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1da177e4 LT |
1 | #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 | ||
1da177e4 LT |
12 | #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 | */ | |
7c73a746 | 26 | asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum); |
1da177e4 LT |
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 | ||
7c73a746 | 36 | asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, |
b482ad5d PM |
37 | int len, __wsum sum, |
38 | int *src_err_ptr, int *dst_err_ptr); | |
1da177e4 LT |
39 | |
40 | /* | |
41 | * Note: when you get a NULL pointer exception here this means someone | |
b482ad5d PM |
42 | * passed in an incorrect kernel address to one of these functions. |
43 | * | |
44 | * If you use these functions directly please don't forget the | |
e49332bd | 45 | * access_ok(). |
1da177e4 | 46 | */ |
b482ad5d | 47 | static inline |
7c73a746 | 48 | __wsum csum_partial_copy_nocheck(const void *src, void *dst, |
b482ad5d | 49 | int len, __wsum sum) |
1da177e4 | 50 | { |
b482ad5d | 51 | return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL); |
1da177e4 LT |
52 | } |
53 | ||
b482ad5d | 54 | static inline |
7c73a746 | 55 | __wsum csum_partial_copy_from_user(const void __user *src, void *dst, |
b482ad5d | 56 | int len, __wsum sum, int *err_ptr) |
1da177e4 | 57 | { |
7c73a746 AV |
58 | return csum_partial_copy_generic((__force const void *)src, dst, |
59 | len, sum, err_ptr, NULL); | |
1da177e4 LT |
60 | } |
61 | ||
62 | /* | |
63 | * Fold a partial checksum | |
64 | */ | |
65 | ||
b482ad5d | 66 | static inline __sum16 csum_fold(__wsum sum) |
1da177e4 LT |
67 | { |
68 | unsigned int __dummy; | |
69 | __asm__("swap.w %0, %1\n\t" | |
70 | "extu.w %0, %0\n\t" | |
71 | "extu.w %1, %1\n\t" | |
72 | "add %1, %0\n\t" | |
73 | "swap.w %0, %1\n\t" | |
74 | "add %1, %0\n\t" | |
75 | "not %0, %0\n\t" | |
76 | : "=r" (sum), "=&r" (__dummy) | |
77 | : "0" (sum) | |
78 | : "t"); | |
7c73a746 | 79 | return (__force __sum16)sum; |
1da177e4 LT |
80 | } |
81 | ||
82 | /* | |
83 | * This is a version of ip_compute_csum() optimized for IP headers, | |
84 | * which always checksum on 4 octet boundaries. | |
85 | * | |
86 | * i386 version by Jorge Cwik <jorge@laser.satlink.net>, adapted | |
87 | * for linux by * Arnt Gulbrandsen. | |
88 | */ | |
b482ad5d | 89 | static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) |
1da177e4 LT |
90 | { |
91 | unsigned int sum, __dummy0, __dummy1; | |
92 | ||
93 | __asm__ __volatile__( | |
94 | "mov.l @%1+, %0\n\t" | |
95 | "mov.l @%1+, %3\n\t" | |
96 | "add #-2, %2\n\t" | |
97 | "clrt\n\t" | |
98 | "1:\t" | |
99 | "addc %3, %0\n\t" | |
100 | "movt %4\n\t" | |
101 | "mov.l @%1+, %3\n\t" | |
102 | "dt %2\n\t" | |
103 | "bf/s 1b\n\t" | |
104 | " cmp/eq #1, %4\n\t" | |
105 | "addc %3, %0\n\t" | |
106 | "addc %2, %0" /* Here %2 is 0, add carry-bit */ | |
107 | /* Since the input registers which are loaded with iph and ihl | |
108 | are modified, we must also specify them as outputs, or gcc | |
109 | will assume they contain their original values. */ | |
110 | : "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (__dummy0), "=&z" (__dummy1) | |
111 | : "1" (iph), "2" (ihl) | |
112 | : "t"); | |
113 | ||
114 | return csum_fold(sum); | |
115 | } | |
116 | ||
b482ad5d PM |
117 | static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, |
