[mirror_ubuntu-zesty-kernel.git] / drivers / s390 / net / qeth_eddp.c

/*
 * 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/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 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 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 {
		if (queue->card->options.performance_stats)
			queue->card->perf_stats.skbs_sent_pack++;
		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 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 void
qeth_eddp_copy_data_tcp(char *dst, struct qeth_eddp_data *eddp, int len,
			__wsum *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 void
qeth_eddp_create_segment_data_tcp(struct qeth_eddp_context *ctx,
				  struct qeth_eddp_data *eddp, int data_len,
				  __wsum 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 __wsum
qeth_eddp_check_tcp4_hdr(struct qeth_eddp_data *eddp, int data_len)
{
	__wsum 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 __wsum
qeth_eddp_check_tcp6_hdr(struct qeth_eddp_data *eddp, int data_len)
{
	__be32 proto;
	__wsum 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 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 = kzalloc(sizeof(struct qeth_eddp_data), GFP_ATOMIC);
	if (eddp){
		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 void
__qeth_eddp_fill_context_tcp(struct qeth_eddp_context *ctx,
			     struct qeth_eddp_data *eddp)
{
	struct tcphdr *tcph;
	int data_len;
	__wsum 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 = tcp_hdr(eddp->skb);
	while (eddp->skb_offset < eddp->skb->len) {
		data_len = min((int)skb_shinfo(eddp->skb)->gso_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 == htons(ETH_P_IP)){
			eddp->nh.ip4.h.tot_len = htons(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 = htons(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 == htons(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 == htons(ETH_P_IP))
			eddp->nh.ip4.h.id = htons(ntohs(eddp->nh.ip4.h.id) + 1);
		eddp->th.tcp.h.seq = htonl(ntohl(eddp->th.tcp.h.seq) + data_len);
	}
}

static 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 == htons(ETH_P_IP))
		eddp = qeth_eddp_create_eddp_data(qhdr,
						  skb_network_header(skb),
						  ip_hdrlen(skb),
						  skb_transport_header(skb),
						  tcp_hdrlen(skb));
	else
		eddp = qeth_eddp_create_eddp_data(qhdr,
						  skb_network_header(skb),
						  sizeof(struct ipv6hdr),
						  skb_transport_header(skb),
						  tcp_hdrlen(skb));

	if (eddp == NULL) {
		QETH_DBF_TEXT(trace, 2, "eddpfcnm");
		return -ENOMEM;
	}
	if (qhdr->hdr.l2.id == QETH_HEADER_TYPE_LAYER2) {
		skb_set_mac_header(skb, 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] = 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 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)->gso_size + hdr_len);
	if (skbs_per_page > 1){
		ctx->num_pages = (skb_shinfo(skb)->gso_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)->gso_size + hdr_len +
				     PAGE_SIZE) >> PAGE_SHIFT;
		ctx->num_pages = ctx->elements_per_skb *
				 (skb_shinfo(skb)->gso_segs + 1);
	}
	ctx->num_elements = ctx->elements_per_skb *
			    (skb_shinfo(skb)->gso_segs + 1);
}

static 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 = kzalloc(sizeof(struct qeth_eddp_context), GFP_ATOMIC);
	if (ctx == NULL){
		QETH_DBF_TEXT(trace, 2, "ceddpcn1");
		return NULL;
	}
	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 = kcalloc(ctx->num_pages, sizeof(u8 *), GFP_ATOMIC);
	if (ctx->pages == NULL){
		QETH_DBF_TEXT(trace, 2, "ceddpcn2");
		kfree(ctx);
		return NULL;
	}
	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 = kcalloc(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;
	}
	/* reset num_elements; will be incremented again in fill_buffer to
	 * reflect number of actually used elements */
	ctx->num_elements = 0;
	return ctx;
}

static 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 == htons(ETH_P_IP))
		ctx = qeth_eddp_create_context_generic(card, skb,
						       (sizeof(struct qeth_hdr) +
						        ip_hdrlen(skb) +
							tcp_hdrlen(skb)));
	else if (skb->protocol == htons(ETH_P_IPV6))
		ctx = qeth_eddp_create_context_generic(card, skb,
			sizeof(struct qeth_hdr) + sizeof(struct ipv6hdr) +
			tcp_hdrlen(skb));
	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	1	/*
e018ba1f	2	* linux/drivers/s390/net/qeth_eddp.c
1da177e4 LT	3	*
	4	* Enhanced Device Driver Packing (EDDP) support for the qeth driver.
