From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
Appropriate amount of extra memory for private data is allocated at
the end of struct net_device. We have a helper - netdev_priv() - that
returns its address but we don't have the reverse: a function which
given the address of the private data, returns the address of struct
net_device.
This has caused many drivers to store the pointer to net_device in
the private data structure, which basically means storing the pointer
to a structure in this very structure.
This patch proposes to add priv_to_netdev() - a helper which converts
the address of the private data to the address of the associated
net_device.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
---
include/linux/netdevice.h | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 130a668049ab..933c6808a87f 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2249,6 +2249,18 @@ static inline void *netdev_priv(const struct net_device *dev)
return (char *)dev + ALIGN(sizeof(struct net_device), NETDEV_ALIGN);
}
+/**
+ * priv_to_netdev - get the net_device from private data
+ * @priv: net_device private data
+ *
+ * Get the address of network device associated with this private data.
+ */
+static inline struct net_device *priv_to_netdev(void *priv)
+{
+ priv = (char *)priv - ALIGN(sizeof(struct net_device), NETDEV_ALIGN);
+ return (struct net_device *)priv;
+}
+
/* Set the sysfs physical device reference for the network logical device
* if set prior to registration will cause a symlink during initialization.
*/
--
2.25.0
