xref: /freebsd/sys/arm/include/in_cksum.h (revision 4f29da19bd44f0e99f021510460a81bf754c21d2)
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. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	from tahoe:	in_cksum.c	1.2	86/01/05
34  *	from:		@(#)in_cksum.c	1.3 (Berkeley) 1/19/91
35  *	from: Id: in_cksum.c,v 1.8 1995/12/03 18:35:19 bde Exp
36  * $FreeBSD$
37  */
38 
39 #ifndef _MACHINE_IN_CKSUM_H_
40 #define	_MACHINE_IN_CKSUM_H_	1
41 
42 #include <sys/cdefs.h>
43 
44 #ifdef _KERNEL
45 u_short in_cksum(struct mbuf *m, int len);
46 u_short in_addword(u_short sum, u_short b);
47 u_short in_cksum_skip(struct mbuf *m, int len, int skip);
48 u_int do_cksum(const void *, int);
49 u_int in_cksum_hdr(const struct ip *);
50 
51 static __inline u_short
52 in_pseudo(u_int sum, u_int b, u_int c)
53 {
54 	__asm __volatile("adds %0, %0, %1\n"
55 	    		"adcs %0, %0, %2\n"
56 			"adc %0, %0, #0\n"
57 			: "+r" (sum)
58 			: "r" (b), "r" (c));
59 	sum = (sum & 0xffff) + (sum >> 16);
60 	if (sum > 0xffff)
61 		sum -= 0xffff;
62 	return (sum);
63 }
64 
65 #endif /* _KERNEL */
66 #endif /* _MACHINE_IN_CKSUM_H_ */
67