[PATCH net-next 3/5] devlink: create a special NDO for getting the devlink instance

[Jakub Kicinski <jakub.kicinski@netronome.com>]

Instead of iterating over all devlink ports add a NDO which
will return the devlink instance from the driver.

Suggested-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 include/linux/netdevice.h |  6 ++++
 net/core/devlink.c        | 62 +++++++++++++--------------------------
 2 files changed, 26 insertions(+), 42 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index aab4d9f6613d..eebcef6b8191 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -940,6 +940,8 @@ struct dev_ifalias {
 	char ifalias[];
 };
 
+struct devlink;
+
 /*
  * This structure defines the management hooks for network devices.
  * The following hooks can be defined; unless noted otherwise, they are
@@ -1248,6 +1250,9 @@ struct dev_ifalias {
  *	that got dropped are freed/returned via xdp_return_frame().
  *	Returns negative number, means general error invoking ndo, meaning
  *	no frames were xmit'ed and core-caller will free all frames.
+ * struct devlink *(*ndo_get_devlink)(struct net_device *dev);
+ *	Get devlink instance associated with a given netdev.
+ *	Called with a reference on the device only, rtnl_lock is not held.
  */
 struct net_device_ops {
 	int			(*ndo_init)(struct net_device *dev);
@@ -1446,6 +1451,7 @@ struct net_device_ops {
 						u32 flags);
 	int			(*ndo_xsk_async_xmit)(struct net_device *dev,
 						      u32 queue_id);
+	struct devlink *	(*ndo_get_devlink)(struct net_device *dev);
 };
 
 /**
diff --git a/net/core/devlink.c b/net/core/devlink.c
index fcf09e02f4c6..050999a68c35 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -6395,9 +6395,6 @@ static void __devlink_compat_running_version(struct devlink *devlink,
 	struct sk_buff *msg;
 	int rem, err;
 
-	if (!devlink->ops->info_get)
-		return;
-
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 	if (!msg)
 		return;
@@ -6429,55 +6426,36 @@ static void __devlink_compat_running_version(struct devlink *devlink,
 void devlink_compat_running_version(struct net_device *dev,
 				    char *buf, size_t len)
 {
-	struct devlink_port *devlink_port;
 	struct devlink *devlink;
 
-	mutex_lock(&devlink_mutex);
-	list_for_each_entry(devlink, &devlink_list, list) {
-		mutex_lock(&devlink->lock);
-		list_for_each_entry(devlink_port, &devlink->port_list, list) {
-			if (devlink_port->type == DEVLINK_PORT_TYPE_ETH &&
-			    devlink_port->type_dev == dev) {
-				__devlink_compat_running_version(devlink,
-								 buf, len);
-				mutex_unlock(&devlink->lock);
-				goto out;
-			}
-		}
-		mutex_unlock(&devlink->lock);
-	}
-out:
-	mutex_unlock(&devlink_mutex);
+	if (!dev->netdev_ops->ndo_get_devlink)
+		return;
+
+	devlink = dev->netdev_ops->ndo_get_devlink(dev);
+	if (!devlink || !devlink->ops->info_get)
+		return;
+
+	mutex_lock(&devlink->lock);
+	__devlink_compat_running_version(devlink, buf, len);
+	mutex_unlock(&devlink->lock);
 }
 
 int devlink_compat_flash_update(struct net_device *dev, const char *file_name)
 {
-	struct devlink_port *devlink_port;
 	struct devlink *devlink;
+	int ret;
 
-	mutex_lock(&devlink_mutex);
-	list_for_each_entry(devlink, &devlink_list, list) {
-		mutex_lock(&devlink->lock);
-		list_for_each_entry(devlink_port, &devlink->port_list, list) {
-			int ret = -EOPNOTSUPP;
-
-			if (devlink_port->type != DEVLINK_PORT_TYPE_ETH ||
-			    devlink_port->type_dev != dev)
-				continue;
+	if (!dev->netdev_ops->ndo_get_devlink)
+		return -EOPNOTSUPP;
 
-			mutex_unlock(&devlink_mutex);
-			if (devlink->ops->flash_update)
-				ret = devlink->ops->flash_update(devlink,
-								 file_name,
-								 NULL, NULL);
-			mutex_unlock(&devlink->lock);
-			return ret;
-		}
-		mutex_unlock(&devlink->lock);
-	}
-	mutex_unlock(&devlink_mutex);
+	devlink = dev->netdev_ops->ndo_get_devlink(dev);
+	if (!devlink || !devlink->ops->flash_update)
+		return -EOPNOTSUPP;
 
-	return -EOPNOTSUPP;
+	mutex_lock(&devlink->lock);
+	ret = devlink->ops->flash_update(devlink, file_name, NULL, NULL);
+	mutex_unlock(&devlink->lock);
+	return ret;
 }
 
 static int __init devlink_init(void)
-- 
2.19.2