152 lines
3.3 KiB
C
152 lines
3.3 KiB
C
/*
|
|
* Copyright (c) 2018 Intel Corporation
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*/
|
|
#ifndef ZEPHYR_KERNEL_INCLUDE_KSWAP_H_
|
|
#define ZEPHYR_KERNEL_INCLUDE_KSWAP_H_
|
|
|
|
#include <ksched.h>
|
|
#include <spinlock.h>
|
|
#include <kernel_arch_func.h>
|
|
|
|
#ifdef CONFIG_STACK_SENTINEL
|
|
extern void z_check_stack_sentinel(void);
|
|
#else
|
|
#define z_check_stack_sentinel() /**/
|
|
#endif
|
|
|
|
/* In SMP, the irq_lock() is a spinlock which is implicitly released
|
|
* and reacquired on context switch to preserve the existing
|
|
* semantics. This means that whenever we are about to return to a
|
|
* thread (via either z_swap() or interrupt/exception return!) we need
|
|
* to restore the lock state to whatever the thread's counter
|
|
* expects.
|
|
*/
|
|
void z_smp_reacquire_global_lock(struct k_thread *thread);
|
|
void z_smp_release_global_lock(struct k_thread *thread);
|
|
|
|
/* context switching and scheduling-related routines */
|
|
#ifdef CONFIG_USE_SWITCH
|
|
|
|
/* New style context switching. arch_switch() is a lower level
|
|
* primitive that doesn't know about the scheduler or return value.
|
|
* Needed for SMP, where the scheduler requires spinlocking that we
|
|
* don't want to have to do in per-architecture assembly.
|
|
*
|
|
* Note that is_spinlock is a compile-time construct which will be
|
|
* optimized out when this function is expanded.
|
|
*/
|
|
static ALWAYS_INLINE unsigned int do_swap(unsigned int key,
|
|
struct k_spinlock *lock,
|
|
int is_spinlock)
|
|
{
|
|
ARG_UNUSED(lock);
|
|
struct k_thread *new_thread, *old_thread;
|
|
|
|
#ifdef CONFIG_EXECUTION_BENCHMARKING
|
|
extern void read_timer_start_of_swap(void);
|
|
read_timer_start_of_swap();
|
|
#endif
|
|
|
|
old_thread = _current;
|
|
|
|
z_check_stack_sentinel();
|
|
|
|
sys_trace_thread_switched_out();
|
|
|
|
if (is_spinlock) {
|
|
k_spin_release(lock);
|
|
}
|
|
|
|
new_thread = z_get_next_ready_thread();
|
|
|
|
if (new_thread != old_thread) {
|
|
#ifdef CONFIG_TIMESLICING
|
|
z_reset_time_slice();
|
|
#endif
|
|
|
|
old_thread->swap_retval = -EAGAIN;
|
|
|
|
#ifdef CONFIG_SMP
|
|
_current_cpu->swap_ok = 0;
|
|
|
|
new_thread->base.cpu = arch_curr_cpu()->id;
|
|
|
|
if (!is_spinlock) {
|
|
z_smp_release_global_lock(new_thread);
|
|
}
|
|
#endif
|
|
_current = new_thread;
|
|
arch_switch(new_thread->switch_handle,
|
|
&old_thread->switch_handle);
|
|
}
|
|
|
|
sys_trace_thread_switched_in();
|
|
|
|
if (is_spinlock) {
|
|
arch_irq_unlock(key);
|
|
} else {
|
|
irq_unlock(key);
|
|
}
|
|
|
|
return _current->swap_retval;
|
|
}
|
|
|
|
static inline int z_swap_irqlock(unsigned int key)
|
|
{
|
|
return do_swap(key, NULL, 0);
|
|
}
|
|
|
|
static inline int z_swap(struct k_spinlock *lock, k_spinlock_key_t key)
|
|
{
|
|
return do_swap(key.key, lock, 1);
|
|
}
|
|
|
|
static inline void z_swap_unlocked(void)
|
|
{
|
|
struct k_spinlock lock = {};
|
|
k_spinlock_key_t key = k_spin_lock(&lock);
|
|
|
|
(void) z_swap(&lock, key);
|
|
}
|
|
|
|
#else /* !CONFIG_USE_SWITCH */
|
|
|
|
extern int arch_swap(unsigned int key);
|
|
|
|
static inline int z_swap_irqlock(unsigned int key)
|
|
{
|
|
int ret;
|
|
z_check_stack_sentinel();
|
|
|
|
#ifndef CONFIG_ARM
|
|
sys_trace_thread_switched_out();
|
|
#endif
|
|
ret = arch_swap(key);
|
|
#ifndef CONFIG_ARM
|
|
sys_trace_thread_switched_in();
|
|
#endif
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* If !USE_SWITCH, then spinlocks are guaranteed degenerate as we
|
|
* can't be in SMP. The k_spin_release() call is just for validation
|
|
* handling.
|
|
*/
|
|
static ALWAYS_INLINE int z_swap(struct k_spinlock *lock, k_spinlock_key_t key)
|
|
{
|
|
k_spin_release(lock);
|
|
return z_swap_irqlock(key.key);
|
|
}
|
|
|
|
static inline void z_swap_unlocked(void)
|
|
{
|
|
(void) z_swap_irqlock(arch_irq_lock());
|
|
}
|
|
|
|
#endif
|
|
|
|
#endif /* ZEPHYR_KERNEL_INCLUDE_KSWAP_H_ */
|