1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
|
/* $OpenBSD: owmem_subr.c,v 1.1 2008/04/07 22:55:57 miod Exp $ */
/*
* Copyright (c) 2008 Miodrag Vallat.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* Common routines to owmac and owserial drivers.
*/
#include <sys/param.h>
#include <sgi/dev/owmem_subr.h>
int
owmem_redirect(uint8_t *redir, u_int npages, u_int page)
{
int skips = 0;
/*
* Follow the redirecting table until we end up in our final
* position. We have to be careful not to loop if the table
* is wrong.
*/
while (redir[page] != 0xff) {
if (++skips >= npages)
return -1;
page = 0xff ^ redir[page];
if (page >= npages)
return -1;
}
return page;
}
|
