1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (C) 2022-2023 Loongson Technology Corporation Limited
4 */
5 #ifndef __ASM_HW_BREAKPOINT_H
6 #define __ASM_HW_BREAKPOINT_H
7
8 #include <asm/loongarch.h>
9
10 #ifdef __KERNEL__
11
12 /* Breakpoint */
13 #define LOONGARCH_BREAKPOINT_EXECUTE (0 << 0)
14
15 /* Watchpoints */
16 #define LOONGARCH_BREAKPOINT_LOAD (1 << 0)
17 #define LOONGARCH_BREAKPOINT_STORE (1 << 1)
18
19 struct arch_hw_breakpoint_ctrl {
20 u32 __reserved : 28,
21 len : 2,
22 type : 2;
23 };
24
25 struct arch_hw_breakpoint {
26 u64 address;
27 u64 mask;
28 struct arch_hw_breakpoint_ctrl ctrl;
29 };
30
31 /* Lengths */
32 #define LOONGARCH_BREAKPOINT_LEN_1 0b11
33 #define LOONGARCH_BREAKPOINT_LEN_2 0b10
34 #define LOONGARCH_BREAKPOINT_LEN_4 0b01
35 #define LOONGARCH_BREAKPOINT_LEN_8 0b00
36
37 /*
38 * Limits.
39 * Changing these will require modifications to the register accessors.
40 */
41 #define LOONGARCH_MAX_BRP 8
42 #define LOONGARCH_MAX_WRP 8
43
44 /* Virtual debug register bases. */
45 #define CSR_CFG_ADDR 0
46 #define CSR_CFG_MASK (CSR_CFG_ADDR + LOONGARCH_MAX_BRP)
47 #define CSR_CFG_CTRL (CSR_CFG_MASK + LOONGARCH_MAX_BRP)
48 #define CSR_CFG_ASID (CSR_CFG_CTRL + LOONGARCH_MAX_WRP)
49
50 /* Debug register names. */
51 #define LOONGARCH_CSR_NAME_ADDR ADDR
52 #define LOONGARCH_CSR_NAME_MASK MASK
53 #define LOONGARCH_CSR_NAME_CTRL CTRL
54 #define LOONGARCH_CSR_NAME_ASID ASID
55
56 /* Accessor macros for the debug registers. */
57 #define LOONGARCH_CSR_WATCH_READ(N, REG, T, VAL) \
58 do { \
59 if (T == 0) \
60 VAL = csr_read64(LOONGARCH_CSR_##IB##N##REG); \
61 else \
62 VAL = csr_read64(LOONGARCH_CSR_##DB##N##REG); \
63 } while (0)
64
65 #define LOONGARCH_CSR_WATCH_WRITE(N, REG, T, VAL) \
66 do { \
67 if (T == 0) \
68 csr_write64(VAL, LOONGARCH_CSR_##IB##N##REG); \
69 else \
70 csr_write64(VAL, LOONGARCH_CSR_##DB##N##REG); \
71 } while (0)
72
73 /* Exact number */
74 #define CSR_FWPC_NUM 0x3f
75 #define CSR_MWPC_NUM 0x3f
76
77 #define CTRL_PLV_ENABLE 0x1e
78
79 #define MWPnCFG3_LoadEn 8
80 #define MWPnCFG3_StoreEn 9
81
82 #define MWPnCFG3_Type_mask 0x3
83 #define MWPnCFG3_Size_mask 0x3
84
encode_ctrl_reg(struct arch_hw_breakpoint_ctrl ctrl)85 static inline u32 encode_ctrl_reg(struct arch_hw_breakpoint_ctrl ctrl)
86 {
87 return (ctrl.len << 10) | (ctrl.type << 8);
88 }
89
decode_ctrl_reg(u32 reg,struct arch_hw_breakpoint_ctrl * ctrl)90 static inline void decode_ctrl_reg(u32 reg, struct arch_hw_breakpoint_ctrl *ctrl)
91 {
92 reg >>= 8;
93 ctrl->type = reg & MWPnCFG3_Type_mask;
94 reg >>= 2;
95 ctrl->len = reg & MWPnCFG3_Size_mask;
96 }
97
98 struct task_struct;
99 struct notifier_block;
100 struct perf_event;
101 struct perf_event_attr;
102
103 extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
104 int *gen_len, int *gen_type, int *offset);
105 extern int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);
106 extern int hw_breakpoint_arch_parse(struct perf_event *bp,
107 const struct perf_event_attr *attr,
108 struct arch_hw_breakpoint *hw);
109 extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
110 unsigned long val, void *data);
111
112 extern int arch_install_hw_breakpoint(struct perf_event *bp);
113 extern void arch_uninstall_hw_breakpoint(struct perf_event *bp);
114 extern int hw_breakpoint_slots(int type);
115 extern void hw_breakpoint_pmu_read(struct perf_event *bp);
116
117 void breakpoint_handler(struct pt_regs *regs);
118 void watchpoint_handler(struct pt_regs *regs);
119
120 #ifdef CONFIG_HAVE_HW_BREAKPOINT
121 extern void ptrace_hw_copy_thread(struct task_struct *task);
122 extern void hw_breakpoint_thread_switch(struct task_struct *next);
123 #else
ptrace_hw_copy_thread(struct task_struct * task)124 static inline void ptrace_hw_copy_thread(struct task_struct *task)
125 {
126 }
hw_breakpoint_thread_switch(struct task_struct * next)127 static inline void hw_breakpoint_thread_switch(struct task_struct *next)
128 {
129 }
130 #endif
131
132 /* Determine number of BRP registers available. */
get_num_brps(void)133 static inline int get_num_brps(void)
134 {
135 return csr_read64(LOONGARCH_CSR_FWPC) & CSR_FWPC_NUM;
136 }
137
138 /* Determine number of WRP registers available. */
get_num_wrps(void)139 static inline int get_num_wrps(void)
140 {
141 return csr_read64(LOONGARCH_CSR_MWPC) & CSR_MWPC_NUM;
142 }
143
144 #endif /* __KERNEL__ */
145 #endif /* __ASM_BREAKPOINT_H */
146