summaryrefslogtreecommitdiff
path: root/arch/arm64/include/asm/hw_breakpoint.h
blob: 6a53e59ced95484ba12e3140ee5dfd0786bb3132 (plain)
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
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
/*
 * Copyright (C) 2012 ARM Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef __ASM_HW_BREAKPOINT_H
#define __ASM_HW_BREAKPOINT_H

#include <asm/cputype.h>
#include <asm/cpufeature.h>
#include <asm/sysreg.h>
#include <asm/virt.h>

#ifdef __KERNEL__

struct arch_hw_breakpoint_ctrl {
	u32 __reserved	: 19,
	len		: 8,
	type		: 2,
	privilege	: 2,
	enabled		: 1;
};

struct arch_hw_breakpoint {
	u64 address;
	u64 trigger;
	struct arch_hw_breakpoint_ctrl ctrl;
};

/* Privilege Levels */
#define AARCH64_BREAKPOINT_EL1	1
#define AARCH64_BREAKPOINT_EL0	2

#define DBG_HMC_HYP		(1 << 13)

static inline u32 encode_ctrl_reg(struct arch_hw_breakpoint_ctrl ctrl)
{
	u32 val = (ctrl.len << 5) | (ctrl.type << 3) | (ctrl.privilege << 1) |
		ctrl.enabled;

	if (is_kernel_in_hyp_mode() && ctrl.privilege == AARCH64_BREAKPOINT_EL1)
		val |= DBG_HMC_HYP;

	return val;
}

static inline void decode_ctrl_reg(u32 reg,
				   struct arch_hw_breakpoint_ctrl *ctrl)
{
	ctrl->enabled	= reg & 0x1;
	reg >>= 1;
	ctrl->privilege	= reg & 0x3;
	reg >>= 2;
	ctrl->type	= reg & 0x3;
	reg >>= 2;
	ctrl->len	= reg & 0xff;
}

/* Breakpoint */
#define ARM_BREAKPOINT_EXECUTE	0

/* Watchpoints */
#define ARM_BREAKPOINT_LOAD	1
#define ARM_BREAKPOINT_STORE	2
#define AARCH64_ESR_ACCESS_MASK	(1 << 6)

/* Lengths */
#define ARM_BREAKPOINT_LEN_1	0x1
#define ARM_BREAKPOINT_LEN_2	0x3
#define ARM_BREAKPOINT_LEN_3	0x7
#define ARM_BREAKPOINT_LEN_4	0xf
#define ARM_BREAKPOINT_LEN_5	0x1f
#define ARM_BREAKPOINT_LEN_6	0x3f
#define ARM_BREAKPOINT_LEN_7	0x7f
#define ARM_BREAKPOINT_LEN_8	0xff

/* Kernel stepping */
#define ARM_KERNEL_STEP_NONE	0
#define ARM_KERNEL_STEP_ACTIVE	1
#define ARM_KERNEL_STEP_SUSPEND	2

/*
 * Limits.
 * Changing these will require modifications to the register accessors.
 */
#define ARM_MAX_BRP		16
#define ARM_MAX_WRP		16

/* Virtual debug register bases. */
#define AARCH64_DBG_REG_BVR	0
#define AARCH64_DBG_REG_BCR	(AARCH64_DBG_REG_BVR + ARM_MAX_BRP)
#define AARCH64_DBG_REG_WVR	(AARCH64_DBG_REG_BCR + ARM_MAX_BRP)
#define AARCH64_DBG_REG_WCR	(AARCH64_DBG_REG_WVR + ARM_MAX_WRP)

/* Debug register names. */
#define AARCH64_DBG_REG_NAME_BVR	bvr
#define AARCH64_DBG_REG_NAME_BCR	bcr
#define AARCH64_DBG_REG_NAME_WVR	wvr
#define AARCH64_DBG_REG_NAME_WCR	wcr

/* Accessor macros for the debug registers. */
#define AARCH64_DBG_READ(N, REG, VAL) do {\
	VAL = read_sysreg(dbg##REG##N##_el1);\
} while (0)

#define AARCH64_DBG_WRITE(N, REG, VAL) do {\
	write_sysreg(VAL, dbg##REG##N##_el1);\
} while (0)

struct task_struct;
struct notifier_block;
struct perf_event_attr;
struct perf_event;
struct pmu;

extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
				  int *gen_len, int *gen_type, int *offset);
extern int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);
extern int hw_breakpoint_arch_parse(struct perf_event *bp,
				    const struct perf_event_attr *attr,
				    struct arch_hw_breakpoint *hw);
extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
					   unsigned long val, void *data);

extern int arch_install_hw_breakpoint(struct perf_event *bp);
extern void arch_uninstall_hw_breakpoint(struct perf_event *bp);
extern void hw_breakpoint_pmu_read(struct perf_event *bp);
extern int hw_breakpoint_slots(int type);

#ifdef CONFIG_HAVE_HW_BREAKPOINT
extern void hw_breakpoint_thread_switch(struct task_struct *next);
extern void ptrace_hw_copy_thread(struct task_struct *task);
#else
static inline void hw_breakpoint_thread_switch(struct task_struct *next)
{
}
static inline void ptrace_hw_copy_thread(struct task_struct *task)
{
}
#endif

/* Determine number of BRP registers available. */
static inline int get_num_brps(void)
{
	u64 dfr0 = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1);
	return 1 +
		cpuid_feature_extract_unsigned_field(dfr0,
						ID_AA64DFR0_BRPS_SHIFT);
}

/* Determine number of WRP registers available. */
static inline int get_num_wrps(void)
{
	u64 dfr0 = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1);
	return 1 +
		cpuid_feature_extract_unsigned_field(dfr0,
						ID_AA64DFR0_WRPS_SHIFT);
}

#endif	/* __KERNEL__ */
#endif	/* __ASM_BREAKPOINT_H */