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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 */
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 */
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#ifdef CONFIG_GENERIC_CSUM
16#include <asm-generic/checksum.h>
17#else
18
19#include <linux/in6.h>
20
21#include <linux/uaccess.h>
22
23/*
24 * computes the checksum of a memory block at buff, length len,
25 * and adds in "sum" (32-bit)
26 *
27 * returns a 32-bit number suitable for feeding into itself
28 * or csum_tcpudp_magic
29 *
30 * this function must be called with even lengths, except
31 * for the last fragment, which may be odd
32 *
33 * it's best to have buff aligned on a 32-bit boundary
34 */
35__wsum csum_partial(const void *buff, int len, __wsum sum);
36
37__wsum __csum_partial_copy_from_user(const void __user *src, void *dst, int len);
38__wsum __csum_partial_copy_to_user(const void *src, void __user *dst, int len);
39
40#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
41static inline
42__wsum csum_and_copy_from_user(const void __user *src, void *dst, int len)
43{
44 might_fault();
45 if (!access_ok(src, len))
46 return 0;
47 return __csum_partial_copy_from_user(src, dst, len);
48}
49
50/*
51 * Copy and checksum to user
52 */
53#define HAVE_CSUM_COPY_USER
54static inline
55__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len)
56{
57 might_fault();
58 if (!access_ok(dst, len))
59 return 0;
60 return __csum_partial_copy_to_user(src, dst, len);
61}
62
63/*
64 * the same as csum_partial, but copies from user space (but on MIPS
65 * we have just one address space, so this is identical to the above)
66 */
67#define _HAVE_ARCH_CSUM_AND_COPY
68__wsum __csum_partial_copy_nocheck(const void *src, void *dst, int len);
69static inline __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len)
70{
71 return __csum_partial_copy_nocheck(src, dst, len);
72}
73
74/*
75 * Fold a partial checksum without adding pseudo headers
76 */
77static inline __sum16 csum_fold(__wsum csum)
78{
79 u32 sum = (__force u32)csum;
80
81 sum += (sum << 16);
82 csum = (__force __wsum)(sum < (__force u32)csum);
83 sum >>= 16;
84 sum += (__force u32)csum;
85
86 return (__force __sum16)~sum;
87}
88#define csum_fold csum_fold
89
90/*
91 * This is a version of ip_compute_csum() optimized for IP headers,
92 * which always checksum on 4 octet boundaries.
93 *
94 * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
95 * Arnt Gulbrandsen.
96 */
97static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
98{
99 const unsigned int *word = iph;
100 const unsigned int *stop = word + ihl;
101 unsigned int csum;
102 int carry;
103
104 csum = word[0];
105 csum += word[1];
106 carry = (csum < word[1]);
107 csum += carry;
108
109 csum += word[2];
110 carry = (csum < word[2]);
111 csum += carry;
112
113 csum += word[3];
114 carry = (csum < word[3]);
115 csum += carry;
116
117 word += 4;
118 do {
119 csum += *word;
120 carry = (csum < *word);
121 csum += carry;
122 word++;
123 } while (word != stop);
124
125 return csum_fold(csum);
126}
127#define ip_fast_csum ip_fast_csum
128
129static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
130 __u32 len, __u8 proto,
131 __wsum sum)
132{
133 unsigned long tmp = (__force unsigned long)sum;
134
135 __asm__(
136 " .set push # csum_tcpudp_nofold\n"
137 " .set noat \n"
138#ifdef CONFIG_32BIT
139 " addu %0, %2 \n"
140 " sltu $1, %0, %2 \n"
141 " addu %0, $1 \n"
142
143 " addu %0, %3 \n"
144 " sltu $1, %0, %3 \n"
145 " addu %0, $1 \n"
146
147 " addu %0, %4 \n"
148 " sltu $1, %0, %4 \n"
149 " addu %0, $1 \n"
150#endif
151#ifdef CONFIG_64BIT
152 " daddu %0, %2 \n"
153 " daddu %0, %3 \n"
154 " daddu %0, %4 \n"
155 " dsll32 $1, %0, 0 \n"
156 " daddu %0, $1 \n"
157 " sltu $1, %0, $1 \n"
158 " dsra32 %0, %0, 0 \n"
159 " addu %0, $1 \n"
160#endif
161 " .set pop"
162 : "=r" (tmp)
163 : "0" ((__force unsigned long)daddr),
164 "r" ((__force unsigned long)saddr),
165#ifdef __MIPSEL__
166 "r" ((proto + len) << 8),
167#else
168 "r" (proto + len),
169#endif
170 "r" ((__force unsigned long)sum));
171
172 return (__force __wsum)tmp;
173}
174#define csum_tcpudp_nofold csum_tcpudp_nofold
175
176/*
177 * this routine is used for miscellaneous IP-like checksums, mainly
178 * in icmp.c
179 */
180static inline __sum16 ip_compute_csum(const void *buff, int len)
181{
182 return csum_fold(csum_partial(buff, len, 0));
183}
184
185#define _HAVE_ARCH_IPV6_CSUM
186static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
187 const struct in6_addr *daddr,
188 __u32 len, __u8 proto,
189 __wsum sum)
190{
191 __wsum tmp;
192
193 __asm__(
194 " .set push # csum_ipv6_magic\n"
195 " .set noreorder \n"
196 " .set noat \n"
197 " addu %0, %5 # proto (long in network byte order)\n"
198 " sltu $1, %0, %5 \n"
199 " addu %0, $1 \n"
200
201 " addu %0, %6 # csum\n"
202 " sltu $1, %0, %6 \n"
203 " lw %1, 0(%2) # four words source address\n"
204 " addu %0, $1 \n"
205 " addu %0, %1 \n"
206 " sltu $1, %0, %1 \n"
207
208 " lw %1, 4(%2) \n"
209 " addu %0, $1 \n"
210 " addu %0, %1 \n"
211 " sltu $1, %0, %1 \n"
212
213 " lw %1, 8(%2) \n"
214 " addu %0, $1 \n"
215 " addu %0, %1 \n"
216 " sltu $1, %0, %1 \n"
217
218 " lw %1, 12(%2) \n"
219 " addu %0, $1 \n"
220 " addu %0, %1 \n"
221 " sltu $1, %0, %1 \n"
222
223 " lw %1, 0(%3) \n"
224 " addu %0, $1 \n"
225 " addu %0, %1 \n"
226 " sltu $1, %0, %1 \n"
227
228 " lw %1, 4(%3) \n"
229 " addu %0, $1 \n"
230 " addu %0, %1 \n"
231 " sltu $1, %0, %1 \n"
232
233 " lw %1, 8(%3) \n"
234 " addu %0, $1 \n"
235 " addu %0, %1 \n"
236 " sltu $1, %0, %1 \n"
237
238 " lw %1, 12(%3) \n"
239 " addu %0, $1 \n"
240 " addu %0, %1 \n"
241 " sltu $1, %0, %1 \n"
242
243 " addu %0, $1 # Add final carry\n"
244 " .set pop"
245 : "=&r" (sum), "=&r" (tmp)
246 : "r" (saddr), "r" (daddr),
247 "0" (htonl(len)), "r" (htonl(proto)), "r" (sum));
248
249 return csum_fold(sum);
250}
251
252#include <asm-generic/checksum.h>
253#endif /* CONFIG_GENERIC_CSUM */
254
255#endif /* _ASM_CHECKSUM_H */