xref: /freebsd/sys/arm/include/in_cksum.h (revision f4b37ed0f8b307b1f3f0f630ca725d68f1dff30d)
1 /*-
2  * Copyright (c) 1990 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	from tahoe:	in_cksum.c	1.2	86/01/05
30  *	from:		@(#)in_cksum.c	1.3 (Berkeley) 1/19/91
31  *	from: Id: in_cksum.c,v 1.8 1995/12/03 18:35:19 bde Exp
32  * $FreeBSD$
33  */
34 
35 #ifndef _MACHINE_IN_CKSUM_H_
36 #define	_MACHINE_IN_CKSUM_H_	1
37 
38 #include <sys/cdefs.h>
39 
40 #ifdef _KERNEL
41 u_short in_cksum(struct mbuf *m, int len);
42 u_short in_addword(u_short sum, u_short b);
43 u_short in_cksum_skip(struct mbuf *m, int len, int skip);
44 u_int do_cksum(const void *, int);
45 #if defined(IPVERSION) && (IPVERSION == 4)
46 u_int in_cksum_hdr(const struct ip *);
47 #endif
48 
49 static __inline u_short
50 in_pseudo(u_int sum, u_int b, u_int c)
51 {
52 	__asm __volatile("adds %0, %0, %1\n"
53 	    		"adcs %0, %0, %2\n"
54 			"adc %0, %0, #0\n"
55 			: "+r" (sum)
56 			: "r" (b), "r" (c));
57 	sum = (sum & 0xffff) + (sum >> 16);
58 	if (sum > 0xffff)
59 		sum -= 0xffff;
60 	return (sum);
61 }
62 
63 #endif /* _KERNEL */
64 #endif /* _MACHINE_IN_CKSUM_H_ */
65