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1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1995, 96, 97, 98, 99, 2001 by Ralf Baechle
7 * Copyright (C) 1999 Silicon Graphics, Inc.
8 * Copyright (C) 2001 Thiemo Seufer.
9 * Copyright (C) 2002 Maciej W. Rozycki
10 * Copyright (C) 2014 Imagination Technologies Ltd.
11 */
12#ifndef _ASM_CHECKSUM_H
13#define _ASM_CHECKSUM_H
14
15#include <linux/in6.h>
16
17#include <asm/uaccess.h>
18
19/*
20 * computes the checksum of a memory block at buff, length len,
21 * and adds in "sum" (32-bit)
22 *
23 * returns a 32-bit number suitable for feeding into itself
24 * or csum_tcpudp_magic
25 *
26 * this function must be called with even lengths, except
27 * for the last fragment, which may be odd
28 *
29 * it's best to have buff aligned on a 32-bit boundary
30 */
31__wsum csum_partial(const void *buff, int len, __wsum sum);
32
33__wsum __csum_partial_copy_kernel(const void *src, void *dst,
34 int len, __wsum sum, int *err_ptr);
35
36__wsum __csum_partial_copy_from_user(const void *src, void *dst,
37 int len, __wsum sum, int *err_ptr);
38__wsum __csum_partial_copy_to_user(const void *src, void *dst,
39 int len, __wsum sum, int *err_ptr);
40/*
41 * this is a new version of the above that records errors it finds in *errp,
42 * but continues and zeros the rest of the buffer.
43 */
44static inline
45__wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len,
46 __wsum sum, int *err_ptr)
47{
48 might_fault();
49 if (segment_eq(get_fs(), get_ds()))
50 return __csum_partial_copy_kernel((__force void *)src, dst,
51 len, sum, err_ptr);
52 else
53 return __csum_partial_copy_from_user((__force void *)src, dst,
54 len, sum, err_ptr);
55}
56
57#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
58static inline
59__wsum csum_and_copy_from_user(const void __user *src, void *dst,
60 int len, __wsum sum, int *err_ptr)
61{
62 if (access_ok(VERIFY_READ, src, len))
63 return csum_partial_copy_from_user(src, dst, len, sum,
64 err_ptr);
65 if (len)
66 *err_ptr = -EFAULT;
67
68 return sum;
69}
70
71/*
72 * Copy and checksum to user
73 */
74#define HAVE_CSUM_COPY_USER
75static inline
76__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len,
77 __wsum sum, int *err_ptr)
78{
79 might_fault();
80 if (access_ok(VERIFY_WRITE, dst, len)) {
81 if (segment_eq(get_fs(), get_ds()))
82 return __csum_partial_copy_kernel(src,
83 (__force void *)dst,
84 len, sum, err_ptr);
85 else
86 return __csum_partial_copy_to_user(src,
87 (__force void *)dst,
88 len, sum, err_ptr);
89 }
90 if (len)
91 *err_ptr = -EFAULT;
92
93 return (__force __wsum)-1; /* invalid checksum */
94}
95
96/*
97 * the same as csum_partial, but copies from user space (but on MIPS
98 * we have just one address space, so this is identical to the above)
99 */
100__wsum csum_partial_copy_nocheck(const void *src, void *dst,
101 int len, __wsum sum);
102
103/*
104 * Fold a partial checksum without adding pseudo headers
105 */
106static inline __sum16 csum_fold(__wsum sum)
107{
108 __asm__(
109 " .set push # csum_fold\n"
110 " .set noat \n"
111 " sll $1, %0, 16 \n"
112 " addu %0, $1 \n"
113 " sltu $1, %0, $1 \n"
114 " srl %0, %0, 16 \n"
115 " addu %0, $1 \n"
116 " xori %0, 0xffff \n"
117 " .set pop"
118 : "=r" (sum)
119 : "0" (sum));
120
121 return (__force __sum16)sum;
122}
123
124/*
125 * This is a version of ip_compute_csum() optimized for IP headers,
126 * which always checksum on 4 octet boundaries.
127 *
128 * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
129 * Arnt Gulbrandsen.
