Commit e517b649 authored by Julian Wiedmann's avatar Julian Wiedmann Committed by David S. Miller
Browse files

s390/qeth: prepare for copy-free TSO transmission 



Add all the necessary TSO plumbing to the copy-less transmit path.
This includes calculating the right length of required protocol headers,
and always building a separate buffer element for the TSO headers.

A follow-up patch will then switch TSO traffic over to this path.

Signed-off-by: default avatarJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 55494264

drivers/s390/net/qeth_core.h

+1 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include <net/ipv6.h>

#include <net/if_inet6.h>

#include <net/addrconf.h>

#include <net/tcp.h>



#include <asm/debug.h>

#include <asm/qdio.h>

drivers/s390/net/qeth_core_main.c

+8 −2
Original line number Diff line number Diff line
@@ -3845,7 +3845,8 @@ int qeth_hdr_chk_and_bounce(struct sk_buff *skb, struct qeth_hdr **hdr, int len) 
}

EXPORT_SYMBOL_GPL(qeth_hdr_chk_and_bounce);



#define QETH_HDR_CACHE_OBJ_SIZE		(sizeof(struct qeth_hdr) + ETH_HLEN)

#define QETH_HDR_CACHE_OBJ_SIZE		(sizeof(struct qeth_hdr_tso) + \

					 MAX_TCP_HEADER)



/**

 * qeth_add_hw_header() - add a HW header to an skb.
@@ -3880,6 +3881,10 @@ check_layout: 
	if (qeth_get_elements_for_range(start, end + contiguous) == 1) {

		/* Push HW header into same page as first protocol header. */

		push_ok = true;

		/* ... but TSO always needs a separate element for headers: */

		if (skb_is_gso(skb))

			__elements = 1 + qeth_count_elements(skb, proto_len);

		else

			__elements = qeth_count_elements(skb, 0);

	} else if (!proto_len && qeth_get_elements_for_range(start, end) == 1) {

		/* Push HW header into a new page. */
@@ -4193,6 +4198,7 @@ int qeth_xmit(struct qeth_card *card, struct sk_buff *skb, 
		hd_len = hw_hdr_len + proto_len;

		data_offset = proto_len;

	}

	memset(hdr, 0, hw_hdr_len);

	fill_header(card, hdr, skb, ipv, cast_type, frame_len);



	is_sg = skb_is_nonlinear(skb);

drivers/s390/net/qeth_l2_main.c

+0 −1
Original line number Diff line number Diff line
@@ -199,7 +199,6 @@ static void qeth_l2_fill_header(struct qeth_card *card, struct qeth_hdr *hdr, 
{

	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb_mac_header(skb);



	memset(hdr, 0, sizeof(struct qeth_hdr));

	hdr->hdr.l2.id = QETH_HEADER_TYPE_LAYER2;

	hdr->hdr.l2.pkt_length = data_len;

drivers/s390/net/qeth_l3_main.c

+68 −25
Original line number Diff line number Diff line
@@ -2008,7 +2008,6 @@ static void qeth_l3_fill_af_iucv_hdr(struct qeth_hdr *hdr, struct sk_buff *skb, 
	char daddr[16];

	struct af_iucv_trans_hdr *iucv_hdr;



	memset(hdr, 0, sizeof(struct qeth_hdr));

	hdr->hdr.l3.id = QETH_HEADER_TYPE_LAYER3;

	hdr->hdr.l3.length = data_len;

	hdr->hdr.l3.flags = QETH_HDR_IPV6 | QETH_CAST_UNICAST;
@@ -2038,10 +2037,22 @@ static void qeth_l3_fill_header(struct qeth_card *card, struct qeth_hdr *hdr, 
{

	struct vlan_ethhdr *veth = vlan_eth_hdr(skb);



	memset(hdr, 0, sizeof(struct qeth_hdr));

	hdr->hdr.l3.id = QETH_HEADER_TYPE_LAYER3;

	hdr->hdr.l3.length = data_len;



	if (skb_is_gso(skb)) {

		hdr->hdr.l3.id = QETH_HEADER_TYPE_TSO;

	} else {

		hdr->hdr.l3.id = QETH_HEADER_TYPE_LAYER3;

		if (skb->ip_summed == CHECKSUM_PARTIAL) {

			qeth_tx_csum(skb, &hdr->hdr.l3.ext_flags, ipv);

			/* some HW requires combined L3+L4 csum offload: */

			if (ipv == 4)

				hdr->hdr.l3.ext_flags |= QETH_HDR_EXT_CSUM_HDR_REQ;

			if (card->options.performance_stats)

				card->perf_stats.tx_csum++;

		}

	}



	if (ipv == 4 || IS_IQD(card)) {

		/* NETIF_F_HW_VLAN_CTAG_TX */

		if (skb_vlan_tag_present(skb)) {
@@ -2053,15 +2064,6 @@ static void qeth_l3_fill_header(struct qeth_card *card, struct qeth_hdr *hdr, 
		hdr->hdr.l3.vlan_id = ntohs(veth->h_vlan_TCI);

	}



	if (!skb_is_gso(skb) && skb->ip_summed == CHECKSUM_PARTIAL) {

		qeth_tx_csum(skb, &hdr->hdr.l3.ext_flags, ipv);

		/* some HW requires combined L3+L4 csum offload: */

		if (ipv == 4)

			hdr->hdr.l3.ext_flags |= QETH_HDR_EXT_CSUM_HDR_REQ;

		if (card->options.performance_stats)

			card->perf_stats.tx_csum++;

