Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 9f2e7334 authored by YOSHIFUJI Hideaki / 吉藤英明's avatar YOSHIFUJI Hideaki / 吉藤英明 Committed by David S. Miller
Browse files

ipv6: 64bit version of ipv6_addr_diff(). 



Introduce __ipv6_addr_diff64() to to find the first different
bit between two addresses on 64bit architectures.

32bit version is still available as __ipv6_addr_diff32(),
and __ipv6_addr_diff() automatically selects appropriate
version.

Signed-off-by: default avatarYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 25d46f43

include/net/ipv6.h

+28 −1
Original line number Diff line number Diff line
@@ -507,7 +507,7 @@ static inline void ipv6_addr_set_v4mapped(const __be32 addr, 
 * find the first different bit between two addresses

 * length of address must be a multiple of 32bits

 */

static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)

static inline int __ipv6_addr_diff32(const void *token1, const void *token2, int addrlen)

{

	const __be32 *a1 = token1, *a2 = token2;

	int i;
@@ -539,6 +539,33 @@ static inline int __ipv6_addr_diff(const void *token1, const void *token2, int a 
	return addrlen << 5;

}



#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64

static inline int __ipv6_addr_diff64(const void *token1, const void *token2, int addrlen)

{

	const __be64 *a1 = token1, *a2 = token2;

	int i;



	addrlen >>= 3;



	for (i = 0; i < addrlen; i++) {

		__be64 xb = a1[i] ^ a2[i];

		if (xb)

			return i * 64 + 63 - __fls(be64_to_cpu(xb));

	}



	return addrlen << 6;

}

#endif



static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)

{

#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64

	if (__builtin_constant_p(addrlen) && !(addrlen & 7))

		return __ipv6_addr_diff64(token1, token2, addrlen);

#endif

	return __ipv6_addr_diff32(token1, token2, addrlen);

}



static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)

{

	return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));