	5	*
	6	* Copyright 2004 IBM Corporation
	7	*
	8	* Author(s): Thomas Spatzier <tspat@de.ibm.com>
	9	*
1da177e4	10	*/
1da177e4 LT	11	#include <linux/errno.h>
	12	#include <linux/ip.h>
	13	#include <linux/inetdevice.h>
	14	#include <linux/netdevice.h>
	15	#include <linux/kernel.h>
	16	#include <linux/tcp.h>
	17	#include <net/tcp.h>
	18	#include <linux/skbuff.h>
	19
	20	#include <net/ip.h>
	21
	22	#include "qeth.h"
	23	#include "qeth_mpc.h"
	24	#include "qeth_eddp.h"
	25
	26	int
	27	qeth_eddp_check_buffers_for_context(struct qeth_qdio_out_q *queue,
	28	struct qeth_eddp_context *ctx)
	29	{
	30	int index = queue->next_buf_to_fill;
	31	int elements_needed = ctx->num_elements;
	32	int elements_in_buffer;
	33	int skbs_in_buffer;
	34	int buffers_needed = 0;
	35
	36	QETH_DBF_TEXT(trace, 5, "eddpcbfc");
	37	while(elements_needed > 0) {
	38	buffers_needed++;
	39	if (atomic_read(&queue->bufs[index].state) !=
	40	QETH_QDIO_BUF_EMPTY)
	41	return -EBUSY;
	42
	43	elements_in_buffer = QETH_MAX_BUFFER_ELEMENTS(queue->card) -
	44	queue->bufs[index].next_element_to_fill;
	45	skbs_in_buffer = elements_in_buffer / ctx->elements_per_skb;
	46	elements_needed -= skbs_in_buffer * ctx->elements_per_skb;
	47	index = (index + 1) % QDIO_MAX_BUFFERS_PER_Q;
	48	}
	49	return buffers_needed;
	50	}
	51
4d284cac	52	static void
1da177e4 LT	53	qeth_eddp_free_context(struct qeth_eddp_context *ctx)
	54	{
	55	int i;
	56
	57	QETH_DBF_TEXT(trace, 5, "eddpfctx");
	58	for (i = 0; i < ctx->num_pages; ++i)
	59	free_page((unsigned long)ctx->pages[i]);
	60	kfree(ctx->pages);
66cc5d5a	61	kfree(ctx->elements);
1da177e4 LT	62	kfree(ctx);
	63	}
	64
	65
	66	static inline void
	67	qeth_eddp_get_context(struct qeth_eddp_context *ctx)
	68	{
	69	atomic_inc(&ctx->refcnt);
	70	}
	71
	72	void
	73	qeth_eddp_put_context(struct qeth_eddp_context *ctx)
	74	{
	75	if (atomic_dec_return(&ctx->refcnt) == 0)
	76	qeth_eddp_free_context(ctx);
	77	}
	78
	79	void
	80	qeth_eddp_buf_release_contexts(struct qeth_qdio_out_buffer *buf)
	81	{
	82	struct qeth_eddp_context_reference *ref;
e82b0f2c	83
1da177e4 LT	84	QETH_DBF_TEXT(trace, 6, "eddprctx");
	85	while (!list_empty(&buf->ctx_list)){
	86	ref = list_entry(buf->ctx_list.next,
	87	struct qeth_eddp_context_reference, list);
	88	qeth_eddp_put_context(ref->ctx);
	89	list_del(&ref->list);
	90	kfree(ref);
	91	}
	92	}
	93
4d284cac	94	static int
1da177e4 LT	95	qeth_eddp_buf_ref_context(struct qeth_qdio_out_buffer *buf,
	96	struct qeth_eddp_context *ctx)
	97	{
	98	struct qeth_eddp_context_reference *ref;
	99
	100	QETH_DBF_TEXT(trace, 6, "eddprfcx");
	101	ref = kmalloc(sizeof(struct qeth_eddp_context_reference), GFP_ATOMIC);
	102	if (ref == NULL)
	103	return -ENOMEM;
	104	qeth_eddp_get_context(ctx);
	105	ref->ctx = ctx;
	106	list_add_tail(&ref->list, &buf->ctx_list);
	107	return 0;
	108	}
	109
	110	int
	111	qeth_eddp_fill_buffer(struct qeth_qdio_out_q *queue,
	112	struct qeth_eddp_context *ctx,
	113	int index)
	114	{
	115	struct qeth_qdio_out_buffer *buf = NULL;
	116	struct qdio_buffer *buffer;
