fef
7e6dbad05f
The old strategy was to only do context switching from within the PendSV handler. This worked fine until now because all syscalls were handled either atomically or just returned -EAGAIN if the resource was locked or busy. However, with the introduction of I/O wait, we need to be able to sleep directly from within the kernel by moving the context switching completely into the kernel.
41 lines
1.2 KiB
C
41 lines
1.2 KiB
C
/* See the end of this file for copyright, license, and warranty information. */
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#pragma once
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#include <arch/hardware.h>
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#include <ardix/sched.h>
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#include <toolchain.h>
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/**
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* @brief New tasks point their initial program counter here.
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*/
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extern void _leave(void);
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extern void _do_switch(struct context *old, struct context *new);
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/**
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* @brief Perform an in-kernel context switch.
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* This is called from `schedule()`, and will suspend the current task.
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* The call returns when the current task is woken back up.
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*
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* @param old Currently running task in whose TCB the context will be stored
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* @param new Task to switch to, must not be the same as `old`
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*/
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__always_inline void do_switch(struct task *old, struct task *new)
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{
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_do_switch(&old->tcb.context, &new->tcb.context);
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}
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/*
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* This file is part of Ardix.
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* Copyright (c) 2020, 2021 Felix Kopp <owo@fef.moe>.
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*
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* Ardix is non-violent software: you may only use, redistribute,
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* and/or modify it under the terms of the CNPLv6+ as found in
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* the LICENSE file in the source code root directory or at
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* <https://git.pixie.town/thufie/CNPL>.
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*
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* Ardix comes with ABSOLUTELY NO WARRANTY, to the extent
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* permitted by applicable law. See the CNPLv6+ for details.
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*/
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