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1da177e4 LT |
1 | /* checksum.h: FRV checksumming |
2 | * | |
3 | * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells (dhowells@redhat.com) | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #ifndef _ASM_CHECKSUM_H | |
13 | #define _ASM_CHECKSUM_H | |
14 | ||
15 | #include <linux/in6.h> | |
16 | ||
17 | /* | |
18 | * computes the checksum of a memory block at buff, length len, | |
19 | * and adds in "sum" (32-bit) | |
20 | * | |
21 | * returns a 32-bit number suitable for feeding into itself | |
22 | * or csum_tcpudp_magic | |
23 | * | |
24 | * this function must be called with even lengths, except | |
25 | * for the last fragment, which may be odd | |
26 | * | |
27 | * it's best to have buff aligned on a 32-bit boundary | |
28 | */ | |
29 | unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum); | |
30 | ||
31 | /* | |
32 | * the same as csum_partial, but copies from src while it | |
33 | * checksums | |
34 | * | |
35 | * here even more important to align src and dst on a 32-bit (or even | |
36 | * better 64-bit) boundary | |
37 | */ | |
38 | unsigned int csum_partial_copy(const char *src, char *dst, int len, int sum); | |
39 | ||
40 | /* | |
41 | * the same as csum_partial_copy, but copies from user space. | |
42 | * | |
43 | * here even more important to align src and dst on a 32-bit (or even | |
44 | * better 64-bit) boundary | |
45 | */ | |
46 | extern unsigned int csum_partial_copy_from_user(const char *src, char *dst, | |
47 | int len, int sum, int *csum_err); | |
48 | ||
49 | #define csum_partial_copy_nocheck(src, dst, len, sum) \ | |
50 | csum_partial_copy((src), (dst), (len), (sum)) | |
51 | ||
52 | /* | |
53 | * This is a version of ip_compute_csum() optimized for IP headers, | |
54 | * which always checksum on 4 octet boundaries. | |
55 | * | |
56 | */ | |
57 | static inline | |
58 | unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl) | |
59 | { | |
60 | unsigned int tmp, inc, sum = 0; | |
61 | ||
62 | asm(" addcc gr0,gr0,gr0,icc0\n" /* clear icc0.C */ | |
63 | " subi %1,#4,%1 \n" | |
64 | "0: \n" | |
65 | " ldu.p @(%1,%3),%4 \n" | |
66 | " subicc %2,#1,%2,icc1 \n" | |
67 | " addxcc.p %4,%0,%0,icc0 \n" | |
68 | " bhi icc1,#2,0b \n" | |
69 | ||
70 | /* fold the 33-bit result into 16-bits */ | |
71 | " addxcc gr0,%0,%0,icc0 \n" | |
72 | " srli %0,#16,%1 \n" | |
73 | " sethi #0,%0 \n" | |
74 | " add %1,%0,%0 \n" | |
75 | " srli %0,#16,%1 \n" | |
76 | " add %1,%0,%0 \n" | |
77 | ||
78 | : "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (inc), "=&r"(tmp) | |
79 | : "0" (sum), "1" (iph), "2" (ihl), "3" (4), | |
80 | "m"(*(volatile struct { int _[100]; } *)iph) | |
81 | : "icc0", "icc1" | |
82 | ); | |
83 | ||
84 | return ~sum; | |
85 | } | |
86 | ||
87 | /* | |
88 | * Fold a partial checksum | |
89 | */ | |
90 | static inline unsigned int csum_fold(unsigned int sum) | |
91 | { | |
92 | unsigned int tmp; | |
93 | ||
94 | asm(" srli %0,#16,%1 \n" | |
95 | " sethi #0,%0 \n" | |
96 | " add %1,%0,%0 \n" | |
97 | " srli %0,#16,%1 \n" | |
98 | " add %1,%0,%0 \n" | |
99 | : "=r"(sum), "=&r"(tmp) | |
100 | : "0"(sum) | |
101 | ); | |
102 | ||
103 | return ~sum; | |
104 | } | |
105 | ||
106 | /* | |
107 | * computes the checksum of the TCP/UDP pseudo-header | |
108 | * returns a 16-bit checksum, already complemented | |
109 | */ | |
110 | static inline unsigned int | |
111 | csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len, | |
112 | unsigned short proto, unsigned int sum) | |
113 | { | |
114 | asm(" addcc %1,%0,%0,icc0 \n" | |
115 | " addxcc %2,%0,%0,icc0 \n" | |
116 | " addxcc %3,%0,%0,icc0 \n" | |
117 | " addxcc gr0,%0,%0,icc0 \n" | |
118 | : "=r" (sum) | |
119 | : "r" (daddr), "r" (saddr), "r" (len + proto), "0"(sum) | |
120 | : "icc0" | |
121 | ); | |
122 | return sum; | |
123 | } | |
124 | ||
125 | static inline unsigned short int | |
126 | csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len, | |
127 | unsigned short proto, unsigned int sum) | |
128 | { | |
129 | return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); | |
130 | } | |
131 | ||
132 | /* | |
133 | * this routine is used for miscellaneous IP-like checksums, mainly | |
134 | * in icmp.c | |
135 | */ | |
136 | extern unsigned short ip_compute_csum(const unsigned char * buff, int len); | |
137 | ||
138 | #define _HAVE_ARCH_IPV6_CSUM | |
139 | static inline unsigned short int | |
140 | csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr, | |
141 | __u32 len, unsigned short proto, unsigned int sum) | |
142 | { | |
143 | unsigned long tmp, tmp2; | |
144 | ||
145 | asm(" addcc %2,%0,%0,icc0 \n" | |
146 | ||
147 | /* add up the source addr */ | |
148 | " ldi @(%3,0),%1 \n" | |
149 | " addxcc %1,%0,%0,icc0 \n" | |
150 | " ldi @(%3,4),%2 \n" | |
151 | " addxcc %2,%0,%0,icc0 \n" | |
152 | " ldi @(%3,8),%1 \n" | |
153 | " addxcc %1,%0,%0,icc0 \n" | |
154 | " ldi @(%3,12),%2 \n" | |
155 | " addxcc %2,%0,%0,icc0 \n" | |
156 | ||
157 | /* add up the dest addr */ | |
158 | " ldi @(%4,0),%1 \n" | |
159 | " addxcc %1,%0,%0,icc0 \n" | |
160 | " ldi @(%4,4),%2 \n" | |
161 | " addxcc %2,%0,%0,icc0 \n" | |
162 | " ldi @(%4,8),%1 \n" | |
163 | " addxcc %1,%0,%0,icc0 \n" | |
164 | " ldi @(%4,12),%2 \n" | |
165 | " addxcc %2,%0,%0,icc0 \n" | |
166 | ||
167 | /* fold the 33-bit result into 16-bits */ | |
168 | " addxcc gr0,%0,%0,icc0 \n" | |
169 | " srli %0,#16,%1 \n" | |
170 | " sethi #0,%0 \n" | |
171 | " add %1,%0,%0 \n" | |
172 | " srli %0,#16,%1 \n" | |
173 | " add %1,%0,%0 \n" | |
174 | ||
175 | : "=r" (sum), "=&r" (tmp), "=r" (tmp2) | |
176 | : "r" (saddr), "r" (daddr), "0" (sum), "2" (len + proto) | |
177 | : "icc0" | |
178 | ); | |
179 | ||
180 | return ~sum; | |
181 | } | |
182 | ||
183 | #endif /* _ASM_CHECKSUM_H */ |