ibmvnic: Free and re-allocate scrqs when tx/rx scrqs change

When the driver resets it is possible that the number of tx/rx
sub-crqs can change. This patch handles this so that the driver does
not try to access non-existent sub-crqs.

The count for releasing sub crqs depends on the adapter state. The
active queue count is not set in probe, so if we are relasing in probe
state we use the request queue count.

Additionally, a parameter is added to release_sub_crqs() so that
we know if the h_call to free the sub-crq needs to be made. In
the reset path we have to do a reset of the main crq, which is
a free followed by a register of the main crq. The free of main
crq results in all of the sub crq's being free'ed. When updating
sub-crq count in the reset path we do not want to h_free the
sub-crqs, they are already free'ed.
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ibm/ibmvnic.c

@@ -90,7 +90,7 @@ MODULE_VERSION(IBMVNIC_DRIVER_VERSION);
 
 static int ibmvnic_version = IBMVNIC_INITIAL_VERSION;
 static int ibmvnic_remove(struct vio_dev *);
-static void release_sub_crqs(struct ibmvnic_adapter *);
+static void release_sub_crqs(struct ibmvnic_adapter *, bool);
 static int ibmvnic_reset_crq(struct ibmvnic_adapter *);
 static int ibmvnic_send_crq_init(struct ibmvnic_adapter *);
 static int ibmvnic_reenable_crq_queue(struct ibmvnic_adapter *);
@@ -740,7 +740,7 @@ static int ibmvnic_login(struct net_device *netdev)
 	do {
 		if (adapter->renegotiate) {
 			adapter->renegotiate = false;
-			release_sub_crqs(adapter);
+			release_sub_crqs(adapter, 1);
 
 			reinit_completion(&adapter->init_done);
 			send_cap_queries(adapter);
@@ -1648,7 +1648,7 @@ static int do_reset(struct ibmvnic_adapter *adapter,
 	if (adapter->reset_reason == VNIC_RESET_CHANGE_PARAM ||
 	    adapter->wait_for_reset) {
 		release_resources(adapter);
-		release_sub_crqs(adapter);
+		release_sub_crqs(adapter, 1);
 		release_crq_queue(adapter);
 	}
 
@@ -2288,13 +2288,15 @@ static int reset_sub_crq_queues(struct ibmvnic_adapter *adapter)
 }
 
 static void release_sub_crq_queue(struct ibmvnic_adapter *adapter,
-				  struct ibmvnic_sub_crq_queue *scrq)
+				  struct ibmvnic_sub_crq_queue *scrq,
+				  bool do_h_free)
 {
 	struct device *dev = &adapter->vdev->dev;
 	long rc;
 
 	netdev_dbg(adapter->netdev, "Releasing sub-CRQ\n");
 
+	if (do_h_free) {
 		/* Close the sub-crqs */
 		do {
 			rc = plpar_hcall_norets(H_FREE_SUB_CRQ,
@@ -2307,6 +2309,7 @@ static void release_sub_crq_queue(struct ibmvnic_adapter *adapter,
 				   "Failed to release sub-CRQ %16lx, rc = %ld\n",
 				   scrq->crq_num, rc);
 		}
+	}
 
 	dma_unmap_single(dev, scrq->msg_token, 4 * PAGE_SIZE,
 			 DMA_BIDIRECTIONAL);
@@ -2373,12 +2376,21 @@ static struct ibmvnic_sub_crq_queue *init_sub_crq_queue(struct ibmvnic_adapter
 	return NULL;
 }
 
-static void release_sub_crqs(struct ibmvnic_adapter *adapter)
+static void release_sub_crqs(struct ibmvnic_adapter *adapter, bool do_h_free)
 {
+	u64 num_tx_scrqs, num_rx_scrqs;
 	int i;
 
+	if (adapter->state == VNIC_PROBED) {
+		num_tx_scrqs = adapter->req_tx_queues;
+		num_rx_scrqs = adapter->req_rx_queues;
+	} else {
+		num_tx_scrqs = adapter->num_active_tx_scrqs;
+		num_rx_scrqs = adapter->num_active_rx_scrqs;
+	}
+
 	if (adapter->tx_scrq) {
-		for (i = 0; i < adapter->req_tx_queues; i++) {
+		for (i = 0; i < num_tx_scrqs; i++) {
 			if (!adapter->tx_scrq[i])
 				continue;
 
