* $Revision: 1.13 $ $Date: 2005/05/04 20:19:18 $
1da177e4 LT	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);
17fd682e	65	kfree(ctx->elements);
1da177e4 LT	66	kfree(ctx);
	67	}
	68
	69
	70	static inline void
	71	qeth_eddp_get_context(struct qeth_eddp_context *ctx)
	72	{
	73	atomic_inc(&ctx->refcnt);
	74	}
	75
	76	void
	77	qeth_eddp_put_context(struct qeth_eddp_context *ctx)
	78	{
	79	if (atomic_dec_return(&ctx->refcnt) == 0)
	80	qeth_eddp_free_context(ctx);
	81	}
	82
	83	void
	84	qeth_eddp_buf_release_contexts(struct qeth_qdio_out_buffer *buf)
	85	{
	86	struct qeth_eddp_context_reference *ref;
05e08a2a	87
1da177e4 LT	88	QETH_DBF_TEXT(trace, 6, "eddprctx");
	89	while (!list_empty(&buf->ctx_list)){
	90	ref = list_entry(buf->ctx_list.next,
	91	struct qeth_eddp_context_reference, list);
	92	qeth_eddp_put_context(ref->ctx);
	93	list_del(&ref->list);
	94	kfree(ref);
	95	}
	96	}
	97
	98	static inline int
	99	qeth_eddp_buf_ref_context(struct qeth_qdio_out_buffer *buf,
	100	struct qeth_eddp_context *ctx)
	101	{
	102	struct qeth_eddp_context_reference *ref;
	103
	104	QETH_DBF_TEXT(trace, 6, "eddprfcx");
	105	ref = kmalloc(sizeof(struct qeth_eddp_context_reference), GFP_ATOMIC);
	106	if (ref == NULL)
	107	return -ENOMEM;
	108	qeth_eddp_get_context(ctx);
	109	ref->ctx = ctx;
	110	list_add_tail(&ref->list, &buf->ctx_list);
	111	return 0;
	112	}
	113
	114	int
	115	qeth_eddp_fill_buffer(struct qeth_qdio_out_q *queue,
	116	struct qeth_eddp_context *ctx,
	117	int index)
	118	{
	119	struct qeth_qdio_out_buffer *buf = NULL;
	120	struct qdio_buffer *buffer;
	121	int elements = ctx->num_elements;
	122	int element = 0;
	123	int flush_cnt = 0;
	124	int must_refcnt = 1;
	125	int i;
	126
	127	QETH_DBF_TEXT(trace, 5, "eddpfibu");
	128	while (elements > 0) {
	129	buf = &queue->bufs[index];
	130	if (atomic_read(&buf->state) != QETH_QDIO_BUF_EMPTY){
	131	/* normally this should not happen since we checked for
	132	* available elements in qeth_check_elements_for_context
	133	*/
	134	if (element == 0)
	135	return -EBUSY;
	136	else {
	137	PRINT_WARN("could only partially fill eddp "
	138	"buffer!\n");
	139	goto out;
	140	}
05e08a2a	141	}
1da177e4 LT	142	/* check if the whole next skb fits into current buffer */
	143	if ((QETH_MAX_BUFFER_ELEMENTS(queue->card) -
	144	buf->next_element_to_fill)
	145	< ctx->elements_per_skb){
	146	/* no -> go to next buffer */
	147	atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
	148	index = (index + 1) % QDIO_MAX_BUFFERS_PER_Q;
	149	flush_cnt++;
	150	/* new buffer, so we have to add ctx to buffer'ctx_list
	151	* and increment ctx's refcnt */
	152	must_refcnt = 1;
	153	continue;
05e08a2a	154	}
1da177e4 LT	155	if (must_refcnt){
	156	must_refcnt = 0;
	157	if (qeth_eddp_buf_ref_context(buf, ctx)){
	158	PRINT_WARN("no memory to create eddp context "
	159	"reference\n");
	160	goto out_check;
	161	}
	162	}
	163	buffer = buf->buffer;
	164	/* fill one skb into buffer */
	165	for (i = 0; i < ctx->elements_per_skb; ++i){
	166	buffer->element[buf->next_element_to_fill].addr =
	167	ctx->elements[element].addr;
