xref: /openbmc/linux/arch/nios2/include/asm/checksum.h (revision 852a53a0)
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 __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len,
16 				__wsum sum);
17 #define csum_partial_copy_nocheck csum_partial_copy_nocheck
18 
19 extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
20 extern __sum16 ip_compute_csum(const void *buff, int len);
21 
22 /*
23  * Fold a partial checksum
24  */
25 static inline __sum16 csum_fold(__wsum sum)
26 {
27 	__asm__ __volatile__(
28 		"add	%0, %1, %0\n"
29 		"cmpltu	r8, %0, %1\n"
30 		"srli	%0, %0, 16\n"
31 		"add	%0, %0, r8\n"
32 		"nor	%0, %0, %0\n"
33 		: "=r" (sum)
34 		: "r" (sum << 16), "0" (sum)
35 		: "r8");
36 	return (__force __sum16) sum;
37 }
38 
39 /*
40  * computes the checksum of the TCP/UDP pseudo-header
41  * returns a 16-bit checksum, already complemented
42  */
43 #define csum_tcpudp_nofold csum_tcpudp_nofold
44 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
45 					__u32 len, __u8 proto,
46 					__wsum sum)
47 {
48 	__asm__ __volatile__(
49 		"add	%0, %1, %0\n"
50 		"cmpltu	r8, %0, %1\n"
51 		"add	%0, %0, r8\n"	/* add carry */
52 		"add	%0, %2, %0\n"
53 		"cmpltu	r8, %0, %2\n"
54 		"add	%0, %0, r8\n"	/* add carry */
55 		"add	%0, %3, %0\n"
56 		"cmpltu	r8, %0, %3\n"
57 		"add	%0, %0, r8\n"	/* add carry */
58 		: "=r" (sum), "=r" (saddr)
59 		: "r" (daddr), "r" ((len + proto) << 8),
60 		  "0" (sum),
61 		  "1" (saddr)
62 		: "r8");
63 
64 	return sum;
65 }
66 
67 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
68 					__u32 len, __u8 proto,
69 					__wsum sum)
70 {
71 	return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
72 }
73 
74 #endif /* _ASM_NIOS_CHECKSUM_H */
75