Merge branch 's390-qeth-fixes-2020-11-20'

Julian Wiedmann says:

====================
s390/qeth: fixes 2020-11-20

This brings several fixes for qeth's af_iucv-specific code paths.

Also one fix by Alexandra for the recently added BR_LEARNING_SYNC
support. We want to trust the feature indication bit, so that HW can
mask it out if there's any issues on their end.
====================

Link: https://lore.kernel.org/r/20201120090939.101406-1-jwi@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: kuba-moo

drivers/s390/net/qeth_core.h

@@ -417,10 +417,13 @@ enum qeth_qdio_out_buffer_state {
 	QETH_QDIO_BUF_EMPTY,
 	/* Filled by driver; owned by hardware in order to be sent. */
 	QETH_QDIO_BUF_PRIMED,
-	/* Identified to be pending in TPQ. */
+	/* Discovered by the TX completion code: */
 	QETH_QDIO_BUF_PENDING,
-	/* Found in completion queue. */
-	QETH_QDIO_BUF_IN_CQ,
+	/* Finished by the TX completion code: */
+	QETH_QDIO_BUF_NEED_QAOB,
+	/* Received QAOB notification on CQ: */
+	QETH_QDIO_BUF_QAOB_OK,
+	QETH_QDIO_BUF_QAOB_ERROR,
 	/* Handled via transfer pending / completion queue. */
 	QETH_QDIO_BUF_HANDLED_DELAYED,
 };

drivers/s390/net/qeth_core_main.c

@@ -33,6 +33,7 @@
 
 #include <net/iucv/af_iucv.h>
 #include <net/dsfield.h>
+#include <net/sock.h>
 
 #include <asm/ebcdic.h>
 #include <asm/chpid.h>
@@ -499,17 +500,12 @@ static void qeth_cleanup_handled_pending(struct qeth_qdio_out_q *q, int bidx,
 
 		}
 	}
-	if (forced_cleanup && (atomic_read(&(q->bufs[bidx]->state)) ==
-					QETH_QDIO_BUF_HANDLED_DELAYED)) {
-		/* for recovery situations */
-		qeth_init_qdio_out_buf(q, bidx);
-		QETH_CARD_TEXT(q->card, 2, "clprecov");
-	}
 }
 
 static void qeth_qdio_handle_aob(struct qeth_card *card,
 				 unsigned long phys_aob_addr)
 {
+	enum qeth_qdio_out_buffer_state new_state = QETH_QDIO_BUF_QAOB_OK;
 	struct qaob *aob;
 	struct qeth_qdio_out_buffer *buffer;
 	enum iucv_tx_notify notification;
@@ -521,22 +517,6 @@ static void qeth_qdio_handle_aob(struct qeth_card *card,
 	buffer = (struct qeth_qdio_out_buffer *) aob->user1;
 	QETH_CARD_TEXT_(card, 5, "%lx", aob->user1);
 
-	if (atomic_cmpxchg(&buffer->state, QETH_QDIO_BUF_PRIMED,
-			   QETH_QDIO_BUF_IN_CQ) == QETH_QDIO_BUF_PRIMED) {
-		notification = TX_NOTIFY_OK;
-	} else {
-		WARN_ON_ONCE(atomic_read(&buffer->state) !=
-							QETH_QDIO_BUF_PENDING);
-		atomic_set(&buffer->state, QETH_QDIO_BUF_IN_CQ);
-		notification = TX_NOTIFY_DELAYED_OK;
-	}
-
-	if (aob->aorc != 0)  {
-		QETH_CARD_TEXT_(card, 2, "aorc%02X", aob->aorc);
-		notification = qeth_compute_cq_notification(aob->aorc, 1);
-	}
-	qeth_notify_skbs(buffer->q, buffer, notification);
-
 	/* Free dangling allocations. The attached skbs are handled by
 	 * qeth_cleanup_handled_pending().
 	 */
@@ -548,7 +528,33 @@ static void qeth_qdio_handle_aob(struct qeth_card *card,
 		if (data && buffer->is_header[i])
 			kmem_cache_free(qeth_core_header_cache, data);
 	}
-	atomic_set(&buffer->state, QETH_QDIO_BUF_HANDLED_DELAYED);
+
+	if (aob->aorc) {
+		QETH_CARD_TEXT_(card, 2, "aorc%02X", aob->aorc);
+		new_state = QETH_QDIO_BUF_QAOB_ERROR;
+	}
+
+	switch (atomic_xchg(&buffer->state, new_state)) {
+	case QETH_QDIO_BUF_PRIMED:
+		/* Faster than TX completion code. */
+		notification = qeth_compute_cq_notification(aob->aorc, 0);
+		qeth_notify_skbs(buffer->q, buffer, notification);
+		atomic_set(&buffer->state, QETH_QDIO_BUF_HANDLED_DELAYED);
+		break;
+	case QETH_QDIO_BUF_PENDING:
+		/* TX completion code is active and will handle the async
+		 * completion for us.
+		 */
+		break;
+	case QETH_QDIO_BUF_NEED_QAOB:
+		/* TX completion code is already finished. */
+		notification = qeth_compute_cq_notification(aob->aorc, 1);
+		qeth_notify_skbs(buffer->q, buffer, notification);
+		atomic_set(&buffer->state, QETH_QDIO_BUF_HANDLED_DELAYED);
+		break;
+	default:
+		WARN_ON_ONCE(1);
+	}
 
