s390/qeth: allow configuration of TX queues for OSA devices

For OSA devices that are _not_ configured in prio-queue mode, give users
the option of selecting the number of active TX queues.
This requires setting up the HW queues with a reasonable default QoS
value in the QIB's PQUE parm area.

As with the other device types, we bring up the device with a minimal
number of TX queues for compatibility reasons.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/s390/net/qeth_core.h

@@ -278,6 +278,10 @@ struct qeth_hdr {
 	} hdr;
 } __attribute__ ((packed));
 
+#define QETH_QIB_PQUE_ORDER_RR		0
+#define QETH_QIB_PQUE_UNITS_SBAL	2
+#define QETH_QIB_PQUE_PRIO_DEFAULT	4
+
 struct qeth_qib_parms {
 	char pcit_magic[4];
 	u32 pcit_a;
@@ -287,6 +291,11 @@ struct qeth_qib_parms {
 	u32 blkt_total;
 	u32 blkt_inter_packet;
 	u32 blkt_inter_packet_jumbo;
+	char pque_magic[4];
+	u8 pque_order;
+	u8 pque_units;
+	u16 reserved;
+	u32 pque_priority[4];
 };
 
 /*TCP Segmentation Offload header*/
@@ -492,6 +501,7 @@ struct qeth_qdio_out_q {
 	struct qdio_outbuf_state *bufstates; /* convenience pointer */
 	struct qeth_out_q_stats stats;
 	spinlock_t lock;
+	unsigned int priority;
 	u8 next_buf_to_fill;
 	u8 max_elements;
 	u8 queue_no;
@@ -885,10 +895,18 @@ struct qeth_trap_id {
 /*some helper functions*/
 #define QETH_CARD_IFNAME(card) (((card)->dev)? (card)->dev->name : "")
 
+static inline bool qeth_uses_tx_prio_queueing(struct qeth_card *card)
+{
+	return card->qdio.do_prio_queueing != QETH_NO_PRIO_QUEUEING;
+}
+
 static inline unsigned int qeth_tx_actual_queues(struct qeth_card *card)
 {
 	struct qeth_priv *priv = netdev_priv(card->dev);
 
+	if (qeth_uses_tx_prio_queueing(card))
+		return min(card->dev->num_tx_queues, card->qdio.no_out_queues);
+
 	return min(priv->tx_wanted_queues, card->qdio.no_out_queues);
 }
 

drivers/s390/net/qeth_core_main.c

@@ -2683,6 +2683,7 @@ static int qeth_alloc_qdio_queues(struct qeth_card *card)
 		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) {
@@ -2746,6 +2747,9 @@ static void qeth_free_qdio_queues(struct qeth_card *card)
 static void qeth_fill_qib_parms(struct qeth_card *card,
 				struct qeth_qib_parms *parms)
 {
+	struct qeth_qdio_out_q *queue;
+	unsigned int i;
+
 	parms->pcit_magic[0] = 'P';
 	parms->pcit_magic[1] = 'C';
 	parms->pcit_magic[2] = 'I';
@@ -2763,6 +2767,21 @@ static void qeth_fill_qib_parms(struct qeth_card *card,
 	parms->blkt_total = card->info.blkt.time_total;
 	parms->blkt_inter_packet = card->info.blkt.inter_packet;
 	parms->blkt_inter_packet_jumbo = card->info.blkt.inter_packet_jumbo;
+
+	/* Prio-queueing implicitly uses the default priorities: */
+	if (qeth_uses_tx_prio_queueing(card) || card->qdio.no_out_queues == 1)
+		return;
+
+	parms->pque_magic[0] = 'P';
+	parms->pque_magic[1] = 'Q';
+	parms->pque_magic[2] = 'U';
+	parms->pque_magic[3] = 'E';
+	ASCEBC(parms->pque_magic, sizeof(parms->pque_magic));
+	parms->pque_order = QETH_QIB_PQUE_ORDER_RR;
+	parms->pque_units = QETH_QIB_PQUE_UNITS_SBAL;
+
+	qeth_for_each_output_queue(card, queue, i)
+		parms->pque_priority[i] = queue->priority;
 }
 
 static int qeth_qdio_activate(struct qeth_card *card)
@@ -5298,19 +5317,9 @@ static int qeth_set_online(struct qeth_card *card)
 
 	qeth_print_status_message(card);
 
