[PATCH net-next] etherdevice: Optimize is_broadcast_ether_addr

[Qingfang Deng <dqfext@gmail.com>]

From: Qingfang Deng <qingfang.deng@siflower.com.cn>

Like is_zero_ether_addr, is_broadcast_ether_addr can also be optimized
by using a 32-bit load if CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is set.
Sign extension is used to populate the upper 16-bit of the 16-bit load.

Signed-off-by: Qingfang Deng <qingfang.deng@siflower.com.cn>
---
 include/linux/etherdevice.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h
index 2ad1ffa4ccb9..23b9cc5e299d 100644
--- a/include/linux/etherdevice.h
+++ b/include/linux/etherdevice.h
@@ -174,9 +174,14 @@ static inline bool is_local_ether_addr(const u8 *addr)
  */
 static inline bool is_broadcast_ether_addr(const u8 *addr)
 {
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
+	return (*(const s32 *)(addr + 0) &
+		*(const s16 *)(addr + 4)) == (s32)0xffffffff;
+#else
 	return (*(const u16 *)(addr + 0) &
 		*(const u16 *)(addr + 2) &
 		*(const u16 *)(addr + 4)) == 0xffff;
+#endif
 }
 
 /**
-- 
2.34.1