130 */
131static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
132{
133 const unsigned int *word = iph;
134 const unsigned int *stop = word + ihl;
135 unsigned int csum;
136 int carry;
137
138 csum = word[0];
139 csum += word[1];
140 carry = (csum < word[1]);
141 csum += carry;
142
143 csum += word[2];
144 carry = (csum < word[2]);
145 csum += carry;
146
147 csum += word[3];
148 carry = (csum < word[3]);
149 csum += carry;
150
151 word += 4;
152 do {
153 csum += *word;
154 carry = (csum < *word);
155 csum += carry;
156 word++;
157 } while (word != stop);
158
159 return csum_fold(csum);
160}
161
162static inline __wsum csum_tcpudp_nofold(__be32 saddr,
163 __be32 daddr, unsigned short len, unsigned short proto,
164 __wsum sum)
165{
166 __asm__(
167 " .set push # csum_tcpudp_nofold\n"
168 " .set noat \n"
169#ifdef CONFIG_32BIT
170 " addu %0, %2 \n"
171 " sltu $1, %0, %2 \n"
172 " addu %0, $1 \n"
173
174 " addu %0, %3 \n"
175 " sltu $1, %0, %3 \n"
176 " addu %0, $1 \n"
177
178 " addu %0, %4 \n"
179 " sltu $1, %0, %4 \n"
180 " addu %0, $1 \n"
181#endif
182#ifdef CONFIG_64BIT
183 " daddu %0, %2 \n"
184 " daddu %0, %3 \n"
185 " daddu %0, %4 \n"
186 " dsll32 $1, %0, 0 \n"
187 " daddu %0, $1 \n"
188 " dsra32 %0, %0, 0 \n"
189#endif
190 " .set pop"
191 : "=r" (sum)
192 : "0" ((__force unsigned long)daddr),
193 "r" ((__force unsigned long)saddr),
194#ifdef __MIPSEL__
195 "r" ((proto + len) << 8),
196#else
197 "r" (proto + len),
198#endif
199 "r" ((__force unsigned long)sum));
200
201 return sum;
202}
203
204/*
205 * computes the checksum of the TCP/UDP pseudo-header
206 * returns a 16-bit checksum, already complemented
207 */
208static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
209 unsigned short len,
210 unsigned short proto,
211 __wsum sum)
212{
213 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
214}
215
216/*
217 * this routine is used for miscellaneous IP-like checksums, mainly
218 * in icmp.c
219 */
220static inline __sum16 ip_compute_csum(const void *buff, int len)
221{
222 return csum_fold(csum_partial(buff, len, 0));
223}
224
225#define _HAVE_ARCH_IPV6_CSUM
226static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
227 const struct in6_addr *daddr,
228 __u32 len, unsigned short proto,
229 __wsum sum)
230{
231 __asm__(
232 " .set push # csum_ipv6_magic\n"
233 " .set noreorder \n"
234 " .set noat \n"
235 " addu %0, %5 # proto (long in network byte order)\n"
236 " sltu $1, %0, %5 \n"
237 " addu %0, $1 \n"
238
239 " addu %0, %6 # csum\n"
240 " sltu $1, %0, %6 \n"
241 " lw %1, 0(%2) # four words source address\n"
242 " addu %0, $1 \n"
243 " addu %0, %1 \n"
244 " sltu $1, %0, %1 \n"
245
246 " lw %1, 4(%2) \n"
247 " addu %0, $1 \n"
248 " addu %0, %1 \n"
249 " sltu $1, %0, %1 \n"
250
251 " lw %1, 8(%2) \n"
252 " addu %0, $1 \n"
253 " addu %0, %1 \n"
254 " sltu $1, %0, %1 \n"
255
256 " lw %1, 12(%2) \n"
257 " addu %0, $1 \n"
258 " addu %0, %1 \n"
259 " sltu $1, %0, %1 \n"
260
261 " lw %1, 0(%3) \n"
262 " addu %0, $1 \n"
263 " addu %0, %1 \n"
264 " sltu $1, %0, %1 \n"
265
266 " lw %1, 4(%3) \n"
267 " addu %0, $1 \n"
268 " addu %0, %1 \n"
269 " sltu $1, %0, %1 \n"
270
271 " lw %1, 8(%3) \n"
272 " addu %0, $1 \n"
273 " addu %0, %1 \n"
274 " sltu $1, %0, %1 \n"
275
276 " lw %1, 12(%3) \n"
277 " addu %0, $1 \n"
278 " addu %0, %1 \n"
279 " sltu $1, %0, %1 \n"
280
281 " addu %0, $1 # Add final carry\n"
282 " .set pop"
283 : "=r" (sum), "=r" (proto)
284 : "r" (saddr), "r" (daddr),
285 "0" (htonl(len)), "1" (htonl(proto)), "r" (sum));
286
287 return csum_fold(sum);
288}
289
290#endif /* _ASM_CHECKSUM_H */
1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1995, 96, 97, 98, 99, 2001 by Ralf Baechle
7 * Copyright (C) 1999 Silicon Graphics, Inc.