	168	buffer->element[buf->next_element_to_fill].length =
	169	ctx->elements[element].length;
	170	buffer->element[buf->next_element_to_fill].flags =
	171	ctx->elements[element].flags;
	172	buf->next_element_to_fill++;
	173	element++;
	174	elements--;
	175	}
	176	}
	177	out_check:
	178	if (!queue->do_pack) {
	179	QETH_DBF_TEXT(trace, 6, "fillbfnp");
	180	/* set state to PRIMED -> will be flushed */
	181	if (buf->next_element_to_fill > 0){
	182	atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
	183	flush_cnt++;
	184	}
	185	} else {
	186	#ifdef CONFIG_QETH_PERF_STATS
	187	queue->card->perf_stats.skbs_sent_pack++;
	188	#endif
	189	QETH_DBF_TEXT(trace, 6, "fillbfpa");
	190	if (buf->next_element_to_fill >=
	191	QETH_MAX_BUFFER_ELEMENTS(queue->card)) {
	192	/*
	193	* packed buffer if full -> set state PRIMED
	194	* -> will be flushed
	195	*/
	196	atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
	197	flush_cnt++;
	198	}
	199	}
	200	out:
	201	return flush_cnt;
	202	}
	203
1da177e4 LT	204	static inline void
1da177e4 LT	205	qeth_eddp_create_segment_hdrs(struct qeth_eddp_context *ctx,
05e08a2a	206	struct qeth_eddp_data *eddp, int data_len)
1da177e4 LT	207	{
	208	u8 *page;
	209	int page_remainder;
	210	int page_offset;
05e08a2a	211	int pkt_len;
1da177e4 LT	212	struct qeth_eddp_element *element;
	213
	214	QETH_DBF_TEXT(trace, 5, "eddpcrsh");
	215	page = ctx->pages[ctx->offset >> PAGE_SHIFT];
	216	page_offset = ctx->offset % PAGE_SIZE;
	217	element = &ctx->elements[ctx->num_elements];
05e08a2a	218	pkt_len = eddp->nhl + eddp->thl + data_len;
1da177e4 LT	219	/* FIXME: layer2 and VLAN !!! */
1da177e4 LT	220	if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2)
05e08a2a	221	pkt_len += ETH_HLEN;
1da177e4	222	if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
05e08a2a FP	223	pkt_len += VLAN_HLEN;
05e08a2a FP	224	/* does complete packet fit in current page ? */
1da177e4	225	page_remainder = PAGE_SIZE - page_offset;
05e08a2a	226	if (page_remainder < (sizeof(struct qeth_hdr) + pkt_len)){
1da177e4 LT	227	/* no -> go to start of next page */
	228	ctx->offset += page_remainder;
	229	page = ctx->pages[ctx->offset >> PAGE_SHIFT];
	230	page_offset = 0;
	231	}
	232	memcpy(page + page_offset, &eddp->qh, sizeof(struct qeth_hdr));
	233	element->addr = page + page_offset;
	234	element->length = sizeof(struct qeth_hdr);
	235	ctx->offset += sizeof(struct qeth_hdr);
	236	page_offset += sizeof(struct qeth_hdr);
	237	/* add mac header (?) */
	238	if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2){
	239	memcpy(page + page_offset, &eddp->mac, ETH_HLEN);
	240	element->length += ETH_HLEN;
	241	ctx->offset += ETH_HLEN;
	242	page_offset += ETH_HLEN;
	243	}
	244	/* add VLAN tag */
	245	if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q)){
	246	memcpy(page + page_offset, &eddp->vlan, VLAN_HLEN);
	247	element->length += VLAN_HLEN;
	248	ctx->offset += VLAN_HLEN;
	249	page_offset += VLAN_HLEN;
	250	}
	251	/* add network header */
	252	memcpy(page + page_offset, (u8 *)&eddp->nh, eddp->nhl);
	253	element->length += eddp->nhl;
