From: Julian Wiedmann <jwi@linux.ibm.com>
Subject: s390/qeth: replace open-coded skb_queue_walk()
Patch-mainline: v4.20-rc1
Git-commit: dc149e3764d8b724b110f8841b198e0f867e413a
References: FATE#326377, LTC#169210, bsc#1115382

Summary:        qeth: Full-blown TCP Segmentation Offload
Description:    As of now, qeth only supports TCP Segmentation Offload (TSO)
                for IPv4 in Layer3 devices. This feature extends the existing
                support to IPv6, and adds support for TSO in both IP variants
                for Layer2.

                To cleanly pull in all the necessary changes to the transmit
                code, update the qeth driver to the current 4.20 level.


Upstream-Description:

             s390/qeth: replace open-coded skb_queue_walk()

             To match the use of __skb_queue_purge(), also make the skb's enqueue in
             qeth_fill_buffer() lockless.

             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_core_main.c |   19 ++++---------------
 1 file changed, 4 insertions(+), 15 deletions(-)

--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -1175,10 +1175,7 @@ static void qeth_notify_skbs(struct qeth
 {
 	struct sk_buff *skb;
 
-	if (skb_queue_empty(&buf->skb_list))
-		goto out;
-	skb = skb_peek(&buf->skb_list);
-	while (skb) {
+	skb_queue_walk(&buf->skb_list, skb) {
 		QETH_CARD_TEXT_(q->card, 5, "skbn%d", notification);
 		QETH_CARD_TEXT_(q->card, 5, "%lx", (long) skb);
 		if (be16_to_cpu(skb->protocol) == ETH_P_AF_IUCV) {
@@ -1187,13 +1184,7 @@ static void qeth_notify_skbs(struct qeth
 				iucv->sk_txnotify(skb, notification);
 			}
 		}
-		if (skb_queue_is_last(&buf->skb_list, skb))
-			skb = NULL;
-		else
-			skb = skb_queue_next(&buf->skb_list, skb);
 	}
-out:
-	return;
 }
 
 static void qeth_release_skbs(struct qeth_qdio_out_buffer *buf)
@@ -1208,8 +1199,7 @@ static void qeth_release_skbs(struct qet
 	/* release may never happen from within CQ tasklet scope */
 	WARN_ON_ONCE(atomic_read(&buf->state) == QETH_QDIO_BUF_IN_CQ);
 
-	skb = skb_dequeue(&buf->skb_list);
-	while (skb) {
+	skb_queue_walk(&buf->skb_list, skb) {
 		QETH_CARD_TEXT(buf->q->card, 5, "skbr");
 		QETH_CARD_TEXT_(buf->q->card, 5, "%lx", (long) skb);
 		if (notify_general_error &&
@@ -1220,9 +1210,8 @@ static void qeth_release_skbs(struct qet
 			}
 		}
 		refcount_dec(&skb->users);
-		dev_kfree_skb_any(skb);
-		skb = skb_dequeue(&buf->skb_list);
 	}
+	__skb_queue_purge(&buf->skb_list);
 }
 
 static void qeth_clear_output_buffer(struct qeth_qdio_out_q *queue,
@@ -3997,7 +3986,7 @@ static int qeth_fill_buffer(struct qeth_
 	int flush_cnt = 0;
 
 	refcount_inc(&skb->users);
-	skb_queue_tail(&buf->skb_list, skb);
+	__skb_queue_tail(&buf->skb_list, skb);
 
 	/* build dedicated header element */
 	if (hd_len) {