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checksum: align buffers

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If buffer is not aligned use sum_16b() only on the not aligned
part, and then use csum_avx2() on the remaining part

Remove unneeded now function csum_unaligned().

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-ID: <20240303135114.1023026-3-lvivier@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
Laurent Vivier 2024-03-06 16:58:31 +11:00 committed by Stefano Brivio
parent 94502fa15e
commit 907621eaae
1 changed files with 24 additions and 23 deletions
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47
checksum.c
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@ -56,6 +56,8 @@
#include <linux/udp.h> #include <linux/udp.h>
#include <linux/icmpv6.h> #include <linux/icmpv6.h>
#include "util.h"
/* Checksums are optional for UDP over IPv4, so we usually just set /* 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 * them to 0. Change this to 1 to calculate real UDP over IPv4
* checksums * checksums
@ -110,20 +112,7 @@ uint16_t csum_fold(uint32_t sum)
return sum; return sum;
} }
/** uint16_t csum(const void *buf, size_t len, uint32_t init);
* 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);
}
/** /**
* csum_ip4_header() - Calculate and set IPv4 header checksum * 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) void csum_ip4_header(struct iphdr *ip4h)
{ {
ip4h->check = 0; 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); + htons(IPPROTO_UDP);
/* Add in partial checksum for the UDP header alone */ /* Add in partial checksum for the UDP header alone */
psum += sum_16b(udp4hr, sizeof(*udp4hr)); 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 */ /* Partial checksum for ICMP header alone */
psum = sum_16b(icmp4hr, sizeof(*icmp4hr)); 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; udp6hr->check = 0;
/* Add in partial checksum for the UDP header alone */ /* Add in partial checksum for the UDP header alone */
psum += sum_16b(udp6hr, sizeof(*udp6hr)); 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; icmp6hr->icmp6_cksum = 0;
/* Add in partial checksum for the ICMPv6 header alone */ /* Add in partial checksum for the ICMPv6 header alone */
psum += sum_16b(icmp6hr, sizeof(*icmp6hr)); psum += sum_16b(icmp6hr, sizeof(*icmp6hr));
icmp6hr->icmp6_cksum = csum_unaligned(payload, len, psum); icmp6hr->icmp6_cksum = csum(payload, len, psum);
} }
#ifdef __AVX2__ #ifdef __AVX2__
@ -397,17 +386,29 @@ less_than_128_bytes:
/** /**
* csum() - Compute TCP/IP-style checksum * csum() - Compute TCP/IP-style checksum
* @buf: Input buffer, must be aligned to 32-byte boundary * @buf: Input buffer
* @len: Input length * @len: Input length
* @init: 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 sum * Return: 16-bit folded, complemented checksum
*/ */
/* NOLINTNEXTLINE(clang-diagnostic-unknown-attributes) */ /* NOLINTNEXTLINE(clang-diagnostic-unknown-attributes) */
__attribute__((optimize("-fno-strict-aliasing"))) /* See csum_16b() */ __attribute__((optimize("-fno-strict-aliasing"))) /* See csum_16b() */
uint16_t csum(const void *buf, size_t len, uint32_t init) 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__ */ #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() */ __attribute__((optimize("-fno-strict-aliasing"))) /* See csum_16b() */
uint16_t csum(const void *buf, size_t len, uint32_t init) 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__ */ #endif /* !__AVX2__ */