x86/lib/csum-partial_64.c

1 // SPDX-License-Identifier: GPL-2.0
3  * arch/x86_64/lib/csum-partial.c
6  * in an architecture-specific manner due to speed.
12 #include <asm/word-at-a-time.h>
35  * Returns a 32bit checksum.
41  * checksums on IPv6 headers (40 bytes) and other small parts.
42  * it's best to have buff aligned on a 64-bit boundary
48 	/* Do two 40-byte chunks in parallel to get better ILP */  in csum_partial()
53 			temp64_2 = update_csum_40b(temp64_2, buff + 40);  in csum_partial()
55 			len -= 80;  in csum_partial()
64 	 * len == 40 is the hot case due to IPv6 headers, so return  in csum_partial()
67 	if (len >= 40) {  in csum_partial()
69 		len -= 40;  in csum_partial()
72 		buff += 40;  in csum_partial()
101 		unsigned int shift = (-len << 3) & 63;  in csum_partial()
116  * this routine is used for miscellaneous IP-like checksums, mainly