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