Subject: [PATCH net-next 3/4] device property: add a helper for loading netdev->dev_addr

From: Jakub Kicinski <[email-masked]>
Date: Tue, 5 Oct 2021 08:53:20 -0700

Commit 406f42fa0d3c ("net-next: When a bond have a massive amount
of VLANs...") introduced a rbtree for faster Ethernet address look
up. To maintain netdev->dev_addr in this tree we need to make all
the writes to it got through appropriate helpers.

There is a handful of drivers which pass netdev->dev_addr as
the destination buffer to device_get_mac_address(). Add a helper
which takes a dev pointer instead, so it can call an appropriate
helper.

Signed-off-by: Jakub Kicinski <[email-masked]>
---
 drivers/base/property.c  | 20 ++++++++++++++++++++
 include/linux/property.h |  2 ++
 2 files changed, 22 insertions(+)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 453918eb7390..1c8d4676addc 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -997,6 +997,26 @@ void *device_get_mac_address(struct device *dev, char *addr, int alen)
 }
 EXPORT_SYMBOL(device_get_mac_address);
 
+/**
+ * device_get_ethdev_addr - Set netdev's MAC address from a given device
+ * @dev:	Pointer to the device
+ * @netdev:	Pointer to netdev to write the address to
+ *
+ * Wrapper around device_get_mac_address() which writes the address
+ * directly to netdev->dev_addr.
+ */
+void *device_get_ethdev_addr(struct device *dev, struct net_device *netdev)
+{
+	u8 addr[ETH_ALEN];
+	void *ret;
+
+	ret = device_get_mac_address(dev, addr, ETH_ALEN);
+	if (ret)
+		eth_hw_addr_set(netdev, addr);
+	return ret;
+}
+EXPORT_SYMBOL(device_get_ethdev_addr);
+
 /**
  * fwnode_irq_get - Get IRQ directly from a fwnode
  * @fwnode:	Pointer to the firmware node
diff --git a/include/linux/property.h b/include/linux/property.h
index 357513a977e5..24dc4d2b9dbd 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -15,6 +15,7 @@
 #include <linux/types.h>
 
 struct device;
+struct net_device;
 
 enum dev_prop_type {
 	DEV_PROP_U8,
@@ -390,6 +391,7 @@ const void *device_get_match_data(struct device *dev);
 int device_get_phy_mode(struct device *dev);
 
 void *device_get_mac_address(struct device *dev, char *addr, int alen);
+void *device_get_ethdev_addr(struct device *dev, struct net_device *netdev);
 
 int fwnode_get_phy_mode(struct fwnode_handle *fwnode);
 void *fwnode_get_mac_address(struct fwnode_handle *fwnode,
-- 
2.31.1