	117	int elements = ctx->num_elements;
	118	int element = 0;
	119	int flush_cnt = 0;
	120	int must_refcnt = 1;
	121	int i;
	122
	123	QETH_DBF_TEXT(trace, 5, "eddpfibu");
	124	while (elements > 0) {
	125	buf = &queue->bufs[index];
	126	if (atomic_read(&buf->state) != QETH_QDIO_BUF_EMPTY){
	127	/* normally this should not happen since we checked for
	128	* available elements in qeth_check_elements_for_context
	129	*/
	130	if (element == 0)
	131	return -EBUSY;
	132	else {
	133	PRINT_WARN("could only partially fill eddp "
	134	"buffer!\n");
	135	goto out;
	136	}
e82b0f2c	137	}
1da177e4 LT	138	/* check if the whole next skb fits into current buffer */
	139	if ((QETH_MAX_BUFFER_ELEMENTS(queue->card) -
	140	buf->next_element_to_fill)
	141	< ctx->elements_per_skb){
	142	/* no -> go to next buffer */
	143	atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
	144	index = (index + 1) % QDIO_MAX_BUFFERS_PER_Q;
	145	flush_cnt++;
	146	/* new buffer, so we have to add ctx to buffer'ctx_list
	147	* and increment ctx's refcnt */
	148	must_refcnt = 1;
	149	continue;
e82b0f2c	150	}
1da177e4 LT	151	if (must_refcnt){
	152	must_refcnt = 0;
	153	if (qeth_eddp_buf_ref_context(buf, ctx)){
	154	PRINT_WARN("no memory to create eddp context "
	155	"reference\n");
	156	goto out_check;
	157	}
	158	}
	159	buffer = buf->buffer;
	160	/* fill one skb into buffer */
	161	for (i = 0; i < ctx->elements_per_skb; ++i){
	162	buffer->element[buf->next_element_to_fill].addr =
	163	ctx->elements[element].addr;
	164	buffer->element[buf->next_element_to_fill].length =
	165	ctx->elements[element].length;
	166	buffer->element[buf->next_element_to_fill].flags =
	167	ctx->elements[element].flags;
	168	buf->next_element_to_fill++;
	169	element++;
	170	elements--;
	171	}
	172	}
	173	out_check:
	174	if (!queue->do_pack) {
	175	QETH_DBF_TEXT(trace, 6, "fillbfnp");
	176	/* set state to PRIMED -> will be flushed */
	177	if (buf->next_element_to_fill > 0){
	178	atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
	179	flush_cnt++;
	180	}
	181	} else {
09d2d38a FP	182	if (queue->card->options.performance_stats)
09d2d38a FP	183	queue->card->perf_stats.skbs_sent_pack++;
1da177e4 LT	184	QETH_DBF_TEXT(trace, 6, "fillbfpa");
	185	if (buf->next_element_to_fill >=
	186	QETH_MAX_BUFFER_ELEMENTS(queue->card)) {
	187	/*
	188	* packed buffer if full -> set state PRIMED
	189	* -> will be flushed
	190	*/
	191	atomic_set(&buf->state, QETH_QDIO_BUF_PRIMED);
	192	flush_cnt++;
	193	}
	194	}
	195	out:
	196	return flush_cnt;
	197	}
	198
4d284cac	199	static void
1da177e4	200	qeth_eddp_create_segment_hdrs(struct qeth_eddp_context *ctx,
05e08a2a	201	struct qeth_eddp_data *eddp, int data_len)
1da177e4 LT	202	{
	203	u8 *page;
	204	int page_remainder;
	205	int page_offset;
05e08a2a	206	int pkt_len;
1da177e4 LT	207	struct qeth_eddp_element *element;
	208
	209	QETH_DBF_TEXT(trace, 5, "eddpcrsh");
	210	page = ctx->pages[ctx->offset >> PAGE_SHIFT];
	211	page_offset = ctx->offset % PAGE_SIZE;
