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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-ppc64/checksum.h
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/asm-ppc64/checksum.h')
-rw-r--r--include/asm-ppc64/checksum.h107
1 files changed, 107 insertions, 0 deletions
diff --git a/include/asm-ppc64/checksum.h b/include/asm-ppc64/checksum.h
new file mode 100644
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+++ b/include/asm-ppc64/checksum.h
@@ -0,0 +1,107 @@
1#ifndef _PPC64_CHECKSUM_H
2#define _PPC64_CHECKSUM_H
3
4/*
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version
8 * 2 of the License, or (at your option) any later version.
9 */
10
11/*
12 * This is a version of ip_compute_csum() optimized for IP headers,
13 * which always checksum on 4 octet boundaries. ihl is the number
14 * of 32-bit words and is always >= 5.
15 */
16extern unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl);
17
18/*
19 * computes the checksum of the TCP/UDP pseudo-header
20 * returns a 16-bit checksum, already complemented
21 */
22extern unsigned short csum_tcpudp_magic(unsigned long saddr,
23 unsigned long daddr,
24 unsigned short len,
25 unsigned short proto,
26 unsigned int sum);
27
28/*
29 * computes the checksum of a memory block at buff, length len,
30 * and adds in "sum" (32-bit)
31 *
32 * returns a 32-bit number suitable for feeding into itself
33 * or csum_tcpudp_magic
34 *
35 * this function must be called with even lengths, except
36 * for the last fragment, which may be odd
37 *
38 * it's best to have buff aligned on a 32-bit boundary
39 */
40extern unsigned int csum_partial(const unsigned char * buff, int len,
41 unsigned int sum);
42
43/*
44 * the same as csum_partial, but copies from src to dst while it
45 * checksums
46 */
47extern unsigned int csum_partial_copy_generic(const char *src, char *dst,
48 int len, unsigned int sum,
49 int *src_err, int *dst_err);
50/*
51 * the same as csum_partial, but copies from src to dst while it
52 * checksums.
53 */
54
55unsigned int csum_partial_copy_nocheck(const char *src,
56 char *dst,
57 int len,
58 unsigned int sum);
59
60/*
61 * turns a 32-bit partial checksum (e.g. from csum_partial) into a
62 * 1's complement 16-bit checksum.
63 */
64static inline unsigned int csum_fold(unsigned int sum)
65{
66 unsigned int tmp;
67
68 /* swap the two 16-bit halves of sum */
69 __asm__("rlwinm %0,%1,16,0,31" : "=r" (tmp) : "r" (sum));
70 /* if there is a carry from adding the two 16-bit halves,
71 it will carry from the lower half into the upper half,
72 giving us the correct sum in the upper half. */
73 sum = ~(sum + tmp) >> 16;
74 return sum;
75}
76
77/*
78 * this routine is used for miscellaneous IP-like checksums, mainly
79 * in icmp.c
80 */
81static inline unsigned short ip_compute_csum(unsigned char * buff, int len)
82{
83 return csum_fold(csum_partial(buff, len, 0));
84}
85
86#define csum_partial_copy_from_user(src, dst, len, sum, errp) \
87 csum_partial_copy_generic((src), (dst), (len), (sum), (errp), NULL)
88
89#define csum_partial_copy_nocheck(src, dst, len, sum) \
90 csum_partial_copy_generic((src), (dst), (len), (sum), NULL, NULL)
91
92static inline u32 csum_tcpudp_nofold(u32 saddr,
93 u32 daddr,
94 unsigned short len,
95 unsigned short proto,
96 unsigned int sum)
97{
98 unsigned long s = sum;
99
100 s += saddr;
101 s += daddr;
102 s += (proto << 16) + len;
103 s += (s >> 32);
104 return (u32) s;
105}
106
107#endif