Merge branch 's390-qeth-fixes'

Julian Wiedmann says:

====================
s390/qeth: fixes 2021-03-09

please apply the following patch series to netdev's net tree.

This brings one fix for a memleak in an error path of the setup code.
Also several fixes for dealing with pending TX buffers - two for old
bugs in their completion handling, and one recent regression in a
teardown path.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/s390/net/qeth_core.h

@@ -436,7 +436,7 @@ struct qeth_qdio_out_buffer {
 	int is_header[QDIO_MAX_ELEMENTS_PER_BUFFER];
 
 	struct qeth_qdio_out_q *q;
-	struct qeth_qdio_out_buffer *next_pending;
+	struct list_head list_entry;
 };
 
 struct qeth_card;
@@ -500,6 +500,7 @@ struct qeth_qdio_out_q {
 	struct qdio_buffer *qdio_bufs[QDIO_MAX_BUFFERS_PER_Q];
 	struct qeth_qdio_out_buffer *bufs[QDIO_MAX_BUFFERS_PER_Q];
 	struct qdio_outbuf_state *bufstates; /* convenience pointer */
+	struct list_head pending_bufs;
 	struct qeth_out_q_stats stats;
 	spinlock_t lock;
 	unsigned int priority;

drivers/s390/net/qeth_core_main.c

@@ -73,8 +73,6 @@ static void qeth_free_qdio_queues(struct qeth_card *card);
 static void qeth_notify_skbs(struct qeth_qdio_out_q *queue,
 		struct qeth_qdio_out_buffer *buf,
 		enum iucv_tx_notify notification);
-static void qeth_tx_complete_buf(struct qeth_qdio_out_buffer *buf, bool error,
-				 int budget);
 
 static void qeth_close_dev_handler(struct work_struct *work)
 {
@@ -465,41 +463,6 @@ static enum iucv_tx_notify qeth_compute_cq_notification(int sbalf15,
 	return n;
 }
 
-static void qeth_cleanup_handled_pending(struct qeth_qdio_out_q *q, int bidx,
-					 int forced_cleanup)
-{
-	if (q->card->options.cq != QETH_CQ_ENABLED)
-		return;
-
-	if (q->bufs[bidx]->next_pending != NULL) {
-		struct qeth_qdio_out_buffer *head = q->bufs[bidx];
-		struct qeth_qdio_out_buffer *c = q->bufs[bidx]->next_pending;
-
-		while (c) {
-			if (forced_cleanup ||
-			    atomic_read(&c->state) == QETH_QDIO_BUF_EMPTY) {
-				struct qeth_qdio_out_buffer *f = c;
-
-				QETH_CARD_TEXT(f->q->card, 5, "fp");
-				QETH_CARD_TEXT_(f->q->card, 5, "%lx", (long) f);
-				/* release here to avoid interleaving between
-				   outbound tasklet and inbound tasklet
-				   regarding notifications and lifecycle */
-				qeth_tx_complete_buf(c, forced_cleanup, 0);
-
-				c = f->next_pending;
-				WARN_ON_ONCE(head->next_pending != f);
-				head->next_pending = c;
-				kmem_cache_free(qeth_qdio_outbuf_cache, f);
-			} else {
-				head = c;
-				c = c->next_pending;
-			}
-
-		}
-	}
-}
-
 static void qeth_qdio_handle_aob(struct qeth_card *card,
 				 unsigned long phys_aob_addr)
 {
@@ -507,6 +470,7 @@ static void qeth_qdio_handle_aob(struct qeth_card *card,
 	struct qaob *aob;
 	struct qeth_qdio_out_buffer *buffer;
 	enum iucv_tx_notify notification;
+	struct qeth_qdio_out_q *queue;
 	unsigned int i;
 
 	aob = (struct qaob *) phys_to_virt(phys_aob_addr);
@@ -537,7 +501,7 @@ static void qeth_qdio_handle_aob(struct qeth_card *card,
 		qeth_notify_skbs(buffer->q, buffer, notification);
 
 		/* Free dangling allocations. The attached skbs are handled by
-		 * qeth_cleanup_handled_pending().
+		 * qeth_tx_complete_pending_bufs().
 		 */
 		for (i = 0;
 		     i < aob->sb_count && i < QETH_MAX_BUFFER_ELEMENTS(card);
@@ -549,7 +513,9 @@ static void qeth_qdio_handle_aob(struct qeth_card *card,
 			buffer->is_header[i] = 0;
 		}
 
