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