1 /*
2  * Copyright (C) 2012 ARM Ltd.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
15  */
16 #ifndef __ASM_HW_BREAKPOINT_H
17 #define __ASM_HW_BREAKPOINT_H
18 
19 #ifdef __KERNEL__
20 
21 struct arch_hw_breakpoint_ctrl {
22 	u32 __reserved	: 19,
23 	len		: 8,
24 	type		: 2,
25 	privilege	: 2,
26 	enabled		: 1;
27 };
28 
29 struct arch_hw_breakpoint {
30 	u64 address;
31 	u64 trigger;
32 	struct arch_hw_breakpoint_ctrl ctrl;
33 };
34 
35 static inline u32 encode_ctrl_reg(struct arch_hw_breakpoint_ctrl ctrl)
36 {
37 	return (ctrl.len << 5) | (ctrl.type << 3) | (ctrl.privilege << 1) |
38 		ctrl.enabled;
39 }
40 
41 static inline void decode_ctrl_reg(u32 reg,
42 				   struct arch_hw_breakpoint_ctrl *ctrl)
43 {
44 	ctrl->enabled	= reg & 0x1;
45 	reg >>= 1;
46 	ctrl->privilege	= reg & 0x3;
47 	reg >>= 2;
48 	ctrl->type	= reg & 0x3;
49 	reg >>= 2;
50 	ctrl->len	= reg & 0xff;
51 }
52 
53 /* Breakpoint */
54 #define ARM_BREAKPOINT_EXECUTE	0
55 
56 /* Watchpoints */
57 #define ARM_BREAKPOINT_LOAD	1
58 #define ARM_BREAKPOINT_STORE	2
59 #define AARCH64_ESR_ACCESS_MASK	(1 << 6)
60 
61 /* Privilege Levels */
62 #define AARCH64_BREAKPOINT_EL1	1
63 #define AARCH64_BREAKPOINT_EL0	2
64 
65 /* Lengths */
66 #define ARM_BREAKPOINT_LEN_1	0x1
67 #define ARM_BREAKPOINT_LEN_2	0x3
68 #define ARM_BREAKPOINT_LEN_4	0xf
69 #define ARM_BREAKPOINT_LEN_8	0xff
70 
71 /* Kernel stepping */
72 #define ARM_KERNEL_STEP_NONE	0
73 #define ARM_KERNEL_STEP_ACTIVE	1
74 #define ARM_KERNEL_STEP_SUSPEND	2
75 
76 /*
77  * Limits.
78  * Changing these will require modifications to the register accessors.
79  */
80 #define ARM_MAX_BRP		16
81 #define ARM_MAX_WRP		16
82 
83 /* Virtual debug register bases. */
84 #define AARCH64_DBG_REG_BVR	0
85 #define AARCH64_DBG_REG_BCR	(AARCH64_DBG_REG_BVR + ARM_MAX_BRP)
86 #define AARCH64_DBG_REG_WVR	(AARCH64_DBG_REG_BCR + ARM_MAX_BRP)
87 #define AARCH64_DBG_REG_WCR	(AARCH64_DBG_REG_WVR + ARM_MAX_WRP)
88 
89 /* Debug register names. */
90 #define AARCH64_DBG_REG_NAME_BVR	"bvr"
91 #define AARCH64_DBG_REG_NAME_BCR	"bcr"
92 #define AARCH64_DBG_REG_NAME_WVR	"wvr"
93 #define AARCH64_DBG_REG_NAME_WCR	"wcr"
94 
95 /* Accessor macros for the debug registers. */
96 #define AARCH64_DBG_READ(N, REG, VAL) do {\
97 	asm volatile("mrs %0, dbg" REG #N "_el1" : "=r" (VAL));\
98 } while (0)
99 
100 #define AARCH64_DBG_WRITE(N, REG, VAL) do {\
101 	asm volatile("msr dbg" REG #N "_el1, %0" :: "r" (VAL));\
102 } while (0)
103 
104 struct task_struct;
105 struct notifier_block;
106 struct perf_event;
107 struct pmu;
108 
109 extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
110 				  int *gen_len, int *gen_type);
111 extern int arch_check_bp_in_kernelspace(struct perf_event *bp);
112 extern int arch_validate_hwbkpt_settings(struct perf_event *bp);
113 extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
114 					   unsigned long val, void *data);
115 
116 extern int arch_install_hw_breakpoint(struct perf_event *bp);
117 extern void arch_uninstall_hw_breakpoint(struct perf_event *bp);
118 extern void hw_breakpoint_pmu_read(struct perf_event *bp);
119 extern int hw_breakpoint_slots(int type);
120 
121 #ifdef CONFIG_HAVE_HW_BREAKPOINT
122 extern void hw_breakpoint_thread_switch(struct task_struct *next);
123 extern void ptrace_hw_copy_thread(struct task_struct *task);
124 #else
125 static inline void hw_breakpoint_thread_switch(struct task_struct *next)
126 {
127 }
128 static inline void ptrace_hw_copy_thread(struct task_struct *task)
129 {
130 }
131 #endif
132 
133 extern struct pmu perf_ops_bp;
134 
135 #endif	/* __KERNEL__ */
136 #endif	/* __ASM_BREAKPOINT_H */
137