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/*
* Copyright (c) 1997-2016 Wind River Systems, Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr/kernel.h>
#include <zephyr/init.h>
#include <zephyr/internal/syscall_handler.h>
#include <stdbool.h>
#include <zephyr/spinlock.h>
#include <ksched.h>
#include <wait_q.h>
static struct k_spinlock lock;
#ifdef CONFIG_OBJ_CORE_TIMER
static struct k_obj_type obj_type_timer;
#endif
/**
* @brief Handle expiration of a kernel timer object.
*
* @param t Timeout used by the timer.
*/
void z_timer_expiration_handler(struct _timeout *t)
{
struct k_timer *timer = CONTAINER_OF(t, struct k_timer, timeout);
struct k_thread *thread;
k_spinlock_key_t key = k_spin_lock(&lock);
/* In sys_clock_announce(), when a timeout expires, it is first removed
* from the timeout list, then its expiration handler is called (with
* unlocked interrupts). For kernel timers, the expiration handler is
* this function. Usually, the timeout structure related to the timer
* that is handled here will not be linked to the timeout list at this
* point. But it may happen that before this function is executed and
* interrupts are locked again, a given timer gets restarted from an
* interrupt context that has a priority higher than the system timer
* interrupt. Then, the timeout structure for this timer will turn out
* to be linked to the timeout list. And in such case, since the timer
* was restarted, its expiration handler should not be executed then,
* so the function exits immediately.
*/
if (sys_dnode_is_linked(&t->node)) {
k_spin_unlock(&lock, key);
return;
}
/*
* if the timer is periodic, start it again; don't add _TICK_ALIGN
* since we're already aligned to a tick boundary
*/
if (!K_TIMEOUT_EQ(timer->period, K_NO_WAIT) &&
!K_TIMEOUT_EQ(timer->period, K_FOREVER)) {
k_timeout_t next = timer->period;
/* see note about z_add_timeout() in z_impl_k_timer_start() */
next.ticks = MAX(next.ticks - 1, 0);
#ifdef CONFIG_TIMEOUT_64BIT
/* Exploit the fact that uptime during a kernel
* timeout handler reflects the time of the scheduled
* event and not real time to get some inexpensive
* protection against late interrupts. If we're
* delayed for any reason, we still end up calculating
* the next expiration as a regular stride from where
* we "should" have run. Requires absolute timeouts.
* (Note offset by one: we're nominally at the
* beginning of a tick, so need to defeat the "round
* down" behavior on timeout addition).
*/
next = K_TIMEOUT_ABS_TICKS(k_uptime_ticks() + 1 + next.ticks);
#endif
z_add_timeout(&timer->timeout, z_timer_expiration_handler,
next);
}
/* update timer's status */
timer->status += 1U;
/* invoke timer expiry function */
if (timer->expiry_fn != NULL) {
/* Unlock for user handler. */
k_spin_unlock(&lock, key);
timer->expiry_fn(timer);
key = k_spin_lock(&lock);
}
if (!IS_ENABLED(CONFIG_MULTITHREADING)) {
k_spin_unlock(&lock, key);
return;
}
thread = z_waitq_head(&timer->wait_q);
if (thread == NULL) {
k_spin_unlock(&lock, key);
return;
}
z_unpend_thread_no_timeout(thread);
arch_thread_return_value_set(thread, 0);
k_spin_unlock(&lock, key);
z_ready_thread(thread);
}
void k_timer_init(struct k_timer *timer,
k_timer_expiry_t expiry_fn,
k_timer_stop_t stop_fn)
{
timer->expiry_fn = expiry_fn;
timer->stop_fn = stop_fn;
timer->status = 0U;
if (IS_ENABLED(CONFIG_MULTITHREADING)) {
z_waitq_init(&timer->wait_q);
}
z_init_timeout(&timer->timeout);
SYS_PORT_TRACING_OBJ_INIT(k_timer, timer);
timer->user_data = NULL;
k_object_init(timer);
#ifdef CONFIG_OBJ_CORE_TIMER
k_obj_core_init_and_link(K_OBJ_CORE(timer), &obj_type_timer);
#endif
}
void z_impl_k_timer_start(struct k_timer *timer, k_timeout_t duration,
k_timeout_t period)
{
SYS_PORT_TRACING_OBJ_FUNC(k_timer, start, timer, duration, period);
/* Acquire spinlock to ensure safety during concurrent calls to
* k_timer_start for scheduling or rescheduling. This is necessary
* since k_timer_start can be preempted, especially for the same
* timer instance.
*/
k_spinlock_key_t key = k_spin_lock(&lock);
if (K_TIMEOUT_EQ(duration, K_FOREVER)) {
k_spin_unlock(&lock, key);
return;
}
/* z_add_timeout() always adds one to the incoming tick count
* to round up to the next tick (by convention it waits for
* "at least as long as the specified timeout"), but the
* period interval is always guaranteed to be reset from
* within the timer ISR, so no round up is desired and 1 is
* subtracted in there.
*
* Note that the duration (!) value gets the same treatment
* for backwards compatibility. This is unfortunate
* (i.e. k_timer_start() doesn't treat its initial sleep
* argument the same way k_sleep() does), but historical. The
* timer_api test relies on this behavior.
