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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#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 isum)
132{
133 const unsigned int sh32 = IS_ENABLED(CONFIG_64BIT) ? 32 : 0;
134 unsigned long sum = (__force unsigned long)daddr;
135 unsigned long tmp;
136 __u32 osum;
137
138 tmp = (__force unsigned long)saddr;
139 sum += tmp;
140
141 if (IS_ENABLED(CONFIG_32BIT))
142 sum += sum < tmp;
143
144 /*
145 * We know PROTO + LEN has the sign bit clear, so cast to a signed
146 * type to avoid an extraneous zero-extension where TMP is 64-bit.
147 */
148 tmp = (__s32)(proto + len);
149 tmp <<= IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? 8 : 0;
150 sum += tmp;
151 if (IS_ENABLED(CONFIG_32BIT))
152 sum += sum < tmp;
153
154 tmp = (__force unsigned long)isum;
155 sum += tmp;
156
157 if (IS_ENABLED(CONFIG_32BIT)) {
158 sum += sum < tmp;
159 osum = sum;
160 } else if (IS_ENABLED(CONFIG_64BIT)) {
161 tmp = sum << sh32;
162 sum += tmp;
163 osum = sum < tmp;
164 osum += sum >> sh32;
165 } else {
166 BUILD_BUG();
167 }
168
169 return (__force __wsum)osum;
170}
171#define csum_tcpudp_nofold csum_tcpudp_nofold
172
173/*
174 * this routine is used for miscellaneous IP-like checksums, mainly
175 * in icmp.c
176 */
177static inline __sum16 ip_compute_csum(const void *buff, int len)
178{
179 return csum_fold(csum_partial(buff, len, 0));
180}
181
182#define _HAVE_ARCH_IPV6_CSUM
183static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
184 const struct in6_addr *daddr,
185 __u32 len, __u8 proto,
186 __wsum sum)
187{
188 __wsum tmp;
189
190 __asm__(
191 " .set push # csum_ipv6_magic\n"
192 " .set noreorder \n"
193 " .set noat \n"
194 " addu %0, %5 # proto (long in network byte order)\n"
195 " sltu $1, %0, %5 \n"
196 " addu %0, $1 \n"
197
198 " addu %0, %6 # csum\n"
199 " sltu $1, %0, %6 \n"
200 " lw %1, 0(%2) # four words source address\n"
201 " addu %0, $1 \n"
202 " addu %0, %1 \n"
203 " sltu $1, %0, %1 \n"
204
205 " lw %1, 4(%2) \n"
206 " addu %0, $1 \n"
207 " addu %0, %1 \n"
208 " sltu $1, %0, %1 \n"
209
210 " lw %1, 8(%2) \n"
211 " addu %0, $1 \n"
212 " addu %0, %1 \n"
213 " sltu $1, %0, %1 \n"
214
215 " lw %1, 12(%2) \n"
216 " addu %0, $1 \n"
217 " addu %0, %1 \n"
218 " sltu $1, %0, %1 \n"
219
220 " lw %1, 0(%3) \n"
221 " addu %0, $1 \n"
222 " addu %0, %1 \n"
223 " sltu $1, %0, %1 \n"
224
225 " lw %1, 4(%3) \n"
226 " addu %0, $1 \n"
227 " addu %0, %1 \n"
228 " sltu $1, %0, %1 \n"
229
230 " lw %1, 8(%3) \n"
231 " addu %0, $1 \n"
232 " addu %0, %1 \n"
233 " sltu $1, %0, %1 \n"
234
235 " lw %1, 12(%3) \n"
236 " addu %0, $1 \n"
237 " addu %0, %1 \n"
238 " sltu $1, %0, %1 \n"
239
240 " addu %0, $1 # Add final carry\n"
241 " .set pop"
242 : "=&r" (sum), "=&r" (tmp)
243 : "r" (saddr), "r" (daddr),
244 "0" (htonl(len)), "r" (htonl(proto)), "r" (sum)
245 : "memory");
246
247 return csum_fold(sum);
248}
249
250#include <asm-generic/checksum.h>
251#endif /* CONFIG_GENERIC_CSUM */
252
253#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 <asm/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_kernel(const void *src, void *dst,
38 int len, __wsum sum, int *err_ptr);
39
40__wsum __csum_partial_copy_from_user(const void *src, void *dst,
41 int len, __wsum sum, int *err_ptr);
42__wsum __csum_partial_copy_to_user(const void *src, void *dst,
43 int len, __wsum sum, int *err_ptr);
44/*
45 * this is a new version of the above that records errors it finds in *errp,
46 * but continues and zeros the rest of the buffer.
