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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-m68k/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-m68k/checksum.h')
-rw-r--r--include/asm-m68k/checksum.h150
1 files changed, 150 insertions, 0 deletions
diff --git a/include/asm-m68k/checksum.h b/include/asm-m68k/checksum.h
new file mode 100644
index 000000000000..78860c20db01
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+++ b/include/asm-m68k/checksum.h
@@ -0,0 +1,150 @@
1#ifndef _M68K_CHECKSUM_H
2#define _M68K_CHECKSUM_H
3
4#include <linux/in6.h>
5
6/*
7 * computes the checksum of a memory block at buff, length len,
8 * and adds in "sum" (32-bit)
9 *
10 * returns a 32-bit number suitable for feeding into itself
11 * or csum_tcpudp_magic
12 *
13 * this function must be called with even lengths, except
14 * for the last fragment, which may be odd
15 *
16 * it's best to have buff aligned on a 32-bit boundary
17 */
18unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
19
20/*
21 * the same as csum_partial, but copies from src while it
22 * checksums
23 *
24 * here even more important to align src and dst on a 32-bit (or even
25 * better 64-bit) boundary
26 */
27
28extern unsigned int csum_partial_copy_from_user(const unsigned char *src,
29 unsigned char *dst,
30 int len, int sum,
31 int *csum_err);
32
33extern unsigned int csum_partial_copy_nocheck(const unsigned char *src,
34 unsigned char *dst, int len,
35 int sum);
36
37/*
38 * This is a version of ip_compute_csum() optimized for IP headers,
39 * which always checksum on 4 octet boundaries.
40 *
41 */
42static inline unsigned short
43ip_fast_csum(unsigned char *iph, unsigned int ihl)
44{
45 unsigned int sum = 0;
46 unsigned long tmp;
47
48 __asm__ ("subqw #1,%2\n"
49 "1:\t"
50 "movel %1@+,%3\n\t"
51 "addxl %3,%0\n\t"
52 "dbra %2,1b\n\t"
53 "movel %0,%3\n\t"
54 "swap %3\n\t"
55 "addxw %3,%0\n\t"
56 "clrw %3\n\t"
57 "addxw %3,%0\n\t"
58 : "=d" (sum), "=&a" (iph), "=&d" (ihl), "=&d" (tmp)
59 : "0" (sum), "1" (iph), "2" (ihl)
60 : "memory");
61 return ~sum;
62}
63
64/*
65 * Fold a partial checksum
66 */
67
68static inline unsigned int csum_fold(unsigned int sum)
69{
70 unsigned int tmp = sum;
71 __asm__("swap %1\n\t"
72 "addw %1, %0\n\t"
73 "clrw %1\n\t"
74 "addxw %1, %0"
75 : "=&d" (sum), "=&d" (tmp)
76 : "0" (sum), "1" (tmp));
77 return ~sum;
78}
79
80
81static inline unsigned int
82csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len,
83 unsigned short proto, unsigned int sum)
84{
85 __asm__ ("addl %2,%0\n\t"
86 "addxl %3,%0\n\t"
87 "addxl %4,%0\n\t"
88 "clrl %1\n\t"
89 "addxl %1,%0"
90 : "=&d" (sum), "=d" (saddr)
91 : "g" (daddr), "1" (saddr), "d" (len + proto),
92 "0" (sum));
93 return sum;
94}
95
96
97/*
98 * computes the checksum of the TCP/UDP pseudo-header
99 * returns a 16-bit checksum, already complemented
100 */
101static inline unsigned short int
102csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, 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
113static inline unsigned short
114ip_compute_csum(unsigned char * buff, int len)
115{
116 return csum_fold (csum_partial(buff, len, 0));
117}
118
119#define _HAVE_ARCH_IPV6_CSUM
120static __inline__ unsigned short int
121csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr,
122 __u32 len, unsigned short proto, unsigned int sum)
123{
124 register unsigned long tmp;
125 __asm__("addl %2@,%0\n\t"
126 "movel %2@(4),%1\n\t"
127 "addxl %1,%0\n\t"
128 "movel %2@(8),%1\n\t"
129 "addxl %1,%0\n\t"
130 "movel %2@(12),%1\n\t"
131 "addxl %1,%0\n\t"
132 "movel %3@,%1\n\t"
133 "addxl %1,%0\n\t"
134 "movel %3@(4),%1\n\t"
135 "addxl %1,%0\n\t"
136 "movel %3@(8),%1\n\t"
137 "addxl %1,%0\n\t"
138 "movel %3@(12),%1\n\t"
139 "addxl %1,%0\n\t"
140 "addxl %4,%0\n\t"
141 "clrl %1\n\t"
142 "addxl %1,%0"
143 : "=&d" (sum), "=&d" (tmp)
144 : "a" (saddr), "a" (daddr), "d" (len + proto),
145 "0" (sum));
146
147 return csum_fold(sum);
148}
149
150#endif /* _M68K_CHECKSUM_H */