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 */
14extern __wsum csum_partial(const void *buff, int len, __wsum sum);
15extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
16extern __sum16 ip_compute_csum(const void *buff, int len);
17
18/*
19 * Fold a partial checksum
20 */
21static 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), "0" (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
40static 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		  "0" (sum),
57		  "1" (saddr)
58		: "r8");
59
60	return sum;
61}
62
63static 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 */