*/
if (Z_TICK_ABS(duration.ticks) < 0) {
duration.ticks = MAX(duration.ticks - 1, 0);
}
(void)z_abort_timeout(&timer->timeout);
timer->period = period;
timer->status = 0U;
z_add_timeout(&timer->timeout, z_timer_expiration_handler,
duration);
k_spin_unlock(&lock, key);
}
#ifdef CONFIG_USERSPACE
static inline void z_vrfy_k_timer_start(struct k_timer *timer,
k_timeout_t duration,
k_timeout_t period)
{
K_OOPS(K_SYSCALL_OBJ(timer, K_OBJ_TIMER));
z_impl_k_timer_start(timer, duration, period);
}
#include <syscalls/k_timer_start_mrsh.c>
#endif
void z_impl_k_timer_stop(struct k_timer *timer)
{
SYS_PORT_TRACING_OBJ_FUNC(k_timer, stop, timer);
bool inactive = (z_abort_timeout(&timer->timeout) != 0);
if (inactive) {
return;
}
if (timer->stop_fn != NULL) {
timer->stop_fn(timer);
}
if (IS_ENABLED(CONFIG_MULTITHREADING)) {
struct k_thread *pending_thread = z_unpend1_no_timeout(&timer->wait_q);
if (pending_thread != NULL) {
z_ready_thread(pending_thread);
z_reschedule_unlocked();
}
}
}
#ifdef CONFIG_USERSPACE
static inline void z_vrfy_k_timer_stop(struct k_timer *timer)
{
K_OOPS(K_SYSCALL_OBJ(timer, K_OBJ_TIMER));
z_impl_k_timer_stop(timer);
}
#include <syscalls/k_timer_stop_mrsh.c>
#endif
uint32_t z_impl_k_timer_status_get(struct k_timer *timer)
{
k_spinlock_key_t key = k_spin_lock(&lock);
uint32_t result = timer->status;
timer->status = 0U;
k_spin_unlock(&lock, key);
return result;
}
#ifdef CONFIG_USERSPACE
static inline uint32_t z_vrfy_k_timer_status_get(struct k_timer *timer)
{
K_OOPS(K_SYSCALL_OBJ(timer, K_OBJ_TIMER));
return z_impl_k_timer_status_get(timer);
}
#include <syscalls/k_timer_status_get_mrsh.c>
#endif
uint32_t z_impl_k_timer_status_sync(struct k_timer *timer)
{
__ASSERT(!arch_is_in_isr(), "");
SYS_PORT_TRACING_OBJ_FUNC_ENTER(k_timer, status_sync, timer);
if (!IS_ENABLED(CONFIG_MULTITHREADING)) {
uint32_t result;
do {
k_spinlock_key_t key = k_spin_lock(&lock);
if (!z_is_inactive_timeout(&timer->timeout)) {
result = *(volatile uint32_t *)&timer->status;
timer->status = 0U;
k_spin_unlock(&lock, key);
if (result > 0) {
break;
}
} else {
result = timer->status;
k_spin_unlock(&lock, key);
break;
}
} while (true);
return result;
}
k_spinlock_key_t key = k_spin_lock(&lock);
uint32_t result = timer->status;
if (result == 0U) {
if (!z_is_inactive_timeout(&timer->timeout)) {
SYS_PORT_TRACING_OBJ_FUNC_BLOCKING(k_timer, status_sync, timer, K_FOREVER);
/* wait for timer to expire or stop */
(void)z_pend_curr(&lock, key, &timer->wait_q, K_FOREVER);
/* get updated timer status */
key = k_spin_lock(&lock);
result = timer->status;
} else {
/* timer is already stopped */
}
} else {
/* timer has already expired at least once */
}
timer->status = 0U;
k_spin_unlock(&lock, key);
/**
* @note New tracing hook
*/
SYS_PORT_TRACING_OBJ_FUNC_EXIT(k_timer, status_sync, timer, result);
return result;
}
#ifdef CONFIG_USERSPACE
static inline uint32_t z_vrfy_k_timer_status_sync(struct k_timer *timer)
{
K_OOPS(K_SYSCALL_OBJ(timer, K_OBJ_TIMER));
return z_impl_k_timer_status_sync(timer);
}
#include <syscalls/k_timer_status_sync_mrsh.c>
static inline k_ticks_t z_vrfy_k_timer_remaining_ticks(
const struct k_timer *timer)
{
K_OOPS(K_SYSCALL_OBJ(timer, K_OBJ_TIMER));
return z_impl_k_timer_remaining_ticks(timer);
}
#include <syscalls/k_timer_remaining_ticks_mrsh.c>
static inline k_ticks_t z_vrfy_k_timer_expires_ticks(
const struct k_timer *timer)
{
K_OOPS(K_SYSCALL_OBJ(timer, K_OBJ_TIMER));
return z_impl_k_timer_expires_ticks(timer);
}
#include <syscalls/k_timer_expires_ticks_mrsh.c>
static inline void *z_vrfy_k_timer_user_data_get(const struct k_timer *timer)
{
K_OOPS(K_SYSCALL_OBJ(timer, K_OBJ_TIMER));
return z_impl_k_timer_user_data_get(timer);
}
#include <syscalls/k_timer_user_data_get_mrsh.c>
static inline void z_vrfy_k_timer_user_data_set(struct k_timer *timer,
void *user_data)
{
K_OOPS(K_SYSCALL_OBJ(timer, K_OBJ_TIMER));
z_impl_k_timer_user_data_set(timer, user_data);
}
#include <syscalls/k_timer_user_data_set_mrsh.c>
#endif
#ifdef CONFIG_OBJ_CORE_TIMER
static int init_timer_obj_core_list(void)
{
/* Initialize timer object type */
z_obj_type_init(&obj_type_timer, K_OBJ_TYPE_TIMER_ID,
offsetof(struct k_timer, obj_core));
/* Initialize and link statically defined timers */
STRUCT_SECTION_FOREACH(k_timer, timer) {
k_obj_core_init_and_link(K_OBJ_CORE(timer), &obj_type_timer);
}
return 0;
}
SYS_INIT(init_timer_obj_core_list, PRE_KERNEL_1,
CONFIG_KERNEL_INIT_PRIORITY_OBJECTS);
#endif