	212	element = &ctx->elements[ctx->num_elements];
05e08a2a	213	pkt_len = eddp->nhl + eddp->thl + data_len;
1da177e4 LT	214	/* FIXME: layer2 and VLAN !!! */
1da177e4 LT	215	if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2)
05e08a2a	216	pkt_len += ETH_HLEN;
1da177e4	217	if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
05e08a2a FP	218	pkt_len += VLAN_HLEN;
05e08a2a FP	219	/* does complete packet fit in current page ? */
1da177e4	220	page_remainder = PAGE_SIZE - page_offset;
05e08a2a	221	if (page_remainder < (sizeof(struct qeth_hdr) + pkt_len)){
1da177e4 LT	222	/* no -> go to start of next page */
	223	ctx->offset += page_remainder;
	224	page = ctx->pages[ctx->offset >> PAGE_SHIFT];
	225	page_offset = 0;
	226	}
	227	memcpy(page + page_offset, &eddp->qh, sizeof(struct qeth_hdr));
	228	element->addr = page + page_offset;
	229	element->length = sizeof(struct qeth_hdr);
	230	ctx->offset += sizeof(struct qeth_hdr);
	231	page_offset += sizeof(struct qeth_hdr);
	232	/* add mac header (?) */
	233	if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2){
	234	memcpy(page + page_offset, &eddp->mac, ETH_HLEN);
	235	element->length += ETH_HLEN;
	236	ctx->offset += ETH_HLEN;
	237	page_offset += ETH_HLEN;
	238	}
	239	/* add VLAN tag */
	240	if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q)){
	241	memcpy(page + page_offset, &eddp->vlan, VLAN_HLEN);
	242	element->length += VLAN_HLEN;
	243	ctx->offset += VLAN_HLEN;
	244	page_offset += VLAN_HLEN;
	245	}
	246	/* add network header */
	247	memcpy(page + page_offset, (u8 *)&eddp->nh, eddp->nhl);
	248	element->length += eddp->nhl;
	249	eddp->nh_in_ctx = page + page_offset;
	250	ctx->offset += eddp->nhl;
	251	page_offset += eddp->nhl;
	252	/* add transport header */
	253	memcpy(page + page_offset, (u8 *)&eddp->th, eddp->thl);
	254	element->length += eddp->thl;
	255	eddp->th_in_ctx = page + page_offset;
	256	ctx->offset += eddp->thl;
	257	}
	258
4d284cac	259	static void
1da177e4	260	qeth_eddp_copy_data_tcp(char dst, struct qeth_eddp_data eddp, int len,
5a5a852e	261	__wsum *hcsum)
1da177e4 LT	262	{
	263	struct skb_frag_struct *frag;
	264	int left_in_frag;
	265	int copy_len;
	266	u8 *src;
e82b0f2c	267
1da177e4 LT	268	QETH_DBF_TEXT(trace, 5, "eddpcdtc");
	269	if (skb_shinfo(eddp->skb)->nr_frags == 0) {
	270	memcpy(dst, eddp->skb->data + eddp->skb_offset, len);
	271	*hcsum = csum_partial(eddp->skb->data + eddp->skb_offset, len,
	272	*hcsum);
	273	eddp->skb_offset += len;
	274	} else {
	275	while (len > 0) {
	276	if (eddp->frag < 0) {
	277	/* we're in skb->data */
05e08a2a	278	left_in_frag = (eddp->skb->len - eddp->skb->data_len)
1da177e4 LT	279	- eddp->skb_offset;
	280	src = eddp->skb->data + eddp->skb_offset;
	281	} else {
	282	frag = &skb_shinfo(eddp->skb)->
	283	frags[eddp->frag];
	284	left_in_frag = frag->size - eddp->frag_offset;
	285	src = (u8 *)(
	286	(page_to_pfn(frag->page) << PAGE_SHIFT)+
	287	frag->page_offset + eddp->frag_offset);
	288	}
	289	if (left_in_frag <= 0) {
	290	eddp->frag++;
	291	eddp->frag_offset = 0;