+		queue = buffer->q;
 		atomic_set(&buffer->state, QETH_QDIO_BUF_EMPTY);
+		napi_schedule(&queue->napi);
 		break;
 	default:
 		WARN_ON_ONCE(1);
@@ -1424,9 +1390,6 @@ 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;
 
-	if (atomic_read(&buf->state) == QETH_QDIO_BUF_PENDING)
-		qeth_notify_skbs(queue, buf, TX_NOTIFY_GENERALERROR);
-
 	/* Empty buffer? */
 	if (buf->next_element_to_fill == 0)
 		return;
@@ -1488,14 +1451,38 @@ static void qeth_clear_output_buffer(struct qeth_qdio_out_q *queue,
 	atomic_set(&buf->state, QETH_QDIO_BUF_EMPTY);
 }
 
+static void qeth_tx_complete_pending_bufs(struct qeth_card *card,
+					  struct qeth_qdio_out_q *queue,
+					  bool drain)
+{
+	struct qeth_qdio_out_buffer *buf, *tmp;
+
+	list_for_each_entry_safe(buf, tmp, &queue->pending_bufs, list_entry) {
+		if (drain || atomic_read(&buf->state) == QETH_QDIO_BUF_EMPTY) {
+			QETH_CARD_TEXT(card, 5, "fp");
+			QETH_CARD_TEXT_(card, 5, "%lx", (long) buf);
+
+			if (drain)
+				qeth_notify_skbs(queue, buf,
+						 TX_NOTIFY_GENERALERROR);
+			qeth_tx_complete_buf(buf, drain, 0);
+
+			list_del(&buf->list_entry);
+			kmem_cache_free(qeth_qdio_outbuf_cache, buf);
+		}
+	}
+}
+
 static void qeth_drain_output_queue(struct qeth_qdio_out_q *q, bool free)
 {
 	int j;
 
+	qeth_tx_complete_pending_bufs(q->card, q, true);
+
 	for (j = 0; j < QDIO_MAX_BUFFERS_PER_Q; ++j) {
 		if (!q->bufs[j])
 			continue;
-		qeth_cleanup_handled_pending(q, j, 1);
+
 		qeth_clear_output_buffer(q, q->bufs[j], true, 0);
 		if (free) {
 			kmem_cache_free(qeth_qdio_outbuf_cache, q->bufs[j]);
@@ -2615,7 +2602,6 @@ static int qeth_init_qdio_out_buf(struct qeth_qdio_out_q *q, int bidx)
 	skb_queue_head_init(&newbuf->skb_list);
 	lockdep_set_class(&newbuf->skb_list.lock, &qdio_out_skb_queue_key);
 	newbuf->q = q;
-	newbuf->next_pending = q->bufs[bidx];
 	atomic_set(&newbuf->state, QETH_QDIO_BUF_EMPTY);
 	q->bufs[bidx] = newbuf;
 	return 0;
@@ -2634,15 +2620,28 @@ static void qeth_free_output_queue(struct qeth_qdio_out_q *q)
 static struct qeth_qdio_out_q *qeth_alloc_output_queue(void)
 {
 	struct qeth_qdio_out_q *q = kzalloc(sizeof(*q), GFP_KERNEL);
+	unsigned int i;
 
 	if (!q)
 		return NULL;
 
-	if (qdio_alloc_buffers(q->qdio_bufs, QDIO_MAX_BUFFERS_PER_Q)) {
-		kfree(q);
-		return NULL;
+	if (qdio_alloc_buffers(q->qdio_bufs, QDIO_MAX_BUFFERS_PER_Q))
+		goto err_qdio_bufs;
+
+	for (i = 0; i < QDIO_MAX_BUFFERS_PER_Q; i++) {
+		if (qeth_init_qdio_out_buf(q, i))
+			goto err_out_bufs;
 	}
+
 	return q;
+
+err_out_bufs:
+	while (i > 0)
+		kmem_cache_free(qeth_qdio_outbuf_cache, q->bufs[--i]);
+	qdio_free_buffers(q->qdio_bufs, QDIO_MAX_BUFFERS_PER_Q);
+err_qdio_bufs:
+	kfree(q);
+	return NULL;
 }
 
 static void qeth_tx_completion_timer(struct timer_list *timer)
@@ -2655,7 +2654,7 @@ static void qeth_tx_completion_timer(struct timer_list *timer)
 
 static int qeth_alloc_qdio_queues(struct qeth_card *card)
 {
-	int i, j;
+	unsigned int i;
 
