On Wed, Feb 14, 2024 at 09:56:23AM +0100, Laurent Vivier wrote:if buffer is not aligned use sum_16b() only on the not alignedNit: s/if/If/part, and then use csum_avx2() on the remaining part Remove unneeded now function csum_unaligned(). Signed-off-by: Laurent Vivier <lvivier(a)redhat.com>Reviewed-by: David Gibson <david(a)gibson.dropbear.id.au>--- Notes: v2: - use ROUND_UP() and sizeof(__m256i) - fix function comment - remove csum_unaligned() and use csum() instead checksum.c | 47 ++++++++++++++++++++++++----------------------- 1 file changed, 24 insertions(+), 23 deletions(-) diff --git a/checksum.c b/checksum.c index f21c9b7a14d1..65486b4625ba 100644 --- a/checksum.c +++ b/checksum.c @@ -56,6 +56,8 @@ #include <linux/udp.h> #include <linux/icmpv6.h> +#include "util.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 * checksums @@ -110,20 +112,7 @@ uint16_t csum_fold(uint32_t sum) return sum; } -/** - * csum_unaligned() - Compute TCP/IP-style checksum for not 32-byte aligned data - * @buf: Input data - * @len: Input length - * @init: Initial 32-bit checksum, 0 for no pre-computed checksum - * - * Return: 16-bit IPv4-style checksum - */ -/* NOLINTNEXTLINE(clang-diagnostic-unknown-attributes) */ -__attribute__((optimize("-fno-strict-aliasing"))) /* See csum_16b() */ -uint16_t csum_unaligned(const void *buf, size_t len, uint32_t init) -{ - return (uint16_t)~csum_fold(sum_16b(buf, len) + init); -} +uint16_t csum(const void *buf, size_t len, uint32_t init); /** * csum_ip4_header() - Calculate and set IPv4 header checksum @@ -132,7 +121,7 @@ uint16_t csum_unaligned(const void *buf, size_t len, uint32_t init) void csum_ip4_header(struct iphdr *ip4h) { ip4h->check = 0; - ip4h->check = csum_unaligned(ip4h, (size_t)ip4h->ihl * 4, 0); + ip4h->check = csum(ip4h, (size_t)ip4h->ihl * 4, 0); } /** @@ -159,7 +148,7 @@ void csum_udp4(struct udphdr *udp4hr, + htons(IPPROTO_UDP); /* Add in partial checksum for the UDP header alone */ psum += sum_16b(udp4hr, sizeof(*udp4hr)); - udp4hr->check = csum_unaligned(payload, len, psum); + udp4hr->check = csum(payload, len, psum); } } @@ -178,7 +167,7 @@ void csum_icmp4(struct icmphdr *icmp4hr, const void *payload, size_t len) /* Partial checksum for ICMP header alone */ psum = sum_16b(icmp4hr, sizeof(*icmp4hr)); - icmp4hr->checksum = csum_unaligned(payload, len, psum); + icmp4hr->checksum = csum(payload, len, psum); } /** @@ -199,7 +188,7 @@ void csum_udp6(struct udphdr *udp6hr, udp6hr->check = 0; /* Add in partial checksum for the UDP header alone */ psum += sum_16b(udp6hr, sizeof(*udp6hr)); - udp6hr->check = csum_unaligned(payload, len, psum); + udp6hr->check = csum(payload, len, psum); } /** @@ -222,7 +211,7 @@ void csum_icmp6(struct icmp6hdr *icmp6hr, icmp6hr->icmp6_cksum = 0; /* Add in partial checksum for the ICMPv6 header alone */ psum += sum_16b(icmp6hr, sizeof(*icmp6hr)); - icmp6hr->icmp6_cksum = csum_unaligned(payload, len, psum); + icmp6hr->icmp6_cksum = csum(payload, len, psum); } #ifdef __AVX2__ @@ -397,17 +386,29 @@ less_than_128_bytes: /** * csum() - Compute TCP/IP-style checksum - * @buf: Input buffer, must be aligned to 32-byte boundary + * @buf: Input buffer * @len: Input length * @init: Initial 32-bit checksum, 0 for no pre-computed checksum * - * Return: 16-bit folded, complemented checksum sum + * Return: 16-bit folded, complemented checksum */ /* 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) { - return (uint16_t)~csum_fold(csum_avx2(buf, len, init)); + intptr_t align = ROUND_UP((intptr_t)buf, sizeof(__m256i)); + unsigned int pad = align - (intptr_t)buf; + + if (len < pad) + pad = len; + + if (pad) + init += sum_16b(buf, pad); + + if (len > pad) + init = csum_avx2((void *)align, len - pad, init); + + return (uint16_t)~csum_fold(init); } #else /* __AVX2__ */ @@ -424,7 +425,7 @@ 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 csum_unaligned(buf, len, init); + return (uint16_t)~csum_fold(sum_16b(buf, len) + init); } #endif /* !__AVX2__ */-- 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