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Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2012 ARM Ltd.
4 */
5#ifndef __ASM_HW_BREAKPOINT_H
6#define __ASM_HW_BREAKPOINT_H
7
8#include <asm/cputype.h>
9#include <asm/cpufeature.h>
10#include <asm/sysreg.h>
11#include <asm/virt.h>
12
13struct arch_hw_breakpoint_ctrl {
14 u32 __reserved : 19,
15 len : 8,
16 type : 2,
17 privilege : 2,
18 enabled : 1;
19};
20
21struct arch_hw_breakpoint {
22 u64 address;
23 u64 trigger;
24 struct arch_hw_breakpoint_ctrl ctrl;
25};
26
27/* Privilege Levels */
28#define AARCH64_BREAKPOINT_EL1 1
29#define AARCH64_BREAKPOINT_EL0 2
30
31#define DBG_HMC_HYP (1 << 13)
32
33static inline u32 encode_ctrl_reg(struct arch_hw_breakpoint_ctrl ctrl)
34{
35 u32 val = (ctrl.len << 5) | (ctrl.type << 3) | (ctrl.privilege << 1) |
36 ctrl.enabled;
37
38 if (is_kernel_in_hyp_mode() && ctrl.privilege == AARCH64_BREAKPOINT_EL1)
39 val |= DBG_HMC_HYP;
40
41 return val;
42}
43
44static inline void decode_ctrl_reg(u32 reg,
45 struct arch_hw_breakpoint_ctrl *ctrl)
46{
47 ctrl->enabled = reg & 0x1;
48 reg >>= 1;
49 ctrl->privilege = reg & 0x3;
50 reg >>= 2;
51 ctrl->type = reg & 0x3;
52 reg >>= 2;
53 ctrl->len = reg & 0xff;
54}
55
56/* Breakpoint */
57#define ARM_BREAKPOINT_EXECUTE 0
58
59/* Watchpoints */
60#define ARM_BREAKPOINT_LOAD 1
61#define ARM_BREAKPOINT_STORE 2
62
63/* Lengths */
64#define ARM_BREAKPOINT_LEN_1 0x1
65#define ARM_BREAKPOINT_LEN_2 0x3
66#define ARM_BREAKPOINT_LEN_3 0x7
67#define ARM_BREAKPOINT_LEN_4 0xf
68#define ARM_BREAKPOINT_LEN_5 0x1f
69#define ARM_BREAKPOINT_LEN_6 0x3f
70#define ARM_BREAKPOINT_LEN_7 0x7f
71#define ARM_BREAKPOINT_LEN_8 0xff
72
73/* Kernel stepping */
74#define ARM_KERNEL_STEP_NONE 0
75#define ARM_KERNEL_STEP_ACTIVE 1
76#define ARM_KERNEL_STEP_SUSPEND 2
77
78/*
79 * Limits.
80 * Changing these will require modifications to the register accessors.
81 */
82#define ARM_MAX_BRP 16
83#define ARM_MAX_WRP 16
84
85/* Virtual debug register bases. */
86#define AARCH64_DBG_REG_BVR 0
87#define AARCH64_DBG_REG_BCR (AARCH64_DBG_REG_BVR + ARM_MAX_BRP)
88#define AARCH64_DBG_REG_WVR (AARCH64_DBG_REG_BCR + ARM_MAX_BRP)
89#define AARCH64_DBG_REG_WCR (AARCH64_DBG_REG_WVR + ARM_MAX_WRP)
90
91/* Debug register names. */
92#define AARCH64_DBG_REG_NAME_BVR bvr
93#define AARCH64_DBG_REG_NAME_BCR bcr
94#define AARCH64_DBG_REG_NAME_WVR wvr
95#define AARCH64_DBG_REG_NAME_WCR wcr
96
97/* Accessor macros for the debug registers. */
98#define AARCH64_DBG_READ(N, REG, VAL) do {\
99 VAL = read_sysreg(dbg##REG##N##_el1);\
100} while (0)
101
102#define AARCH64_DBG_WRITE(N, REG, VAL) do {\
103 write_sysreg(VAL, dbg##REG##N##_el1);\
104} while (0)
105
106struct task_struct;
107struct notifier_block;
108struct perf_event_attr;
109struct perf_event;
110struct pmu;
111
112extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
113 int *gen_len, int *gen_type, int *offset);
114extern int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);
115extern int hw_breakpoint_arch_parse(struct perf_event *bp,
116 const struct perf_event_attr *attr,
117 struct arch_hw_breakpoint *hw);
118extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
119 unsigned long val, void *data);
120
121extern int arch_install_hw_breakpoint(struct perf_event *bp);
122extern void arch_uninstall_hw_breakpoint(struct perf_event *bp);
123extern void hw_breakpoint_pmu_read(struct perf_event *bp);
124extern int hw_breakpoint_slots(int type);
125
126#ifdef CONFIG_HAVE_HW_BREAKPOINT
127extern void hw_breakpoint_thread_switch(struct task_struct *next);
128extern void ptrace_hw_copy_thread(struct task_struct *task);
129#else
130static inline void hw_breakpoint_thread_switch(struct task_struct *next)
131{
132}
133static inline void ptrace_hw_copy_thread(struct task_struct *task)
134{
135}
136#endif
137
138/* Determine number of BRP registers available. */
139static inline int get_num_brps(void)
140{
141 u64 dfr0 = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1);
142 return 1 +
143 cpuid_feature_extract_unsigned_field(dfr0,
144 ID_AA64DFR0_EL1_BRPs_SHIFT);
145}
146
147/* Determine number of WRP registers available. */
148static inline int get_num_wrps(void)
149{
150 u64 dfr0 = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1);
151 return 1 +
152 cpuid_feature_extract_unsigned_field(dfr0,
153 ID_AA64DFR0_EL1_WRPs_SHIFT);
154}
155
156#ifdef CONFIG_CPU_PM
157extern void cpu_suspend_set_dbg_restorer(int (*hw_bp_restore)(unsigned int));
158#else
159static inline void cpu_suspend_set_dbg_restorer(int (*hw_bp_restore)(unsigned int))
160{
161}
162#endif
163
164#endif /* __ASM_BREAKPOINT_H */