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author | Christophe Leroy <christophe.leroy@c-s.fr> | 2015-09-22 16:34:25 +0200 |
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committer | Scott Wood <oss@buserror.net> | 2016-03-04 21:49:49 -0600 |
commit | 37e08cad8f177f7bf6226a9b3724234ac3d3c81d (patch) | |
tree | 984dc76493e20ac92f062ccfcd41e48560237a25 /arch/powerpc/include | |
parent | 03bc8b0fc87616c75c6dd060a2191e7fc8faacb6 (diff) | |
download | linux-37e08cad8f177f7bf6226a9b3724234ac3d3c81d.tar.gz linux-37e08cad8f177f7bf6226a9b3724234ac3d3c81d.tar.bz2 linux-37e08cad8f177f7bf6226a9b3724234ac3d3c81d.zip |
powerpc: inline ip_fast_csum()
In several architectures, ip_fast_csum() is inlined
There are functions like ip_send_check() which do nothing
much more than calling ip_fast_csum().
Inlining ip_fast_csum() allows the compiler to optimise better
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[scottwood: whitespace and cast fixes]
Signed-off-by: Scott Wood <oss@buserror.net>
Diffstat (limited to 'arch/powerpc/include')
-rw-r--r-- | arch/powerpc/include/asm/checksum.h | 45 |
1 files changed, 38 insertions, 7 deletions
diff --git a/arch/powerpc/include/asm/checksum.h b/arch/powerpc/include/asm/checksum.h index afa6722cb7d2..1778f75bf769 100644 --- a/arch/powerpc/include/asm/checksum.h +++ b/arch/powerpc/include/asm/checksum.h @@ -9,16 +9,9 @@ * 2 of the License, or (at your option) any later version. */ -/* - * This is a version of ip_compute_csum() optimized for IP headers, - * which always checksum on 4 octet boundaries. ihl is the number - * of 32-bit words and is always >= 5. - */ #ifdef CONFIG_GENERIC_CSUM #include <asm-generic/checksum.h> #else -extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl); - /* * computes the checksum of a memory block at buff, length len, * and adds in "sum" (32-bit) @@ -137,6 +130,44 @@ static inline __wsum csum_add(__wsum csum, __wsum addend) #endif } +/* + * This is a version of ip_compute_csum() optimized for IP headers, + * which always checksum on 4 octet boundaries. ihl is the number + * of 32-bit words and is always >= 5. + */ +static inline __wsum ip_fast_csum_nofold(const void *iph, unsigned int ihl) +{ + const u32 *ptr = (const u32 *)iph + 1; +#ifdef __powerpc64__ + unsigned int i; + u64 s = *(const u32 *)iph; + + for (i = 0; i < ihl - 1; i++, ptr++) + s += *ptr; + s += (s >> 32); + return (__force __wsum)s; +#else + __wsum sum, tmp; + + asm("mtctr %3;" + "addc %0,%4,%5;" + "1: lwzu %1, 4(%2);" + "adde %0,%0,%1;" + "bdnz 1b;" + "addze %0,%0;" + : "=r" (sum), "=r" (tmp), "+b" (ptr) + : "r" (ihl - 2), "r" (*(const u32 *)iph), "r" (*ptr) + : "ctr", "xer", "memory"); + + return sum; +#endif +} + +static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) +{ + return csum_fold(ip_fast_csum_nofold(iph, ihl)); +} + #endif #endif /* __KERNEL__ */ #endif |