118 | unsigned short len, | |
119 | unsigned short proto, | |
120 | __wsum sum) | |
1da177e4 LT |
121 | { |
122 | #ifdef __LITTLE_ENDIAN__ | |
7c73a746 | 123 | unsigned long len_proto = (proto + len) << 8; |
1da177e4 | 124 | #else |
7c73a746 | 125 | unsigned long len_proto = proto + len; |
1da177e4 LT |
126 | #endif |
127 | __asm__("clrt\n\t" | |
128 | "addc %0, %1\n\t" | |
129 | "addc %2, %1\n\t" | |
130 | "addc %3, %1\n\t" | |
131 | "movt %0\n\t" | |
132 | "add %1, %0" | |
133 | : "=r" (sum), "=r" (len_proto) | |
134 | : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum) | |
135 | : "t"); | |
b482ad5d | 136 | |
1da177e4 LT |
137 | return sum; |
138 | } | |
139 | ||
140 | /* | |
141 | * computes the checksum of the TCP/UDP pseudo-header | |
142 | * returns a 16-bit checksum, already complemented | |
143 | */ | |
b482ad5d PM |
144 | static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, |
145 | unsigned short len, | |
146 | unsigned short proto, | |
147 | __wsum sum) | |
1da177e4 | 148 | { |
b482ad5d | 149 | return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); |
1da177e4 LT |
150 | } |
151 | ||
152 | /* | |
153 | * this routine is used for miscellaneous IP-like checksums, mainly | |
154 | * in icmp.c | |
155 | */ | |
b482ad5d | 156 | static inline __sum16 ip_compute_csum(const void *buff, int len) |
1da177e4 | 157 | { |
b482ad5d | 158 | return csum_fold(csum_partial(buff, len, 0)); |
1da177e4 LT |
159 | } |
160 | ||
161 | #define _HAVE_ARCH_IPV6_CSUM | |
b482ad5d PM |
162 | static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr, |
163 | const struct in6_addr *daddr, | |
164 | __u32 len, unsigned short proto, | |
165 | __wsum sum) | |
1da177e4 LT |
166 | { |
167 | unsigned int __dummy; | |
168 | __asm__("clrt\n\t" | |
169 | "mov.l @(0,%2), %1\n\t" | |
170 | "addc %1, %0\n\t" | |
171 | "mov.l @(4,%2), %1\n\t" | |
172 | "addc %1, %0\n\t" | |
173 | "mov.l @(8,%2), %1\n\t" | |
174 | "addc %1, %0\n\t" | |
175 | "mov.l @(12,%2), %1\n\t" | |
176 | "addc %1, %0\n\t" | |
177 | "mov.l @(0,%3), %1\n\t" | |
178 | "addc %1, %0\n\t" | |
179 | "mov.l @(4,%3), %1\n\t" | |
180 | "addc %1, %0\n\t" | |
181 | "mov.l @(8,%3), %1\n\t" | |
182 | "addc %1, %0\n\t" | |
183 | "mov.l @(12,%3), %1\n\t" | |
184 | "addc %1, %0\n\t" | |
185 | "addc %4, %0\n\t" | |
186 | "addc %5, %0\n\t" | |
187 | "movt %1\n\t" | |
188 | "add %1, %0\n" | |
189 | : "=r" (sum), "=&r" (__dummy) | |
b482ad5d | 190 | : "r" (saddr), "r" (daddr), |
1da177e4 LT |
191 | "r" (htonl(len)), "r" (htonl(proto)), "0" (sum) |
192 | : "t"); | |
193 | ||
194 | return csum_fold(sum); | |
195 | } | |
196 | ||
b482ad5d | 197 | /* |
1da177e4 LT |
198 | * Copy and checksum to user |
199 | */ | |
200 | #define HAVE_CSUM_COPY_USER | |
b482ad5d PM |
201 | static inline __wsum csum_and_copy_to_user(const void *src, |
202 | void __user *dst, | |
203 | int len, __wsum sum, | |
204 | int *err_ptr) | |
1da177e4 LT |
205 | { |
206 | if (access_ok(VERIFY_WRITE, dst, len)) | |
7c73a746 AV |
207 | return csum_partial_copy_generic((__force const void *)src, |
208 | dst, len, sum, NULL, err_ptr); | |
1da177e4 LT |
209 | |
210 | if (len) | |
211 | *err_ptr = -EFAULT; | |
212 | ||
7c73a746 | 213 | return (__force __wsum)-1; /* invalid checksum */ |
1da177e4 LT |
214 | } |
215 | #endif /* __ASM_SH_CHECKSUM_H */ |