47 */
48static inline
49__wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len,
50 __wsum sum, int *err_ptr)
51{
52 might_fault();
53 if (segment_eq(get_fs(), get_ds()))
54 return __csum_partial_copy_kernel((__force void *)src, dst,
55 len, sum, err_ptr);
56 else
57 return __csum_partial_copy_from_user((__force void *)src, dst,
58 len, sum, err_ptr);
59}
60
61#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
62static inline
63__wsum csum_and_copy_from_user(const void __user *src, void *dst,
64 int len, __wsum sum, int *err_ptr)
65{
66 if (access_ok(VERIFY_READ, src, len))
67 return csum_partial_copy_from_user(src, dst, len, sum,
68 err_ptr);
69 if (len)
70 *err_ptr = -EFAULT;
71
72 return sum;
73}
74
75/*
76 * Copy and checksum to user
77 */
78#define HAVE_CSUM_COPY_USER
79static inline
80__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len,
81 __wsum sum, int *err_ptr)
82{
83 might_fault();
84 if (access_ok(VERIFY_WRITE, dst, len)) {
85 if (segment_eq(get_fs(), get_ds()))
86 return __csum_partial_copy_kernel(src,
87 (__force void *)dst,
88 len, sum, err_ptr);
89 else
90 return __csum_partial_copy_to_user(src,
91 (__force void *)dst,
92 len, sum, err_ptr);
93 }
94 if (len)
95 *err_ptr = -EFAULT;
96
97 return (__force __wsum)-1; /* invalid checksum */
98}
99
100/*
101 * the same as csum_partial, but copies from user space (but on MIPS
102 * we have just one address space, so this is identical to the above)
103 */
104__wsum csum_partial_copy_nocheck(const void *src, void *dst,
105 int len, __wsum sum);
106#define csum_partial_copy_nocheck csum_partial_copy_nocheck
107
108/*
109 * Fold a partial checksum without adding pseudo headers
110 */
111static inline __sum16 csum_fold(__wsum csum)
112{
113 u32 sum = (__force u32)csum;;
114
115 sum += (sum << 16);
116 csum = (sum < csum);
117 sum >>= 16;
118 sum += csum;
119
120 return (__force __sum16)~sum;
121}
122#define csum_fold csum_fold
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#define ip_fast_csum ip_fast_csum
162
163static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
164 __u32 len, __u8 proto,
165 __wsum sum)
166{
167 __asm__(
168 " .set push # csum_tcpudp_nofold\n"
169 " .set noat \n"
170#ifdef CONFIG_32BIT
171 " addu %0, %2 \n"
172 " sltu $1, %0, %2 \n"
173 " addu %0, $1 \n"
174
175 " addu %0, %3 \n"
176 " sltu $1, %0, %3 \n"
177 " addu %0, $1 \n"
178
179 " addu %0, %4 \n"
180 " sltu $1, %0, %4 \n"
181 " addu %0, $1 \n"
182#endif
183#ifdef CONFIG_64BIT
184 " daddu %0, %2 \n"
185 " daddu %0, %3 \n"
186 " daddu %0, %4 \n"
187 " dsll32 $1, %0, 0 \n"
188 " daddu %0, $1 \n"
189 " dsra32 %0, %0, 0 \n"
190#endif
191 " .set pop"
192 : "=r" (sum)
193 : "0" ((__force unsigned long)daddr),
194 "r" ((__force unsigned long)saddr),
195#ifdef __MIPSEL__
196 "r" ((proto + len) << 8),
197#else
198 "r" (proto + len),
199#endif
200 "r" ((__force unsigned long)sum));
201
202 return sum;
203}
204#define csum_tcpudp_nofold csum_tcpudp_nofold
205
206/*
207 * this routine is used for miscellaneous IP-like checksums, mainly
208 * in icmp.c
209 */
210static inline __sum16 ip_compute_csum(const void *buff, int len)
211{
212 return csum_fold(csum_partial(buff, len, 0));
213}
214
215#define _HAVE_ARCH_IPV6_CSUM
216static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
217 const struct in6_addr *daddr,
218 __u32 len, __u8 proto,
219 __wsum sum)
220{
221 __wsum tmp;
222
223 __asm__(
224 " .set push # csum_ipv6_magic\n"
225 " .set noreorder \n"
226 " .set noat \n"
227 " addu %0, %5 # proto (long in network byte order)\n"
228 " sltu $1, %0, %5 \n"
229 " addu %0, $1 \n"
230
231 " addu %0, %6 # csum\n"
232 " sltu $1, %0, %6 \n"
233 " lw %1, 0(%2) # four words source address\n"
234 " addu %0, $1 \n"
235 " addu %0, %1 \n"
236 " sltu $1, %0, %1 \n"
237
238 " lw %1, 4(%2) \n"
239 " addu %0, $1 \n"
240 " addu %0, %1 \n"
241 " sltu $1, %0, %1 \n"
242
243 " lw %1, 8(%2) \n"
244 " addu %0, $1 \n"
245 " addu %0, %1 \n"
246 " sltu $1, %0, %1 \n"
247
248 " lw %1, 12(%2) \n"
249 " addu %0, $1 \n"
250 " addu %0, %1 \n"
251 " sltu $1, %0, %1 \n"
252
253 " lw %1, 0(%3) \n"
254 " addu %0, $1 \n"
255 " addu %0, %1 \n"
256 " sltu $1, %0, %1 \n"
257
258 " lw %1, 4(%3) \n"
259 " addu %0, $1 \n"
260 " addu %0, %1 \n"
261 " sltu $1, %0, %1 \n"
262
263 " lw %1, 8(%3) \n"
264 " addu %0, $1 \n"
265 " addu %0, %1 \n"
266 " sltu $1, %0, %1 \n"
267
268 " lw %1, 12(%3) \n"
269 " addu %0, $1 \n"
270 " addu %0, %1 \n"
271 " sltu $1, %0, %1 \n"
272
273 " addu %0, $1 # Add final carry\n"
274 " .set pop"
275 : "=&r" (sum), "=&r" (tmp)
276 : "r" (saddr), "r" (daddr),
277 "0" (htonl(len)), "r" (htonl(proto)), "r" (sum));
278
279 return csum_fold(sum);
280}
281
282#include <asm-generic/checksum.h>
283#endif /* CONFIG_GENERIC_CSUM */
284
285#endif /* _ASM_CHECKSUM_H */