ibmvnic: Serialize device queries

Provide some serialization for device CRQ commands
and queries to ensure that the shared variable used for
storing return codes is properly synchronized.
Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ibm/ibmvnic.c

@@ -210,11 +210,14 @@ static int alloc_long_term_buff(struct ibmvnic_adapter *adapter,
 	ltb->map_id = adapter->map_id;
 	adapter->map_id++;
 
+	mutex_lock(&adapter->fw_lock);
+	adapter->fw_done_rc = 0;
 	reinit_completion(&adapter->fw_done);
 	rc = send_request_map(adapter, ltb->addr,
 			      ltb->size, ltb->map_id);
 	if (rc) {
 		dma_free_coherent(dev, ltb->size, ltb->buff, ltb->addr);
+		mutex_unlock(&adapter->fw_lock);
 		return rc;
 	}
 
@@ -224,6 +227,7 @@ static int alloc_long_term_buff(struct ibmvnic_adapter *adapter,
 			"Long term map request aborted or timed out,rc = %d\n",
 			rc);
 		dma_free_coherent(dev, ltb->size, ltb->buff, ltb->addr);
+		mutex_unlock(&adapter->fw_lock);
 		return rc;
 	}
 
@@ -231,8 +235,10 @@ static int alloc_long_term_buff(struct ibmvnic_adapter *adapter,
 		dev_err(dev, "Couldn't map long term buffer,rc = %d\n",
 			adapter->fw_done_rc);
 		dma_free_coherent(dev, ltb->size, ltb->buff, ltb->addr);
+		mutex_unlock(&adapter->fw_lock);
 		return -1;
 	}
+	mutex_unlock(&adapter->fw_lock);
 	return 0;
 }
 
@@ -258,15 +264,21 @@ static int reset_long_term_buff(struct ibmvnic_adapter *adapter,
 
 	memset(ltb->buff, 0, ltb->size);
 
+	mutex_lock(&adapter->fw_lock);
+	adapter->fw_done_rc = 0;
+
 	reinit_completion(&adapter->fw_done);
 	rc = send_request_map(adapter, ltb->addr, ltb->size, ltb->map_id);
-	if (rc)
+	if (rc) {
+		mutex_unlock(&adapter->fw_lock);
 		return rc;
+	}
 
 	rc = ibmvnic_wait_for_completion(adapter, &adapter->fw_done, 10000);
 	if (rc) {
 		dev_info(dev,
 			 "Reset failed, long term map request timed out or aborted\n");
+		mutex_unlock(&adapter->fw_lock);
 		return rc;
 	}
 
@@ -274,8 +286,10 @@ static int reset_long_term_buff(struct ibmvnic_adapter *adapter,
 		dev_info(dev,
 			 "Reset failed, attempting to free and reallocate buffer\n");
 		free_long_term_buff(adapter, ltb);
+		mutex_unlock(&adapter->fw_lock);
 		return alloc_long_term_buff(adapter, ltb, ltb->size);
 	}
+	mutex_unlock(&adapter->fw_lock);
 	return 0;
 }
 
@@ -992,18 +1006,25 @@ static int ibmvnic_get_vpd(struct ibmvnic_adapter *adapter)
 	if (adapter->vpd->buff)
 		len = adapter->vpd->len;
 
+	mutex_lock(&adapter->fw_lock);
+	adapter->fw_done_rc = 0;
 	reinit_completion(&adapter->fw_done);
+
 	crq.get_vpd_size.first = IBMVNIC_CRQ_CMD;
 	crq.get_vpd_size.cmd = GET_VPD_SIZE;
 	rc = ibmvnic_send_crq(adapter, &crq);
-	if (rc)
+	if (rc) {
+		mutex_unlock(&adapter->fw_lock);
 		return rc;
+	}
 
 	rc = ibmvnic_wait_for_completion(adapter, &adapter->fw_done, 10000);
 	if (rc) {
 		dev_err(dev, "Could not retrieve VPD size, rc = %d\n", rc);
+		mutex_unlock(&adapter->fw_lock);
 		return rc;
 	}
+	mutex_unlock(&adapter->fw_lock);
 
 	if (!adapter->vpd->len)
 		return -ENODATA;
@@ -1030,7 +1051,10 @@ static int ibmvnic_get_vpd(struct ibmvnic_adapter *adapter)
 		return -ENOMEM;
 	}
 
+	mutex_lock(&adapter->fw_lock);
+	adapter->fw_done_rc = 0;
 	reinit_completion(&adapter->fw_done);
+
 	crq.get_vpd.first = IBMVNIC_CRQ_CMD;
 	crq.get_vpd.cmd = GET_VPD;
 	crq.get_vpd.ioba = cpu_to_be32(adapter->vpd->dma_addr);
@@ -1039,6 +1063,7 @@ static int ibmvnic_get_vpd(struct ibmvnic_adapter *adapter)
 	if (rc) {
 		kfree(adapter->vpd->buff);
 		adapter->vpd->buff = NULL;
+		mutex_unlock(&adapter->fw_lock);
 		return rc;
 	}
 
