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 
13 struct arch_hw_breakpoint_ctrl {
14 	u32 __reserved	: 19,
15 	len		: 8,
16 	type		: 2,
17 	privilege	: 2,
18 	enabled		: 1;
19 };
20 
21 struct 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 
33 static 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 
44 static 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 #define AARCH64_ESR_ACCESS_MASK	(1 << 6)
63 
64 /* Lengths */
65 #define ARM_BREAKPOINT_LEN_1	0x1
66 #define ARM_BREAKPOINT_LEN_2	0x3
67 #define ARM_BREAKPOINT_LEN_3	0x7
68 #define ARM_BREAKPOINT_LEN_4	0xf
69 #define ARM_BREAKPOINT_LEN_5	0x1f
70 #define ARM_BREAKPOINT_LEN_6	0x3f
71 #define ARM_BREAKPOINT_LEN_7	0x7f
72 #define ARM_BREAKPOINT_LEN_8	0xff
73 
74 /* Kernel stepping */
75 #define ARM_KERNEL_STEP_NONE	0
76 #define ARM_KERNEL_STEP_ACTIVE	1
77 #define ARM_KERNEL_STEP_SUSPEND	2
78 
79 /*
80  * Limits.
81  * Changing these will require modifications to the register accessors.
82  */
83 #define ARM_MAX_BRP		16
84 #define ARM_MAX_WRP		16
85 
86 /* Virtual debug register bases. */
87 #define AARCH64_DBG_REG_BVR	0
88 #define AARCH64_DBG_REG_BCR	(AARCH64_DBG_REG_BVR + ARM_MAX_BRP)
89 #define AARCH64_DBG_REG_WVR	(AARCH64_DBG_REG_BCR + ARM_MAX_BRP)
90 #define AARCH64_DBG_REG_WCR	(AARCH64_DBG_REG_WVR + ARM_MAX_WRP)
91 
92 /* Debug register names. */
93 #define AARCH64_DBG_REG_NAME_BVR	bvr
94 #define AARCH64_DBG_REG_NAME_BCR	bcr
95 #define AARCH64_DBG_REG_NAME_WVR	wvr
96 #define AARCH64_DBG_REG_NAME_WCR	wcr
97 
98 /* Accessor macros for the debug registers. */
99 #define AARCH64_DBG_READ(N, REG, VAL) do {\
100 	VAL = read_sysreg(dbg##REG##N##_el1);\
101 } while (0)
102 
103 #define AARCH64_DBG_WRITE(N, REG, VAL) do {\
104 	write_sysreg(VAL, dbg##REG##N##_el1);\
105 } while (0)
106 
107 struct task_struct;
108 struct notifier_block;
109 struct perf_event_attr;
110 struct perf_event;
111 struct pmu;
112 
113 extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
114 				  int *gen_len, int *gen_type, int *offset);
115 extern int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);
116 extern int hw_breakpoint_arch_parse(struct perf_event *bp,
117 				    const struct perf_event_attr *attr,
118 				    struct arch_hw_breakpoint *hw);
119 extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
120 					   unsigned long val, void *data);
121 
122 extern int arch_install_hw_breakpoint(struct perf_event *bp);
123 extern void arch_uninstall_hw_breakpoint(struct perf_event *bp);
124 extern void hw_breakpoint_pmu_read(struct perf_event *bp);
125 extern int hw_breakpoint_slots(int type);
126 
127 #ifdef CONFIG_HAVE_HW_BREAKPOINT
128 extern void hw_breakpoint_thread_switch(struct task_struct *next);
129 extern void ptrace_hw_copy_thread(struct task_struct *task);
130 #else
131 static inline void hw_breakpoint_thread_switch(struct task_struct *next)
132 {
133 }
134 static inline void ptrace_hw_copy_thread(struct task_struct *task)
135 {
136 }
137 #endif
138 
139 /* Determine number of BRP registers available. */
140 static inline int get_num_brps(void)
141 {
142 	u64 dfr0 = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1);
143 	return 1 +
144 		cpuid_feature_extract_unsigned_field(dfr0,
145 						ID_AA64DFR0_EL1_BRPs_SHIFT);
146 }
147 
148 /* Determine number of WRP registers available. */
149 static inline int get_num_wrps(void)
150 {
151 	u64 dfr0 = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1);
152 	return 1 +
153 		cpuid_feature_extract_unsigned_field(dfr0,
154 						ID_AA64DFR0_EL1_WRPs_SHIFT);
155 }
156 
157 #endif	/* __ASM_BREAKPOINT_H */
158