1/*	$NetBSD: dbregs.h,v 1.8 2019/01/13 10:01:07 maxv Exp $	*/
2
3/*
4 * Copyright (c) 2016 The NetBSD Foundation, Inc.
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 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef	_X86_DBREGS_H_
30#define	_X86_DBREGS_H_
31
32#include <sys/param.h>
33#include <sys/types.h>
34#include <machine/reg.h>
35
36/*
37 * CPU Debug Status Register (DR6)
38 *
39 * Reserved bits: 4-12 and on x86_64 32-64
40 */
41#define X86_DR6_DR0_BREAKPOINT_CONDITION_DETECTED	__BIT(0)
42#define X86_DR6_DR1_BREAKPOINT_CONDITION_DETECTED	__BIT(1)
43#define X86_DR6_DR2_BREAKPOINT_CONDITION_DETECTED	__BIT(2)
44#define X86_DR6_DR3_BREAKPOINT_CONDITION_DETECTED	__BIT(3)
45#define X86_DR6_DEBUG_REGISTER_ACCESS_DETECTED		__BIT(13)
46#define X86_DR6_SINGLE_STEP				__BIT(14)
47#define X86_DR6_TASK_SWITCH				__BIT(15)
48#define X86_DR6_MBZ					__BITS(32, 63)
49
50/*
51 * CPU Debug Control Register (DR7)
52 *
53 * LOCAL_EXACT_BREAKPOINT and GLOBAL_EXACT_BREAKPOINT are no longer used
54 * since the P6 processor family - portable code should set these bits
55 * unconditionally in order to get exact breakpoints.
56 *
57 * Reserved bits: 10, 12, 14-15 and on x86_64 32-64.
58 */
59#define X86_DR7_LOCAL_DR0_BREAKPOINT		__BIT(0)
60#define X86_DR7_GLOBAL_DR0_BREAKPOINT		__BIT(1)
61#define X86_DR7_LOCAL_DR1_BREAKPOINT		__BIT(2)
62#define X86_DR7_GLOBAL_DR1_BREAKPOINT		__BIT(3)
63#define X86_DR7_LOCAL_DR2_BREAKPOINT		__BIT(4)
64#define X86_DR7_GLOBAL_DR2_BREAKPOINT		__BIT(5)
65#define X86_DR7_LOCAL_DR3_BREAKPOINT		__BIT(6)
66#define X86_DR7_GLOBAL_DR3_BREAKPOINT		__BIT(7)
67#define X86_DR7_LOCAL_EXACT_BREAKPOINT		__BIT(8)
68#define X86_DR7_GLOBAL_EXACT_BREAKPOINT		__BIT(9)
69#define X86_DR7_RESTRICTED_TRANSACTIONAL_MEMORY	__BIT(11)
70#define X86_DR7_GENERAL_DETECT_ENABLE		__BIT(13)
71#define X86_DR7_DR0_CONDITION_MASK		__BITS(16, 17)
72#define X86_DR7_DR0_LENGTH_MASK			__BITS(18, 19)
73#define X86_DR7_DR1_CONDITION_MASK		__BITS(20, 21)
74#define X86_DR7_DR1_LENGTH_MASK			__BITS(22, 23)
75#define X86_DR7_DR2_CONDITION_MASK		__BITS(24, 25)
76#define X86_DR7_DR2_LENGTH_MASK			__BITS(26, 27)
77#define X86_DR7_DR3_CONDITION_MASK		__BITS(28, 29)
78#define X86_DR7_DR3_LENGTH_MASK			__BITS(30, 31)
79#define X86_DR7_MBZ				__BITS(32, 63)
80
81/*
82 * X86_DR7_CONDITION_IO_READWRITE is currently unused. It requires DE
83 * (debug extension) flag in control register CR4 set, and not all CPUs
84 * support it.
85 */
86enum x86_dr7_condition {
87	X86_DR7_CONDITION_EXECUTION		= 0x0,
88	X86_DR7_CONDITION_DATA_WRITE		= 0x1,
89	X86_DR7_CONDITION_IO_READWRITE		= 0x2,
90	X86_DR7_CONDITION_DATA_READWRITE	= 0x3
91};
92
93/*
94 * 0x2 is currently unimplemented - it reflects 8 bytes on modern CPUs.
95 */
96enum x86_dr7_length {
97	X86_DR7_LENGTH_BYTE		= 0x0,
98	X86_DR7_LENGTH_TWOBYTES		= 0x1,
99	/* 0x2 undefined */
100	X86_DR7_LENGTH_FOURBYTES	= 0x3
101};
102
103/*
104 * The number of available watchpoint/breakpoint registers available since
105 * Intel 80386. New CPUs (x86_64) ship with up to 16 Debug Registers but they
106 * still offer the same number of watchpoints/breakpoints.
107 */
108#define X86_DBREGS	4
109
110void x86_dbregs_init(void);
111void x86_dbregs_clear(struct lwp *);
112void x86_dbregs_abandon(struct lwp *);
113void x86_dbregs_read(struct lwp *, struct dbreg *);
114
115void x86_dbregs_save(struct lwp *);
116void x86_dbregs_restore(struct lwp *);
117
118void x86_dbregs_store_dr6(struct lwp *);
119int x86_dbregs_user_trap(void);
120int x86_dbregs_validate(const struct dbreg *);
121void x86_dbregs_write(struct lwp *, const struct dbreg *);
122void x86_dbregs_switch(struct lwp *, struct lwp *);
123
124#endif /* !_X86_DBREGS_H_ */
125