 	qdio_release_aob(aob);
 }
@@ -1405,7 +1411,7 @@ static void qeth_notify_skbs(struct qeth_qdio_out_q *q,
 	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 (skb->protocol == htons(ETH_P_AF_IUCV) && skb->sk)
+		if (skb->sk && skb->sk->sk_family == PF_IUCV)
 			iucv_sk(skb->sk)->sk_txnotify(skb, notification);
 	}
 }
@@ -1416,9 +1422,6 @@ static void qeth_tx_complete_buf(struct qeth_qdio_out_buffer *buf, bool error,
 	struct qeth_qdio_out_q *queue = buf->q;
 	struct sk_buff *skb;
 
-	/* release may never happen from within CQ tasklet scope */
-	WARN_ON_ONCE(atomic_read(&buf->state) == QETH_QDIO_BUF_IN_CQ);
-
 	if (atomic_read(&buf->state) == QETH_QDIO_BUF_PENDING)
 		qeth_notify_skbs(queue, buf, TX_NOTIFY_GENERALERROR);
 
@@ -5869,9 +5872,32 @@ static void qeth_iqd_tx_complete(struct qeth_qdio_out_q *queue,
 
 		if (atomic_cmpxchg(&buffer->state, QETH_QDIO_BUF_PRIMED,
 						   QETH_QDIO_BUF_PENDING) ==
-		    QETH_QDIO_BUF_PRIMED)
+		    QETH_QDIO_BUF_PRIMED) {
 			qeth_notify_skbs(queue, buffer, TX_NOTIFY_PENDING);
 
+			/* Handle race with qeth_qdio_handle_aob(): */
+			switch (atomic_xchg(&buffer->state,
+					    QETH_QDIO_BUF_NEED_QAOB)) {
+			case QETH_QDIO_BUF_PENDING:
+				/* No concurrent QAOB notification. */
+				break;
+			case QETH_QDIO_BUF_QAOB_OK:
+				qeth_notify_skbs(queue, buffer,
+						 TX_NOTIFY_DELAYED_OK);
+				atomic_set(&buffer->state,
+					   QETH_QDIO_BUF_HANDLED_DELAYED);
+				break;
+			case QETH_QDIO_BUF_QAOB_ERROR:
+				qeth_notify_skbs(queue, buffer,
+						 TX_NOTIFY_DELAYED_GENERALERROR);
+				atomic_set(&buffer->state,
+					   QETH_QDIO_BUF_HANDLED_DELAYED);
+				break;
+			default:
+				WARN_ON_ONCE(1);
+			}
+		}
+
 		QETH_CARD_TEXT_(card, 5, "pel%u", bidx);
 
 		/* prepare the queue slot for re-use: */

drivers/s390/net/qeth_l2_main.c

@@ -985,32 +985,19 @@ static void qeth_l2_setup_bridgeport_attrs(struct qeth_card *card)
  *	change notification' and thus can support the learning_sync bridgeport
  *	attribute
  *	@card: qeth_card structure pointer
- *
- *	This is a destructive test and must be called before dev2br or
- *	bridgeport address notification is enabled!
  */
 static void qeth_l2_detect_dev2br_support(struct qeth_card *card)
 {
 	struct qeth_priv *priv = netdev_priv(card->dev);
 	bool dev2br_supported;
-	int rc;
 
 	QETH_CARD_TEXT(card, 2, "d2brsup");
 	if (!IS_IQD(card))
 		return;
 
 	/* dev2br requires valid cssid,iid,chid */
-	if (!card->info.ids_valid) {
-		dev2br_supported = false;
-	} else if (css_general_characteristics.enarf) {
-		dev2br_supported = true;
-	} else {
-		/* Old machines don't have the feature bit:
-		 * Probe by testing whether a disable succeeds
-		 */
-		rc = qeth_l2_pnso(card, PNSO_OC_NET_ADDR_INFO, 0, NULL, NULL);
-		dev2br_supported = !rc;
-	}
+	dev2br_supported = card->info.ids_valid &&
+			   css_general_characteristics.enarf;
 	QETH_CARD_TEXT_(card, 2, "D2Bsup%02x", dev2br_supported);
 
 	if (dev2br_supported)
@@ -2233,7 +2220,6 @@ static int qeth_l2_set_online(struct qeth_card *card, bool carrier_ok)
 	struct net_device *dev = card->dev;
 	int rc = 0;
 
-	/* query before bridgeport_notification may be enabled */
 	qeth_l2_detect_dev2br_support(card);
 
 	mutex_lock(&card->sbp_lock);