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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 | ||
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 | */ | |
26 | asmlinkage __wsum csum_partial(const void *buff, int len, __wsum 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 | ||
36 | asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, | |
37 | int len, __wsum sum, | |
38 | int *src_err_ptr, int *dst_err_ptr); | |
39 | ||
40 | /* | |
41 | * Note: when you get a NULL pointer exception here this means someone | |
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 | |
45 | * access_ok(). | |
46 | */ | |
47 | static inline | |
48 | __wsum csum_partial_copy_nocheck(const void *src, void *dst, | |
49 | int len, __wsum sum) | |
50 | { | |
51 | return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL); | |
52 | } | |
53 | ||
54 | static inline | |
55 | __wsum csum_partial_copy_from_user(const void __user *src, void *dst, | |
56 | int len, __wsum sum, int *err_ptr) | |
57 | { | |
58 | return csum_partial_copy_generic((__force const void *)src, dst, | |
59 | len, sum, err_ptr, NULL); | |
60 | } | |
61 | ||
62 | /* | |
63 | * Fold a partial checksum | |
64 | */ | |
65 | ||
66 | static inline __sum16 csum_fold(__wsum sum) | |
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"); | |
79 | return (__force __sum16)sum; | |
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 | */ | |
89 | static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) | |
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) | |
d02d6be5 | 112 | : "t", "memory"); |
fcfdd0f1 PM |
113 | |
114 | return csum_fold(sum); | |
115 | } | |
116 | ||
117 | static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, | |
01cfbad7 | 118 | __u32 len, __u8 proto, |
fcfdd0f1 PM |
119 | __wsum sum) |
120 | { | |
121 | #ifdef __LITTLE_ENDIAN__ | |
122 | unsigned long len_proto = (proto + len) << 8; | |
123 | #else | |
124 | unsigned long len_proto = proto + 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 | ||
136 | return sum; | |
137 | } | |
138 | ||
139 | /* | |
140 | * computes the checksum of the TCP/UDP pseudo-header | |
141 | * returns a 16-bit checksum, already complemented | |
142 | */ | |
143 | static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, | |
01cfbad7 | 144 | __u32 len, __u8 proto, |
fcfdd0f1 PM |
145 | __wsum sum) |
146 | { | |
147 | return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); | |
148 | } | |
149 | ||
150 | /* | |
151 | * this routine is used for miscellaneous IP-like checksums, mainly | |
152 | * in icmp.c | |
153 | */ | |
154 | static inline __sum16 ip_compute_csum(const void *buff, int len) | |
155 | { | |
156 | return csum_fold(csum_partial(buff, len, 0)); | |
157 | } | |
158 | ||
159 | #define _HAVE_ARCH_IPV6_CSUM | |
160 | static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr, | |
161 | const struct in6_addr *daddr, | |
1e940829 | 162 | __u32 len, __u8 proto, __wsum sum) |
fcfdd0f1 PM |
163 | { |
164 | unsigned int __dummy; | |
165 | __asm__("clrt\n\t" | |
166 | "mov.l @(0,%2), %1\n\t" | |
167 | "addc %1, %0\n\t" | |
168 | "mov.l @(4,%2), %1\n\t" | |
169 | "addc %1, %0\n\t" | |
170 | "mov.l @(8,%2), %1\n\t" | |
171 | "addc %1, %0\n\t" | |
172 | "mov.l @(12,%2), %1\n\t" | |
173 | "addc %1, %0\n\t" | |
174 | "mov.l @(0,%3), %1\n\t" | |
175 | "addc %1, %0\n\t" | |
176 | "mov.l @(4,%3), %1\n\t" | |
177 | "addc %1, %0\n\t" | |
178 | "mov.l @(8,%3), %1\n\t" | |
179 | "addc %1, %0\n\t" | |
180 | "mov.l @(12,%3), %1\n\t" | |
181 | "addc %1, %0\n\t" | |
182 | "addc %4, %0\n\t" | |
183 | "addc %5, %0\n\t" | |
184 | "movt %1\n\t" | |
185 | "add %1, %0\n" | |
186 | : "=r" (sum), "=&r" (__dummy) | |
187 | : "r" (saddr), "r" (daddr), | |
188 | "r" (htonl(len)), "r" (htonl(proto)), "0" (sum) | |
189 | : "t"); | |
190 | ||
191 | return csum_fold(sum); | |
192 | } | |
193 | ||
194 | /* | |
195 | * Copy and checksum to user | |
196 | */ | |
197 | #define HAVE_CSUM_COPY_USER | |
198 | static inline __wsum csum_and_copy_to_user(const void *src, | |
199 | void __user *dst, | |
200 | int len, __wsum sum, | |
201 | int *err_ptr) | |
202 | { | |
203 | if (access_ok(VERIFY_WRITE, dst, len)) | |
204 | return csum_partial_copy_generic((__force const void *)src, | |
205 | dst, len, sum, NULL, err_ptr); | |
206 | ||
207 | if (len) | |
208 | *err_ptr = -EFAULT; | |
209 | ||
210 | return (__force __wsum)-1; /* invalid checksum */ | |
211 | } | |
212 | #endif /* __ASM_SH_CHECKSUM_H */ |