@@ -2391,7 +2403,8 @@ static void release_sub_crqs(struct ibmvnic_adapter *adapter)
 				adapter->tx_scrq[i]->irq = 0;
 			}
 
-			release_sub_crq_queue(adapter, adapter->tx_scrq[i]);
+			release_sub_crq_queue(adapter, adapter->tx_scrq[i],
+					      do_h_free);
 		}
 
 		kfree(adapter->tx_scrq);
@@ -2399,7 +2412,7 @@ static void release_sub_crqs(struct ibmvnic_adapter *adapter)
 	}
 
 	if (adapter->rx_scrq) {
-		for (i = 0; i < adapter->req_rx_queues; i++) {
+		for (i = 0; i < num_rx_scrqs; i++) {
 			if (!adapter->rx_scrq[i])
 				continue;
 
@@ -2412,7 +2425,8 @@ static void release_sub_crqs(struct ibmvnic_adapter *adapter)
 				adapter->rx_scrq[i]->irq = 0;
 			}
 
-			release_sub_crq_queue(adapter, adapter->rx_scrq[i]);
+			release_sub_crq_queue(adapter, adapter->rx_scrq[i],
+					      do_h_free);
 		}
 
 		kfree(adapter->rx_scrq);
@@ -2622,7 +2636,7 @@ static int init_sub_crq_irqs(struct ibmvnic_adapter *adapter)
 		free_irq(adapter->tx_scrq[j]->irq, adapter->tx_scrq[j]);
 		irq_dispose_mapping(adapter->rx_scrq[j]->irq);
 	}
-	release_sub_crqs(adapter);
+	release_sub_crqs(adapter, 1);
 	return rc;
 }
 
@@ -2704,7 +2718,7 @@ static int init_sub_crqs(struct ibmvnic_adapter *adapter)
 	adapter->tx_scrq = NULL;
 tx_failed:
 	for (i = 0; i < registered_queues; i++)
-		release_sub_crq_queue(adapter, allqueues[i]);
+		release_sub_crq_queue(adapter, allqueues[i], 1);
 	kfree(allqueues);
 	return -1;
 }
@@ -4331,6 +4345,7 @@ static int ibmvnic_init(struct ibmvnic_adapter *adapter)
 {
 	struct device *dev = &adapter->vdev->dev;
 	unsigned long timeout = msecs_to_jiffies(30000);
+	u64 old_num_rx_queues, old_num_tx_queues;
 	int rc;
 
 	if (adapter->resetting && !adapter->wait_for_reset) {
@@ -4348,6 +4363,9 @@ static int ibmvnic_init(struct ibmvnic_adapter *adapter)
 
 	adapter->from_passive_init = false;
 
+	old_num_rx_queues = adapter->req_rx_queues;
+	old_num_tx_queues = adapter->req_tx_queues;
+
 	init_completion(&adapter->init_done);
 	adapter->init_done_rc = 0;
 	ibmvnic_send_crq_init(adapter);
@@ -4367,10 +4385,18 @@ static int ibmvnic_init(struct ibmvnic_adapter *adapter)
 		return -1;
 	}
 
-	if (adapter->resetting && !adapter->wait_for_reset)
+	if (adapter->resetting && !adapter->wait_for_reset) {
+		if (adapter->req_rx_queues != old_num_rx_queues ||
+		    adapter->req_tx_queues != old_num_tx_queues) {
+			release_sub_crqs(adapter, 0);
+			rc = init_sub_crqs(adapter);
+		} else {
 			rc = reset_sub_crq_queues(adapter);
-	else
+		}
+	} else {
 		rc = init_sub_crqs(adapter);
+	}
+
 	if (rc) {
 		dev_err(dev, "Initialization of sub crqs failed\n");
 		release_crq_queue(adapter);
@@ -4470,7 +4496,7 @@ static int ibmvnic_probe(struct vio_dev *dev, const struct vio_device_id *id)
 	device_remove_file(&dev->dev, &dev_attr_failover);
 
 ibmvnic_init_fail:
-	release_sub_crqs(adapter);
+	release_sub_crqs(adapter, 1);
 	release_crq_queue(adapter);
 	free_netdev(netdev);
 
@@ -4487,7 +4513,7 @@ static int ibmvnic_remove(struct vio_dev *dev)
 	mutex_lock(&adapter->reset_lock);
 
 	release_resources(adapter);
-	release_sub_crqs(adapter);
+	release_sub_crqs(adapter, 1);
 	release_crq_queue(adapter);
 
 	adapter->state = VNIC_REMOVED;