1/* $Id: checksum.h,v 1.1.1.1 2007/08/03 18:53:36 Exp $ */
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 <asm/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 */
33extern __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 */
41extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
42					      int len, __wsum sum);
43
44extern long __csum_partial_copy_from_user(const void __user *src,
45					  void *dst, int len,
46					  __wsum sum);
47
48static inline __wsum
49csum_partial_copy_from_user(const void __user *src,
50			    void *dst, int len,
51			    __wsum sum, int *err)
52{
53	long ret = __csum_partial_copy_from_user(src, dst, len, sum);
54	if (ret < 0)
55		*err = -EFAULT;
56	return (__force __wsum) ret;
57}
58
59/*
60 *	Copy and checksum to user
61 */
62#define HAVE_CSUM_COPY_USER
63extern long __csum_partial_copy_to_user(const void *src,
64					void __user *dst, int len,
65					  __wsum sum);
66
67static inline __wsum
68csum_and_copy_to_user(const void *src,
69		      void __user *dst, int len,
70		      __wsum sum, int *err)
71{
72	long ret = __csum_partial_copy_to_user(src, dst, len, sum);
73	if (ret < 0)
74		*err = -EFAULT;
75	return (__force __wsum) ret;
76}
77
78/* ihl is always 5 or greater, almost always is 5, and iph is word aligned
79 * the majority of the time.
80 */
81extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
82
83/* Fold a partial checksum without adding pseudo headers. */
84static inline __sum16 csum_fold(__wsum sum)
85{
86	unsigned int tmp;
87
88	__asm__ __volatile__(
89"	addcc		%0, %1, %1\n"
90"	srl		%1, 16, %1\n"
91"	addc		%1, %%g0, %1\n"
92"	xnor		%%g0, %1, %0\n"
93	: "=&r" (sum), "=r" (tmp)
94	: "0" (sum), "1" ((__force u32)sum<<16)
95	: "cc");
96	return (__force __sum16)sum;
97}
98
99static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
100					       unsigned int len,
101					       unsigned short proto,
102					       __wsum sum)
103{
104	__asm__ __volatile__(
105"	addcc		%1, %0, %0\n"
106"	addccc		%2, %0, %0\n"
107"	addccc		%3, %0, %0\n"
108"	addc		%0, %%g0, %0\n"
109	: "=r" (sum), "=r" (saddr)
110	: "r" (daddr), "r" (proto + len), "0" (sum), "1" (saddr)
111	: "cc");
112	return sum;
113}
114
115/*
116 * computes the checksum of the TCP/UDP pseudo-header
117 * returns a 16-bit checksum, already complemented
118 */
119static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
120						   unsigned short len,
121						   unsigned short proto,
122						   __wsum sum)
123{
124	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
125}
126
127#define _HAVE_ARCH_IPV6_CSUM
128
129static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
130				      const struct in6_addr *daddr,
131				      __u32 len, unsigned short proto,
132				      __wsum sum)
133{
134	__asm__ __volatile__ (
135"	addcc		%3, %4, %%g7\n"
136"	addccc		%5, %%g7, %%g7\n"
137"	lduw		[%2 + 0x0c], %%g2\n"
138"	lduw		[%2 + 0x08], %%g3\n"
139"	addccc		%%g2, %%g7, %%g7\n"
140"	lduw		[%2 + 0x04], %%g2\n"
141"	addccc		%%g3, %%g7, %%g7\n"
142"	lduw		[%2 + 0x00], %%g3\n"
143"	addccc		%%g2, %%g7, %%g7\n"
144"	lduw		[%1 + 0x0c], %%g2\n"
145"	addccc		%%g3, %%g7, %%g7\n"
146"	lduw		[%1 + 0x08], %%g3\n"
147"	addccc		%%g2, %%g7, %%g7\n"
148"	lduw		[%1 + 0x04], %%g2\n"
149"	addccc		%%g3, %%g7, %%g7\n"
150"	lduw		[%1 + 0x00], %%g3\n"
151"	addccc		%%g2, %%g7, %%g7\n"
152"	addccc		%%g3, %%g7, %0\n"
153"	addc		0, %0, %0\n"
154	: "=&r" (sum)
155	: "r" (saddr), "r" (daddr), "r"(htonl(len)),
156	  "r"(htonl(proto)), "r"(sum)
157	: "g2", "g3", "g7", "cc");
158
159	return csum_fold(sum);
160}
161
162/* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
163static inline __sum16 ip_compute_csum(const void *buff, int len)
164{
165	return csum_fold(csum_partial(buff, len, 0));
166}
167
168#endif /* !(__SPARC64_CHECKSUM_H) */
169