-	if (card->dev->reg_state != NETREG_REGISTERED) {
-		struct qeth_priv *priv = netdev_priv(card->dev);
-
-		if (IS_IQD(card))
-			priv->tx_wanted_queues = QETH_IQD_MIN_TXQ;
-		else if (IS_VM_NIC(card))
-			priv->tx_wanted_queues = 1;
-		else
-			priv->tx_wanted_queues = card->dev->num_tx_queues;
-
+	if (card->dev->reg_state != NETREG_REGISTERED)
 		/* no need for locking / error handling at this early stage: */
 		qeth_set_real_num_tx_queues(card, qeth_tx_actual_queues(card));
-	}
 
 	rc = card->discipline->set_online(card, carrier_ok);
 	if (rc)
@@ -6236,6 +6245,7 @@ static struct net_device *qeth_alloc_netdev(struct qeth_card *card)
 
 	priv = netdev_priv(dev);
 	priv->rx_copybreak = QETH_RX_COPYBREAK;
+	priv->tx_wanted_queues = IS_IQD(card) ? QETH_IQD_MIN_TXQ : 1;
 
 	dev->ml_priv = card;
 	dev->watchdog_timeo = QETH_TX_TIMEOUT;

drivers/s390/net/qeth_core_sys.c

@@ -164,9 +164,11 @@ static ssize_t qeth_dev_prioqing_show(struct device *dev,
 		return sprintf(buf, "%s\n", "by skb-priority");
 	case QETH_PRIO_Q_ING_VLAN:
 		return sprintf(buf, "%s\n", "by VLAN headers");
-	default:
+	case QETH_PRIO_Q_ING_FIXED:
 		return sprintf(buf, "always queue %i\n",
 			       card->qdio.default_out_queue);
+	default:
+		return sprintf(buf, "disabled\n");
 	}
 }
 

drivers/s390/net/qeth_ethtool.c

@@ -220,6 +220,10 @@ static int qeth_set_channels(struct net_device *dev,
 	if (channels->tx_count > card->qdio.no_out_queues)
 		return -EINVAL;
 
+	/* Prio-queueing needs all TX queues: */
+	if (qeth_uses_tx_prio_queueing(card))
+		return -EPERM;
+
 	if (IS_IQD(card)) {
 		if (channels->tx_count < QETH_IQD_MIN_TXQ)
 			return -EINVAL;
@@ -230,10 +234,6 @@ static int qeth_set_channels(struct net_device *dev,
 		if (netif_running(dev) &&
 		    channels->tx_count < dev->real_num_tx_queues)
 			return -EPERM;
-	} else {
-		/* OSA still uses the legacy prio-queue mechanism: */
-		if (!IS_VM_NIC(card))
-			return -EOPNOTSUPP;
 	}
 
 	rc = qeth_set_real_num_tx_queues(card, channels->tx_count);

drivers/s390/net/qeth_l2_main.c

@@ -571,9 +571,10 @@ static u16 qeth_l2_select_queue(struct net_device *dev, struct sk_buff *skb,
 		return qeth_iqd_select_queue(dev, skb,
 					     qeth_get_ether_cast_type(skb),
 					     sb_dev);
+	if (qeth_uses_tx_prio_queueing(card))
+		return qeth_get_priority_queue(card, skb);
 
-	return IS_VM_NIC(card) ? netdev_pick_tx(dev, skb, sb_dev) :
-				 qeth_get_priority_queue(card, skb);
+	return netdev_pick_tx(dev, skb, sb_dev);
 }
 
 static void qeth_l2_set_rx_mode(struct net_device *dev)

drivers/s390/net/qeth_l3_main.c

@@ -1831,8 +1831,10 @@ static u16 qeth_l3_osa_select_queue(struct net_device *dev, struct sk_buff *skb,
 {
 	struct qeth_card *card = dev->ml_priv;
 
-	return IS_VM_NIC(card) ? netdev_pick_tx(dev, skb, sb_dev) :
-				 qeth_get_priority_queue(card, skb);
+	if (qeth_uses_tx_prio_queueing(card))
+		return qeth_get_priority_queue(card, skb);
+
+	return netdev_pick_tx(dev, skb, sb_dev);
 }
 
 static const struct net_device_ops qeth_l3_netdev_ops = {