@@ -1047,9 +1072,11 @@ static int ibmvnic_get_vpd(struct ibmvnic_adapter *adapter)
 		dev_err(dev, "Unable to retrieve VPD, rc = %d\n", rc);
 		kfree(adapter->vpd->buff);
 		adapter->vpd->buff = NULL;
+		mutex_unlock(&adapter->fw_lock);
 		return rc;
 	}
 
+	mutex_unlock(&adapter->fw_lock);
 	return 0;
 }
 
@@ -1750,10 +1777,14 @@ static int __ibmvnic_set_mac(struct net_device *netdev, u8 *dev_addr)
 	crq.change_mac_addr.cmd = CHANGE_MAC_ADDR;
 	ether_addr_copy(&crq.change_mac_addr.mac_addr[0], dev_addr);
 
+	mutex_lock(&adapter->fw_lock);
+	adapter->fw_done_rc = 0;
 	reinit_completion(&adapter->fw_done);
+
 	rc = ibmvnic_send_crq(adapter, &crq);
 	if (rc) {
 		rc = -EIO;
+		mutex_unlock(&adapter->fw_lock);
 		goto err;
 	}
 
@@ -1761,9 +1792,10 @@ static int __ibmvnic_set_mac(struct net_device *netdev, u8 *dev_addr)
 	/* netdev->dev_addr is changed in handle_change_mac_rsp function */
 	if (rc || adapter->fw_done_rc) {
 		rc = -EIO;
+		mutex_unlock(&adapter->fw_lock);
 		goto err;
 	}
-
+	mutex_unlock(&adapter->fw_lock);
 	return 0;
 err:
 	ether_addr_copy(adapter->mac_addr, netdev->dev_addr);
@@ -4486,15 +4518,24 @@ static int send_query_phys_parms(struct ibmvnic_adapter *adapter)
 	memset(&crq, 0, sizeof(crq));
 	crq.query_phys_parms.first = IBMVNIC_CRQ_CMD;
 	crq.query_phys_parms.cmd = QUERY_PHYS_PARMS;
+
+	mutex_lock(&adapter->fw_lock);
+	adapter->fw_done_rc = 0;
 	reinit_completion(&adapter->fw_done);
+
 	rc = ibmvnic_send_crq(adapter, &crq);
-	if (rc)
+	if (rc) {
+		mutex_unlock(&adapter->fw_lock);
 		return rc;
+	}
 
 	rc = ibmvnic_wait_for_completion(adapter, &adapter->fw_done, 10000);
-	if (rc)
+	if (rc) {
+		mutex_unlock(&adapter->fw_lock);
 		return rc;
+	}
 
+	mutex_unlock(&adapter->fw_lock);
 	return adapter->fw_done_rc ? -EIO : 0;
 }
 
@@ -5050,6 +5091,7 @@ static int ibmvnic_probe(struct vio_dev *dev, const struct vio_device_id *id)
 			  __ibmvnic_delayed_reset);
 	INIT_LIST_HEAD(&adapter->rwi_list);
 	spin_lock_init(&adapter->rwi_lock);
+	mutex_init(&adapter->fw_lock);
 	init_completion(&adapter->init_done);
 	init_completion(&adapter->fw_done);
 	init_completion(&adapter->reset_done);
@@ -5111,6 +5153,7 @@ static int ibmvnic_probe(struct vio_dev *dev, const struct vio_device_id *id)
 ibmvnic_init_fail:
 	release_sub_crqs(adapter, 1);
 	release_crq_queue(adapter);
+	mutex_destroy(&adapter->fw_lock);
 	free_netdev(netdev);
 
 	return rc;
@@ -5135,6 +5178,7 @@ static int ibmvnic_remove(struct vio_dev *dev)
 	adapter->state = VNIC_REMOVED;
 
 	rtnl_unlock();
+	mutex_destroy(&adapter->fw_lock);
 	device_remove_file(&dev->dev, &dev_attr_failover);
 	free_netdev(netdev);
 	dev_set_drvdata(&dev->dev, NULL);

drivers/net/ethernet/ibm/ibmvnic.h

@@ -1026,6 +1026,8 @@ struct ibmvnic_adapter {
 	int init_done_rc;
 
 	struct completion fw_done;
+	/* Used for serialization of device commands */
+	struct mutex fw_lock;
 	int fw_done_rc;
 
 	struct completion reset_done;