Commit a647a025 authored by Julian Wiedmann's avatar Julian Wiedmann Committed by David S. Miller
Browse files

s390/qeth: speed-up L3 IQD xmit 



This implements a new xmit path for L3 HiperSockets, which carves the
HW header from skb headroom instead of allocating it from the hdr cache.
It also adds NETIF_F_SG support.

The delta in qeth_l3_xmit() is all just removal of IQD-specific code and
some minor consolidation.

Signed-off-by: default avatarJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ea1d4a0c

drivers/s390/net/qeth_l3_main.c

+128 −83
Original line number Diff line number Diff line
@@ -2000,19 +2000,18 @@ static int qeth_l3_get_cast_type(struct sk_buff *skb) 
	return RTN_UNICAST;

}



static void qeth_l3_fill_af_iucv_hdr(struct qeth_card *card,

		struct qeth_hdr *hdr, struct sk_buff *skb)

static void qeth_l3_fill_af_iucv_hdr(struct qeth_hdr *hdr, struct sk_buff *skb,

				     unsigned int data_len)

{

	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.ext_flags = 0;

	hdr->hdr.l3.length = skb->len - ETH_HLEN;

	hdr->hdr.l3.length = data_len;

	hdr->hdr.l3.flags = QETH_HDR_IPV6 | QETH_CAST_UNICAST;



	iucv_hdr = (struct af_iucv_trans_hdr *) (skb->data + ETH_HLEN);

	iucv_hdr = (struct af_iucv_trans_hdr *)(skb_mac_header(skb) + ETH_HLEN);

	memset(daddr, 0, sizeof(daddr));

	daddr[0] = 0xfe;

	daddr[1] = 0x80;
@@ -2156,45 +2155,106 @@ static int qeth_l3_get_elements_no_tso(struct qeth_card *card, 
	return elements;

}



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, nr_frags;

	unsigned char eth_hdr[ETH_HLEN];

	unsigned int hdr_elements = 0;

	struct qeth_hdr *hdr = NULL;

	unsigned int hd_len = 0;

	int push_len, rc;



	/* compress skb to fit into one IO buffer: */

	if (!qeth_get_elements_no(card, skb, 0, 0)) {

		rc = skb_linearize(skb);



		if (card->options.performance_stats) {

			if (rc)

				card->perf_stats.tx_linfail++;

			else

				card->perf_stats.tx_lin++;

		}

		if (rc)

			return rc;

	}



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

	rc = skb_cow_head(skb, hw_hdr_len - ETH_HLEN);

	if (rc)

		return rc;

	skb_copy_from_linear_data(skb, eth_hdr, ETH_HLEN);

	skb_pull(skb, ETH_HLEN);

	frame_len = skb->len;

	nr_frags = skb_shinfo(skb)->nr_frags;



	push_len = qeth_push_hdr(skb, &hdr, hw_hdr_len);

	if (push_len < 0)

		return push_len;

	if (!push_len) {

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

		hd_len = hw_hdr_len;

		hdr_elements = 1;

	}



	if (!qeth_get_elements_no(card, skb, hdr_elements, 0)) {

		rc = -E2BIG;

		goto out;

	}



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

		qeth_l3_fill_af_iucv_hdr(hdr, skb, frame_len);

	else

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



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

out:

	if (!rc) {

		if (card->options.performance_stats && nr_frags) {

			card->perf_stats.sg_skbs_sent++;

			/* nr_frags + skb->data */

			card->perf_stats.sg_frags_sent += nr_frags + 1;

		}

	} else {

		if (!push_len)

			kmem_cache_free(qeth_core_header_cache, hdr);

		if (rc == -EBUSY) {

			/* roll back to ETH header */

			skb_pull(skb, push_len);

			skb_push(skb, ETH_HLEN);

			skb_copy_to_linear_data(skb, eth_hdr, ETH_HLEN);

		}

	}

	return rc;