	254	eddp->nh_in_ctx = page + page_offset;
	255	ctx->offset += eddp->nhl;
	256	page_offset += eddp->nhl;
	257	/* add transport header */
	258	memcpy(page + page_offset, (u8 *)&eddp->th, eddp->thl);
	259	element->length += eddp->thl;
	260	eddp->th_in_ctx = page + page_offset;
	261	ctx->offset += eddp->thl;
	262	}
	263
	264	static inline void
	265	qeth_eddp_copy_data_tcp(char dst, struct qeth_eddp_data eddp, int len,
	266	u32 *hcsum)
	267	{
	268	struct skb_frag_struct *frag;
	269	int left_in_frag;
	270	int copy_len;
	271	u8 *src;
05e08a2a	272
1da177e4 LT	273	QETH_DBF_TEXT(trace, 5, "eddpcdtc");
	274	if (skb_shinfo(eddp->skb)->nr_frags == 0) {
	275	memcpy(dst, eddp->skb->data + eddp->skb_offset, len);
	276	*hcsum = csum_partial(eddp->skb->data + eddp->skb_offset, len,
	277	*hcsum);
	278	eddp->skb_offset += len;
	279	} else {
	280	while (len > 0) {
	281	if (eddp->frag < 0) {
	282	/* we're in skb->data */
05e08a2a	283	left_in_frag = (eddp->skb->len - eddp->skb->data_len)
1da177e4 LT	284	- eddp->skb_offset;
	285	src = eddp->skb->data + eddp->skb_offset;
	286	} else {
	287	frag = &skb_shinfo(eddp->skb)->
	288	frags[eddp->frag];
	289	left_in_frag = frag->size - eddp->frag_offset;
	290	src = (u8 *)(
	291	(page_to_pfn(frag->page) << PAGE_SHIFT)+
	292	frag->page_offset + eddp->frag_offset);
	293	}
	294	if (left_in_frag <= 0) {
	295	eddp->frag++;
	296	eddp->frag_offset = 0;
	297	continue;
	298	}
	299	copy_len = min(left_in_frag, len);
	300	memcpy(dst, src, copy_len);
	301	hcsum = csum_partial(src, copy_len, hcsum);
	302	dst += copy_len;
	303	eddp->frag_offset += copy_len;
	304	eddp->skb_offset += copy_len;
	305	len -= copy_len;
	306	}
	307	}
	308	}
	309
	310	static inline void
	311	qeth_eddp_create_segment_data_tcp(struct qeth_eddp_context *ctx,
	312	struct qeth_eddp_data *eddp, int data_len,
	313	u32 hcsum)
	314	{
	315	u8 *page;
	316	int page_remainder;
	317	int page_offset;
	318	struct qeth_eddp_element *element;
	319	int first_lap = 1;
	320
	321	QETH_DBF_TEXT(trace, 5, "eddpcsdt");
	322	page = ctx->pages[ctx->offset >> PAGE_SHIFT];
	323	page_offset = ctx->offset % PAGE_SIZE;
	324	element = &ctx->elements[ctx->num_elements];
	325	while (data_len){
	326	page_remainder = PAGE_SIZE - page_offset;
	327	if (page_remainder < data_len){
	328	qeth_eddp_copy_data_tcp(page + page_offset, eddp,
	329	page_remainder, &hcsum);
	330	element->length += page_remainder;
	331	if (first_lap)
	332	element->flags = SBAL_FLAGS_FIRST_FRAG;
	333	else
	334	element->flags = SBAL_FLAGS_MIDDLE_FRAG;
	335	ctx->num_elements++;
	336	element++;
	337	data_len -= page_remainder;
	338	ctx->offset += page_remainder;
	339	page = ctx->pages[ctx->offset >> PAGE_SHIFT];
	340	page_offset = 0;
	341	element->addr = page + page_offset;
	342	} else {
	343	qeth_eddp_copy_data_tcp(page + page_offset, eddp,
	344	data_len, &hcsum);
	345	element->length += data_len;
	346	if (!first_lap)
	347	element->flags = SBAL_FLAGS_LAST_FRAG;
348	ctx->num_elements++;
349	ctx->offset += data_len;
350	data_len = 0;
351	}
352	first_lap = 0;
353	}