	292	continue;
	293	}
	294	copy_len = min(left_in_frag, len);
	295	memcpy(dst, src, copy_len);
	296	hcsum = csum_partial(src, copy_len, hcsum);
	297	dst += copy_len;
	298	eddp->frag_offset += copy_len;
	299	eddp->skb_offset += copy_len;
	300	len -= copy_len;
	301	}
	302	}
	303	}
	304
4d284cac	305	static void
1da177e4 LT	306	qeth_eddp_create_segment_data_tcp(struct qeth_eddp_context *ctx,
1da177e4 LT	307	struct qeth_eddp_data *eddp, int data_len,
5a5a852e	308	__wsum hcsum)
1da177e4 LT	309	{
	310	u8 *page;
	311	int page_remainder;
	312	int page_offset;
	313	struct qeth_eddp_element *element;
	314	int first_lap = 1;
	315
	316	QETH_DBF_TEXT(trace, 5, "eddpcsdt");
	317	page = ctx->pages[ctx->offset >> PAGE_SHIFT];
	318	page_offset = ctx->offset % PAGE_SIZE;
	319	element = &ctx->elements[ctx->num_elements];
	320	while (data_len){
	321	page_remainder = PAGE_SIZE - page_offset;
	322	if (page_remainder < data_len){
	323	qeth_eddp_copy_data_tcp(page + page_offset, eddp,
	324	page_remainder, &hcsum);
	325	element->length += page_remainder;
	326	if (first_lap)
	327	element->flags = SBAL_FLAGS_FIRST_FRAG;
	328	else
	329	element->flags = SBAL_FLAGS_MIDDLE_FRAG;
	330	ctx->num_elements++;
	331	element++;
	332	data_len -= page_remainder;
	333	ctx->offset += page_remainder;
	334	page = ctx->pages[ctx->offset >> PAGE_SHIFT];
	335	page_offset = 0;
	336	element->addr = page + page_offset;
	337	} else {
	338	qeth_eddp_copy_data_tcp(page + page_offset, eddp,
	339	data_len, &hcsum);
	340	element->length += data_len;
	341	if (!first_lap)
	342	element->flags = SBAL_FLAGS_LAST_FRAG;
	343	ctx->num_elements++;
	344	ctx->offset += data_len;
	345	data_len = 0;
	346	}
	347	first_lap = 0;
	348	}
	349	((struct tcphdr *)eddp->th_in_ctx)->check = csum_fold(hcsum);
	350	}
	351
4d284cac	352	static __wsum
1da177e4 LT	353	qeth_eddp_check_tcp4_hdr(struct qeth_eddp_data *eddp, int data_len)
1da177e4 LT	354	{
5a5a852e	355	__wsum phcsum; /* pseudo header checksum */
1da177e4 LT	356
	357	QETH_DBF_TEXT(trace, 5, "eddpckt4");
	358	eddp->th.tcp.h.check = 0;
	359	/* compute pseudo header checksum */
	360	phcsum = csum_tcpudp_nofold(eddp->nh.ip4.h.saddr, eddp->nh.ip4.h.daddr,
	361	eddp->thl + data_len, IPPROTO_TCP, 0);
	362	/* compute checksum of tcp header */
	363	return csum_partial((u8 *)&eddp->th, eddp->thl, phcsum);
	364	}
	365
4d284cac	366	static __wsum
1da177e4 LT	367	qeth_eddp_check_tcp6_hdr(struct qeth_eddp_data *eddp, int data_len)
1da177e4 LT	368	{
5a5a852e AV	369	__be32 proto;
5a5a852e AV	370	__wsum phcsum; /* pseudo header checksum */
1da177e4 LT	371
	372	QETH_DBF_TEXT(trace, 5, "eddpckt6");
	373	eddp->th.tcp.h.check = 0;
	374	/* compute pseudo header checksum */
	375	phcsum = csum_partial((u8 *)&eddp->nh.ip6.h.saddr,
	376	sizeof(struct in6_addr), 0);
	377	phcsum = csum_partial((u8 *)&eddp->nh.ip6.h.daddr,
	378	sizeof(struct in6_addr), phcsum);
	379	proto = htonl(IPPROTO_TCP);
	380	phcsum = csum_partial((u8 *)&proto, sizeof(u32), phcsum);
	381	return phcsum;
	382	}
	383
