101 lines
3.5 KiB
C
101 lines
3.5 KiB
C
/* SPDX-License-Identifier: BSD-3-Clause */
|
|
/* See the end of this file for copyright, licensing, and warranty information. */
|
|
|
|
#include <arch/sched.h>
|
|
#include <arch/at91sam3x8e/hardware.h>
|
|
#include <arch/at91sam3x8e/interrupt.h>
|
|
|
|
#include <ardix/atomic.h>
|
|
#include <ardix/string.h>
|
|
#include <ardix/sched.h>
|
|
|
|
extern struct task *_sched_current_task;
|
|
|
|
void irq_sys_tick(void)
|
|
{
|
|
/*
|
|
* fire a PendSV interrupt and do the actual context switching there
|
|
* because it is faster that way (according to the docs, at least)
|
|
*/
|
|
if (!is_atomic_context())
|
|
arch_irq_invoke(IRQNO_PEND_SV);
|
|
}
|
|
|
|
/**
|
|
* Set the NVIC priority grouping field in `AIRCR`.
|
|
* Only values from 0..7 are allowed, see the SAM3X documentation.
|
|
*
|
|
* @param prio_group: The new priority grouping value.
|
|
*/
|
|
static inline void sched_nvic_set_prio_group(uint32_t prio_group)
|
|
{
|
|
uint32_t reg_val = REG_SCB_AIRCR;
|
|
|
|
reg_val &= ~(REG_SCB_AIRCR_VECTKEY_MASK | REG_SCB_AIRCR_PRIGROUP_MASK);
|
|
reg_val = reg_val
|
|
| REG_SCB_AIRCR_VECTKEY_VAL(REG_SCB_AIRCR_VECTKEY_MAGIC)
|
|
| REG_SCB_AIRCR_PRIGROUP_VAL(prio_group);
|
|
|
|
REG_SCB_AIRCR = reg_val;
|
|
}
|
|
|
|
int arch_sched_hwtimer_init(unsigned int freq)
|
|
{
|
|
uint32_t ticks = sys_core_clock / freq;
|
|
if (ticks > REG_SYSTICK_LOAD_RELOAD_MASK)
|
|
return 1;
|
|
|
|
/* Ensure SysTick and PendSV are preemptive */
|
|
sched_nvic_set_prio_group(0b011);
|
|
|
|
REG_SYSTICK_LOAD = (ticks & REG_SYSTICK_LOAD_RELOAD_MASK) - 1;
|
|
REG_SYSTICK_VAL = 0U;
|
|
REG_SYSTICK_CTRL = REG_SYSTICK_CTRL_CLKSOURCE_BIT /* MCK */
|
|
| REG_SYSTICK_CTRL_TICKINT_BIT /* trigger exception */
|
|
| REG_SYSTICK_CTRL_ENABLE_BIT; /* enable SysTick */
|
|
|
|
return 0;
|
|
}
|
|
|
|
void arch_sched_task_init(struct task *task, void (*entry)(void))
|
|
{
|
|
struct reg_snapshot *regs = task->stack_bottom - sizeof(*regs);
|
|
task->sp = regs;
|
|
|
|
memset(regs, 0, sizeof(*regs));
|
|
regs->hw.pc = entry;
|
|
regs->hw.psr = 0x01000000U;
|
|
regs->sw.lr = (void *)0xFFFFFFF9U;
|
|
}
|
|
|
|
void sched_yield(enum task_state state)
|
|
{
|
|
REG_SYSTICK_VAL = 0U; /* Reset timer */
|
|
_sched_current_task->state = state;
|
|
arch_irq_invoke(IRQNO_PEND_SV);
|
|
}
|
|
|
|
/*
|
|
* Copyright (c) 2020 Felix Kopp <sandtler@sandtler.club>
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without modification, are permitted
|
|
* provided that the following conditions are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright notice, this list of
|
|
* conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright notice, this list of
|
|
* conditions and the following disclaimer in the documentation and/or other materials
|
|
* provided with the distribution.
|
|
* 3. Neither the name of the copyright holder nor the names of its contributors may be
|
|
* used to endorse or promote products derived from this software without specific prior
|
|
* written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
|
|
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
|
|
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
|
|
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
|
|
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
|
|
* WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|