From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Perches Subject: [PATCH -next] etherdevice: Optimize a few is__ether_addr functions Date: Fri, 06 Dec 2013 15:44:21 -0800 Message-ID: <1386373461.31845.50.camel@joe-AO722> References: <1386317890.31845.26.camel@joe-AO722> <20131206.153944.1382127535160341376.davem@davemloft.net> <1386364621.31845.32.camel@joe-AO722> <20131206.163806.1555069105347405484.davem@davemloft.net> <1386368461.31845.38.camel@joe-AO722> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: David Miller Return-path: In-Reply-To: <1386368461.31845.38.camel@joe-AO722> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org If CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is set, several is__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 --- include/linux/etherdevice.h | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h index 3526e81..9518e59 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) {