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1da177e4 LT |
1 | /* |
2 | * include/asm-v850/checksum.h -- Checksum ops | |
3 | * | |
4 | * Copyright (C) 2001 NEC Corporation | |
5 | * Copyright (C) 2001 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 | */ | |
29 | extern unsigned int csum_partial (const unsigned char * buff, int len, | |
30 | unsigned int sum); | |
31 | ||
32 | /* | |
33 | * the same as csum_partial, but copies from src while it | |
34 | * checksums | |
35 | * | |
36 | * here even more important to align src and dst on a 32-bit (or even | |
37 | * better 64-bit) boundary | |
38 | */ | |
39 | extern unsigned csum_partial_copy (const char *src, char *dst, int len, | |
40 | unsigned sum); | |
41 | ||
42 | ||
43 | /* | |
44 | * the same as csum_partial_copy, but copies from user space. | |
45 | * | |
46 | * here even more important to align src and dst on a 32-bit (or even | |
47 | * better 64-bit) boundary | |
48 | */ | |
49 | extern unsigned csum_partial_copy_from_user (const char *src, char *dst, | |
50 | int len, unsigned sum, | |
51 | int *csum_err); | |
52 | ||
53 | #define csum_partial_copy_nocheck(src, dst, len, sum) \ | |
54 | csum_partial_copy ((src), (dst), (len), (sum)) | |
55 | ||
56 | unsigned short ip_fast_csum (unsigned char *iph, unsigned int ihl); | |
57 | ||
58 | /* | |
59 | * Fold a partial checksum | |
60 | */ | |
61 | static inline unsigned int csum_fold (unsigned long sum) | |
62 | { | |
63 | unsigned int result; | |
64 | /* | |
65 | %0 %1 | |
66 | hsw %1, %0 H L L H | |
67 | add %1, %0 H L H+L+C H+L | |
68 | */ | |
69 | asm ("hsw %1, %0; add %1, %0" : "=&r" (result) : "r" (sum)); | |
70 | return (~result) >> 16; | |
71 | } | |
72 | ||
73 | ||
74 | /* | |
75 | * computes the checksum of the TCP/UDP pseudo-header | |
76 | * returns a 16-bit checksum, already complemented | |
77 | */ | |
78 | static inline unsigned int | |
79 | csum_tcpudp_nofold (unsigned long saddr, unsigned long daddr, | |
80 | unsigned short len, | |
81 | unsigned short proto, unsigned int sum) | |
82 | { | |
83 | int __carry; | |
84 | __asm__ ("add %2, %0;" | |
85 | "setf c, %1;" | |
86 | "add %1, %0;" | |
87 | "add %3, %0;" | |
88 | "setf c, %1;" | |
89 | "add %1, %0;" | |
90 | "add %4, %0;" | |
91 | "setf c, %1;" | |
92 | "add %1, %0" | |
93 | : "=&r" (sum), "=&r" (__carry) | |
94 | : "r" (daddr), "r" (saddr), | |
95 | "r" (ntohs (len) + (proto << 8)), | |
96 | "0" (sum)); | |
97 | return sum; | |
98 | } | |
99 | ||
100 | static inline unsigned short int | |
101 | csum_tcpudp_magic (unsigned long saddr, unsigned long daddr, | |
102 | unsigned short len, | |
103 | unsigned short proto, unsigned int sum) | |
104 | { | |
105 | return csum_fold (csum_tcpudp_nofold (saddr, daddr, len, proto, sum)); | |
106 | } | |
107 | ||
108 | /* | |
109 | * this routine is used for miscellaneous IP-like checksums, mainly | |
110 | * in icmp.c | |
111 | */ | |
112 | extern unsigned short ip_compute_csum (const unsigned char * buff, int len); | |
113 | ||
114 | ||
115 | #endif /* __V850_CHECKSUM_H__ */ |