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| author |   YOSHIFUJI Hideaki / 吉藤英明 <yoshfuji@linux-ipv6.org> | 2013-01-14 07:09:54 +0000 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2013-01-14 13:17:00 -0500 |
| commit | 9f2e73345ad9466618edfec35d98c074f2e0570d (patch) | |
| tree | 504a464901e3a7b5054a288b8e86874f267fae47 /include/net | |
| parent | ipv6: Move comment to right place. (diff) | |
| download | linux-dev-9f2e73345ad9466618edfec35d98c074f2e0570d.tar.xz linux-dev-9f2e73345ad9466618edfec35d98c074f2e0570d.zip | |
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: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net')
| -rw-r--r-- | include/net/ipv6.h | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/include/net/ipv6.h b/include/net/ipv6.h index ed672080c690..ace1113bef85 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -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)); |