Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH v3 2/2] powerpc: add support for csum_add() | Date | Fri, 22 May 2015 15:57:38 +0000 |
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From: Linuxppc-dev Christophe Leroy > Sent: 19 May 2015 16:19 ... > diff --git a/arch/powerpc/include/asm/checksum.h b/arch/powerpc/include/asm/checksum.h > index 5e43d2d..e8d9ef4 100644 > --- a/arch/powerpc/include/asm/checksum.h > +++ b/arch/powerpc/include/asm/checksum.h > @@ -130,6 +130,22 @@ static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, > return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); > } > > +#define HAVE_ARCH_CSUM_ADD > +static inline __wsum csum_add(__wsum csum, __wsum addend) > +{ > +#ifdef __powerpc64__ > + u64 res = (__force u64)csum; > + > + res += (__force u64)addend; > + return (__force __wsum)((u32)res + (res >> 32)); > +#else > + asm("addc %0,%0,%1;" > + "addze %0,%0;" > + : "+r" (csum) : "r" (addend)); > + return csum; > +#endif
I'd have thought it better to test for the cpu type where you want the 'asm' variant, and then fall back on the C version for all others. I know (well suspect) there are only two cases here.
I'd also have thought that the 64bit C version above would be generally 'good'.
David
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