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Bryan Wu1394f032007-05-06 14:50:22 -07001#ifndef _BFIN_CHECKSUM_H
2#define _BFIN_CHECKSUM_H
3
4/*
5 * MODIFIED FOR BFIN April 30, 2001 akbar.hussain@lineo.com
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 * the same as csum_partial_copy, but copies from user space.
33 *
34 * here even more important to align src and dst on a 32-bit (or even
35 * better 64-bit) boundary
36 */
37
38extern unsigned int csum_partial_copy_from_user(const unsigned char *src,
39 unsigned char *dst, int len,
40 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 while (sum >> 16)
54 sum = (sum & 0xffff) + (sum >> 16);
55 return ((~(sum << 16)) >> 16);
56}
57
58/*
59 * computes the checksum of the TCP/UDP pseudo-header
60 * returns a 16-bit checksum, already complemented
61 */
62
63static inline unsigned int
64csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len,
65 unsigned short proto, unsigned int sum)
66{
67
68 __asm__ ("%0 = %0 + %1;\n\t"
69 "CC = AC0;\n\t"
70 "if !CC jump 4;\n\t"
71 "%0 = %0 + %4;\n\t"
72 "%0 = %0 + %2;\n\t"
73 "CC = AC0;\n\t"
74 "if !CC jump 4;\n\t"
75 "%0 = %0 + %4;\n\t"
76 "%0 = %0 + %3;\n\t"
77 "CC = AC0;\n\t"
78 "if !CC jump 4;\n\t"
79 "%0 = %0 + %4;\n\t"
80 "NOP;\n\t"
81 : "=d" (sum)
82 : "d" (daddr), "d" (saddr), "d" ((ntohs(len)<<16)+proto*256), "d" (1), "0"(sum));
83
84 return (sum);
85}
86
87static inline unsigned short int
88csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len,
89 unsigned short proto, unsigned int sum)
90{
91 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
92}
93
94/*
95 * this routine is used for miscellaneous IP-like checksums, mainly
96 * in icmp.c
97 */
98
99extern unsigned short ip_compute_csum(const unsigned char *buff, int len);
100
101#endif /* _BFIN_CHECKSUM_H */