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Commit f6b85b6c authored by Frank Blaschka's avatar Frank Blaschka Committed by David S. Miller
Browse files

qeth: exploit HW TX checksumming 



OSA supports HW TX checksumming in layer 3 mode. Enable this
feature and remove software fallback used for TSO. Cleanup
checksum bits to indicate OSA can do checksumming only for
IPv4 TCP and UDP.

Signed-off-by: default avatarFrank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2d6c9ffc

drivers/s390/net/qeth_core.h

+2 −1
Original line number Diff line number Diff line
@@ -351,7 +351,7 @@ enum qeth_header_ids { 
#define QETH_HDR_EXT_SRC_MAC_ADDR     0x08

#define QETH_HDR_EXT_CSUM_HDR_REQ     0x10

#define QETH_HDR_EXT_CSUM_TRANSP_REQ  0x20

#define QETH_HDR_EXT_UDP_TSO          0x40 /*bit off for TCP*/

#define QETH_HDR_EXT_UDP	      0x40 /*bit off for TCP*/



static inline int qeth_is_last_sbale(struct qdio_buffer_element *sbale)

{
@@ -630,6 +630,7 @@ struct qeth_card_info { 
	int unique_id;

	struct qeth_card_blkt blkt;

	__u32 csum_mask;

	__u32 tx_csum_mask;

	enum qeth_ipa_promisc_modes promisc_mode;

};

drivers/s390/net/qeth_l3_main.c

+67 −25
Original line number Diff line number Diff line
@@ -54,16 +54,16 @@ int qeth_l3_set_large_send(struct qeth_card *card, 
	if (card->options.large_send == QETH_LARGE_SEND_TSO) {

		if (qeth_is_supported(card, IPA_OUTBOUND_TSO)) {

			card->dev->features |= NETIF_F_TSO | NETIF_F_SG |

					NETIF_F_HW_CSUM;

					NETIF_F_IP_CSUM;

		} else {

			card->dev->features &= ~(NETIF_F_TSO | NETIF_F_SG |

					NETIF_F_HW_CSUM);

					NETIF_F_IP_CSUM);

			card->options.large_send = QETH_LARGE_SEND_NO;

			rc = -EOPNOTSUPP;

		}

	} else {

		card->dev->features &= ~(NETIF_F_TSO | NETIF_F_SG |

					NETIF_F_HW_CSUM);

					NETIF_F_IP_CSUM);

		card->options.large_send = QETH_LARGE_SEND_NO;

	}

	return rc;
@@ -1108,6 +1108,13 @@ static int qeth_l3_default_setassparms_cb(struct qeth_card *card, 
		card->info.csum_mask = cmd->data.setassparms.data.flags_32bit;

		QETH_DBF_TEXT_(TRACE, 3, "csum:%d", card->info.csum_mask);

	}

	if (cmd->data.setassparms.hdr.assist_no == IPA_OUTBOUND_CHECKSUM &&

	    cmd->data.setassparms.hdr.command_code == IPA_CMD_ASS_START) {

		card->info.tx_csum_mask =

			cmd->data.setassparms.data.flags_32bit;

		QETH_DBF_TEXT_(TRACE, 3, "tcsu:%d", card->info.tx_csum_mask);

	}



	return 0;

}
@@ -1536,6 +1543,28 @@ static int qeth_l3_start_ipa_checksum(struct qeth_card *card) 
	return rc;

}



static int qeth_l3_start_ipa_tx_checksum(struct qeth_card *card)

{

	int rc = 0;



	if (!qeth_is_supported(card, IPA_OUTBOUND_CHECKSUM))

		return rc;

	rc = qeth_l3_send_simple_setassparms(card, IPA_OUTBOUND_CHECKSUM,

			  IPA_CMD_ASS_START, 0);

	if (rc)

		goto err_out;

	rc = qeth_l3_send_simple_setassparms(card, IPA_OUTBOUND_CHECKSUM,

			  IPA_CMD_ASS_ENABLE, card->info.tx_csum_mask);

	if (rc)

		goto err_out;

	dev_info(&card->gdev->dev, "HW TX Checksumming enabled\n");

	return rc;

err_out:

	dev_warn(&card->gdev->dev, "Enabling HW TX checksumming for %s "

