etherdevice: introduce help function eth_zero_addr()

a lot of code has either the memset or an inefficient copy
from a static array that contains the all-zeros Ethernet address.
Introduce help function eth_zero_addr() to fill an address with
all zeros, making the code clearer and allowing us to get rid of
some constant arrays.

Signed-off-by: Duan Jiong <djduanjiong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h
index d426336d92d9..b006ba0a9f42 100644
--- a/include/linux/etherdevice.h
+++ b/include/linux/etherdevice.h
@@ -151,6 +151,17 @@ static inline void eth_broadcast_addr(u8 *addr)
 }
 
 /**
+ * eth_zero_addr - Assign zero address
+ * @addr: Pointer to a six-byte array containing the Ethernet address
+ *
+ * Assign the zero address to the given address array.
+ */
+static inline void eth_zero_addr(u8 *addr)
+{
+        memset(addr, 0x00, ETH_ALEN);
+}
+
+/**
  * eth_hw_addr_random - Generate software assigned random Ethernet and
  * set device flag
  * @dev: pointer to net_device structure