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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef __ASM_SH_CHECKSUM_H
2#define __ASM_SH_CHECKSUM_H
3
4/*
5 * This file is subject to the terms and conditions of the GNU General Public
6 * License. See the file "COPYING" in the main directory of this archive
7 * for more details.
8 *
9 * Copyright (C) 1999 by Kaz Kojima & Niibe Yutaka
10 */
11
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/in6.h>
13
14/*
15 * computes the checksum of a memory block at buff, length len,
16 * and adds in "sum" (32-bit)
17 *
18 * returns a 32-bit number suitable for feeding into itself
19 * or csum_tcpudp_magic
20 *
21 * this function must be called with even lengths, except
22 * for the last fragment, which may be odd
23 *
24 * it's best to have buff aligned on a 32-bit boundary
25 */
26asmlinkage unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
27
28/*
29 * the same as csum_partial, but copies from src while it
30 * checksums, and handles user-space pointer exceptions correctly, when needed.
31 *
32 * here even more important to align src and dst on a 32-bit (or even
33 * better 64-bit) boundary
34 */
35
36asmlinkage unsigned int csum_partial_copy_generic(const unsigned char *src, unsigned char *dst,
37 int len, int sum, int *src_err_ptr, int *dst_err_ptr);
38
39/*
40 * Note: when you get a NULL pointer exception here this means someone
41 * passed in an incorrect kernel address to one of these functions.
42 *
43 * If you use these functions directly please don't forget the
Jesper Juhle49332b2005-05-01 08:59:08 -070044 * access_ok().
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 */
46static __inline__
47unsigned int csum_partial_copy_nocheck (const unsigned char *src, unsigned char *dst,
48 int len, int sum)
49{
50 return csum_partial_copy_generic ( src, dst, len, sum, NULL, NULL);
51}
52
53static __inline__
54unsigned int csum_partial_copy_from_user (const unsigned char *src, unsigned char *dst,
55 int len, int sum, int *err_ptr)
56{
57 return csum_partial_copy_generic ( src, dst, len, sum, err_ptr, NULL);
58}
59
60/*
61 * Fold a partial checksum
62 */
63
64static __inline__ unsigned int csum_fold(unsigned int sum)
65{
66 unsigned int __dummy;
67 __asm__("swap.w %0, %1\n\t"
68 "extu.w %0, %0\n\t"
69 "extu.w %1, %1\n\t"
70 "add %1, %0\n\t"
71 "swap.w %0, %1\n\t"
72 "add %1, %0\n\t"
73 "not %0, %0\n\t"
74 : "=r" (sum), "=&r" (__dummy)
75 : "0" (sum)
76 : "t");
77 return sum;
78}
79
80/*
81 * This is a version of ip_compute_csum() optimized for IP headers,
82 * which always checksum on 4 octet boundaries.
83 *
84 * i386 version by Jorge Cwik <jorge@laser.satlink.net>, adapted
85 * for linux by * Arnt Gulbrandsen.
86 */
87static __inline__ unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl)
88{
89 unsigned int sum, __dummy0, __dummy1;
90
91 __asm__ __volatile__(
92 "mov.l @%1+, %0\n\t"
93 "mov.l @%1+, %3\n\t"
94 "add #-2, %2\n\t"
95 "clrt\n\t"
96 "1:\t"
97 "addc %3, %0\n\t"
98 "movt %4\n\t"
99 "mov.l @%1+, %3\n\t"
100 "dt %2\n\t"
101 "bf/s 1b\n\t"
102 " cmp/eq #1, %4\n\t"
103 "addc %3, %0\n\t"
104 "addc %2, %0" /* Here %2 is 0, add carry-bit */
105 /* Since the input registers which are loaded with iph and ihl
106 are modified, we must also specify them as outputs, or gcc
107 will assume they contain their original values. */
108 : "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (__dummy0), "=&z" (__dummy1)
109 : "1" (iph), "2" (ihl)
110 : "t");
111
112 return csum_fold(sum);
113}
114
115static __inline__ unsigned long csum_tcpudp_nofold(unsigned long saddr,
116 unsigned long daddr,
117 unsigned short len,
118 unsigned short proto,
119 unsigned int sum)
120{
121#ifdef __LITTLE_ENDIAN__
122 unsigned long len_proto = (ntohs(len)<<16)+proto*256;
123#else
124 unsigned long len_proto = (proto<<16)+len;
125#endif
126 __asm__("clrt\n\t"
127 "addc %0, %1\n\t"
128 "addc %2, %1\n\t"
129 "addc %3, %1\n\t"
130 "movt %0\n\t"
131 "add %1, %0"
132 : "=r" (sum), "=r" (len_proto)
133 : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum)
134 : "t");
135 return sum;
136}
137
138/*
139 * computes the checksum of the TCP/UDP pseudo-header
140 * returns a 16-bit checksum, already complemented
141 */
142static __inline__ unsigned short int csum_tcpudp_magic(unsigned long saddr,
143 unsigned long daddr,
144 unsigned short len,
145 unsigned short proto,
146 unsigned int sum)
147{
148 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
149}
150
151/*
152 * this routine is used for miscellaneous IP-like checksums, mainly
153 * in icmp.c
154 */
155
156static __inline__ unsigned short ip_compute_csum(unsigned char * buff, int len)
157{
158 return csum_fold (csum_partial(buff, len, 0));
159}
160
161#define _HAVE_ARCH_IPV6_CSUM
162static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
163 struct in6_addr *daddr,
164 __u32 len,
165 unsigned short proto,
166 unsigned int sum)
167{
168 unsigned int __dummy;
169 __asm__("clrt\n\t"
170 "mov.l @(0,%2), %1\n\t"
171 "addc %1, %0\n\t"
172 "mov.l @(4,%2), %1\n\t"
173 "addc %1, %0\n\t"
174 "mov.l @(8,%2), %1\n\t"
175 "addc %1, %0\n\t"
176 "mov.l @(12,%2), %1\n\t"
177 "addc %1, %0\n\t"
178 "mov.l @(0,%3), %1\n\t"
179 "addc %1, %0\n\t"
180 "mov.l @(4,%3), %1\n\t"
181 "addc %1, %0\n\t"
182 "mov.l @(8,%3), %1\n\t"
183 "addc %1, %0\n\t"
184 "mov.l @(12,%3), %1\n\t"
185 "addc %1, %0\n\t"
186 "addc %4, %0\n\t"
187 "addc %5, %0\n\t"
188 "movt %1\n\t"
189 "add %1, %0\n"
190 : "=r" (sum), "=&r" (__dummy)
191 : "r" (saddr), "r" (daddr),
192 "r" (htonl(len)), "r" (htonl(proto)), "0" (sum)
193 : "t");
194
195 return csum_fold(sum);
196}
197
198/*
199 * Copy and checksum to user
200 */
201#define HAVE_CSUM_COPY_USER
202static __inline__ unsigned int csum_and_copy_to_user (const unsigned char *src,
203 unsigned char __user *dst,
204 int len, int sum,
205 int *err_ptr)
206{
207 if (access_ok(VERIFY_WRITE, dst, len))
208 return csum_partial_copy_generic(src, dst, len, sum, NULL, err_ptr);
209
210 if (len)
211 *err_ptr = -EFAULT;
212
213 return -1; /* invalid checksum */
214}
215#endif /* __ASM_SH_CHECKSUM_H */