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 __wsum csum_partial(const void *buff, int len, __wsum 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 __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum 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 __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
47 int len, __wsum sum, int *csum_err);
48
49 /*
50 * This is a version of ip_compute_csum() optimized for IP headers,
51 * which always checksum on 4 octet boundaries.
52 *
53 */
54 static inline
ip_fast_csum(const void * iph,unsigned int ihl)55 __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
56 {
57 unsigned int tmp, inc, sum = 0;
58
59 asm(" addcc gr0,gr0,gr0,icc0\n" /* clear icc0.C */
60 " subi %1,#4,%1 \n"
61 "0: \n"
62 " ldu.p @(%1,%3),%4 \n"
63 " subicc %2,#1,%2,icc1 \n"
64 " addxcc.p %4,%0,%0,icc0 \n"
65 " bhi icc1,#2,0b \n"
66
67 /* fold the 33-bit result into 16-bits */
68 " addxcc gr0,%0,%0,icc0 \n"
69 " srli %0,#16,%1 \n"
70 " sethi #0,%0 \n"
71 " add %1,%0,%0 \n"
72 " srli %0,#16,%1 \n"
73 " add %1,%0,%0 \n"
74
75 : "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (inc), "=&r"(tmp)
76 : "0" (sum), "1" (iph), "2" (ihl), "3" (4),
77 "m"(*(volatile struct { int _[100]; } *)iph)
78 : "icc0", "icc1", "memory"
79 );
80
81 return (__force __sum16)~sum;
82 }
83
84 /*
85 * Fold a partial checksum
86 */
csum_fold(__wsum sum)87 static inline __sum16 csum_fold(__wsum sum)
88 {
89 unsigned int tmp;
90
91 asm(" srli %0,#16,%1 \n"
92 " sethi #0,%0 \n"
93 " add %1,%0,%0 \n"
94 " srli %0,#16,%1 \n"
95 " add %1,%0,%0 \n"
96 : "=r"(sum), "=&r"(tmp)
97 : "0"(sum)
98 );
99
100 return (__force __sum16)~sum;
101 }
102
103 /*
104 * computes the checksum of the TCP/UDP pseudo-header
105 * returns a 16-bit checksum, already complemented
106 */
107 static inline __wsum
csum_tcpudp_nofold(__be32 saddr,__be32 daddr,unsigned short len,unsigned short proto,__wsum sum)108 csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
109 unsigned short proto, __wsum sum)
110 {
111 asm(" addcc %1,%0,%0,icc0 \n"
112 " addxcc %2,%0,%0,icc0 \n"
113 " addxcc %3,%0,%0,icc0 \n"
114 " addxcc gr0,%0,%0,icc0 \n"
115 : "=r" (sum)
116 : "r" (daddr), "r" (saddr), "r" (len + proto), "0"(sum)
117 : "icc0"
118 );
119 return sum;
120 }
121
122 static inline __sum16
csum_tcpudp_magic(__be32 saddr,__be32 daddr,unsigned short len,unsigned short proto,__wsum sum)123 csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len,
124 unsigned short proto, __wsum sum)
125 {
126 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
127 }
128
129 /*
130 * this routine is used for miscellaneous IP-like checksums, mainly
131 * in icmp.c
132 */
133 extern __sum16 ip_compute_csum(const void *buff, int len);
134
135 #define _HAVE_ARCH_IPV6_CSUM
136 static inline __sum16
csum_ipv6_magic(const struct in6_addr * saddr,const struct in6_addr * daddr,__u32 len,unsigned short proto,__wsum sum)137 csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
138 __u32 len, unsigned short proto, __wsum sum)
139 {
140 unsigned long tmp, tmp2;
141
142 asm(" addcc %2,%0,%0,icc0 \n"
143
144 /* add up the source addr */
145 " ldi @(%3,0),%1 \n"
146 " addxcc %1,%0,%0,icc0 \n"
147 " ldi @(%3,4),%2 \n"
148 " addxcc %2,%0,%0,icc0 \n"
149 " ldi @(%3,8),%1 \n"
150 " addxcc %1,%0,%0,icc0 \n"
151 " ldi @(%3,12),%2 \n"
152 " addxcc %2,%0,%0,icc0 \n"
153
154 /* add up the dest addr */
155 " ldi @(%4,0),%1 \n"
156 " addxcc %1,%0,%0,icc0 \n"
157 " ldi @(%4,4),%2 \n"
158 " addxcc %2,%0,%0,icc0 \n"
159 " ldi @(%4,8),%1 \n"
160 " addxcc %1,%0,%0,icc0 \n"
161 " ldi @(%4,12),%2 \n"
162 " addxcc %2,%0,%0,icc0 \n"
163
164 /* fold the 33-bit result into 16-bits */
165 " addxcc gr0,%0,%0,icc0 \n"
166 " srli %0,#16,%1 \n"
167 " sethi #0,%0 \n"
168 " add %1,%0,%0 \n"
169 " srli %0,#16,%1 \n"
170 " add %1,%0,%0 \n"
171
172 : "=r" (sum), "=&r" (tmp), "=r" (tmp2)
173 : "r" (saddr), "r" (daddr), "0" (sum), "2" (len + proto)
174 : "icc0"
175 );
176
177 return (__force __sum16)~sum;
178 }
179
180 #endif /* _ASM_CHECKSUM_H */
181