From: Laurent Vivier <lvivier@redhat.com>
To: passt-dev@passt.top
Cc: Laurent Vivier <lvivier@redhat.com>,
David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH v5 3/9] checksum: add csum_iov()
Date: Sun, 3 Mar 2024 14:51:08 +0100 [thread overview]
Message-ID: <20240303135114.1023026-4-lvivier@redhat.com> (raw)
In-Reply-To: <20240303135114.1023026-1-lvivier@redhat.com>
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@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
---
Notes:
v4:
- rebase
v3:
- update comments
- use size_t for the IO vectors length
- include checksum.h in checksum.c
- export csum_unfolded() (for later)
v2:
- fix typo and superfluous space
- update comments
checksum.c | 56 ++++++++++++++++++++++++++++++++++++++++++------------
checksum.h | 2 ++
2 files changed, 46 insertions(+), 12 deletions(-)
diff --git a/checksum.c b/checksum.c
index 65486b4625ba..74e3742bc6f6 100644
--- a/checksum.c
+++ b/checksum.c
@@ -57,6 +57,7 @@
#include <linux/icmpv6.h>
#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
@@ -385,16 +386,16 @@ 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
*/
-/* 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 +409,30 @@ 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 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 +440,24 @@ 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
+ */
+uint16_t csum_iov(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);
+}
diff --git a/checksum.h b/checksum.h
index 21c0310d3804..dfa705a04a24 100644
--- a/checksum.h
+++ b/checksum.h
@@ -24,6 +24,8 @@ void csum_udp6(struct udphdr *udp6hr,
void csum_icmp6(struct icmp6hdr *icmp6hr,
const struct in6_addr *saddr, const struct in6_addr *daddr,
const void *payload, size_t len);
+uint32_t csum_unfolded(const void *buf, size_t len, uint32_t init);
uint16_t csum(const void *buf, size_t len, uint32_t init);
+uint16_t csum_iov(struct iovec *iov, size_t n, uint32_t init);
#endif /* CHECKSUM_H */
--
@@ -24,6 +24,8 @@ void csum_udp6(struct udphdr *udp6hr,
void csum_icmp6(struct icmp6hdr *icmp6hr,
const struct in6_addr *saddr, const struct in6_addr *daddr,
const void *payload, size_t len);
+uint32_t csum_unfolded(const void *buf, size_t len, uint32_t init);
uint16_t csum(const void *buf, size_t len, uint32_t init);
+uint16_t csum_iov(struct iovec *iov, size_t n, uint32_t init);
#endif /* CHECKSUM_H */
--
2.42.0
next prev parent reply other threads:[~2024-03-03 13:51 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-03 13:51 [PATCH v5 0/9] Add vhost-user support to passt (part 1) Laurent Vivier
2024-03-03 13:51 ` [PATCH v5 1/9] pcap: add pcap_iov() Laurent Vivier
2024-03-03 13:51 ` [PATCH v5 2/9] checksum: align buffers Laurent Vivier
2024-03-03 13:51 ` Laurent Vivier [this message]
2024-03-03 13:51 ` [PATCH v5 4/9] util: move IP stuff from util.[ch] to ip.[ch] Laurent Vivier
2024-03-03 13:51 ` [PATCH v5 5/9] udp: little cleanup in udp_update_hdrX() to prepare future changes Laurent Vivier
2024-03-04 0:46 ` David Gibson
2024-03-03 13:51 ` [PATCH v5 6/9] checksum: use csum_ip4_header() in udp.c and tcp.c Laurent Vivier
2024-03-03 13:51 ` [PATCH v5 7/9] checksum: introduce functions to compute the header part checksum for TCP/UDP Laurent Vivier
2024-03-04 0:52 ` David Gibson
2024-03-03 13:51 ` [PATCH v5 8/9] tap: make tap_update_mac() generic Laurent Vivier
2024-03-03 13:51 ` [PATCH v5 9/9] tcp: Introduce ipv4_fill_headers()/ipv6_fill_headers() Laurent Vivier
2024-03-04 0:54 ` David Gibson
2024-03-05 22:12 ` [PATCH v5 0/9] Add vhost-user support to passt (part 1) Stefano Brivio
2024-03-06 3:22 ` David Gibson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240303135114.1023026-4-lvivier@redhat.com \
--to=lvivier@redhat.com \
--cc=david@gibson.dropbear.id.au \
--cc=passt-dev@passt.top \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://passt.top/passt
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for IMAP folder(s).