4d284cac	384	static struct qeth_eddp_data *
1da177e4 LT	385	qeth_eddp_create_eddp_data(struct qeth_hdr qh, u8 nh, u8 nhl, u8 *th, u8 thl)
	386	{
	387	struct qeth_eddp_data *eddp;
	388
	389	QETH_DBF_TEXT(trace, 5, "eddpcrda");
88abaab4	390	eddp = kzalloc(sizeof(struct qeth_eddp_data), GFP_ATOMIC);
1da177e4	391	if (eddp){
1da177e4 LT	392	eddp->nhl = nhl;
	393	eddp->thl = thl;
	394	memcpy(&eddp->qh, qh, sizeof(struct qeth_hdr));
	395	memcpy(&eddp->nh, nh, nhl);
	396	memcpy(&eddp->th, th, thl);
	397	eddp->frag = -1; /* initially we're in skb->data */
	398	}
	399	return eddp;
	400	}
	401
4d284cac	402	static void
1da177e4 LT	403	__qeth_eddp_fill_context_tcp(struct qeth_eddp_context *ctx,
	404	struct qeth_eddp_data *eddp)
	405	{
	406	struct tcphdr *tcph;
	407	int data_len;
5a5a852e	408	__wsum hcsum;
e82b0f2c	409
1da177e4 LT	410	QETH_DBF_TEXT(trace, 5, "eddpftcp");
1da177e4 LT	411	eddp->skb_offset = sizeof(struct qeth_hdr) + eddp->nhl + eddp->thl;
66cc5d5a FP	412	if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2) {
	413	eddp->skb_offset += sizeof(struct ethhdr);
	414	#ifdef CONFIG_QETH_VLAN
	415	if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
	416	eddp->skb_offset += VLAN_HLEN;
	417	#endif /* CONFIG_QETH_VLAN */
	418	}
aa8223c7	419	tcph = tcp_hdr(eddp->skb);
1da177e4	420	while (eddp->skb_offset < eddp->skb->len) {
7967168c	421	data_len = min((int)skb_shinfo(eddp->skb)->gso_size,
1da177e4 LT	422	(int)(eddp->skb->len - eddp->skb_offset));
	423	/* prepare qdio hdr */
	424	if (eddp->qh.hdr.l2.id == QETH_HEADER_TYPE_LAYER2){
	425	eddp->qh.hdr.l2.pkt_length = data_len + ETH_HLEN +
	426	eddp->nhl + eddp->thl -
	427	sizeof(struct qeth_hdr);
	428	#ifdef CONFIG_QETH_VLAN
	429	if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q))
	430	eddp->qh.hdr.l2.pkt_length += VLAN_HLEN;
	431	#endif /* CONFIG_QETH_VLAN */
	432	} else
	433	eddp->qh.hdr.l3.length = data_len + eddp->nhl +
	434	eddp->thl;
	435	/* prepare ip hdr */
5a5a852e AV	436	if (eddp->skb->protocol == htons(ETH_P_IP)){
	437	eddp->nh.ip4.h.tot_len = htons(data_len + eddp->nhl +
	438	eddp->thl);
1da177e4 LT	439	eddp->nh.ip4.h.check = 0;
	440	eddp->nh.ip4.h.check =
	441	ip_fast_csum((u8 *)&eddp->nh.ip4.h,
	442	eddp->nh.ip4.h.ihl);
	443	} else
5a5a852e	444	eddp->nh.ip6.h.payload_len = htons(data_len + eddp->thl);
1da177e4 LT	445	/* prepare tcp hdr */
	446	if (data_len == (eddp->skb->len - eddp->skb_offset)){
	447	/* last segment -> set FIN and PSH flags */
	448	eddp->th.tcp.h.fin = tcph->fin;
	449	eddp->th.tcp.h.psh = tcph->psh;
	450	}
5a5a852e	451	if (eddp->skb->protocol == htons(ETH_P_IP))
1da177e4 LT	452	hcsum = qeth_eddp_check_tcp4_hdr(eddp, data_len);
	453	else
	454	hcsum = qeth_eddp_check_tcp6_hdr(eddp, data_len);
	455	/* fill the next segment into the context */
05e08a2a	456	qeth_eddp_create_segment_hdrs(ctx, eddp, data_len);
1da177e4 LT	457	qeth_eddp_create_segment_data_tcp(ctx, eddp, data_len, hcsum);
	458	if (eddp->skb_offset >= eddp->skb->len)
	459	break;
	460	/* prepare headers for next round */