 	QETH_CARD_TEXT(card, 2, "allcqdbf");
 
@@ -2684,18 +2683,12 @@ static int qeth_alloc_qdio_queues(struct qeth_card *card)
 		card->qdio.out_qs[i] = queue;
 		queue->card = card;
 		queue->queue_no = i;
+		INIT_LIST_HEAD(&queue->pending_bufs);
 		spin_lock_init(&queue->lock);
 		timer_setup(&queue->timer, qeth_tx_completion_timer, 0);
 		queue->coalesce_usecs = QETH_TX_COALESCE_USECS;
 		queue->max_coalesced_frames = QETH_TX_MAX_COALESCED_FRAMES;
 		queue->priority = QETH_QIB_PQUE_PRIO_DEFAULT;
-
-		/* give outbound qeth_qdio_buffers their qdio_buffers */
-		for (j = 0; j < QDIO_MAX_BUFFERS_PER_Q; ++j) {
-			WARN_ON(queue->bufs[j]);
-			if (qeth_init_qdio_out_buf(queue, j))
-				goto out_freeoutqbufs;
-		}
 	}
 
 	/* completion */
@@ -2704,13 +2697,6 @@ static int qeth_alloc_qdio_queues(struct qeth_card *card)
 
 	return 0;
 
-out_freeoutqbufs:
-	while (j > 0) {
-		--j;
-		kmem_cache_free(qeth_qdio_outbuf_cache,
-				card->qdio.out_qs[i]->bufs[j]);
-		card->qdio.out_qs[i]->bufs[j] = NULL;
-	}
 out_freeoutq:
 	while (i > 0) {
 		qeth_free_output_queue(card->qdio.out_qs[--i]);
@@ -6107,6 +6093,8 @@ static void qeth_iqd_tx_complete(struct qeth_qdio_out_q *queue,
 					qeth_schedule_recovery(card);
 				}
 
+				list_add(&buffer->list_entry,
+					 &queue->pending_bufs);
 				/* Skip clearing the buffer: */
 				return;
 			case QETH_QDIO_BUF_QAOB_OK:
@@ -6162,6 +6150,8 @@ static int qeth_tx_poll(struct napi_struct *napi, int budget)
 		unsigned int bytes = 0;
 		int completed;
 
+		qeth_tx_complete_pending_bufs(card, queue, false);
+
 		if (qeth_out_queue_is_empty(queue)) {
 			napi_complete(napi);
 			return 0;
@@ -6194,7 +6184,6 @@ static int qeth_tx_poll(struct napi_struct *napi, int budget)
 
 			qeth_handle_send_error(card, buffer, error);
 			qeth_iqd_tx_complete(queue, bidx, error, budget);
-			qeth_cleanup_handled_pending(queue, bidx, false);
 		}
 
 		netdev_tx_completed_queue(txq, packets, bytes);
@@ -7249,9 +7238,7 @@ int qeth_open(struct net_device *dev)
 	card->data.state = CH_STATE_UP;
 	netif_tx_start_all_queues(dev);
 
-	napi_enable(&card->napi);
 	local_bh_disable();
-	napi_schedule(&card->napi);
 	if (IS_IQD(card)) {
 		struct qeth_qdio_out_q *queue;
 		unsigned int i;
@@ -7263,8 +7250,12 @@ int qeth_open(struct net_device *dev)
 			napi_schedule(&queue->napi);
 		}
 	}
+
+	napi_enable(&card->napi);
+	napi_schedule(&card->napi);
 	/* kick-start the NAPI softirq: */
 	local_bh_enable();
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(qeth_open);
@@ -7274,6 +7265,11 @@ int qeth_stop(struct net_device *dev)
 	struct qeth_card *card = dev->ml_priv;
 
 	QETH_CARD_TEXT(card, 4, "qethstop");
+
+	napi_disable(&card->napi);
+	cancel_delayed_work_sync(&card->buffer_reclaim_work);
+	qdio_stop_irq(CARD_DDEV(card));
+
 	if (IS_IQD(card)) {
 		struct qeth_qdio_out_q *queue;
 		unsigned int i;
@@ -7294,10 +7290,6 @@ int qeth_stop(struct net_device *dev)
 		netif_tx_disable(dev);
 	}
 
-	napi_disable(&card->napi);
-	cancel_delayed_work_sync(&card->buffer_reclaim_work);
-	qdio_stop_irq(CARD_DDEV(card));
-
 	return 0;
 }
 EXPORT_SYMBOL_GPL(qeth_stop);