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Kumar Galad95bbcb2005-10-20 11:44:46 -05001#ifndef _ASM_POWERPC_CHECKSUM_H
2#define _ASM_POWERPC_CHECKSUM_H
Arnd Bergmann88ced032005-12-16 22:43:46 +01003#ifdef __KERNEL__
Linus Torvalds1da177e2005-04-16 15:20:36 -07004
5/*
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12/*
13 * This is a version of ip_compute_csum() optimized for IP headers,
14 * which always checksum on 4 octet boundaries. ihl is the number
15 * of 32-bit words and is always >= 5.
16 */
Al Viro879178c2006-11-14 21:21:58 -080017extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
Linus Torvalds1da177e2005-04-16 15:20:36 -070018
19/*
20 * computes the checksum of the TCP/UDP pseudo-header
21 * returns a 16-bit checksum, already complemented
22 */
Al Viro879178c2006-11-14 21:21:58 -080023extern __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
Linus Torvalds1da177e2005-04-16 15:20:36 -070024 unsigned short len,
25 unsigned short proto,
Al Viro879178c2006-11-14 21:21:58 -080026 __wsum sum);
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
28/*
29 * computes the checksum of a memory block at buff, length len,
30 * and adds in "sum" (32-bit)
31 *
32 * returns a 32-bit number suitable for feeding into itself
33 * or csum_tcpudp_magic
34 *
35 * this function must be called with even lengths, except
36 * for the last fragment, which may be odd
37 *
38 * it's best to have buff aligned on a 32-bit boundary
39 */
Al Viro879178c2006-11-14 21:21:58 -080040extern __wsum csum_partial(const void *buff, int len, __wsum sum);
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
42/*
Kumar Galad95bbcb2005-10-20 11:44:46 -050043 * Computes the checksum of a memory block at src, length len,
44 * and adds in "sum" (32-bit), while copying the block to dst.
45 * If an access exception occurs on src or dst, it stores -EFAULT
46 * to *src_err or *dst_err respectively (if that pointer is not
47 * NULL), and, for an error on src, zeroes the rest of dst.
48 *
49 * Like csum_partial, this must be called with even lengths,
50 * except for the last fragment.
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 */
Al Viro879178c2006-11-14 21:21:58 -080052extern __wsum csum_partial_copy_generic(const void *src, void *dst,
53 int len, __wsum sum,
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 int *src_err, int *dst_err);
55/*
56 * the same as csum_partial, but copies from src to dst while it
57 * checksums.
58 */
Kumar Galad95bbcb2005-10-20 11:44:46 -050059#define csum_partial_copy_from_user(src, dst, len, sum, errp) \
Al Viro879178c2006-11-14 21:21:58 -080060 csum_partial_copy_generic((__force const void *)(src), (dst), (len), (sum), (errp), NULL)
Kumar Galad95bbcb2005-10-20 11:44:46 -050061
62#define csum_partial_copy_nocheck(src, dst, len, sum) \
63 csum_partial_copy_generic((src), (dst), (len), (sum), NULL, NULL)
64
65
Linus Torvalds1da177e2005-04-16 15:20:36 -070066/*
67 * turns a 32-bit partial checksum (e.g. from csum_partial) into a
68 * 1's complement 16-bit checksum.
69 */
Al Viro879178c2006-11-14 21:21:58 -080070static inline __sum16 csum_fold(__wsum sum)
Linus Torvalds1da177e2005-04-16 15:20:36 -070071{
72 unsigned int tmp;
73
74 /* swap the two 16-bit halves of sum */
75 __asm__("rlwinm %0,%1,16,0,31" : "=r" (tmp) : "r" (sum));
76 /* if there is a carry from adding the two 16-bit halves,
77 it will carry from the lower half into the upper half,
78 giving us the correct sum in the upper half. */
Al Viro879178c2006-11-14 21:21:58 -080079 return (__force __sum16)(~((__force u32)sum + tmp) >> 16);
Linus Torvalds1da177e2005-04-16 15:20:36 -070080}
81
82/*
83 * this routine is used for miscellaneous IP-like checksums, mainly
84 * in icmp.c
85 */
Al Viro879178c2006-11-14 21:21:58 -080086static inline __sum16 ip_compute_csum(const void *buff, int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -070087{
88 return csum_fold(csum_partial(buff, len, 0));
89}
90
Al Viro879178c2006-11-14 21:21:58 -080091static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 unsigned short len,
93 unsigned short proto,
Al Viro879178c2006-11-14 21:21:58 -080094 __wsum sum)
Linus Torvalds1da177e2005-04-16 15:20:36 -070095{
Al Viro879178c2006-11-14 21:21:58 -080096#ifdef __powerpc64__
97 unsigned long s = (__force u32)sum;
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
Al Viro879178c2006-11-14 21:21:58 -080099 s += (__force u32)saddr;
100 s += (__force u32)daddr;
101 s += proto + len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 s += (s >> 32);
Al Viro879178c2006-11-14 21:21:58 -0800103 return (__force __wsum) s;
Kumar Galad95bbcb2005-10-20 11:44:46 -0500104#else
Kumar Galad95bbcb2005-10-20 11:44:46 -0500105 __asm__("\n\
106 addc %0,%0,%1 \n\
107 adde %0,%0,%2 \n\
108 adde %0,%0,%3 \n\
109 addze %0,%0 \n\
110 "
111 : "=r" (sum)
Al Viro879178c2006-11-14 21:21:58 -0800112 : "r" (daddr), "r"(saddr), "r"(proto + len), "0"(sum));
113 return sum;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114#endif
Al Viro879178c2006-11-14 21:21:58 -0800115}
Arnd Bergmann88ced032005-12-16 22:43:46 +0100116#endif /* __KERNEL__ */
Kumar Galad95bbcb2005-10-20 11:44:46 -0500117#endif