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 __wsum csum_partial_copy(const void *src, void *dst, int len,
16				__wsum sum);
17extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
18					int len, __wsum sum, int *csum_err);
19#define csum_partial_copy_nocheck(src, dst, len, sum)	\
20	csum_partial_copy((src), (dst), (len), (sum))
21
22extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
23extern __sum16 ip_compute_csum(const void *buff, int len);
24
25/*
26 * Fold a partial checksum
27 */
28static inline __sum16 csum_fold(__wsum sum)
29{
30	__asm__ __volatile__(
31		"add	%0, %1, %0\n"
32		"cmpltu	r8, %0, %1\n"
33		"srli	%0, %0, 16\n"
34		"add	%0, %0, r8\n"
35		"nor	%0, %0, %0\n"
36		: "=r" (sum)
37		: "r" (sum << 16), "0" (sum)
38		: "r8");
39	return (__force __sum16) sum;
40}
41
42/*
43 * computes the checksum of the TCP/UDP pseudo-header
44 * returns a 16-bit checksum, already complemented
45 */
46#define csum_tcpudp_nofold csum_tcpudp_nofold
47static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
48					__u32 len, __u8 proto,
49					__wsum sum)
50{
51	__asm__ __volatile__(
52		"add	%0, %1, %0\n"
53		"cmpltu	r8, %0, %1\n"
54		"add	%0, %0, r8\n"	/* add carry */
55		"add	%0, %2, %0\n"
56		"cmpltu	r8, %0, %2\n"
57		"add	%0, %0, r8\n"	/* add carry */
58		"add	%0, %3, %0\n"
59		"cmpltu	r8, %0, %3\n"
60		"add	%0, %0, r8\n"	/* add carry */
61		: "=r" (sum), "=r" (saddr)
62		: "r" (daddr), "r" ((len + proto) << 8),
63		  "0" (sum),
64		  "1" (saddr)
65		: "r8");
66
67	return sum;
68}
69
70static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
71					__u32 len, __u8 proto,
72					__wsum sum)
73{
74	return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
75}
76
77#endif /* _ASM_NIOS_CHECKSUM_H */