8 * Copyright (C) 2001 Thiemo Seufer.
9 * Copyright (C) 2002 Maciej W. Rozycki
10 */
11#ifndef _ASM_CHECKSUM_H
12#define _ASM_CHECKSUM_H
13
14#include <linux/in6.h>
15
16#include <asm/uaccess.h>
17
18/*
19 * computes the checksum of a memory block at buff, length len,
20 * and adds in "sum" (32-bit)
21 *
22 * returns a 32-bit number suitable for feeding into itself
23 * or csum_tcpudp_magic
24 *
25 * this function must be called with even lengths, except
26 * for the last fragment, which may be odd
27 *
28 * it's best to have buff aligned on a 32-bit boundary
29 */
30__wsum csum_partial(const void *buff, int len, __wsum sum);
31
32__wsum __csum_partial_copy_user(const void *src, void *dst,
33 int len, __wsum sum, int *err_ptr);
34
35/*
36 * this is a new version of the above that records errors it finds in *errp,
37 * but continues and zeros the rest of the buffer.
38 */
39static inline
40__wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len,
41 __wsum sum, int *err_ptr)
42{
43 might_fault();
44 return __csum_partial_copy_user((__force void *)src, dst,
45 len, sum, err_ptr);
46}
47
48/*
49 * Copy and checksum to user
50 */
51#define HAVE_CSUM_COPY_USER
52static inline
53__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len,
54 __wsum sum, int *err_ptr)
55{
56 might_fault();
57 if (access_ok(VERIFY_WRITE, dst, len))
58 return __csum_partial_copy_user(src, (__force void *)dst,
59 len, sum, err_ptr);
60 if (len)
61 *err_ptr = -EFAULT;
62
63 return (__force __wsum)-1; /* invalid checksum */
64}
65
66/*
67 * the same as csum_partial, but copies from user space (but on MIPS
68 * we have just one address space, so this is identical to the above)
69 */
70__wsum csum_partial_copy_nocheck(const void *src, void *dst,
71 int len, __wsum sum);
72
73/*
74 * Fold a partial checksum without adding pseudo headers
75 */
76static inline __sum16 csum_fold(__wsum sum)
77{
78 __asm__(
79 " .set push # csum_fold\n"
80 " .set noat \n"
81 " sll $1, %0, 16 \n"
82 " addu %0, $1 \n"
83 " sltu $1, %0, $1 \n"
84 " srl %0, %0, 16 \n"
85 " addu %0, $1 \n"
86 " xori %0, 0xffff \n"
87 " .set pop"
88 : "=r" (sum)
89 : "0" (sum));
90
91 return (__force __sum16)sum;
92}
93
94/*
95 * This is a version of ip_compute_csum() optimized for IP headers,
96 * which always checksum on 4 octet boundaries.
97 *
98 * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
99 * Arnt Gulbrandsen.
