From e289d287c6594156cb02f32e64fe8def75fd1cac Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Wed, 6 Mar 2024 16:58:32 +1100 Subject: checksum: add csum_iov() 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 Reviewed-by: David Gibson Message-ID: <20240303135114.1023026-4-lvivier@redhat.com> [dwg: Fixed trivial cppcheck & clang-tidy regressions] Signed-off-by: David Gibson Signed-off-by: Stefano Brivio --- checksum.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 46 insertions(+), 13 deletions(-) (limited to 'checksum.c') diff --git a/checksum.c b/checksum.c index 65486b4..643957b 100644 --- a/checksum.c +++ b/checksum.c @@ -57,6 +57,7 @@ #include #include "util.h" +#include "checksum.h" /* Checksums are optional for UDP over IPv4, so we usually just set * them to 0. Change this to 1 to calculate real UDP over IPv4 @@ -112,8 +113,6 @@ uint16_t csum_fold(uint32_t sum) return sum; } -uint16_t csum(const void *buf, size_t len, uint32_t init); - /** * csum_ip4_header() - Calculate and set IPv4 header checksum * @ip4h: IPv4 header @@ -385,16 +384,17 @@ 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 */ /* 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 +408,31 @@ 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 checksum + */ +/* NOLINTNEXTLINE(clang-diagnostic-unknown-attributes) */ +__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 +440,25 @@ 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__ */ +/** + * csum_iov() - Calculates the unfolded checksum over an array of IO vectors + * + * @iov Pointer to the array of IO vectors + * @n Length of the array + * @init Initial 32-bit checksum, 0 for no pre-computed checksum + * + * Return: 16-bit folded, complemented checksum + */ +/* cppcheck-suppress unusedFunction */ +uint16_t csum_iov(const struct iovec *iov, size_t 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); +} -- cgit v1.2.3