Messages in this thread Patch in this message | | | From | Eric Dumazet <> | Date | Wed, 24 Nov 2021 20:08:41 -0800 | Subject | Re: [tip:x86/core 1/1] arch/x86/um/../lib/csum-partial_64.c:98:12: error: implicit declaration of function 'load_unaligned_zeropad' |
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On Wed, Nov 24, 2021 at 8:00 PM Eric Dumazet <edumazet@google.com> wrote:
> > It is an issue in general, not in standard cases because network > headers are aligned. > > I think it came when I folded csum_partial() and do_csum(), I forgot > to ror() the seed. > > I suspect the following would help: > > diff --git a/arch/x86/lib/csum-partial_64.c b/arch/x86/lib/csum-partial_64.c > index 1eb8f2d11f7c785be624eba315fe9ca7989fd56d..ee7b0e7a6055bcbef42d22f7e1d8f52ddbd6be6d > 100644 > --- a/arch/x86/lib/csum-partial_64.c > +++ b/arch/x86/lib/csum-partial_64.c > @@ -41,6 +41,7 @@ __wsum csum_partial(const void *buff, int len, __wsum sum) > if (unlikely(odd)) { > if (unlikely(len == 0)) > return sum; > + temp64 = ror32((__force u64)sum, 8); > temp64 += (*(unsigned char *)buff << 8); > len--; > buff++; > >
It is a bit late here, I will test the following later this week.
We probably can remove one conditional jump at the end of the function
diff --git a/arch/x86/lib/csum-partial_64.c b/arch/x86/lib/csum-partial_64.c index 1eb8f2d11f7c785be624eba315fe9ca7989fd56d..15986ad42ed5ccb8241ff467a34188cf901ec98e 100644 --- a/arch/x86/lib/csum-partial_64.c +++ b/arch/x86/lib/csum-partial_64.c @@ -41,9 +41,11 @@ __wsum csum_partial(const void *buff, int len, __wsum sum) if (unlikely(odd)) { if (unlikely(len == 0)) return sum; + temp64 = ror32((__force u64)sum, 8); temp64 += (*(unsigned char *)buff << 8); len--; buff++; + odd = 8; }
while (unlikely(len >= 64)) { @@ -129,10 +131,7 @@ __wsum csum_partial(const void *buff, int len, __wsum sum) #endif } result = add32_with_carry(temp64 >> 32, temp64 & 0xffffffff); - if (unlikely(odd)) { - result = from32to16(result); - result = ((result >> 8) & 0xff) | ((result & 0xff) << 8); - } + ror32(result, odd); return (__force __wsum)result; } EXPORT_SYMBOL(csum_partial);
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