blob: dc30bd5f9edf1711b8b66adf2e8bab61e9964992 [file] [log] [blame] [edit]
/* Copyright (c) 2022 Intel corporation
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr/kernel.h>
#include <zephyr/kernel_structs.h>
#include <zephyr/spinlock.h>
#include <kswap.h>
#include <kernel_internal.h>
static atomic_t global_lock;
static atomic_t cpu_start_flag;
static atomic_t ready_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 != 0U) {
_current->base.global_lock_count--;
if (!_current->base.global_lock_count) {
atomic_clear(&global_lock);
}
}
arch_irq_unlock(key);
}
/* 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);
}
}
/* Tiny delay that relaxes bus traffic to avoid spamming a shared
* memory bus looking at an atomic variable
*/
static inline void local_delay(void)
{
for (volatile int i = 0; i < 1000; i++) {
}
}
static void wait_for_start_signal(atomic_t *start_flag)
{
/* Wait for the signal to begin scheduling */
while (!atomic_get(start_flag)) {
local_delay();
}
}
/* Legacy interfaces for early-version SOF CPU bringup. To be removed */
#ifdef CONFIG_SOF
void z_smp_thread_init(void *arg, struct k_thread *thread)
{
z_dummy_thread_init(thread);
wait_for_start_signal(arg);
}
void z_smp_thread_swap(void)
{
z_swap_unlocked();
}
#endif
static inline FUNC_NORETURN void smp_init_top(void *arg)
{
struct k_thread dummy_thread;
(void)atomic_set(&ready_flag, 1);
wait_for_start_signal(arg);
z_dummy_thread_init(&dummy_thread);
#ifdef CONFIG_SYS_CLOCK_EXISTS
smp_timer_init();
#endif
z_swap_unlocked();
CODE_UNREACHABLE; /* LCOV_EXCL_LINE */
}
static void start_cpu(int id, atomic_t *start_flag)
{
z_init_cpu(id);
(void)atomic_clear(&ready_flag);
arch_start_cpu(id, z_interrupt_stacks[id], CONFIG_ISR_STACK_SIZE,
smp_init_top, start_flag);
while (!atomic_get(&ready_flag)) {
local_delay();
}
}
void z_smp_start_cpu(int id)
{
(void)atomic_set(&cpu_start_flag, 1); /* async, don't care */
start_cpu(id, &cpu_start_flag);
}
void z_smp_init(void)
{
(void)atomic_clear(&cpu_start_flag);
unsigned int num_cpus = arch_num_cpus();
for (int i = 1; i < num_cpus; i++) {
start_cpu(i, &cpu_start_flag);
}
(void)atomic_set(&cpu_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;
}