5a5a852e AV	461	if (eddp->skb->protocol == htons(ETH_P_IP))
	462	eddp->nh.ip4.h.id = htons(ntohs(eddp->nh.ip4.h.id) + 1);
	463	eddp->th.tcp.h.seq = htonl(ntohl(eddp->th.tcp.h.seq) + data_len);
1da177e4 LT	464	}
1da177e4 LT	465	}
e82b0f2c	466
4d284cac	467	static int
1da177e4 LT	468	qeth_eddp_fill_context_tcp(struct qeth_eddp_context *ctx,
	469	struct sk_buff skb, struct qeth_hdr qhdr)
	470	{
	471	struct qeth_eddp_data *eddp = NULL;
e82b0f2c	472
1da177e4 LT	473	QETH_DBF_TEXT(trace, 5, "eddpficx");
1da177e4 LT	474	/* create our segmentation headers and copy original headers */
5a5a852e	475	if (skb->protocol == htons(ETH_P_IP))
c9bdd4b5 ACM	476	eddp = qeth_eddp_create_eddp_data(qhdr,
	477	skb_network_header(skb),
	478	ip_hdrlen(skb),
9c70220b	479	skb_transport_header(skb),
ab6a5bb6	480	tcp_hdrlen(skb));
1da177e4	481	else
0660e03f ACM	482	eddp = qeth_eddp_create_eddp_data(qhdr,
	483	skb_network_header(skb),
	484	sizeof(struct ipv6hdr),
9c70220b	485	skb_transport_header(skb),
ab6a5bb6	486	tcp_hdrlen(skb));
1da177e4 LT	487
	488	if (eddp == NULL) {
	489	QETH_DBF_TEXT(trace, 2, "eddpfcnm");
	490	return -ENOMEM;
	491	}
	492	if (qhdr->hdr.l2.id == QETH_HEADER_TYPE_LAYER2) {
48d49d0c	493	skb_set_mac_header(skb, sizeof(struct qeth_hdr));
1da177e4 LT	494	memcpy(&eddp->mac, eth_hdr(skb), ETH_HLEN);
	495	#ifdef CONFIG_QETH_VLAN
	496	if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q)) {
5a5a852e	497	eddp->vlan[0] = skb->protocol;
1da177e4 LT	498	eddp->vlan[1] = htons(vlan_tx_tag_get(skb));
	499	}
	500	#endif /* CONFIG_QETH_VLAN */
	501	}
	502	/* the next flags will only be set on the last segment */
	503	eddp->th.tcp.h.fin = 0;
	504	eddp->th.tcp.h.psh = 0;
	505	eddp->skb = skb;
	506	/* begin segmentation and fill context */
	507	__qeth_eddp_fill_context_tcp(ctx, eddp);
	508	kfree(eddp);
	509	return 0;
	510	}
	511
4d284cac	512	static void
1da177e4 LT	513	qeth_eddp_calc_num_pages(struct qeth_eddp_context ctx, struct sk_buff skb,
	514	int hdr_len)
	515	{
	516	int skbs_per_page;
e82b0f2c	517
1da177e4 LT	518	QETH_DBF_TEXT(trace, 5, "eddpcanp");
1da177e4 LT	519	/* can we put multiple skbs in one page? */
7967168c	520	skbs_per_page = PAGE_SIZE / (skb_shinfo(skb)->gso_size + hdr_len);
1da177e4	521	if (skbs_per_page > 1){
7967168c	522	ctx->num_pages = (skb_shinfo(skb)->gso_segs + 1) /
1da177e4 LT	523	skbs_per_page + 1;
	524	ctx->elements_per_skb = 1;
	525	} else {
	526	/* no -> how many elements per skb? */
7967168c	527	ctx->elements_per_skb = (skb_shinfo(skb)->gso_size + hdr_len +
1da177e4 LT	528	PAGE_SIZE) >> PAGE_SHIFT;
1da177e4 LT	529	ctx->num_pages = ctx->elements_per_skb *
7967168c	530	(skb_shinfo(skb)->gso_segs + 1);
1da177e4 LT	531	}
1da177e4 LT	532	ctx->num_elements = ctx->elements_per_skb *
7967168c	533	(skb_shinfo(skb)->gso_segs + 1);
1da177e4 LT	534	}
1da177e4 LT	535
4d284cac	536	static struct qeth_eddp_context *
1da177e4 LT	537	qeth_eddp_create_context_generic(struct qeth_card card, struct sk_buff skb,
	538	int hdr_len)
	539	{
	540	struct qeth_eddp_context *ctx = NULL;
