1 /*
2 * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
3 * Copyright (C) 2004 Microtronix Datacom Ltd.
4 *
5 * This file is subject to the terms and conditions of the GNU General Public
6 * License. See the file "COPYING" in the main directory of this archive
7 * for more details.
8 */
9
10 #ifndef _ASM_NIOS_CHECKSUM_H
11 #define _ASM_NIOS_CHECKSUM_H
12
13 /* Take these from lib/checksum.c */
14 extern __wsum csum_partial(const void *buff, int len, __wsum sum);
15 extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
16 extern __sum16 ip_compute_csum(const void *buff, int len);
17
18 /*
19 * Fold a partial checksum
20 */
21 static inline __sum16 csum_fold(__wsum sum)
22 {
23 __asm__ __volatile__(
24 "add %0, %1, %0\n"
25 "cmpltu r8, %0, %1\n"
26 "srli %0, %0, 16\n"
27 "add %0, %0, r8\n"
28 "nor %0, %0, %0\n"
29 : "=r" (sum)
30 : "r" (sum << 16), "" (sum)
31 : "r8");
32 return (__force __sum16) sum;
33 }
34
35 /*
36 * computes the checksum of the TCP/UDP pseudo-header
37 * returns a 16-bit checksum, already complemented
38 */
39 #define csum_tcpudp_nofold csum_tcpudp_nofold
40 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
41 __u32 len, __u8 proto,
42 __wsum sum)
43 {
44 __asm__ __volatile__(
45 "add %0, %1, %0\n"
46 "cmpltu r8, %0, %1\n"
47 "add %0, %0, r8\n" /* add carry */
48 "add %0, %2, %0\n"
49 "cmpltu r8, %0, %2\n"
50 "add %0, %0, r8\n" /* add carry */
51 "add %0, %3, %0\n"
52 "cmpltu r8, %0, %3\n"
53 "add %0, %0, r8\n" /* add carry */
54 : "=r" (sum), "=r" (saddr)
55 : "r" (daddr), "r" ((len + proto) << 8),
56 "" (sum),
57 "1" (saddr)
58 : "r8");
59
60 return sum;
61 }
62
63 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
64 __u32 len, __u8 proto,
65 __wsum sum)
66 {
67 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
68 }
69
70 #endif /* _ASM_NIOS_CHECKSUM_H */
71
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