xref: /freebsd/sys/arm/include/in_cksum.h (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1990 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	from tahoe:	in_cksum.c	1.2	86/01/05
32  *	from:		@(#)in_cksum.c	1.3 (Berkeley) 1/19/91
33  *	from: Id: in_cksum.c,v 1.8 1995/12/03 18:35:19 bde Exp
34  */
35 
36 #ifndef _MACHINE_IN_CKSUM_H_
37 #define	_MACHINE_IN_CKSUM_H_	1
38 
39 #ifdef _KERNEL
40 
41 #define	HAVE_MD_IN_CKSUM
42 
43 u_short in_cksum(struct mbuf *m, int len);
44 u_short in_addword(u_short sum, u_short b);
45 u_short in_cksum_skip(struct mbuf *m, int len, int skip);
46 u_int do_cksum(const void *, int);
47 #if defined(IPVERSION) && (IPVERSION == 4)
48 u_int in_cksum_hdr(const struct ip *);
49 #endif
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