diff options
| author | Joe Perches <joe@perches.com> | 2013-12-07 03:44:21 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-12-10 05:58:11 +0400 |
| commit | 2c722fe1c821a100ca87fcc36e90a9bceb497c7c (patch) | |
| tree | be96c28923670d0daa2119e414efa9c52991928d /include/linux/etherdevice.h | |
| parent | d9cd4fe5ef4373e0f5b2e752b1859bee33bc5644 (diff) | |
| download | linux-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.h | 25 |
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) { |