linux-stable/arch/loongarch/include/asm/switch_to.h
Qing Zhang edffa33c7b LoongArch: Add hardware breakpoints/watchpoints support
Use perf framework to manage hardware instruction and data breakpoints.

LoongArch defines hardware watchpoint functions for instruction fetch
and memory load/store operations. After the software configures hardware
watchpoints, the processor hardware will monitor the access address of
the instruction fetch and load/store operation, and trigger an exception
of the watchpoint when it meets the conditions set by the watchpoint.

The hardware monitoring points for instruction fetching and load/store
operations each have a register for the overall configuration of all
monitoring points, a register for recording the status of all monitoring
points, and four registers required for configuration of each watchpoint
individually.

Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-02-25 22:12:17 +08:00

42 lines
1.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#ifndef _ASM_SWITCH_TO_H
#define _ASM_SWITCH_TO_H
#include <asm/cpu-features.h>
#include <asm/fpu.h>
struct task_struct;
/**
* __switch_to - switch execution of a task
* @prev: The task previously executed.
* @next: The task to begin executing.
* @next_ti: task_thread_info(next).
* @sched_ra: __schedule return address.
* @sched_cfa: __schedule call frame address.
*
* This function is used whilst scheduling to save the context of prev & load
* the context of next. Returns prev.
*/
extern asmlinkage struct task_struct *__switch_to(struct task_struct *prev,
struct task_struct *next, struct thread_info *next_ti,
void *sched_ra, void *sched_cfa);
/*
* For newly created kernel threads switch_to() will return to
* ret_from_kernel_thread, newly created user threads to ret_from_fork.
* That is, everything following __switch_to() will be skipped for new threads.
* So everything that matters to new threads should be placed before __switch_to().
*/
#define switch_to(prev, next, last) \
do { \
lose_fpu_inatomic(1, prev); \
hw_breakpoint_thread_switch(next); \
(last) = __switch_to(prev, next, task_thread_info(next), \
__builtin_return_address(0), __builtin_frame_address(0)); \
} while (0)
#endif /* _ASM_SWITCH_TO_H */