1 /* MN10300 Optimised checksumming code
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11 #ifndef _ASM_CHECKSUM_H
12 #define _ASM_CHECKSUM_H
13
14 extern __wsum csum_partial(const void *buff, int len, __wsum sum);
15 extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
16 int len, __wsum sum);
17 extern __wsum csum_partial_copy_from_user(const void *src, void *dst,
18 int len, __wsum sum,
19 int *err_ptr);
20 extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
21 extern __wsum csum_partial(const void *buff, int len, __wsum sum);
22 extern __sum16 ip_compute_csum(const void *buff, int len);
23
24 #define csum_partial_copy_fromuser csum_partial_copy
25 extern __wsum csum_partial_copy(const void *src, void *dst, int len,
26 __wsum sum);
27
csum_fold(__wsum sum)28 static inline __sum16 csum_fold(__wsum sum)
29 {
30 asm(
31 " add %1,%0 \n"
32 " addc 0xffff,%0 \n"
33 : "=r" (sum)
34 : "r" (sum << 16), "0" (sum & 0xffff0000)
35 : "cc"
36 );
37 return (~sum) >> 16;
38 }
39
csum_tcpudp_nofold(unsigned long saddr,unsigned long daddr,unsigned short len,unsigned short proto,__wsum sum)40 static inline __wsum csum_tcpudp_nofold(unsigned long saddr,
41 unsigned long daddr,
42 unsigned short len,
43 unsigned short proto,
44 __wsum sum)
45 {
46 __wsum tmp;
47
48 tmp = (__wsum) ntohs(len) << 16;
49 tmp += (__wsum) proto << 8;
50
51 asm(
52 " add %1,%0 \n"
53 " addc %2,%0 \n"
54 " addc %3,%0 \n"
55 " addc 0,%0 \n"
56 : "=r" (sum)
57 : "r" (daddr), "r"(saddr), "r"(tmp), "0"(sum)
58 : "cc"
59 );
60 return sum;
61 }
62
63 /*
64 * computes the checksum of the TCP/UDP pseudo-header
65 * returns a 16-bit checksum, already complemented
66 */
csum_tcpudp_magic(unsigned long saddr,unsigned long daddr,unsigned short len,unsigned short proto,__wsum sum)67 static inline __sum16 csum_tcpudp_magic(unsigned long saddr,
68 unsigned long daddr,
69 unsigned short len,
70 unsigned short proto,
71 __wsum sum)
72 {
73 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
74 }
75
76 #undef _HAVE_ARCH_IPV6_CSUM
77
78 /*
79 * Copy and checksum to user
80 */
81 #define HAVE_CSUM_COPY_USER
82 extern __wsum csum_and_copy_to_user(const void *src, void *dst, int len,
83 __wsum sum, int *err_ptr);
84
85
86 #endif /* _ASM_CHECKSUM_H */
87