This source file includes following definitions.
- csum_partial_copy_from_user
- csum_and_copy_from_user
- csum_and_copy_to_user
- csum_fold
- ip_fast_csum
- csum_tcpudp_nofold
- ip_compute_csum
- csum_ipv6_magic
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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
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33
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
46
47
48 static 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 (uaccess_kernel())
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
62 static 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(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
77
78 #define HAVE_CSUM_COPY_USER
79 static 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(dst, len)) {
85 if (uaccess_kernel())
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;
98 }
99
100
101
102
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
110
111 static 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
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130
131 static 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
163 static 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 " sltu $1, %0, $1 \n"
190 " dsra32 %0, %0, 0 \n"
191 " addu %0, $1 \n"
192 #endif
193 " .set pop"
194 : "=r" (sum)
195 : "0" ((__force unsigned long)daddr),
196 "r" ((__force unsigned long)saddr),
197 #ifdef __MIPSEL__
198 "r" ((proto + len) << 8),
199 #else
200 "r" (proto + len),
201 #endif
202 "r" ((__force unsigned long)sum));
203
204 return sum;
205 }
206 #define csum_tcpudp_nofold csum_tcpudp_nofold
207
208
209
210
211
212 static inline __sum16 ip_compute_csum(const void *buff, int len)
213 {
214 return csum_fold(csum_partial(buff, len, 0));
215 }
216
217 #define _HAVE_ARCH_IPV6_CSUM
218 static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
219 const struct in6_addr *daddr,
220 __u32 len, __u8 proto,
221 __wsum sum)
222 {
223 __wsum tmp;
224
225 __asm__(
226 " .set push # csum_ipv6_magic\n"
227 " .set noreorder \n"
228 " .set noat \n"
229 " addu %0, %5 # proto (long in network byte order)\n"
230 " sltu $1, %0, %5 \n"
231 " addu %0, $1 \n"
232
233 " addu %0, %6 # csum\n"
234 " sltu $1, %0, %6 \n"
235 " lw %1, 0(%2) # four words source address\n"
236 " addu %0, $1 \n"
237 " addu %0, %1 \n"
238 " sltu $1, %0, %1 \n"
239
240 " lw %1, 4(%2) \n"
241 " addu %0, $1 \n"
242 " addu %0, %1 \n"
243 " sltu $1, %0, %1 \n"
244
245 " lw %1, 8(%2) \n"
246 " addu %0, $1 \n"
247 " addu %0, %1 \n"
248 " sltu $1, %0, %1 \n"
249
250 " lw %1, 12(%2) \n"
251 " addu %0, $1 \n"
252 " addu %0, %1 \n"
253 " sltu $1, %0, %1 \n"
254
255 " lw %1, 0(%3) \n"
256 " addu %0, $1 \n"
257 " addu %0, %1 \n"
258 " sltu $1, %0, %1 \n"
259
260 " lw %1, 4(%3) \n"
261 " addu %0, $1 \n"
262 " addu %0, %1 \n"
263 " sltu $1, %0, %1 \n"
264
265 " lw %1, 8(%3) \n"
266 " addu %0, $1 \n"
267 " addu %0, %1 \n"
268 " sltu $1, %0, %1 \n"
269
270 " lw %1, 12(%3) \n"
271 " addu %0, $1 \n"
272 " addu %0, %1 \n"
273 " sltu $1, %0, %1 \n"
274
275 " addu %0, $1 # Add final carry\n"
276 " .set pop"
277 : "=&r" (sum), "=&r" (tmp)
278 : "r" (saddr), "r" (daddr),
279 "0" (htonl(len)), "r" (htonl(proto)), "r" (sum));
280
281 return csum_fold(sum);
282 }
283
284 #include <asm-generic/checksum.h>
285 #endif
286
287 #endif