blob: 808b3af1a6058e49546343162da54dbf706b6451 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Kernel debug stuff to use the Watch registers.
7 * Useful to find stack overflows, dangling pointers etc.
8 *
9 * Copyright (C) 1995, 1996, 1999 by Ralf Baechle
10 */
11#include <asm/asm.h>
12#include <asm/mipsregs.h>
13#include <asm/regdef.h>
14
15 .set noreorder
16/*
17 * Parameter: a0 - logic address to watch
18 * Currently only KSEG0 addresses are allowed!
19 * a1 - set bit #1 to trap on load references
20 * bit #0 to trap on store references
21 * Results : none
22 */
23 LEAF(__watch_set)
24 li t0, 0x80000000
25 subu a0, t0
26 ori a0, 7
27 xori a0, 7
28 or a0, a1
29 mtc0 a0, CP0_WATCHLO
30 sw a0, watch_savelo
31
32 jr ra
33 mtc0 zero, CP0_WATCHHI
34 END(__watch_set)
35
36/*
37 * Parameter: none
38 * Results : none
39 */
40 LEAF(__watch_clear)
41 jr ra
42 mtc0 zero, CP0_WATCHLO
43 END(__watch_clear)
44
45/*
46 * Parameter: none
47 * Results : none
48 */
49 LEAF(__watch_reenable)
50 lw t0, watch_savelo
51 jr ra
52 mtc0 t0, CP0_WATCHLO
53 END(__watch_reenable)
54
55/*
56 * Saved value of the c0_watchlo register for watch_reenable()
57 */
58 .data
59watch_savelo: .word 0
60 .text