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s390/qeth: speed up L2 IQD xmit
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Modify the L2 OSA xmit path so that it also supports L2 IQD devices
(in particular, their HW header requirements). This allows IQD devices
to advertise NETIF_F_SG support, and eliminates the allocation overhead
for the HW header.

Signed-off-by: Julian Wiedmann <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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@julianwiedmann @davem330
julianwiedmann authored and davem330 committed Jul 21, 2018
1 parent a7c2f4a commit 5f89eca
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Showing 3 changed files with 30 additions and 56 deletions.
7 changes: 7 additions & 0 deletions drivers/s390/net/qeth_core_main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -5731,6 +5731,13 @@ static struct net_device *qeth_alloc_netdev(struct qeth_card *card)
dev->mtu = 0;
SET_NETDEV_DEV(dev, &card->gdev->dev);
netif_carrier_off(dev);

if (!IS_OSN(card)) {
dev->priv_flags &= ~IFF_TX_SKB_SHARING;
dev->hw_features |= NETIF_F_SG;
dev->vlan_features |= NETIF_F_SG;
}

return dev;
}

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76 changes: 23 additions & 53 deletions drivers/s390/net/qeth_l2_main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -641,37 +641,13 @@ static void qeth_l2_set_rx_mode(struct net_device *dev)
qeth_promisc_to_bridge(card);
}

static int qeth_l2_xmit_iqd(struct qeth_card *card, struct sk_buff *skb,
struct qeth_qdio_out_q *queue, int cast_type)
{
unsigned int data_offset = ETH_HLEN;
struct qeth_hdr *hdr;
int rc;

hdr = kmem_cache_alloc(qeth_core_header_cache, GFP_ATOMIC);
if (!hdr)
return -ENOMEM;
qeth_l2_fill_header(hdr, skb, cast_type, skb->len);
skb_copy_from_linear_data(skb, ((char *)hdr) + sizeof(*hdr),
data_offset);

if (!qeth_get_elements_no(card, skb, 1, data_offset)) {
rc = -E2BIG;
goto out;
}
rc = qeth_do_send_packet_fast(queue, skb, hdr, data_offset,
sizeof(*hdr) + data_offset);
out:
if (rc)
kmem_cache_free(qeth_core_header_cache, hdr);
return rc;
}

static int qeth_l2_xmit_osa(struct qeth_card *card, struct sk_buff *skb,
struct qeth_qdio_out_q *queue, int cast_type,
int ipv)
static int qeth_l2_xmit(struct qeth_card *card, struct sk_buff *skb,
struct qeth_qdio_out_q *queue, int cast_type, int ipv)
{
const unsigned int proto_len = IS_IQD(card) ? ETH_HLEN : 0;
const unsigned int hw_hdr_len = sizeof(struct qeth_hdr);
unsigned int frame_len = skb->len;
unsigned int data_offset = 0;
struct qeth_hdr *hdr = NULL;
unsigned int hd_len = 0;
unsigned int elements;
Expand All @@ -682,25 +658,32 @@ static int qeth_l2_xmit_osa(struct qeth_card *card, struct sk_buff *skb,
if (rc)
return rc;

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 allocated from cache */
hd_len = sizeof(*hdr);
/* HW header needs its own buffer element. */
hd_len = hw_hdr_len + proto_len;
data_offset = proto_len;
}
qeth_l2_fill_header(hdr, skb, cast_type, skb->len - push_len);
qeth_l2_fill_header(hdr, skb, cast_type, frame_len);
if (skb->ip_summed == CHECKSUM_PARTIAL) {
qeth_tx_csum(skb, &hdr->hdr.l2.flags[1], ipv);
if (card->options.performance_stats)
card->perf_stats.tx_csum++;
}

is_sg = skb_is_nonlinear(skb);
/* TODO: remove the skb_orphan() once TX completion is fast enough */
skb_orphan(skb);
rc = qeth_do_send_packet(card, queue, skb, hdr, 0, hd_len, elements);
if (IS_IQD(card)) {
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, data_offset,
hd_len, elements);
}

if (!rc) {
if (card->options.performance_stats) {
Expand Down Expand Up @@ -759,16 +742,10 @@ static netdev_tx_t qeth_l2_hard_start_xmit(struct sk_buff *skb,
}
netif_stop_queue(dev);

switch (card->info.type) {
case QETH_CARD_TYPE_OSN:
if (IS_OSN(card))
rc = qeth_l2_xmit_osn(card, skb, queue);
break;
case QETH_CARD_TYPE_IQD:
rc = qeth_l2_xmit_iqd(card, skb, queue, cast_type);
break;
default:
rc = qeth_l2_xmit_osa(card, skb, queue, cast_type, ipv);
}
else
rc = qeth_l2_xmit(card, skb, queue, cast_type, ipv);

if (!rc) {
card->stats.tx_packets++;
Expand Down Expand Up @@ -927,21 +904,14 @@ static int qeth_l2_setup_netdev(struct qeth_card *card)
card->dev->flags |= IFF_NOARP;
} else {
card->dev->ethtool_ops = &qeth_l2_ethtool_ops;
card->dev->needed_headroom = sizeof(struct qeth_hdr);
}

if (card->info.type == QETH_CARD_TYPE_OSM)
card->dev->features |= NETIF_F_VLAN_CHALLENGED;
else
card->dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;

if (card->info.type != QETH_CARD_TYPE_OSN &&
card->info.type != QETH_CARD_TYPE_IQD) {
card->dev->priv_flags &= ~IFF_TX_SKB_SHARING;
card->dev->needed_headroom = sizeof(struct qeth_hdr);
card->dev->hw_features |= NETIF_F_SG;
card->dev->vlan_features |= NETIF_F_SG;
}

if (card->info.type == QETH_CARD_TYPE_OSD && !card->info.guestlan) {
card->dev->features |= NETIF_F_SG;
/* OSA 3S and earlier has no RX/TX support */
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3 changes: 0 additions & 3 deletions drivers/s390/net/qeth_l3_main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2556,13 +2556,10 @@ static int qeth_l3_setup_netdev(struct qeth_card *card)
return -ENODEV;

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;
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)
Expand Down

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