blob: d930d1679f58a2817aeb56ff567956dffc45f2ee [file] [log] [blame]
/*
* Copyright (c) 2010-2014 Wind River Systems, Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @brief Kernel thread support
*
* This module provides general purpose thread support.
*/
#include <kernel.h>
#include <toolchain.h>
#include <linker/sections.h>
#include <kernel_structs.h>
#include <misc/printk.h>
#include <sys_clock.h>
#include <drivers/system_timer.h>
#include <ksched.h>
#include <wait_q.h>
#include <atomic.h>
#include <syscall_handler.h>
extern struct _static_thread_data _static_thread_data_list_start[];
extern struct _static_thread_data _static_thread_data_list_end[];
#ifdef CONFIG_USERSPACE
/* Each thread gets assigned an index into a permission bitfield */
static atomic_t thread_index;
static unsigned int thread_index_get(void)
{
unsigned int retval;
retval = (int)atomic_inc(&thread_index);
__ASSERT(retval < 8 * CONFIG_MAX_THREAD_BYTES,
"too many threads created, increase CONFIG_MAX_THREAD_BYTES");
return retval;
}
#endif
#define _FOREACH_STATIC_THREAD(thread_data) \
for (struct _static_thread_data *thread_data = \
_static_thread_data_list_start; \
thread_data < _static_thread_data_list_end; \
thread_data++)
int k_is_in_isr(void)
{
return _is_in_isr();
}
/*
* This function tags the current thread as essential to system operation.
* Exceptions raised by this thread will be treated as a fatal system error.
*/
void _thread_essential_set(void)
{
_current->base.user_options |= K_ESSENTIAL;
}
/*
* This function tags the current thread as not essential to system operation.
* Exceptions raised by this thread may be recoverable.
* (This is the default tag for a thread.)
*/
void _thread_essential_clear(void)
{
_current->base.user_options &= ~K_ESSENTIAL;
}
/*
* This routine indicates if the current thread is an essential system thread.
*
* Returns non-zero if current thread is essential, zero if it is not.
*/
int _is_thread_essential(void)
{
return _current->base.user_options & K_ESSENTIAL;
}
void k_busy_wait(u32_t usec_to_wait)
{
#if defined(CONFIG_TICKLESS_KERNEL) && \
!defined(CONFIG_BUSY_WAIT_USES_ALTERNATE_CLOCK)
int saved_always_on = k_enable_sys_clock_always_on();
#endif
/* use 64-bit math to prevent overflow when multiplying */
u32_t cycles_to_wait = (u32_t)(
(u64_t)usec_to_wait *
(u64_t)sys_clock_hw_cycles_per_sec /
(u64_t)USEC_PER_SEC
);
u32_t start_cycles = k_cycle_get_32();
for (;;) {
u32_t current_cycles = k_cycle_get_32();
/* this handles the rollover on an unsigned 32-bit value */
if ((current_cycles - start_cycles) >= cycles_to_wait) {
break;
}
}
#if defined(CONFIG_TICKLESS_KERNEL) && \
!defined(CONFIG_BUSY_WAIT_USES_ALTERNATE_CLOCK)
_sys_clock_always_on = saved_always_on;
#endif
}
#ifdef CONFIG_THREAD_CUSTOM_DATA
void _impl_k_thread_custom_data_set(void *value)
{
_current->custom_data = value;
}
#ifdef CONFIG_USERSPACE
_SYSCALL_HANDLER1(k_thread_custom_data_set, data)
{
_impl_k_thread_custom_data_set((void *)data);
return 0;
}
#endif
void *_impl_k_thread_custom_data_get(void)
{
return _current->custom_data;
}
#ifdef CONFIG_USERSPACE
_SYSCALL_HANDLER0_SIMPLE(k_thread_custom_data_get);
#endif /* CONFIG_USERSPACE */
#endif /* CONFIG_THREAD_CUSTOM_DATA */
#if defined(CONFIG_THREAD_MONITOR)
/*
* Remove a thread from the kernel's list of active threads.
*/
void _thread_monitor_exit(struct k_thread *thread)
{
unsigned int key = irq_lock();
if (thread == _kernel.threads) {
_kernel.threads = _kernel.threads->next_thread;
} else {
struct k_thread *prev_thread;
prev_thread = _kernel.threads;
while (thread != prev_thread->next_thread) {
prev_thread = prev_thread->next_thread;
}
prev_thread->next_thread = thread->next_thread;
}
irq_unlock(key);
}
#endif /* CONFIG_THREAD_MONITOR */
#ifdef CONFIG_STACK_SENTINEL
/* Check that the stack sentinel is still present
*
* The stack sentinel feature writes a magic value to the lowest 4 bytes of
* the thread's stack when the thread is initialized. This value gets checked
* in a few places:
*
* 1) In k_yield() if the current thread is not swapped out
* 2) After servicing a non-nested interrupt
* 3) In _Swap(), check the sentinel in the outgoing thread
*
* Item 2 requires support in arch/ code.
