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