RDMA/core: Replace the ib_port_data hw_stats pointers with a ib_port pointer

It is much saner to store a pointer to the kobject structure that contains
the cannonical stats pointer than to copy the stats pointers into a public
structure.

Future patches will require the sysfs pointer for other purposes.

Link: https://lore.kernel.org/r/f90551dfd296cde1cb507bbef27cca9891d19871.1623427137.git.leonro@nvidia.com
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/core/core_priv.h

@@ -378,6 +378,7 @@ struct net_device *rdma_read_gid_attr_ndev_rcu(const struct ib_gid_attr *attr);
 
 void ib_free_port_attrs(struct ib_core_device *coredev);
 int ib_setup_port_attrs(struct ib_core_device *coredev);
+struct rdma_hw_stats *ib_get_hw_stats_port(struct ib_device *ibdev, u32 port_num);
 
 int rdma_compatdev_set(u8 enable);
 

drivers/infiniband/core/nldev.c

@@ -2066,7 +2066,8 @@ static int stat_get_doit_default_counter(struct sk_buff *skb,
 	}
 
 	port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
-	if (!rdma_is_port_valid(device, port)) {
+	stats = ib_get_hw_stats_port(device, port);
+	if (!stats) {
 		ret = -EINVAL;
 		goto err;
 	}
@@ -2088,11 +2089,6 @@ static int stat_get_doit_default_counter(struct sk_buff *skb,
 		goto err_msg;
 	}
 
-	stats = device->port_data ? device->port_data[port].hw_stats : NULL;
-	if (stats == NULL) {
-		ret = -EINVAL;
-		goto err_msg;
-	}
 	mutex_lock(&stats->lock);
 
 	num_cnts = device->ops.get_hw_stats(device, stats, port, 0);

drivers/infiniband/core/sysfs.c

@@ -1031,8 +1031,6 @@ static void setup_hw_stats(struct ib_device *device, struct ib_port *port,
 			goto err;
 		port->hw_stats_ag = hsag;
 		port->hw_stats = stats;
-		if (device->port_data)
-			device->port_data[port_num].hw_stats = stats;
 	} else {
 		struct kobject *kobj = &device->dev.kobj;
 		ret = sysfs_create_group(kobj, hsag);
@@ -1053,6 +1051,14 @@ err_free_stats:
 	kfree(stats);
 }
 
+struct rdma_hw_stats *ib_get_hw_stats_port(struct ib_device *ibdev,
+					   u32 port_num)
+{
+	if (!ibdev->port_data || !rdma_is_port_valid(ibdev, port_num))
+		return NULL;
+	return ibdev->port_data[port_num].sysfs->hw_stats;
+}
+
 static int add_port(struct ib_core_device *coredev, int port_num)
 {
 	struct ib_device *device = rdma_device_to_ibdev(&coredev->dev);
@@ -1171,6 +1177,8 @@ static int add_port(struct ib_core_device *coredev, int port_num)
 		setup_hw_stats(device, p, port_num);
 
 	list_add_tail(&p->kobj.entry, &coredev->port_list);
+	if (device->port_data && is_full_dev)
+		device->port_data[port_num].sysfs = p;
 
 	kobject_uevent(&p->kobj, KOBJ_ADD);
 	return 0;
@@ -1361,7 +1369,7 @@ void ib_free_port_attrs(struct ib_core_device *coredev)
 			free_hsag(&port->kobj, port->hw_stats_ag);
 		kfree(port->hw_stats);
 		if (device->port_data && is_full_dev)
-			device->port_data[port->port_num].hw_stats = NULL;
+			device->port_data[port->port_num].sysfs = NULL;
 
 		if (port->pma_table)
 			sysfs_remove_group(p, port->pma_table);

include/rdma/ib_verbs.h

@@ -50,6 +50,7 @@ struct ib_uqp_object;
 struct ib_usrq_object;
 struct ib_uwq_object;
 struct rdma_cm_id;
+struct ib_port;
 
 extern struct workqueue_struct *ib_wq;
 extern struct workqueue_struct *ib_comp_wq;
@@ -2182,7 +2183,7 @@ struct ib_port_data {
 	struct net_device __rcu *netdev;
 	struct hlist_node ndev_hash_link;
 	struct rdma_port_counter port_counter;
-	struct rdma_hw_stats *hw_stats;
+	struct ib_port *sysfs;
 };
 
 /* rdma netdev type - specifies protocol type */