}



static int qeth_l3_xmit(struct qeth_card *card, struct sk_buff *skb,

			struct qeth_qdio_out_q *queue, int ipv, int cast_type)

{

	int rc;

	unsigned int hd_len, nr_frags;

	int elements, len, rc;

	__be16 *tag;

	struct qeth_hdr *hdr = NULL;

	int hdr_elements = 0;

	int elements;

	struct sk_buff *new_skb = NULL;

	int tx_bytes = skb->len;

	unsigned int hd_len = 0;

	bool use_tso;

	int data_offset = -1;

	unsigned int nr_frags;



	/* Ignore segment size from skb_is_gso(), 1 page is always used. */

	use_tso = skb_is_gso(skb) &&

		  (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4);



	if (card->info.type == QETH_CARD_TYPE_IQD) {

		new_skb = skb;

		data_offset = ETH_HLEN;

		hd_len = sizeof(*hdr);

		hdr = kmem_cache_alloc(qeth_core_header_cache, GFP_ATOMIC);

		if (!hdr)

			return -ENOMEM;

		hdr_elements++;

	} else {

	/* create a clone with writeable headroom */

		new_skb = skb_realloc_headroom(skb, sizeof(struct qeth_hdr_tso)

					+ VLAN_HLEN);

	new_skb = skb_realloc_headroom(skb, sizeof(struct qeth_hdr_tso) +

					    VLAN_HLEN);

	if (!new_skb)

		return -ENOMEM;



	if (ipv == 4) {

		skb_pull(new_skb, ETH_HLEN);

		}



		if (ipv != 4 && skb_vlan_tag_present(new_skb)) {

	} else if (skb_vlan_tag_present(new_skb)) {

		skb_push(new_skb, VLAN_HLEN);

		skb_copy_to_linear_data(new_skb, new_skb->data + 4, 4);

		skb_copy_to_linear_data_offset(new_skb, 4,
@@ -2205,14 +2265,12 @@ static int qeth_l3_xmit(struct qeth_card *card, struct sk_buff *skb, 
		*tag = cpu_to_be16(ETH_P_8021Q);

		*(tag + 1) = cpu_to_be16(skb_vlan_tag_get(new_skb));

	}

	}



	/* fix hardware limitation: as long as we do not have sbal

	 * chaining we can not send long frag lists

	 */

	if ((card->info.type != QETH_CARD_TYPE_IQD) &&

	    ((use_tso && !qeth_l3_get_elements_no_tso(card, new_skb, 1)) ||

	     (!use_tso && !qeth_get_elements_no(card, new_skb, 0, 0)))) {

	if ((use_tso && !qeth_l3_get_elements_no_tso(card, new_skb, 1)) ||

	    (!use_tso && !qeth_get_elements_no(card, new_skb, 0, 0))) {

		rc = skb_linearize(new_skb);



		if (card->options.performance_stats) {
@@ -2234,20 +2292,9 @@ static int qeth_l3_xmit(struct qeth_card *card, struct sk_buff *skb, 
		qeth_tso_fill_header(card, hdr, new_skb);

		hdr_elements++;

	} else {

		if (data_offset < 0) {

		hdr = skb_push(new_skb, sizeof(struct qeth_hdr));

		qeth_l3_fill_header(card, hdr, new_skb, ipv, cast_type,

					    new_skb->len -

					    sizeof(struct qeth_hdr));

		} else {

			if (be16_to_cpu(new_skb->protocol) == ETH_P_AF_IUCV)

				qeth_l3_fill_af_iucv_hdr(card, hdr, new_skb);

			else {

				qeth_l3_fill_header(card, hdr, new_skb, ipv,

						    cast_type,

						    new_skb->len - data_offset);

			}

		}

				    new_skb->len - sizeof(struct qeth_hdr));



		if (new_skb->ip_summed == CHECKSUM_PARTIAL) {

			qeth_tx_csum(new_skb, &hdr->hdr.l3.ext_flags, ipv);
@@ -2258,21 +2305,19 @@ static int qeth_l3_xmit(struct qeth_card *card, struct sk_buff *skb, 


	elements = use_tso ?