100 */
101static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
102{
103 const unsigned int *word = iph;
104 const unsigned int *stop = word + ihl;
105 unsigned int csum;
106 int carry;
107
108 csum = word[0];
109 csum += word[1];
110 carry = (csum < word[1]);
111 csum += carry;
112
113 csum += word[2];
114 carry = (csum < word[2]);
115 csum += carry;
116
117 csum += word[3];
118 carry = (csum < word[3]);
119 csum += carry;
120
121 word += 4;
122 do {
123 csum += *word;
124 carry = (csum < *word);
125 csum += carry;
126 word++;
127 } while (word != stop);
128
129 return csum_fold(csum);
130}
131
132static inline __wsum csum_tcpudp_nofold(__be32 saddr,
133 __be32 daddr, unsigned short len, unsigned short proto,
134 __wsum sum)
135{
136 __asm__(
137 " .set push # csum_tcpudp_nofold\n"
138 " .set noat \n"
139#ifdef CONFIG_32BIT
140 " addu %0, %2 \n"
141 " sltu $1, %0, %2 \n"
142 " addu %0, $1 \n"
143
144 " addu %0, %3 \n"
145 " sltu $1, %0, %3 \n"
146 " addu %0, $1 \n"
147
148 " addu %0, %4 \n"
149 " sltu $1, %0, %4 \n"
150 " addu %0, $1 \n"
151#endif
152#ifdef CONFIG_64BIT
153 " daddu %0, %2 \n"
154 " daddu %0, %3 \n"
155 " daddu %0, %4 \n"
156 " dsll32 $1, %0, 0 \n"
157 " daddu %0, $1 \n"
158 " dsra32 %0, %0, 0 \n"
159#endif
160 " .set pop"
161 : "=r" (sum)
162 : "0" ((__force unsigned long)daddr),
163 "r" ((__force unsigned long)saddr),
164#ifdef __MIPSEL__
165 "r" ((proto + len) << 8),
166#else
167 "r" (proto + len),
168#endif
169 "r" ((__force unsigned long)sum));
170
171 return sum;
172}
173
174/*
175 * computes the checksum of the TCP/UDP pseudo-header
176 * returns a 16-bit checksum, already complemented
177 */
178static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
179 unsigned short len,
180 unsigned short proto,
181 __wsum sum)
182{
183 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
184}
185
186/*
187 * this routine is used for miscellaneous IP-like checksums, mainly
188 * in icmp.c
189 */
190static inline __sum16 ip_compute_csum(const void *buff, int len)
191{
192 return csum_fold(csum_partial(buff, len, 0));
193}
194
195#define _HAVE_ARCH_IPV6_CSUM
196static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
197 const struct in6_addr *daddr,
198 __u32 len, unsigned short proto,
199 __wsum sum)
200{
201 __asm__(
202 " .set push # csum_ipv6_magic\n"
203 " .set noreorder \n"
204 " .set noat \n"
205 " addu %0, %5 # proto (long in network byte order)\n"
206 " sltu $1, %0, %5 \n"
207 " addu %0, $1 \n"
208
209 " addu %0, %6 # csum\n"
210 " sltu $1, %0, %6 \n"
211 " lw %1, 0(%2) # four words source address\n"
212 " addu %0, $1 \n"
213 " addu %0, %1 \n"
214 " sltu $1, %0, %1 \n"
215
216 " lw %1, 4(%2) \n"
217 " addu %0, $1 \n"
218 " addu %0, %1 \n"
219 " sltu $1, %0, %1 \n"
220
221 " lw %1, 8(%2) \n"
222 " addu %0, $1 \n"
223 " addu %0, %1 \n"
224 " sltu $1, %0, %1 \n"
225
226 " lw %1, 12(%2) \n"
227 " addu %0, $1 \n"
228 " addu %0, %1 \n"
229 " sltu $1, %0, %1 \n"
230
231 " lw %1, 0(%3) \n"
232 " addu %0, $1 \n"
233 " addu %0, %1 \n"
234 " sltu $1, %0, %1 \n"
235
236 " lw %1, 4(%3) \n"
237 " addu %0, $1 \n"
238 " addu %0, %1 \n"
239 " sltu $1, %0, %1 \n"
240
241 " lw %1, 8(%3) \n"
242 " addu %0, $1 \n"
243 " addu %0, %1 \n"
244 " sltu $1, %0, %1 \n"
245
246 " lw %1, 12(%3) \n"
247 " addu %0, $1 \n"
248 " addu %0, %1 \n"
249 " sltu $1, %0, %1 \n"
250
251 " addu %0, $1 # Add final carry\n"
252 " .set pop"
253 : "=r" (sum), "=r" (proto)
254 : "r" (saddr), "r" (daddr),
255 "0" (htonl(len)), "1" (htonl(proto)), "r" (sum));
256
257 return csum_fold(sum);
258}
259
260#endif /* _ASM_CHECKSUM_H */