checksum_64.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef __SPARC64_CHECKSUM_H
  3#define __SPARC64_CHECKSUM_H
  4
  5/*  checksum.h:  IP/UDP/TCP checksum routines on the V9.
  6 *
  7 *  Copyright(C) 1995 Linus Torvalds
  8 *  Copyright(C) 1995 Miguel de Icaza
  9 *  Copyright(C) 1996 David S. Miller
 10 *  Copyright(C) 1996 Eddie C. Dost
 11 *  Copyright(C) 1997 Jakub Jelinek
 12 *
 13 * derived from:
 14 *	Alpha checksum c-code
 15 *      ix86 inline assembly
 16 *      RFC1071 Computing the Internet Checksum
 17 */
 18
 19#include <linux/in6.h>
 20#include <linux/uaccess.h>
 21
 22/* computes the checksum of a memory block at buff, length len,
 23 * and adds in "sum" (32-bit)
 24 *
 25 * returns a 32-bit number suitable for feeding into itself
 26 * or csum_tcpudp_magic
 27 *
 28 * this function must be called with even lengths, except
 29 * for the last fragment, which may be odd
 30 *
 31 * it's best to have buff aligned on a 32-bit boundary
 32 */
 33__wsum csum_partial(const void * buff, int len, __wsum sum);
 34
 35/* the same as csum_partial, but copies from user space while it
 36 * checksums
 37 *
 38 * here even more important to align src and dst on a 32-bit (or even
 39 * better 64-bit) boundary
 40 */
 41__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len);
 42__wsum csum_and_copy_from_user(const void __user *src, void *dst, int len);
 43__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len);
 44
 45/* ihl is always 5 or greater, almost always is 5, and iph is word aligned
 46 * the majority of the time.
 47 */
 48__sum16 ip_fast_csum(const void *iph, unsigned int ihl);
 49
 50/* Fold a partial checksum without adding pseudo headers. */
 51static inline __sum16 csum_fold(__wsum sum)
 52{
 53	unsigned int tmp;
 54
 55	__asm__ __volatile__(
 56"	addcc		%0, %1, %1\n"
 57"	srl		%1, 16, %1\n"
 58"	addc		%1, %%g0, %1\n"
 59"	xnor		%%g0, %1, %0\n"
 60	: "=&r" (sum), "=r" (tmp)
 61	: "0" (sum), "1" ((__force u32)sum<<16)
 62	: "cc");
 63	return (__force __sum16)sum;
 64}
 65
 66static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
 67					__u32 len, __u8 proto,
 68					__wsum sum)
 69{
 70	__asm__ __volatile__(
 71"	addcc		%1, %0, %0\n"
 72"	addccc		%2, %0, %0\n"
 73"	addccc		%3, %0, %0\n"
 74"	addc		%0, %%g0, %0\n"
 75	: "=r" (sum), "=r" (saddr)
 76	: "r" (daddr), "r" (proto + len), "0" (sum), "1" (saddr)
 77	: "cc");
 78	return sum;
 79}
 80
 81/*
 82 * computes the checksum of the TCP/UDP pseudo-header
 83 * returns a 16-bit checksum, already complemented
 84 */
 85static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
 86					__u32 len, __u8 proto,
 87					__wsum sum)
 88{
 89	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 90}
 91
 92#define _HAVE_ARCH_IPV6_CSUM
 93
 94static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
 95				      const struct in6_addr *daddr,
 96				      __u32 len, __u8 proto, __wsum sum)
 97{
 98	__asm__ __volatile__ (
 99"	addcc		%3, %4, %%g7\n"
100"	addccc		%5, %%g7, %%g7\n"
101"	lduw		[%2 + 0x0c], %%g2\n"
102"	lduw		[%2 + 0x08], %%g3\n"
103"	addccc		%%g2, %%g7, %%g7\n"
104"	lduw		[%2 + 0x04], %%g2\n"
105"	addccc		%%g3, %%g7, %%g7\n"
106"	lduw		[%2 + 0x00], %%g3\n"
107"	addccc		%%g2, %%g7, %%g7\n"
108"	lduw		[%1 + 0x0c], %%g2\n"
109"	addccc		%%g3, %%g7, %%g7\n"
110"	lduw		[%1 + 0x08], %%g3\n"
111"	addccc		%%g2, %%g7, %%g7\n"
112"	lduw		[%1 + 0x04], %%g2\n"
113"	addccc		%%g3, %%g7, %%g7\n"
114"	lduw		[%1 + 0x00], %%g3\n"
115"	addccc		%%g2, %%g7, %%g7\n"
116"	addccc		%%g3, %%g7, %0\n"
117"	addc		0, %0, %0\n"
118	: "=&r" (sum)
119	: "r" (saddr), "r" (daddr), "r"(htonl(len)),
120	  "r"(htonl(proto)), "r"(sum)
121	: "g2", "g3", "g7", "cc");
122
123	return csum_fold(sum);
124}
125
126/* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
127static inline __sum16 ip_compute_csum(const void *buff, int len)
128{
129	return csum_fold(csum_partial(buff, len, 0));
130}
131
132#define HAVE_ARCH_CSUM_ADD
133static inline __wsum csum_add(__wsum csum, __wsum addend)
134{
135	__asm__ __volatile__(
136		"addcc   %0, %1, %0\n"
137		"addx    %0, %%g0, %0"
138		: "=r" (csum)
139		: "r" (addend), "0" (csum));
140
141	return csum;
142}
143
144#endif /* !(__SPARC64_CHECKSUM_H) */