linux/arch/x86/lib/csum-partial_64.c

// SPDX-License-Identifier: GPL-2.0
/*
 * arch/x86_64/lib/csum-partial.c
 *
 * This file contains network checksum routines that are better done
 * in an architecture-specific manner due to speed.
 */

#include <linux/compiler.h>
#include <linux/export.h>
#include <asm/checksum.h>
#include <asm/word-at-a-time.h>

static inline __wsum csum_finalize_sum(u64 temp64)
{ … }

static inline unsigned long update_csum_40b(unsigned long sum, const unsigned long m[5])
{ … }

/*
 * Do a checksum on an arbitrary memory area.
 * Returns a 32bit checksum.
 *
 * This isn't as time critical as it used to be because many NICs
 * do hardware checksumming these days.
 *
 * Still, with CHECKSUM_COMPLETE this is called to compute
 * checksums on IPv6 headers (40 bytes) and other small parts.
 * it's best to have buff aligned on a 64-bit boundary
 */
__wsum csum_partial(const void *buff, int len, __wsum sum)
{ … }
EXPORT_SYMBOL(…);

/*
 * this routine is used for miscellaneous IP-like checksums, mainly
 * in icmp.c
 */
__sum16 ip_compute_csum(const void *buff, int len)
{ … }
EXPORT_SYMBOL(…);