ibmvnic: Modify buffer size and number of queues on failover

Using newer backing devices can cause the required padding at the end of
buffer as well as the number of queues to change after a failover.
Since we currently assume that these values never change, after a
failover to a backing device with different capabilities, we can get
errors from the vnic server, attempt to free long term buffers that are
no longer there, or not free long term buffers that should be freed.

This patch resolves the issue by checking whether any of these values
change, and if so perform the necessary re-allocations.

Signed-off-by: John Allen <jallen@linux.vnet.ibm.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ibm/ibmvnic.c

@@ -410,14 +410,28 @@ static int reset_rx_pools(struct ibmvnic_adapter *adapter)
 	struct ibmvnic_rx_pool *rx_pool;
 	int rx_scrqs;
 	int i, j, rc;
+	u64 *size_array;
+
+	size_array = (u64 *)((u8 *)(adapter->login_rsp_buf) +
+		be32_to_cpu(adapter->login_rsp_buf->off_rxadd_buff_size));
 
 	rx_scrqs = be32_to_cpu(adapter->login_rsp_buf->num_rxadd_subcrqs);
 	for (i = 0; i < rx_scrqs; i++) {
 		rx_pool = &adapter->rx_pool[i];
 
 		netdev_dbg(adapter->netdev, "Re-setting rx_pool[%d]\n", i);
 
-		rc = reset_long_term_buff(adapter, &rx_pool->long_term_buff);
+		if (rx_pool->buff_size != be64_to_cpu(size_array[i])) {
+			free_long_term_buff(adapter, &rx_pool->long_term_buff);
+			rx_pool->buff_size = be64_to_cpu(size_array[i]);
+			alloc_long_term_buff(adapter, &rx_pool->long_term_buff,
+					     rx_pool->size *
+					     rx_pool->buff_size);
+		} else {
+			rc = reset_long_term_buff(adapter,
+						  &rx_pool->long_term_buff);
+		}
+
 		if (rc)
 			return rc;
 
@@ -439,14 +453,12 @@ static int reset_rx_pools(struct ibmvnic_adapter *adapter)
 static void release_rx_pools(struct ibmvnic_adapter *adapter)
 {
 	struct ibmvnic_rx_pool *rx_pool;
-	int rx_scrqs;
 	int i, j;
 
 	if (!adapter->rx_pool)
 		return;
 
-	rx_scrqs = be32_to_cpu(adapter->login_rsp_buf->num_rxadd_subcrqs);
-	for (i = 0; i < rx_scrqs; i++) {
+	for (i = 0; i < adapter->num_active_rx_pools; i++) {
 		rx_pool = &adapter->rx_pool[i];
 
 		netdev_dbg(adapter->netdev, "Releasing rx_pool[%d]\n", i);
@@ -469,6 +481,7 @@ static void release_rx_pools(struct ibmvnic_adapter *adapter)
 
 	kfree(adapter->rx_pool);
 	adapter->rx_pool = NULL;
+	adapter->num_active_rx_pools = 0;
 }
 
 static int init_rx_pools(struct net_device *netdev)
@@ -493,6 +506,8 @@ static int init_rx_pools(struct net_device *netdev)
 		return -1;
 	}
 
+	adapter->num_active_rx_pools = 0;
+
 	for (i = 0; i < rxadd_subcrqs; i++) {
 		rx_pool = &adapter->rx_pool[i];
 
@@ -536,6 +551,8 @@ static int init_rx_pools(struct net_device *netdev)
 		rx_pool->next_free = 0;
 	}
 
+	adapter->num_active_rx_pools = rxadd_subcrqs;
+
 	return 0;
 }
 
@@ -586,13 +603,12 @@ static void release_vpd_data(struct ibmvnic_adapter *adapter)
 static void release_tx_pools(struct ibmvnic_adapter *adapter)
 {
 	struct ibmvnic_tx_pool *tx_pool;
-	int i, tx_scrqs;
+	int i;
 
 	if (!adapter->tx_pool)
 		return;
 
-	tx_scrqs = be32_to_cpu(adapter->login_rsp_buf->num_txsubm_subcrqs);
-	for (i = 0; i < tx_scrqs; i++) {
+	for (i = 0; i < adapter->num_active_tx_pools; i++) {
 		netdev_dbg(adapter->netdev, "Releasing tx_pool[%d]\n", i);
 		tx_pool = &adapter->tx_pool[i];
 		kfree(tx_pool->tx_buff);
@@ -603,6 +619,7 @@ static void release_tx_pools(struct ibmvnic_adapter *adapter)
 
 	kfree(adapter->tx_pool);
 	adapter->tx_pool = NULL;
+	adapter->num_active_tx_pools = 0;
 }
 
 static int init_tx_pools(struct net_device *netdev)
@@ -619,6 +636,8 @@ static int init_tx_pools(struct net_device *netdev)
 	if (!adapter->tx_pool)
 		return -1;
 
+	adapter->num_active_tx_pools = 0;
+
 	for (i = 0; i < tx_subcrqs; i++) {
 		tx_pool = &adapter->tx_pool[i];
 
@@ -666,6 +685,8 @@ static int init_tx_pools(struct net_device *netdev)
 		tx_pool->producer_index = 0;
 	}
 
+	adapter->num_active_tx_pools = tx_subcrqs;
+
 	return 0;
 }
 
@@ -1548,6 +1569,7 @@ static int ibmvnic_set_mac(struct net_device *netdev, void *p)
 static int do_reset(struct ibmvnic_adapter *adapter,
 		    struct ibmvnic_rwi *rwi, u32 reset_state)
 {
+	u64 old_num_rx_queues, old_num_tx_queues;
 	struct net_device *netdev = adapter->netdev;
 	int i, rc;
 
@@ -1557,6 +1579,9 @@ static int do_reset(struct ibmvnic_adapter *adapter,
 	netif_carrier_off(netdev);
 	adapter->reset_reason = rwi->reset_reason;
 
+	old_num_rx_queues = adapter->req_rx_queues;
+	old_num_tx_queues = adapter->req_tx_queues;
+
 	if (rwi->reset_reason == VNIC_RESET_MOBILITY) {
 		rc = ibmvnic_reenable_crq_queue(adapter);
 		if (rc)
@@ -1601,6 +1626,12 @@ static int do_reset(struct ibmvnic_adapter *adapter,
 			rc = init_resources(adapter);
 			if (rc)
 				return rc;
+		} else if (adapter->req_rx_queues != old_num_rx_queues ||
+			   adapter->req_tx_queues != old_num_tx_queues) {
+			release_rx_pools(adapter);
+			release_tx_pools(adapter);
+			init_rx_pools(netdev);
+			init_tx_pools(netdev);
 		} else {
 			rc = reset_tx_pools(adapter);
 			if (rc)

drivers/net/ethernet/ibm/ibmvnic.h

@@ -1091,6 +1091,8 @@ struct ibmvnic_adapter {
 	u64 opt_rxba_entries_per_subcrq;
 	__be64 tx_rx_desc_req;
 	u8 map_id;
+	u64 num_active_rx_pools;
+	u64 num_active_tx_pools;
 
 	struct tasklet_struct tasklet;
 	enum vnic_state state;