354	((struct tcphdr *)eddp->th_in_ctx)->check = csum_fold(hcsum);
355	}
356
357	static inline u32
358	qeth_eddp_check_tcp4_hdr(struct qeth_eddp_data *eddp, int data_len)
359	{
360	u32 phcsum; /* pseudo header checksum */
361
362	QETH_DBF_TEXT(trace, 5, "eddpckt4");
363	eddp->th.tcp.h.check = 0;
364	/* compute pseudo header checksum */
365	phcsum = csum_tcpudp_nofold(eddp->nh.ip4.h.saddr, eddp->nh.ip4.h.daddr,
366	eddp->thl + data_len, IPPROTO_TCP, 0);
367	/* compute checksum of tcp header */
368	return csum_partial((u8 *)&eddp->th, eddp->thl, phcsum);
369	}
370
371	static inline u32
372	qeth_eddp_check_tcp6_hdr(struct qeth_eddp_data *eddp, int data_len)
373	{
374	u32 proto;
375	u32 phcsum; /* pseudo header checksum */
376
377	QETH_DBF_TEXT(trace, 5, "eddpckt6");
378	eddp->th.tcp.h.check = 0;
379	/* compute pseudo header checksum */
380	phcsum = csum_partial((u8 *)&eddp->nh.ip6.h.saddr,
381	sizeof(struct in6_addr), 0);
382	phcsum = csum_partial((u8 *)&eddp->nh.ip6.h.daddr,
383	sizeof(struct in6_addr), phcsum);
384	proto = htonl(IPPROTO_TCP);
385	phcsum = csum_partial((u8 *)&proto, sizeof(u32), phcsum);
386	return phcsum;
387	}
388
389	static inline struct qeth_eddp_data *
390	qeth_eddp_create_eddp_data(struct qeth_hdr qh, u8 nh, u8 nhl, u8 *th, u8 thl)
391	{
392	struct qeth_eddp_data *eddp;
393
394	QETH_DBF_TEXT(trace, 5, "eddpcrda");
395	eddp = kmalloc(sizeof(struct qeth_eddp_data), GFP_ATOMIC);
396	if (eddp){
397	memset(eddp, 0, sizeof(struct qeth_eddp_data));
398	eddp->nhl = nhl;
399	eddp->thl = thl;
400	memcpy(&eddp->qh, qh, sizeof(struct qeth_hdr));
401	memcpy(&eddp->nh, nh, nhl);
402	memcpy(&eddp->th, th, thl);
403	eddp->frag = -1; /* initially we're in skb->data */
404	}
405	return eddp;
406	}
407
408	static inline void
409	__qeth_eddp_fill_context_tcp(struct qeth_eddp_context *ctx,
410	struct qeth_eddp_data *eddp)
411	{
412	struct tcphdr *tcph;
413	int data_len;
414	u32 hcsum;
05e08a2a	415
1da177e4 LT	416	QETH_DBF_TEXT(trace, 5, "eddpftcp");
	417	eddp->skb_offset = sizeof(struct qeth_hdr) + eddp->nhl + eddp->thl;
	418	tcph = eddp->skb->h.th;
	419	while (eddp->skb_offset < eddp->skb->len) {
	420	data_len = min((int)skb_shinfo(eddp->skb)->tso_size,
	421	(int)(eddp->skb->len - eddp->skb_offset));
	422	/* prepare qdio hdr */
	423	if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2){
	424	eddp->qh.hdr.l2.pkt_length = data_len + ETH_HLEN +
	425	eddp->nhl + eddp->thl -
	426	sizeof(struct qeth_hdr);
	427	#ifdef CONFIG_QETH_VLAN
	428	if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
	429	eddp->qh.hdr.l2.pkt_length += VLAN_HLEN;
	430	#endif /* CONFIG_QETH_VLAN */
	431	} else
	432	eddp->qh.hdr.l3.length = data_len + eddp->nhl +
	433	eddp->thl;
	434	/* prepare ip hdr */
	435	if (eddp->skb->protocol == ETH_P_IP){
	436	eddp->nh.ip4.h.tot_len = data_len + eddp->nhl +
	437	eddp->thl;
	438	eddp->nh.ip4.h.check = 0;
	439	eddp->nh.ip4.h.check =
	440	ip_fast_csum((u8 *)&eddp->nh.ip4.h,
	441	eddp->nh.ip4.h.ihl);
	442	} else
	443	eddp->nh.ip6.h.payload_len = data_len + eddp->thl;
	444	/* prepare tcp hdr */
	445	if (data_len == (eddp->skb->len - eddp->skb_offset)){
