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1/*
2 * include/asm-v850/checksum.h -- Checksum ops
3 *
4 * Copyright (C) 2001,2005 NEC Corporation
5 * Copyright (C) 2001,2005 Miles Bader <miles@gnu.org>
6 *
7 * This file is subject to the terms and conditions of the GNU General
8 * Public License. See the file COPYING in the main directory of this
9 * archive for more details.
10 *
11 * Written by Miles Bader <miles@gnu.org>
12 */
13
14#ifndef __V850_CHECKSUM_H__
15#define __V850_CHECKSUM_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 */
29extern __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 */
38extern __wsum csum_partial_copy_nocheck(const void *src,
39 void *dst, int len, __wsum sum);
40
41
42/*
43 * the same as csum_partial_copy, but copies from user space.
44 *
45 * here even more important to align src and dst on a 32-bit (or even
46 * better 64-bit) boundary
47 */
48extern __wsum csum_partial_copy_from_user (const void *src,
49 void *dst,
50 int len, __wsum sum,
51 int *csum_err);
52
53__sum16 ip_fast_csum(const void *iph, unsigned int ihl);
54
55/*
56 * Fold a partial checksum
57 */
58static inline __sum16 csum_fold (__wsum sum)
59{
60 unsigned int result;
61 /*
62 %0 %1
63 hsw %1, %0 H L L H
64 add %1, %0 H L H+L+C H+L
65 */
66 asm ("hsw %1, %0; add %1, %0" : "=&r" (result) : "r" (sum));
67 return (__force __sum16)(~result >> 16);
68}
69
70
71/*
72 * computes the checksum of the TCP/UDP pseudo-header
73 * returns a 16-bit checksum, already complemented
74 */
75static inline __wsum
76csum_tcpudp_nofold (__be32 saddr, __be32 daddr,
77 unsigned short len,
78 unsigned short proto, __wsum sum)
79{
80 int __carry;
81 __asm__ ("add %2, %0;"
82 "setf c, %1;"
83 "add %1, %0;"
84 "add %3, %0;"
85 "setf c, %1;"
86 "add %1, %0;"
87 "add %4, %0;"
88 "setf c, %1;"
89 "add %1, %0"
90 : "=&r" (sum), "=&r" (__carry)
91 : "r" (daddr), "r" (saddr),
92 "r" ((len + proto) << 8),
93 "0" (sum));
94 return sum;
95}
96
97static inline __sum16
98csum_tcpudp_magic (__be32 saddr, __be32 daddr,
99 unsigned short len,
100 unsigned short proto, __wsum sum)
101{
102 return csum_fold (csum_tcpudp_nofold (saddr, daddr, len, proto, sum));
103}
104
105/*
106 * this routine is used for miscellaneous IP-like checksums, mainly
107 * in icmp.c
108 */
109extern __sum16 ip_compute_csum(const void *buff, int len);
110
111
112#endif /* __V850_CHECKSUM_H__ */