On Wed, Feb 14, 2024 at 09:56:24AM +0100, Laurent Vivier wrote:Introduce the function csum_unfolded() that computes the unfolded 32-bit checksum of a data buffer, and call it from csum() that returns the folded value. Introduce csum_iov() that computes the checksum using csum_folded() on all vectors of the iovec array and returns the folded result. Signed-off-by: Laurent Vivier <lvivier(a)redhat.com> --- Notes: v2: - fix typo and superfluous space - update comments checksum.c | 46 ++++++++++++++++++++++++++++++++++------------ checksum.h | 1 + 2 files changed, 35 insertions(+), 12 deletions(-) diff --git a/checksum.c b/checksum.c index 65486b4625ba..ac2bc49f7eb0 100644 --- a/checksum.c +++ b/checksum.c @@ -385,16 +385,16 @@ less_than_128_bytes: } /** - * csum() - Compute TCP/IP-style checksum - * @buf: Input buffer - * @len: Input length - * @init: Initial 32-bit checksum, 0 for no pre-computed checksum + * csum_unfolded - Calculate the unfolded checksum of a data buffer. * - * Return: 16-bit folded, complemented checksum + * @buf: Input buffer + * @len: Input length + * @init: Initial 32-bit checksum, 0 for no pre-computed checksum + * + * Return: 32-bit unfolded, complemented checksumThis function neither folds nor complements (indeed, you can't complement until after you fold).*/ -/* NOLINTNEXTLINE(clang-diagnostic-unknown-attributes) */ __attribute__((optimize("-fno-strict-aliasing"))) /* See csum_16b() */ -uint16_t csum(const void *buf, size_t len, uint32_t init) +uint32_t csum_unfolded(const void *buf, size_t len, uint32_t init) { intptr_t align = ROUND_UP((intptr_t)buf, sizeof(__m256i)); unsigned int pad = align - (intptr_t)buf; @@ -408,16 +408,30 @@ uint16_t csum(const void *buf, size_t len, uint32_t init) if (len > pad) init = csum_avx2((void *)align, len - pad, init); - return (uint16_t)~csum_fold(init); + return init; } - #else /* __AVX2__ */ +/** + * csum_unfolded - Calculate the unfolded checksum of a data buffer. + * + * @buf: Input buffer + * @len: Input length + * @init: Initial 32-bit checksum, 0 for no pre-computed checksum + * + * Return: 32-bit unfolded, complemented checksum + */ +__attribute__((optimize("-fno-strict-aliasing"))) /* See csum_16b() */ +uint32_t csum_unfolded(const void *buf, size_t len, uint32_t init) +{ + return sum_16b(buf, len) + init; +} +#endif /* !__AVX2__ */ /** * csum() - Compute TCP/IP-style checksum * @buf: Input buffer * @len: Input length - * @sum: Initial 32-bit checksum, 0 for no pre-computed checksum + * @init: Initial 32-bit checksum, 0 for no pre-computed checksum * * Return: 16-bit folded, complemented checksum */ @@ -425,7 +439,15 @@ uint16_t csum(const void *buf, size_t len, uint32_t init) __attribute__((optimize("-fno-strict-aliasing"))) /* See csum_16b() */ uint16_t csum(const void *buf, size_t len, uint32_t init) { - return (uint16_t)~csum_fold(sum_16b(buf, len) + init); + return (uint16_t)~csum_fold(csum_unfolded(buf, len, init)); } -#endif /* !__AVX2__ */Function comment, please.+uint16_t csum_iov(struct iovec *iov, unsigned int n, uint32_t init) +{ + unsigned int i; + + for (i = 0; i < n; i++) + init = csum_unfolded(iov[i].iov_base, iov[i].iov_len, init); + + return (uint16_t)~csum_fold(init); +} diff --git a/checksum.h b/checksum.h index 21c0310d3804..6a20297a5826 100644 --- a/checksum.h +++ b/checksum.h @@ -25,5 +25,6 @@ void csum_icmp6(struct icmp6hdr *icmp6hr, const struct in6_addr *saddr, const struct in6_addr *daddr, const void *payload, size_t len); uint16_t csum(const void *buf, size_t len, uint32_t init); +uint16_t csum_iov(struct iovec *iov, unsigned int n, uint32_t init); #endif /* CHECKSUM_H */-- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson