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
 19struct arch_hw_breakpoint_ctrl {
 20	u32 __reserved	: 28,
 21	len		: 2,
 22	type		: 2;
 23};
 24
 25struct 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)			\
 58do {								\
 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)			\
 66do {								\
 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
 85static inline u32 encode_ctrl_reg(struct arch_hw_breakpoint_ctrl ctrl)
 86{
 87	return (ctrl.len << 10) | (ctrl.type << 8);
 88}
 89
 90static 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
 98struct task_struct;
 99struct notifier_block;
100struct perf_event;
101struct perf_event_attr;
102
103extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
104				  int *gen_len, int *gen_type, int *offset);
105extern int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);
106extern int hw_breakpoint_arch_parse(struct perf_event *bp,
107				    const struct perf_event_attr *attr,
108				    struct arch_hw_breakpoint *hw);
109extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
110					   unsigned long val, void *data);
111
112extern int arch_install_hw_breakpoint(struct perf_event *bp);
113extern void arch_uninstall_hw_breakpoint(struct perf_event *bp);
114extern int hw_breakpoint_slots(int type);
115extern void hw_breakpoint_pmu_read(struct perf_event *bp);
116
117void breakpoint_handler(struct pt_regs *regs);
118void watchpoint_handler(struct pt_regs *regs);
119
120#ifdef CONFIG_HAVE_HW_BREAKPOINT
121extern void ptrace_hw_copy_thread(struct task_struct *task);
122extern void hw_breakpoint_thread_switch(struct task_struct *next);
123#else
124static inline void ptrace_hw_copy_thread(struct task_struct *task)
125{
126}
127static inline void hw_breakpoint_thread_switch(struct task_struct *next)
128{
129}
130#endif
131
132/* Determine number of BRP registers available. */
133static 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. */
139static 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 */