From: Julian Wiedmann <jwi@linux.ibm.com>
Subject: s390/qeth: speed-up IPv4 OSA xmit
Patch-mainline: v4.19-rc1
Git-commit: fb321f25e582ae45e6b792fb38a3fc261dc5131e
References: FATE#326350, LTC#169511, bsc#1113509
Summary: qeth: performance improvements
Description: This adds recent functional and performance improvements for the
qeth network driver.
Primarily this brings Scatter-Gather support for HiperSockets,
reduced CPU consumption in the L3 IPv4 transmit path for OSA,
improved Promiscuous Mode performance due to IFF_UNICAST_FLT,
support for Scatter-Gather on z/VM virtual NICs, and
support for delayed GRO flushing.
For sanity & stability reasons, this effectively constitutes a
backport of the qeth device driver from 4.19 mainline.
Upstream-Description:
s390/qeth: speed-up IPv4 OSA xmit
Move the xmit of offload-eligible (ie IPv4) traffic on OSA over to the
new, copy-free path.
As with L2, we'll need to preserve the skb_orphan() behaviour of the
old code path until TX completion is sufficiently fast.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/s390/net/qeth_l3_main.c | 33 +++++++++++++++++++++------------
1 file changed, 21 insertions(+), 12 deletions(-)
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -2050,6 +2050,12 @@ static void qeth_l3_fill_header(struct q
hdr->hdr.l3.vlan_id = skb_vlan_tag_get(skb);
}
+ if (!skb_is_gso(skb) && skb->ip_summed == CHECKSUM_PARTIAL) {
+ qeth_tx_csum(skb, &hdr->hdr.l3.ext_flags, ipv);
+ if (card->options.performance_stats)
+ card->perf_stats.tx_csum++;
+ }
+
/* OSA only: */
if (!ipv) {
hdr->hdr.l3.flags = QETH_HDR_PASSTHRU;
@@ -2170,8 +2176,8 @@ static int qeth_l3_xmit_offload(struct q
unsigned char eth_hdr[ETH_HLEN];
unsigned int hdr_elements = 0;
struct qeth_hdr *hdr = NULL;
+ int elements, push_len, rc;
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)) {
@@ -2205,17 +2211,26 @@ static int qeth_l3_xmit_offload(struct q
hdr_elements = 1;
}
- if (!qeth_get_elements_no(card, skb, hdr_elements, 0)) {
+ elements = qeth_get_elements_no(card, skb, hdr_elements, 0);
+ if (!elements) {
rc = -E2BIG;
goto out;
}
+ elements += hdr_elements;
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);
+ if (IS_IQD(card)) {
+ rc = qeth_do_send_packet_fast(queue, skb, hdr, 0, 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);
+ }
out:
if (!rc) {
if (card->options.performance_stats && nr_frags) {
@@ -2301,12 +2316,6 @@ static int qeth_l3_xmit(struct qeth_card
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));
-
- if (new_skb->ip_summed == CHECKSUM_PARTIAL) {
- qeth_tx_csum(new_skb, &hdr->hdr.l3.ext_flags, ipv);
- if (card->options.performance_stats)
- card->perf_stats.tx_csum++;
- }
}
elements = use_tso ?
@@ -2390,7 +2399,7 @@ static netdev_tx_t qeth_l3_hard_start_xm
}
netif_stop_queue(dev);
- if (IS_IQD(card))
+ if (IS_IQD(card) || (!skb_is_gso(skb) && ipv == 4))
rc = qeth_l3_xmit_offload(card, skb, queue, ipv, cast_type);
else
rc = qeth_l3_xmit(card, skb, queue, ipv, cast_type);
@@ -2569,9 +2578,7 @@ static int qeth_l3_setup_netdev(struct q
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)
@@ -2588,6 +2595,8 @@ static int qeth_l3_setup_netdev(struct q
card->dev->max_mtu = ETH_MAX_MTU;
card->dev->dev_port = card->info.portno;
card->dev->ethtool_ops = &qeth_l3_ethtool_ops;
+ card->dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+ card->dev->needed_headroom = sizeof(struct qeth_hdr) - ETH_HLEN;
card->dev->features |= NETIF_F_HW_VLAN_CTAG_TX |
NETIF_F_HW_VLAN_CTAG_RX |
NETIF_F_HW_VLAN_CTAG_FILTER;