	}



	/* OSA only: */

	if (!ipv) {

		hdr->hdr.l3.flags = QETH_HDR_PASSTHRU;
@@ -2100,6 +2102,22 @@ static void qeth_l3_fill_header(struct qeth_card *card, struct qeth_hdr *hdr, 
	rcu_read_unlock();

}



static void qeth_l3_fill_tso_ext(struct qeth_hdr_tso *hdr,

				 unsigned int payload_len, struct sk_buff *skb,

				 unsigned int proto_len)

{

	struct qeth_hdr_ext_tso *ext = &hdr->ext;



	ext->hdr_tot_len = sizeof(*ext);

	ext->imb_hdr_no = 1;

	ext->hdr_type = 1;

	ext->hdr_version = 1;

	ext->hdr_len = 28;

	ext->payload_len = payload_len;

	ext->mss = skb_shinfo(skb)->gso_size;

	ext->dg_hdr_len = proto_len;

}



static void qeth_tso_fill_header(struct qeth_card *card,

		struct qeth_hdr *qhdr, struct sk_buff *skb)

{
@@ -2108,8 +2126,6 @@ static void qeth_tso_fill_header(struct qeth_card *card, 
	struct iphdr *iph = ip_hdr(skb);

	struct ipv6hdr *ip6h = ipv6_hdr(skb);



	/*fix header to TSO values ...*/

	hdr->hdr.hdr.l3.id = QETH_HEADER_TYPE_TSO;

	/*set values which are fix for the first approach ...*/

	hdr->ext.hdr_tot_len = (__u16) sizeof(struct qeth_hdr_ext_tso);

	hdr->ext.imb_hdr_no  = 1;
@@ -2173,20 +2189,35 @@ static void qeth_l3_fixup_headers(struct sk_buff *skb) 
	/* this is safe, IPv6 traffic takes a different path */

	if (skb->ip_summed == CHECKSUM_PARTIAL)

		iph->check = 0;

	if (skb_is_gso(skb)) {

		iph->tot_len = 0;

		tcp_hdr(skb)->check = ~tcp_v4_check(0, iph->saddr,

						    iph->daddr, 0);

	}

}



static int qeth_l3_xmit_offload(struct qeth_card *card, struct sk_buff *skb,

				struct qeth_qdio_out_q *queue, int ipv,

				int cast_type)

{

	const unsigned int hw_hdr_len = sizeof(struct qeth_hdr);

	unsigned int frame_len, elements;

	unsigned int hw_hdr_len, proto_len, frame_len, elements;

	unsigned char eth_hdr[ETH_HLEN];

	bool is_tso = skb_is_gso(skb);

	unsigned int data_offset = 0;

	struct qeth_hdr *hdr = NULL;

	unsigned int hd_len = 0;

	int push_len, rc;

	bool is_sg;



	if (is_tso) {

		hw_hdr_len = sizeof(struct qeth_hdr_tso);

		proto_len = skb_transport_offset(skb) + tcp_hdrlen(skb) -

			    ETH_HLEN;

	} else {

		hw_hdr_len = sizeof(struct qeth_hdr);

		proto_len = 0;

	}



	/* re-use the L2 header area for the HW header: */

	rc = skb_cow_head(skb, hw_hdr_len - ETH_HLEN);

	if (rc)
@@ -2196,28 +2227,36 @@ static int qeth_l3_xmit_offload(struct qeth_card *card, struct sk_buff *skb, 
	frame_len = skb->len;



	qeth_l3_fixup_headers(skb);

	push_len = qeth_add_hw_header(card, skb, &hdr, hw_hdr_len, 0,

	push_len = qeth_add_hw_header(card, skb, &hdr, hw_hdr_len, proto_len,

				      &elements);

	if (push_len < 0)

		return push_len;

	if (!push_len) {

		/* hdr was added discontiguous from skb->data */

		hd_len = hw_hdr_len;

	if (is_tso || !push_len) {

		/* HW header needs its own buffer element. */

		hd_len = hw_hdr_len + proto_len;

		data_offset = push_len + proto_len;

	}

	memset(hdr, 0, hw_hdr_len);



	if (skb->protocol == htons(ETH_P_AF_IUCV))

	if (skb->protocol == htons(ETH_P_AF_IUCV)) {

		qeth_l3_fill_af_iucv_hdr(hdr, skb, frame_len);

	else

	} else {

		qeth_l3_fill_header(card, hdr, skb, ipv, cast_type, frame_len);

		if (is_tso)

			qeth_l3_fill_tso_ext((struct qeth_hdr_tso *) hdr,

					     frame_len - proto_len, skb,

					     proto_len);

	}



	is_sg = skb_is_nonlinear(skb);

	if (IS_IQD(card)) {

		rc = qeth_do_send_packet_fast(queue, skb, hdr, 0, hd_len);

		rc = qeth_do_send_packet_fast(queue, skb, hdr, data_offset,

					      hd_len);

	} else {

		/* TODO: drop skb_orphan() once TX completion is fast enough */

		skb_orphan(skb);

		rc = qeth_do_send_packet(card, queue, skb, hdr, 0, hd_len,

					 elements);

		rc = qeth_do_send_packet(card, queue, skb, hdr, data_offset,

					 hd_len, elements);

	}



	if (!rc) {
@@ -2225,6 +2264,10 @@ static int qeth_l3_xmit_offload(struct qeth_card *card, struct sk_buff *skb, 
			card->perf_stats.buf_elements_sent += elements;

			if (is_sg)

				card->perf_stats.sg_skbs_sent++;

			if (is_tso) {

				card->perf_stats.large_send_bytes += frame_len;

				card->perf_stats.large_send_cnt++;

			}

		}

	} else {

		if (!push_len)

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