		   qeth_l3_get_elements_no_tso(card, new_skb, hdr_elements) :

		   qeth_get_elements_no(card, new_skb, hdr_elements,

					(data_offset > 0) ? data_offset : 0);

		   qeth_get_elements_no(card, new_skb, hdr_elements, 0);

	if (!elements) {

		rc = -E2BIG;

		goto out;

	}

	elements += hdr_elements;



	if (card->info.type != QETH_CARD_TYPE_IQD) {

		int len;

	if (use_tso) {

		hd_len = sizeof(struct qeth_hdr_tso) +

			 ip_hdrlen(new_skb) + tcp_hdrlen(new_skb);

		len = hd_len;

	} else {

		hd_len = 0;

		len = sizeof(struct qeth_hdr_layer3);

	}
@@ -2280,12 +2325,8 @@ static int qeth_l3_xmit(struct qeth_card *card, struct sk_buff *skb, 
		rc = -EINVAL;

		goto out;

	}

		rc = qeth_do_send_packet(card, queue, new_skb, hdr, hd_len,

					 hd_len, elements);

	} else

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

					      hd_len);



	rc = qeth_do_send_packet(card, queue, new_skb, hdr, hd_len, hd_len,

				 elements);

out:

	if (!rc) {

		if (new_skb != skb)
@@ -2304,8 +2345,6 @@ out: 
	} else {

		if (new_skb != skb)

			dev_kfree_skb_any(new_skb);

		if (data_offset >= 0)

			kmem_cache_free(qeth_core_header_cache, hdr);

	}

	return rc;

}
@@ -2345,6 +2384,9 @@ static netdev_tx_t qeth_l3_hard_start_xmit(struct sk_buff *skb, 
	}

	netif_stop_queue(dev);



	if (IS_IQD(card))

		rc = qeth_l3_xmit_offload(card, skb, queue, ipv, cast_type);

	else

		rc = qeth_l3_xmit(card, skb, queue, ipv, cast_type);



	if (!rc) {
@@ -2503,9 +2545,6 @@ static int qeth_l3_setup_netdev(struct qeth_card *card) 
		if (!(card->info.unique_id & UNIQUE_ID_NOT_BY_CARD))

			card->dev->dev_id = card->info.unique_id & 0xffff;



		card->dev->hw_features |= NETIF_F_SG;

		card->dev->vlan_features |= NETIF_F_SG;



		if (!card->info.guestlan) {

			card->dev->features |= NETIF_F_SG;

			card->dev->hw_features |= NETIF_F_TSO |
@@ -2524,7 +2563,10 @@ static int qeth_l3_setup_netdev(struct qeth_card *card) 
		if (!card->dev)

			return -ENODEV;

		card->dev->flags |= IFF_NOARP;

		card->dev->priv_flags &= ~IFF_TX_SKB_SHARING;

		card->dev->netdev_ops = &qeth_l3_netdev_ops;

		card->dev->needed_headroom = sizeof(struct qeth_hdr) - ETH_HLEN;



		rc = qeth_l3_iqd_read_initial_mac(card);

		if (rc)

			return rc;
@@ -2543,6 +2585,9 @@ static int qeth_l3_setup_netdev(struct qeth_card *card) 
	card->dev->features |=	NETIF_F_HW_VLAN_CTAG_TX |

				NETIF_F_HW_VLAN_CTAG_RX |

				NETIF_F_HW_VLAN_CTAG_FILTER;

	card->dev->hw_features |= NETIF_F_SG;

	card->dev->vlan_features |= NETIF_F_SG;



	netif_keep_dst(card->dev);

	if (card->dev->hw_features & NETIF_F_TSO)

		netif_set_gso_max_size(card->dev,

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