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authorJoe Perches <joe@perches.com>2013-12-07 03:44:21 +0400
committerDavid S. Miller <davem@davemloft.net>2013-12-10 05:58:11 +0400
commit2c722fe1c821a100ca87fcc36e90a9bceb497c7c (patch)
treebe96c28923670d0daa2119e414efa9c52991928d /include/linux/etherdevice.h
parentd9cd4fe5ef4373e0f5b2e752b1859bee33bc5644 (diff)
downloadlinux-2c722fe1c821a100ca87fcc36e90a9bceb497c7c.tar.xz
etherdevice: Optimize a few is_<foo>_ether_addr functions
If CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is set, several is_<foo>_ether_addr functions can be slightly improved by using u32 dereferences. I believe all current uses of is_zero_ether_addr and is_broadcast_ether_addr are u16 aligned, so always use u16 references to improve those functions performance. Document the u16 alignment requirements. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/etherdevice.h')
-rw-r--r--include/linux/etherdevice.h25
1 files changed, 23 insertions, 2 deletions
diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h
index 2f0e3d0818bc..f344ac04f858 100644
--- a/include/linux/etherdevice.h
+++ b/include/linux/etherdevice.h
@@ -61,6 +61,8 @@ static const u8 eth_reserved_addr_base[ETH_ALEN] __aligned(2) =
*
* Return true if address is link local reserved addr (01:80:c2:00:00:0X) per
* IEEE 802.1Q 8.6.3 Frame filtering.
+ *
+ * Please note: addr must be aligned to u16.
*/
static inline bool is_link_local_ether_addr(const u8 *addr)
{
@@ -68,7 +70,12 @@ static inline bool is_link_local_ether_addr(const u8 *addr)
static const __be16 *b = (const __be16 *)eth_reserved_addr_base;
static const __be16 m = cpu_to_be16(0xfff0);
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
+ return (((*(const u32 *)addr) ^ (*(const u32 *)b)) |
+ ((a[2] ^ b[2]) & m)) == 0;
+#else
return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
+#endif
}
/**
@@ -76,10 +83,18 @@ static inline bool is_link_local_ether_addr(const u8 *addr)
* @addr: Pointer to a six-byte array containing the Ethernet address
*
* Return true if the address is all zeroes.
+ *
+ * Please note: addr must be aligned to u16.
*/
static inline bool is_zero_ether_addr(const u8 *addr)
{
- return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]);
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
+ return ((*(const u32 *)addr) | (*(const u16 *)(addr + 4))) == 0;
+#else
+ return (*(const u16 *)(addr + 0) |
+ *(const u16 *)(addr + 2) |
+ *(const u16 *)(addr + 4)) == 0;
+#endif
}
/**
@@ -110,10 +125,14 @@ static inline bool is_local_ether_addr(const u8 *addr)
* @addr: Pointer to a six-byte array containing the Ethernet address
*
* Return true if the address is the broadcast address.
+ *
+ * Please note: addr must be aligned to u16.
*/
static inline bool is_broadcast_ether_addr(const u8 *addr)
{
- return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff;
+ return (*(const u16 *)(addr + 0) &
+ *(const u16 *)(addr + 2) &
+ *(const u16 *)(addr + 4)) == 0xffff;
}
/**
@@ -135,6 +154,8 @@ static inline bool is_unicast_ether_addr(const u8 *addr)
* a multicast address, and is not FF:FF:FF:FF:FF:FF.
*
* Return true if the address is valid.
+ *
+ * Please note: addr must be aligned to u16.
*/
static inline bool is_valid_ether_addr(const u8 *addr)
{