arch/loongarch/include/asm/hw_breakpoint.h

   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               14
  42 #define LOONGARCH_MAX_WRP               14
  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 #define CTRL_PLV0_ENABLE        0x02
  79 #define CTRL_PLV3_ENABLE        0x10
  80
  81 #define MWPnCFG3_LoadEn         8
  82 #define MWPnCFG3_StoreEn        9
  83
  84 #define MWPnCFG3_Type_mask      0x3
  85 #define MWPnCFG3_Size_mask      0x3
  86
  87 static inline u32 encode_ctrl_reg(struct arch_hw_breakpoint_ctrl ctrl)
  88 {
  89         return (ctrl.len << 10) | (ctrl.type << 8);
  90 }
  91
  92 static inline void decode_ctrl_reg(u32 reg, struct arch_hw_breakpoint_ctrl *ctrl)
  93 {
  94         reg >>= 8;
  95         ctrl->type = reg & MWPnCFG3_Type_mask;
  96         reg >>= 2;
  97         ctrl->len  = reg & MWPnCFG3_Size_mask;
  98 }
  99
 100 struct task_struct;
 101 struct notifier_block;
 102 struct perf_event;
 103 struct perf_event_attr;
 104
 105 extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
 106                                   int *gen_len, int *gen_type);
 107 extern int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);
 108 extern int hw_breakpoint_arch_parse(struct perf_event *bp,
 109                                     const struct perf_event_attr *attr,
 110                                     struct arch_hw_breakpoint *hw);
 111 extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
 112                                            unsigned long val, void *data);
 113
 114 extern int arch_install_hw_breakpoint(struct perf_event *bp);
 115 extern void arch_uninstall_hw_breakpoint(struct perf_event *bp);
 116 extern int hw_breakpoint_slots(int type);
 117 extern void hw_breakpoint_pmu_read(struct perf_event *bp);
 118
 119 void breakpoint_handler(struct pt_regs *regs);
 120 void watchpoint_handler(struct pt_regs *regs);
 121
 122 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 123 extern void ptrace_hw_copy_thread(struct task_struct *task);
 124 extern void hw_breakpoint_thread_switch(struct task_struct *next);
 125 #else
 126 static inline void ptrace_hw_copy_thread(struct task_struct *task)
 127 {
 128 }
 129 static inline void hw_breakpoint_thread_switch(struct task_struct *next)
 130 {
 131 }
 132 #endif
 133
 134 /* Determine number of BRP registers available. */
 135 static inline int get_num_brps(void)
 136 {
 137         return csr_read64(LOONGARCH_CSR_FWPC) & CSR_FWPC_NUM;
 138 }
 139
 140 /* Determine number of WRP registers available. */
 141 static inline int get_num_wrps(void)
 142 {
 143         return csr_read64(LOONGARCH_CSR_MWPC) & CSR_MWPC_NUM;
 144 }
 145
 146 #endif  /* __KERNEL__ */
 147 #endif  /* __ASM_BREAKPOINT_H */