	446	/* last segment -> set FIN and PSH flags */
	447	eddp->th.tcp.h.fin = tcph->fin;
	448	eddp->th.tcp.h.psh = tcph->psh;
	449	}
	450	if (eddp->skb->protocol == ETH_P_IP)
	451	hcsum = qeth_eddp_check_tcp4_hdr(eddp, data_len);
	452	else
	453	hcsum = qeth_eddp_check_tcp6_hdr(eddp, data_len);
	454	/* fill the next segment into the context */
05e08a2a	455	qeth_eddp_create_segment_hdrs(ctx, eddp, data_len);
1da177e4 LT	456	qeth_eddp_create_segment_data_tcp(ctx, eddp, data_len, hcsum);
	457	if (eddp->skb_offset >= eddp->skb->len)
	458	break;
	459	/* prepare headers for next round */
	460	if (eddp->skb->protocol == ETH_P_IP)
	461	eddp->nh.ip4.h.id++;
	462	eddp->th.tcp.h.seq += data_len;
	463	}
	464	}
05e08a2a	465
1da177e4 LT	466	static inline int
	467	qeth_eddp_fill_context_tcp(struct qeth_eddp_context *ctx,
	468	struct sk_buff skb, struct qeth_hdr qhdr)
	469	{
	470	struct qeth_eddp_data *eddp = NULL;
05e08a2a	471
1da177e4 LT	472	QETH_DBF_TEXT(trace, 5, "eddpficx");
	473	/* create our segmentation headers and copy original headers */
	474	if (skb->protocol == ETH_P_IP)
	475	eddp = qeth_eddp_create_eddp_data(qhdr, (u8 *)skb->nh.iph,
	476	skb->nh.iph->ihl*4,
	477	(u8 )skb->h.th, skb->h.th->doff4);
	478	else
	479	eddp = qeth_eddp_create_eddp_data(qhdr, (u8 *)skb->nh.ipv6h,
	480	sizeof(struct ipv6hdr),
	481	(u8 )skb->h.th, skb->h.th->doff4);
	482
	483	if (eddp == NULL) {
	484	QETH_DBF_TEXT(trace, 2, "eddpfcnm");
	485	return -ENOMEM;
	486	}
	487	if (qhdr->hdr.l2.id == QETH_HEADER_TYPE_LAYER2) {
	488	memcpy(&eddp->mac, eth_hdr(skb), ETH_HLEN);
	489	#ifdef CONFIG_QETH_VLAN
	490	if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q)) {
	491	eddp->vlan[0] = __constant_htons(skb->protocol);
	492	eddp->vlan[1] = htons(vlan_tx_tag_get(skb));
	493	}
	494	#endif /* CONFIG_QETH_VLAN */
	495	}
	496	/* the next flags will only be set on the last segment */
	497	eddp->th.tcp.h.fin = 0;
	498	eddp->th.tcp.h.psh = 0;
	499	eddp->skb = skb;
	500	/* begin segmentation and fill context */
	501	__qeth_eddp_fill_context_tcp(ctx, eddp);
	502	kfree(eddp);
	503	return 0;
	504	}
	505
	506	static inline void
	507	qeth_eddp_calc_num_pages(struct qeth_eddp_context ctx, struct sk_buff skb,
	508	int hdr_len)
	509	{
	510	int skbs_per_page;
05e08a2a	511
1da177e4 LT	512	QETH_DBF_TEXT(trace, 5, "eddpcanp");
	513	/* can we put multiple skbs in one page? */
	514	skbs_per_page = PAGE_SIZE / (skb_shinfo(skb)->tso_size + hdr_len);
	515	if (skbs_per_page > 1){
	516	ctx->num_pages = (skb_shinfo(skb)->tso_segs + 1) /
	517	skbs_per_page + 1;
	518	ctx->elements_per_skb = 1;
	519	} else {
	520	/* no -> how many elements per skb? */
	521	ctx->elements_per_skb = (skb_shinfo(skb)->tso_size + hdr_len +
	522	PAGE_SIZE) >> PAGE_SHIFT;
	523	ctx->num_pages = ctx->elements_per_skb *
	524	(skb_shinfo(skb)->tso_segs + 1);
	525	}
	526	ctx->num_elements = ctx->elements_per_skb *
	527	(skb_shinfo(skb)->tso_segs + 1);
	528	}
	529
	530	static inline struct qeth_eddp_context *
	531	qeth_eddp_create_context_generic(struct qeth_card card, struct sk_buff skb,