	541	u8 *addr;
	542	int i;
	543
	544	QETH_DBF_TEXT(trace, 5, "creddpcg");
	545	/* create the context and allocate pages */
88abaab4	546	ctx = kzalloc(sizeof(struct qeth_eddp_context), GFP_ATOMIC);
1da177e4 LT	547	if (ctx == NULL){
	548	QETH_DBF_TEXT(trace, 2, "ceddpcn1");
	549	return NULL;
	550	}
1da177e4 LT	551	ctx->type = QETH_LARGE_SEND_EDDP;
	552	qeth_eddp_calc_num_pages(ctx, skb, hdr_len);
	553	if (ctx->elements_per_skb > QETH_MAX_BUFFER_ELEMENTS(card)){
	554	QETH_DBF_TEXT(trace, 2, "ceddpcis");
	555	kfree(ctx);
	556	return NULL;
	557	}
88abaab4	558	ctx->pages = kcalloc(ctx->num_pages, sizeof(u8 *), GFP_ATOMIC);
1da177e4 LT	559	if (ctx->pages == NULL){
	560	QETH_DBF_TEXT(trace, 2, "ceddpcn2");
	561	kfree(ctx);
	562	return NULL;
	563	}
1da177e4 LT	564	for (i = 0; i < ctx->num_pages; ++i){
	565	addr = (u8 *)__get_free_page(GFP_ATOMIC);
	566	if (addr == NULL){
	567	QETH_DBF_TEXT(trace, 2, "ceddpcn3");
	568	ctx->num_pages = i;
	569	qeth_eddp_free_context(ctx);
	570	return NULL;
	571	}
	572	memset(addr, 0, PAGE_SIZE);
	573	ctx->pages[i] = addr;
	574	}
88abaab4	575	ctx->elements = kcalloc(ctx->num_elements,
1da177e4 LT	576	sizeof(struct qeth_eddp_element), GFP_ATOMIC);
	577	if (ctx->elements == NULL){
	578	QETH_DBF_TEXT(trace, 2, "ceddpcn4");
	579	qeth_eddp_free_context(ctx);
	580	return NULL;
	581	}
1da177e4 LT	582	/* reset num_elements; will be incremented again in fill_buffer to
	583	* reflect number of actually used elements */
	584	ctx->num_elements = 0;
	585	return ctx;
	586	}
	587
4d284cac	588	static struct qeth_eddp_context *
1da177e4 LT	589	qeth_eddp_create_context_tcp(struct qeth_card card, struct sk_buff skb,
	590	struct qeth_hdr *qhdr)
	591	{
	592	struct qeth_eddp_context *ctx = NULL;
e82b0f2c	593
1da177e4	594	QETH_DBF_TEXT(trace, 5, "creddpct");
5a5a852e	595	if (skb->protocol == htons(ETH_P_IP))
1da177e4	596	ctx = qeth_eddp_create_context_generic(card, skb,
c9bdd4b5 ACM	597	(sizeof(struct qeth_hdr) +
c9bdd4b5 ACM	598	ip_hdrlen(skb) +
ab6a5bb6	599	tcp_hdrlen(skb)));
5a5a852e	600	else if (skb->protocol == htons(ETH_P_IPV6))
1da177e4 LT	601	ctx = qeth_eddp_create_context_generic(card, skb,
1da177e4 LT	602	sizeof(struct qeth_hdr) + sizeof(struct ipv6hdr) +
ab6a5bb6	603	tcp_hdrlen(skb));
1da177e4 LT	604	else
	605	QETH_DBF_TEXT(trace, 2, "cetcpinv");
	606
	607	if (ctx == NULL) {
	608	QETH_DBF_TEXT(trace, 2, "creddpnl");
	609	return NULL;
	610	}
	611	if (qeth_eddp_fill_context_tcp(ctx, skb, qhdr)){
	612	QETH_DBF_TEXT(trace, 2, "ceddptfe");
	613	qeth_eddp_free_context(ctx);
	614	return NULL;
	615	}
	616	atomic_set(&ctx->refcnt, 1);
	617	return ctx;
	618	}
	619
	620	struct qeth_eddp_context *
	621	qeth_eddp_create_context(struct qeth_card card, struct sk_buff skb,
	622	struct qeth_hdr *qhdr)
	623	{
	624	QETH_DBF_TEXT(trace, 5, "creddpc");
	625	switch (skb->sk->sk_protocol){
	626	case IPPROTO_TCP:
	627	return qeth_eddp_create_context_tcp(card, skb, qhdr);
	628	default:
	629	QETH_DBF_TEXT(trace, 2, "eddpinvp");
	630	}
	631	return NULL;
	632	}