From: Julian Wiedmann <jwi@linux.ibm.com>
Subject: s390/qeth: allocate skb from NAPI cache
Patch-mainline: v4.17-rc1
Git-commit: 37cf05d2fff52a8ad1ce977c2a485e91fe793162
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: allocate skb from NAPI cache

             napi_alloc_skb() doesn't need to disable IRQs during the allocation,
             and thus may save us a few cycles.
             Doing so requires a small fix-up in the HiperTransport path, which
             currently assumes a fixed NET_SKB_PAD headroom padding. napi_alloc_skb()
             adds an additional NET_IP_ALIGN padding, so use the proper helper for
             setting up the mac_header offset.

             Use this opportunity to convert the non-NAPI path to netdev_alloc_skb(),
             which means that skb->dev is now always set-up during allocation and
             doesn't need to be assigned manually.

             Signed-off-by: Julian Wiedmann <jwi@linux.vnet.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_core_main.c |    5 +++--
 drivers/s390/net/qeth_l2_main.c   |    1 -
 drivers/s390/net/qeth_l3_main.c   |    4 +---
 3 files changed, 4 insertions(+), 6 deletions(-)

--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -2853,7 +2853,8 @@ static int qeth_init_input_buffer(struct
 	int i;
 
 	if ((card->options.cq == QETH_CQ_ENABLED) && (!buf->rx_skb)) {
-		buf->rx_skb = dev_alloc_skb(QETH_RX_PULL_LEN + ETH_HLEN);
+		buf->rx_skb = netdev_alloc_skb(card->dev,
+					       QETH_RX_PULL_LEN + ETH_HLEN);
 		if (!buf->rx_skb)
 			return 1;
 	}
@@ -5334,7 +5335,7 @@ struct sk_buff *qeth_core_get_next_skb(s
 	} else {
 		unsigned int linear = (use_rx_sg) ? QETH_RX_PULL_LEN : skb_len;
 
-		skb = dev_alloc_skb(linear + headroom);
+		skb = napi_alloc_skb(&card->napi, linear + headroom);
 	}
 	if (!skb)
 		goto no_mem;
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -420,7 +420,6 @@ static int qeth_l2_process_inbound_buffe
 			*done = 1;
 			break;
 		}
-		skb->dev = card->dev;
 		switch (hdr->hdr.l2.id) {
 		case QETH_HEADER_TYPE_LAYER2:
 			skb->pkt_type = PACKET_HOST;
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -1572,7 +1572,6 @@ static int qeth_l3_process_inbound_buffe
 			*done = 1;
 			break;
 		}
-		skb->dev = card->dev;
 		switch (hdr->hdr.l3.id) {
 		case QETH_HEADER_TYPE_LAYER3:
 			magic = *(__u16 *)skb->data;
@@ -1580,11 +1579,10 @@ static int qeth_l3_process_inbound_buffe
 			    (magic == ETH_P_AF_IUCV)) {
 				skb->protocol = cpu_to_be16(ETH_P_AF_IUCV);
 				skb->pkt_type = PACKET_HOST;
-				skb->mac_header = NET_SKB_PAD;
-				skb->dev = card->dev;
 				len = skb->len;
 				card->dev->header_ops->create(skb, card->dev, 0,
 					card->dev->dev_addr, "FAKELL", len);
+				skb_reset_mac_header(skb);
 				netif_receive_skb(skb);
 			} else {
 				qeth_l3_rebuild_skb(card, skb, hdr);