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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _H8300_CHECKSUM_H
2#define _H8300_CHECKSUM_H
3
4/*
5 * computes the checksum of a memory block at buff, length len,
6 * and adds in "sum" (32-bit)
7 *
8 * returns a 32-bit number suitable for feeding into itself
9 * or csum_tcpudp_magic
10 *
11 * this function must be called with even lengths, except
12 * for the last fragment, which may be odd
13 *
14 * it's best to have buff aligned on a 32-bit boundary
15 */
16unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
17
18/*
19 * the same as csum_partial, but copies from src while it
20 * checksums
21 *
22 * here even more important to align src and dst on a 32-bit (or even
23 * better 64-bit) boundary
24 */
25
26unsigned int csum_partial_copy(const char *src, char *dst, int len, int sum);
27
28
29/*
30 * the same as csum_partial_copy, but copies from user space.
31 *
32 * here even more important to align src and dst on a 32-bit (or even
33 * better 64-bit) boundary
34 */
35
36extern unsigned int csum_partial_copy_from_user(const char *src, char *dst,
37 int len, int sum, int *csum_err);
38
39#define csum_partial_copy_nocheck(src, dst, len, sum) \
40 csum_partial_copy((src), (dst), (len), (sum))
41
42unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl);
43
44
45/*
46 * Fold a partial checksum
47 */
48
49static inline unsigned int csum_fold(unsigned int sum)
50{
51 __asm__("mov.l %0,er0\n\t"
52 "add.w e0,r0\n\t"
53 "xor.w e0,e0\n\t"
54 "rotxl.w e0\n\t"
55 "add.w e0,r0\n\t"
56 "sub.w e0,e0\n\t"
57 "mov.l er0,%0"
58 : "=r"(sum)
59 : "0"(sum)
60 : "er0");
61 return ~sum;
62}
63
64
65/*
66 * computes the checksum of the TCP/UDP pseudo-header
67 * returns a 16-bit checksum, already complemented
68 */
69
70static inline unsigned int
71csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len,
72 unsigned short proto, unsigned int sum)
73{
74 __asm__ ("sub.l er0,er0\n\t"
75 "add.l %2,%0\n\t"
76 "addx #0,r0l\n\t"
77 "add.l %3,%0\n\t"
78 "addx #0,r0l\n\t"
79 "add.l %4,%0\n\t"
80 "addx #0,r0l\n\t"
81 "add.l er0,%0\n\t"
82 "bcc 1f\n\t"
83 "inc.l #1,%0\n"
84 "1:"
85 : "=&r" (sum)
86 : "0" (sum), "r" (daddr), "r" (saddr), "r" (len + proto)
87 :"er0");
88 return sum;
89}
90
91static inline unsigned short int
92csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len,
93 unsigned short proto, unsigned int sum)
94{
95 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
96}
97
98/*
99 * this routine is used for miscellaneous IP-like checksums, mainly
100 * in icmp.c
101 */
102
103extern unsigned short ip_compute_csum(const unsigned char * buff, int len);
104
105#endif /* _H8300_CHECKSUM_H */