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