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1 #ifndef _ASM_SCORE_CHECKSUM_H
2 #define _ASM_SCORE_CHECKSUM_H
3 
4 #include <linux/in6.h>
5 #include <asm/uaccess.h>
6 
7 /*
8  * computes the checksum of a memory block at buff, length len,
9  * and adds in "sum" (32-bit)
10  *
11  * returns a 32-bit number suitable for feeding into itself
12  * or csum_tcpudp_magic
13  *
14  * this function must be called with even lengths, except
15  * for the last fragment, which may be odd
16  *
17  * it's best to have buff aligned on a 32-bit boundary
18  */
19 unsigned int csum_partial(const void *buff, int len, __wsum sum);
20 unsigned int csum_partial_copy_from_user(const char *src, char *dst, int len,
21 					unsigned int sum, int *csum_err);
22 unsigned int csum_partial_copy(const char *src, char *dst,
23 					int len, unsigned int sum);
24 
25 /*
26  * this is a new version of the above that records errors it finds in *errp,
27  * but continues and zeros the rest of the buffer.
28  */
29 
30 /*
31  * Copy and checksum to user
32  */
33 #define HAVE_CSUM_COPY_USER
34 static inline
csum_and_copy_to_user(const void * src,void __user * dst,int len,__wsum sum,int * err_ptr)35 __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len,
36 			__wsum sum, int *err_ptr)
37 {
38 	sum = csum_partial(src, len, sum);
39 	if (copy_to_user(dst, src, len)) {
40 		*err_ptr = -EFAULT;
41 		return (__force __wsum) -1; /* invalid checksum */
42 	}
43 	return sum;
44 }
45 
46 
47 #define csum_partial_copy_nocheck csum_partial_copy
48 /*
49  *	Fold a partial checksum without adding pseudo headers
50  */
51 
csum_fold(__wsum sum)52 static inline __sum16 csum_fold(__wsum sum)
53 {
54 	/* the while loop is unnecessary really, it's always enough with two
55 	   iterations */
56 	__asm__ __volatile__(
57 		".set volatile\n\t"
58 		".set\tr1\n\t"
59 		"slli\tr1,%0, 16\n\t"
60 		"add\t%0,%0, r1\n\t"
61 		"cmp.c\tr1, %0\n\t"
62 		"srli\t%0, %0, 16\n\t"
63 		"bleu\t1f\n\t"
64 		"addi\t%0, 0x1\n\t"
65 		"1:ldi\tr30, 0xffff\n\t"
66 		"xor\t%0, %0, r30\n\t"
67 		"slli\t%0, %0, 16\n\t"
68 		"srli\t%0, %0, 16\n\t"
69 		".set\tnor1\n\t"
70 		".set optimize\n\t"
71 		: "=r" (sum)
72 		: "0" (sum));
73 	return sum;
74 }
75 
76 /*
77  *	This is a version of ip_compute_csum() optimized for IP headers,
78  *	which always checksum on 4 octet boundaries.
79  *
80  *	By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
81  *	Arnt Gulbrandsen.
82  */
ip_fast_csum(const void * iph,unsigned int ihl)83 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
84 {
85 	unsigned int sum;
86 	unsigned long dummy;
87 
88 	__asm__ __volatile__(
89 		".set volatile\n\t"
90 		".set\tnor1\n\t"
91 		"lw\t%0, [%1]\n\t"
92 		"subri\t%2, %2, 4\n\t"
93 		"slli\t%2, %2, 2\n\t"
94 		"lw\t%3, [%1, 4]\n\t"
95 		"add\t%2, %2, %1\n\t"
96 		"add\t%0, %0, %3\n\t"
97 		"cmp.c\t%3, %0\n\t"
98 		"lw\t%3, [%1, 8]\n\t"
99 		"bleu\t1f\n\t"
100 		"addi\t%0, 0x1\n\t"
101 		"1:\n\t"
102 		"add\t%0, %0, %3\n\t"
103 		"cmp.c\t%3, %0\n\t"
104 		"lw\t%3, [%1, 12]\n\t"
105 		"bleu\t1f\n\t"
106 		"addi\t%0, 0x1\n\t"
107 		"1:add\t%0, %0, %3\n\t"
108 		"cmp.c\t%3, %0\n\t"
109 		"bleu\t1f\n\t"
110 		"addi\t%0, 0x1\n"
111 
112 		"1:\tlw\t%3, [%1, 16]\n\t"
113 		"addi\t%1, 4\n\t"
114 		"add\t%0, %0, %3\n\t"
115 		"cmp.c\t%3, %0\n\t"
116 		"bleu\t2f\n\t"
117 		"addi\t%0, 0x1\n"
118 		"2:cmp.c\t%2, %1\n\t"
119 		"bne\t1b\n\t"
120 
121 		".set\tr1\n\t"
122 		".set optimize\n\t"
123 		: "=&r" (sum), "=&r" (iph), "=&r" (ihl), "=&r" (dummy)
124 		: "1" (iph), "2" (ihl));
125 
