zephyr/kernel/smp.c

105 lines
1.9 KiB
C

/*
* Copyright (c) 2018 Intel corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <kernel.h>
#include <kernel_structs.h>
#include <spinlock.h>
#include <kswap.h>
#include <kernel_internal.h>
#ifdef CONFIG_SMP
static atomic_t global_lock;
static atomic_t start_flag;
unsigned int z_smp_global_lock(void)
{
unsigned int key = arch_irq_lock();
if (!_current->base.global_lock_count) {
while (!atomic_cas(&global_lock, 0, 1)) {
}
}
_current->base.global_lock_count++;
return key;
}
void z_smp_global_unlock(unsigned int key)
{
if (_current->base.global_lock_count) {
_current->base.global_lock_count--;
if (!_current->base.global_lock_count) {
atomic_clear(&global_lock);
}
}
arch_irq_unlock(key);
}
void z_smp_reacquire_global_lock(struct k_thread *thread)
{
if (thread->base.global_lock_count) {
arch_irq_lock();
while (!atomic_cas(&global_lock, 0, 1)) {
}
}
}
/* Called from within z_swap(), so assumes lock already held */
void z_smp_release_global_lock(struct k_thread *thread)
{
if (!thread->base.global_lock_count) {
atomic_clear(&global_lock);
}
}
#if CONFIG_MP_NUM_CPUS > 1
static FUNC_NORETURN void smp_init_top(void *arg)
{
atomic_t *start_flag = arg;
struct k_thread dummy_thread;
/* Wait for the signal to begin scheduling */
while (!atomic_get(start_flag)) {
}
z_dummy_thread_init(&dummy_thread);
smp_timer_init();
z_swap_unlocked();
CODE_UNREACHABLE;
}
#endif
void z_smp_init(void)
{
(void)atomic_clear(&start_flag);
#if defined(CONFIG_SMP) && (CONFIG_MP_NUM_CPUS > 1)
for (int i = 1; i < CONFIG_MP_NUM_CPUS; i++) {
arch_start_cpu(i, z_interrupt_stacks[i], CONFIG_ISR_STACK_SIZE,
smp_init_top, &start_flag);
}
#endif
(void)atomic_set(&start_flag, 1);
}
bool z_smp_cpu_mobile(void)
{
unsigned int k = arch_irq_lock();
bool pinned = arch_is_in_isr() || !arch_irq_unlocked(k);
arch_irq_unlock(k);
return !pinned;
}
#endif /* CONFIG_SMP */