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