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Linux kernel mirror (for testing)
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kernel
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linux
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
28unsigned int csum_partial_copy(const unsigned char *src, unsigned char *dst,
29 int len, int sum);
30
31
32/*
33 * the same as csum_partial_copy, but copies from user space.
34 *
35 * here even more important to align src and dst on a 32-bit (or even
36 * better 64-bit) boundary
37 */
38
39extern unsigned int csum_partial_copy_from_user(const unsigned char *src,
40 unsigned char *dst, int len, int sum, int *csum_err);
41
42#define csum_partial_copy_nocheck(src, dst, len, sum) \
43 csum_partial_copy((src), (dst), (len), (sum))
44
45unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl);
46
47/*
48 * Fold a partial checksum
49 */
50
51static inline unsigned int csum_fold(unsigned int sum)
52{
53#ifdef CONFIG_COLDFIRE
54 sum = (sum & 0xffff) + (sum >> 16);
55 sum = (sum & 0xffff) + (sum >> 16);
56#else
57 unsigned int tmp = sum;
58 __asm__("swap %1\n\t"
59 "addw %1, %0\n\t"
60 "clrw %1\n\t"
61 "addxw %1, %0"
62 : "=&d" (sum), "=&d" (tmp)
63 : "0" (sum), "1" (sum));
64#endif
65 return ~sum;
66}
67
68
69/*
70 * computes the checksum of the TCP/UDP pseudo-header
71 * returns a 16-bit checksum, already complemented
72 */
73
74static inline unsigned int
75csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len,
76 unsigned short proto, unsigned int sum)
77{
78 __asm__ ("addl %1,%0\n\t"
79 "addxl %4,%0\n\t"
80 "addxl %5,%0\n\t"
81 "clrl %1\n\t"
82 "addxl %1,%0"
83 : "=&d" (sum), "=&d" (saddr)
84 : "0" (daddr), "1" (saddr), "d" (len + proto),
85 "d"(sum));
86 return sum;
87}
88
89static inline unsigned short int
90csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len,
91 unsigned short proto, unsigned int sum)
92{
93 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
94}
95
96/*
97 * this routine is used for miscellaneous IP-like checksums, mainly
98 * in icmp.c
99 */
100
101extern unsigned short ip_compute_csum(const unsigned char * buff, int len);
102
103#define _HAVE_ARCH_IPV6_CSUM
104static __inline__ unsigned short int
105csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr,
106 __u32 len, unsigned short proto, unsigned int sum)
107{
108 register unsigned long tmp;
109 __asm__("addl %2@,%0\n\t"
110 "movel %2@(4),%1\n\t"
111 "addxl %1,%0\n\t"
112 "movel %2@(8),%1\n\t"
113 "addxl %1,%0\n\t"
114 "movel %2@(12),%1\n\t"
115 "addxl %1,%0\n\t"
116 "movel %3@,%1\n\t"
117 "addxl %1,%0\n\t"
118 "movel %3@(4),%1\n\t"
119 "addxl %1,%0\n\t"
120 "movel %3@(8),%1\n\t"
121 "addxl %1,%0\n\t"
122 "movel %3@(12),%1\n\t"
123 "addxl %1,%0\n\t"
124 "addxl %4,%0\n\t"
125 "clrl %1\n\t"
126 "addxl %1,%0"
127 : "=&d" (sum), "=&d" (tmp)
128 : "a" (saddr), "a" (daddr), "d" (len + proto),
129 "0" (sum));
130
131 return csum_fold(sum);
132}
133
134#endif /* _M68K_CHECKSUM_H */