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Commit 2c722fe1 authored by Joe Perches's avatar Joe Perches Committed by David S. Miller
Browse files

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: default avatarJoe Perches <joe@perches.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d9cd4fe5

include/linux/etherdevice.h

+23 −2
Original line number Original line Diff line number Diff line
@@ -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

 * Return true if address is link local reserved addr (01:80:c2:00:00:0X) per

 * IEEE 802.1Q 8.6.3 Frame filtering.

 * 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)

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 *b = (const __be16 *)eth_reserved_addr_base;

	static const __be16 m = cpu_to_be16(0xfff0);

	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;

	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

 * @addr: Pointer to a six-byte array containing the Ethernet address

 *

 *

 * Return true if the address is all zeroes.

 * 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)

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

 * @addr: Pointer to a six-byte array containing the Ethernet address

 *

 *

 * Return true if the address is the broadcast 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)

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.

 * a multicast address, and is not FF:FF:FF:FF:FF:FF.

 *

 *

 * Return true if the address is valid.

 * 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)

static inline bool is_valid_ether_addr(const u8 *addr)

{

{