126 	return csum_fold(sum);
127 }
128 
129 static inline __wsum
csum_tcpudp_nofold(__be32 saddr,__be32 daddr,unsigned short len,unsigned short proto,__wsum sum)130 csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
131 		unsigned short proto, __wsum sum)
132 {
133 	unsigned long tmp = (ntohs(len) << 16) + proto * 256;
134 	__asm__ __volatile__(
135 		".set volatile\n\t"
136 		"add\t%0, %0, %2\n\t"
137 		"cmp.c\t%2, %0\n\t"
138 		"bleu\t1f\n\t"
139 		"addi\t%0, 0x1\n\t"
140 		"1:\n\t"
141 		"add\t%0, %0, %3\n\t"
142 		"cmp.c\t%3, %0\n\t"
143 		"bleu\t1f\n\t"
144 		"addi\t%0, 0x1\n\t"
145 		"1:\n\t"
146 		"add\t%0, %0, %4\n\t"
147 		"cmp.c\t%4, %0\n\t"
148 		"bleu\t1f\n\t"
149 		"addi\t%0, 0x1\n\t"
150 		"1:\n\t"
151 		".set optimize\n\t"
152 		: "=r" (sum)
153 		: "0" (daddr), "r"(saddr),
154 		"r" (tmp),
155 		"r" (sum));
156 	return sum;
157 }
158 
159 /*
160  * computes the checksum of the TCP/UDP pseudo-header
161  * returns a 16-bit checksum, already complemented
162  */
163 static inline __sum16
csum_tcpudp_magic(__be32 saddr,__be32 daddr,unsigned short len,unsigned short proto,__wsum sum)164 csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len,
165 		unsigned short proto, __wsum sum)
166 {
167 	return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
168 }
169 
170 /*
171  * this routine is used for miscellaneous IP-like checksums, mainly
172  * in icmp.c
173  */
174 
ip_compute_csum(const void * buff,int len)175 static inline unsigned short ip_compute_csum(const void *buff, int len)
176 {
177 	return csum_fold(csum_partial(buff, len, 0));
178 }
179 
180 #define _HAVE_ARCH_IPV6_CSUM
csum_ipv6_magic(const struct in6_addr * saddr,const struct in6_addr * daddr,__u32 len,unsigned short proto,__wsum sum)181 static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
182 				const struct in6_addr *daddr,
183 				__u32 len, unsigned short proto,
184 				__wsum sum)
185 {
186 	__asm__ __volatile__(
187 		".set\tvolatile\t\t\t# csum_ipv6_magic\n\t"
188 		"add\t%0, %0, %5\t\t\t# proto (long in network byte order)\n\t"
189 		"cmp.c\t%5, %0\n\t"
190 		"bleu 1f\n\t"
191 		"addi\t%0, 0x1\n\t"
192 		"1:add\t%0, %0, %6\t\t\t# csum\n\t"
193 		"cmp.c\t%6, %0\n\t"
194 		"lw\t%1, [%2, 0]\t\t\t# four words source address\n\t"
195 		"bleu 1f\n\t"
196 		"addi\t%0, 0x1\n\t"
197 		"1:add\t%0, %0, %1\n\t"
198 		"cmp.c\t%1, %0\n\t"
199 		"1:lw\t%1, [%2, 4]\n\t"
200 		"bleu 1f\n\t"
201 		"addi\t%0, 0x1\n\t"
202 		"1:add\t%0, %0, %1\n\t"
203 		"cmp.c\t%1, %0\n\t"
204 		"lw\t%1, [%2,8]\n\t"
205 		"bleu 1f\n\t"
206 		"addi\t%0, 0x1\n\t"
207 		"1:add\t%0, %0, %1\n\t"
208 		"cmp.c\t%1, %0\n\t"
209 		"lw\t%1, [%2, 12]\n\t"
210 		"bleu 1f\n\t"
211 		"addi\t%0, 0x1\n\t"
212 		"1:add\t%0, %0,%1\n\t"
213 		"cmp.c\t%1, %0\n\t"
214 		"lw\t%1, [%3, 0]\n\t"
215 		"bleu 1f\n\t"
216 		"addi\t%0, 0x1\n\t"
217 		"1:add\t%0, %0, %1\n\t"
218 		"cmp.c\t%1, %0\n\t"
219 		"lw\t%1, [%3, 4]\n\t"
220 		"bleu 1f\n\t"
221 		"addi\t%0, 0x1\n\t"
222 		"1:add\t%0, %0, %1\n\t"
223 		"cmp.c\t%1, %0\n\t"
224 		"lw\t%1, [%3, 8]\n\t"
225 		"bleu 1f\n\t"
226 		"addi\t%0, 0x1\n\t"
227 		"1:add\t%0, %0, %1\n\t"
228 		"cmp.c\t%1, %0\n\t"
229 		"lw\t%1, [%3, 12]\n\t"
230 		"bleu 1f\n\t"
231 		"addi\t%0, 0x1\n\t"
232 		"1:add\t%0, %0, %1\n\t"
233 		"cmp.c\t%1, %0\n\t"
234 		"bleu 1f\n\t"
235 		"addi\t%0, 0x1\n\t"
236 		"1:\n\t"
237 		".set\toptimize"
238 		: "=r" (sum), "=r" (proto)
239 		: "r" (saddr), "r" (daddr),
240 		  "0" (htonl(len)), "1" (htonl(proto)), "r" (sum));
241 
242 	return csum_fold(sum);
243 }
244 #endif /* _ASM_SCORE_CHECKSUM_H */
245