	532	int hdr_len)
	533	{
	534	struct qeth_eddp_context *ctx = NULL;
	535	u8 *addr;
	536	int i;
	537
	538	QETH_DBF_TEXT(trace, 5, "creddpcg");
	539	/* create the context and allocate pages */
	540	ctx = kmalloc(sizeof(struct qeth_eddp_context), GFP_ATOMIC);
	541	if (ctx == NULL){
	542	QETH_DBF_TEXT(trace, 2, "ceddpcn1");
	543	return NULL;
	544	}
	545	memset(ctx, 0, sizeof(struct qeth_eddp_context));
	546	ctx->type = QETH_LARGE_SEND_EDDP;
	547	qeth_eddp_calc_num_pages(ctx, skb, hdr_len);
	548	if (ctx->elements_per_skb > QETH_MAX_BUFFER_ELEMENTS(card)){
	549	QETH_DBF_TEXT(trace, 2, "ceddpcis");
	550	kfree(ctx);
	551	return NULL;
	552	}
	553	ctx->pages = kmalloc(ctx->num_pages * sizeof(u8 *), GFP_ATOMIC);
	554	if (ctx->pages == NULL){
	555	QETH_DBF_TEXT(trace, 2, "ceddpcn2");
	556	kfree(ctx);
	557	return NULL;
	558	}
	559	memset(ctx->pages, 0, ctx->num_pages * sizeof(u8 *));
	560	for (i = 0; i < ctx->num_pages; ++i){
	561	addr = (u8 *)__get_free_page(GFP_ATOMIC);
	562	if (addr == NULL){
	563	QETH_DBF_TEXT(trace, 2, "ceddpcn3");
	564	ctx->num_pages = i;
	565	qeth_eddp_free_context(ctx);
	566	return NULL;
	567	}
	568	memset(addr, 0, PAGE_SIZE);
	569	ctx->pages[i] = addr;
	570	}
	571	ctx->elements = kmalloc(ctx->num_elements *
	572	sizeof(struct qeth_eddp_element), GFP_ATOMIC);
	573	if (ctx->elements == NULL){
	574	QETH_DBF_TEXT(trace, 2, "ceddpcn4");
	575	qeth_eddp_free_context(ctx);
576	return NULL;
577	}
578	memset(ctx->elements, 0,
579	ctx->num_elements * sizeof(struct qeth_eddp_element));
580	/* reset num_elements; will be incremented again in fill_buffer to
581	* reflect number of actually used elements */
582	ctx->num_elements = 0;
583	return ctx;
584	}
585
586	static inline struct qeth_eddp_context *
587	qeth_eddp_create_context_tcp(struct qeth_card card, struct sk_buff skb,
588	struct qeth_hdr *qhdr)
589	{
590	struct qeth_eddp_context *ctx = NULL;
05e08a2a	591
1da177e4 LT	592	QETH_DBF_TEXT(trace, 5, "creddpct");
	593	if (skb->protocol == ETH_P_IP)
	594	ctx = qeth_eddp_create_context_generic(card, skb,
	595	sizeof(struct qeth_hdr) + skb->nh.iph->ihl*4 +
	596	skb->h.th->doff*4);
	597	else if (skb->protocol == ETH_P_IPV6)
	598	ctx = qeth_eddp_create_context_generic(card, skb,
	599	sizeof(struct qeth_hdr) + sizeof(struct ipv6hdr) +
	600	skb->h.th->doff*4);
	601	else
	602	QETH_DBF_TEXT(trace, 2, "cetcpinv");
	603
	604	if (ctx == NULL) {
	605	QETH_DBF_TEXT(trace, 2, "creddpnl");
	606	return NULL;
	607	}
	608	if (qeth_eddp_fill_context_tcp(ctx, skb, qhdr)){
	609	QETH_DBF_TEXT(trace, 2, "ceddptfe");
	610	qeth_eddp_free_context(ctx);
	611	return NULL;
	612	}
	613	atomic_set(&ctx->refcnt, 1);
	614	return ctx;
	615	}
	616
	617	struct qeth_eddp_context *
	618	qeth_eddp_create_context(struct qeth_card card, struct sk_buff skb,
	619	struct qeth_hdr *qhdr)
	620	{
	621	QETH_DBF_TEXT(trace, 5, "creddpc");
	622	switch (skb->sk->sk_protocol){
	623	case IPPROTO_TCP:
	624	return qeth_eddp_create_context_tcp(card, skb, qhdr);
	625	default:
	626	QETH_DBF_TEXT(trace, 2, "eddpinvp");
	627	}
	628	return NULL;
	629	}
	630
	631