2b210cb3db
Things had gotten a little tangled in there so let's do some cleanup. Remove the distressingly-special-purpose z_reinit_idle_thread() hook (which existed to support secondary core bringup when SMP_BOOT_DELAY=y), and just fold that into a generic z_init_cpu(), which we can call in obvious and symmetric ways from main initialization, z_smp_init(), and z_smp_start_cpu() (the now-official programmatic hook for starting cpus). Remove the "#if CONFIG_MP_NUM_CPUS > 1" exclusions. These weren't saving any code size and were propagating themselves into platform layers trying to avoid build failures. There are some "special" APIs added for SOF which need to go away in favor of the newer/generic z_smp_start_cpu(). Collect them in one place and put them under a "#ifdef CONFIG_SOF" to prevent them from being used in Zephyr apps. Move some function declarations that didn't have homes into <kernel/thread.h>. Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
129 lines
2.5 KiB
C
129 lines
2.5 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 <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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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) {
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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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smp_timer_init();
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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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for (int i = 1; i < CONFIG_MP_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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