		"failed, using SW TX checksumming\n", QETH_CARD_IFNAME(card));

	return rc;

}



static int qeth_l3_start_ipa_tso(struct qeth_card *card)

{

	int rc;
@@ -1578,6 +1607,7 @@ static int qeth_l3_start_ipassists(struct qeth_card *card) 
	qeth_l3_start_ipa_ipv6(card);		/* go on*/

	qeth_l3_start_ipa_broadcast(card);		/* go on*/

	qeth_l3_start_ipa_checksum(card);		/* go on*/

	qeth_l3_start_ipa_tx_checksum(card);

	qeth_l3_start_ipa_tso(card);		/* go on*/

	return 0;

}
@@ -2817,6 +2847,21 @@ static void qeth_l3_fill_header(struct qeth_card *card, struct qeth_hdr *hdr, 
	}

}



static inline void qeth_l3_hdr_csum(struct qeth_card *card,

		struct qeth_hdr *hdr, struct sk_buff *skb)

{

	struct iphdr *iph = ip_hdr(skb);



	/* tcph->check contains already the pseudo hdr checksum

	 * so just set the header flags

	 */

	if (iph->protocol == IPPROTO_UDP)

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

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

	if (card->options.performance_stats)

		card->perf_stats.tx_csum++;

}



static void qeth_tso_fill_header(struct qeth_card *card,

		struct qeth_hdr *qhdr, struct sk_buff *skb)

{
@@ -2852,21 +2897,6 @@ static void qeth_tso_fill_header(struct qeth_card *card, 
	}

}



static void qeth_tx_csum(struct sk_buff *skb)

{

	__wsum csum;

	int offset;



	skb_set_transport_header(skb, skb->csum_start - skb_headroom(skb));

	offset = skb->csum_start - skb_headroom(skb);

	BUG_ON(offset >= skb_headlen(skb));

	csum = skb_checksum(skb, offset, skb->len - offset, 0);



	offset += skb->csum_offset;

	BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));

	*(__sum16 *)(skb->data + offset) = csum_fold(csum);

}



static inline int qeth_l3_tso_elements(struct sk_buff *skb)

{

	unsigned long tcpd = (unsigned long)tcp_hdr(skb) +
@@ -2923,12 +2953,6 @@ static int qeth_l3_hard_start_xmit(struct sk_buff *skb, struct net_device *dev) 


	if (skb_is_gso(skb))

		large_send = card->options.large_send;

	else

		if (skb->ip_summed == CHECKSUM_PARTIAL) {

			qeth_tx_csum(skb);

			if (card->options.performance_stats)

				card->perf_stats.tx_csum++;

		}



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

	    (skb_shinfo(skb)->nr_frags == 0)) {
@@ -3007,6 +3031,9 @@ static int qeth_l3_hard_start_xmit(struct sk_buff *skb, struct net_device *dev) 
						cast_type);

			hdr->hdr.l3.length = new_skb->len - data_offset;

		}



		if (skb->ip_summed == CHECKSUM_PARTIAL)

			qeth_l3_hdr_csum(card, hdr, new_skb);

	}



	elems = qeth_get_elements_no(card, (void *)hdr, new_skb,
@@ -3132,10 +3159,25 @@ static int qeth_l3_ethtool_set_tso(struct net_device *dev, u32 data) 
	return rc;

}



static int qeth_l3_ethtool_set_tx_csum(struct net_device *dev, u32 data)

{

	struct qeth_card *card = dev->ml_priv;



	if (data) {

		if (qeth_is_supported(card, IPA_OUTBOUND_CHECKSUM))

			dev->features |= NETIF_F_IP_CSUM;

		else

			return -EPERM;

	} else

		dev->features &= ~NETIF_F_IP_CSUM;



	return 0;

}



static const struct ethtool_ops qeth_l3_ethtool_ops = {

	.get_link = ethtool_op_get_link,

	.get_tx_csum = ethtool_op_get_tx_csum,

	.set_tx_csum = ethtool_op_set_tx_hw_csum,

	.set_tx_csum = qeth_l3_ethtool_set_tx_csum,

	.get_rx_csum = qeth_l3_ethtool_get_rx_csum,

	.set_rx_csum = qeth_l3_ethtool_set_rx_csum,

	.get_sg      = ethtool_op_get_sg,