*
* If the check fails, the thread will be terminated appropriately through
* the system fatal error handler.
*/
void _check_stack_sentinel(void)
{
u32_t *stack;
if (_current->base.thread_state == _THREAD_DUMMY) {
return;
}
stack = (u32_t *)_current->stack_info.start;
if (*stack != STACK_SENTINEL) {
/* Restore it so further checks don't trigger this same error */
*stack = STACK_SENTINEL;
_k_except_reason(_NANO_ERR_STACK_CHK_FAIL);
}
}
#endif
/*
* Common thread entry point function (used by all threads)
*
* This routine invokes the actual thread entry point function and passes
* it three arguments. It also handles graceful termination of the thread
* if the entry point function ever returns.
*
* This routine does not return, and is marked as such so the compiler won't
* generate preamble code that is only used by functions that actually return.
*/
FUNC_NORETURN void _thread_entry(k_thread_entry_t entry,
void *p1, void *p2, void *p3)
{
entry(p1, p2, p3);
#ifdef CONFIG_MULTITHREADING
k_thread_abort(k_current_get());
#else
for (;;) {
k_cpu_idle();
}
#endif
/*
* Compiler can't tell that k_thread_abort() won't return and issues a
* warning unless we tell it that control never gets this far.
*/
CODE_UNREACHABLE;
}
#ifdef CONFIG_MULTITHREADING
void _impl_k_thread_start(struct k_thread *thread)
{
int key = irq_lock(); /* protect kernel queues */
if (_has_thread_started(thread)) {
irq_unlock(key);
return;
}
_mark_thread_as_started(thread);
if (_is_thread_ready(thread)) {
_add_thread_to_ready_q(thread);
if (_must_switch_threads()) {
_Swap(key);
return;
}
}
irq_unlock(key);
}
#ifdef CONFIG_USERSPACE
_SYSCALL_HANDLER1_SIMPLE_VOID(k_thread_start, K_OBJ_THREAD, struct k_thread *);
#endif
#endif
#ifdef CONFIG_MULTITHREADING
static void schedule_new_thread(struct k_thread *thread, s32_t delay)
{
#ifdef CONFIG_SYS_CLOCK_EXISTS
if (delay == 0) {
k_thread_start(thread);
} else {
s32_t ticks = _TICK_ALIGN + _ms_to_ticks(delay);
int key = irq_lock();
_add_thread_timeout(thread, NULL, ticks);
irq_unlock(key);
}
#else
ARG_UNUSED(delay);
k_thread_start(thread);
#endif
}
#endif
void _setup_new_thread(struct k_thread *new_thread,
k_thread_stack_t stack, size_t stack_size,
k_thread_entry_t entry,
void *p1, void *p2, void *p3,
int prio, u32_t options)
{
_new_thread(new_thread, stack, stack_size, entry, p1, p2, p3,
prio, options);
#ifdef CONFIG_USERSPACE
new_thread->base.perm_index = thread_index_get();
_k_object_init(new_thread);
/* Any given thread has access to itself */
k_object_access_grant(new_thread, new_thread);
#endif
}
#ifdef CONFIG_MULTITHREADING
k_tid_t k_thread_create(struct k_thread *new_thread,
k_thread_stack_t stack,
size_t stack_size, k_thread_entry_t entry,
void *p1, void *p2, void *p3,
int prio, u32_t options, s32_t delay)
{
__ASSERT(!_is_in_isr(), "Threads may not be created in ISRs");
_setup_new_thread(new_thread, stack, stack_size, entry, p1, p2, p3,
prio, options);
if (delay != K_FOREVER) {
schedule_new_thread(new_thread, delay);
}
return new_thread;
}
#endif
int _impl_k_thread_cancel(k_tid_t tid)
{
struct k_thread *thread = tid;
int key = irq_lock();
if (_has_thread_started(thread) ||
!_is_thread_timeout_active(thread)) {
irq_unlock(key);
return -EINVAL;
}
_abort_thread_timeout(thread);
_thread_monitor_exit(thread);
irq_unlock(key);
return 0;
}
#ifdef CONFIG_USERSPACE
_SYSCALL_HANDLER1_SIMPLE(k_thread_cancel, K_OBJ_THREAD, struct k_thread *);
#endif
static inline int is_in_any_group(struct _static_thread_data *thread_data,
u32_t groups)
{
return !!(thread_data->init_groups & groups);
}
void _k_thread_group_op(u32_t groups, void (*func)(struct k_thread *))
{
unsigned int key;
__ASSERT(!_is_in_isr(), "");
_sched_lock();
/* Invoke func() on each static thread in the specified group set. */
_FOREACH_STATIC_THREAD(thread_data) {
if (is_in_any_group(thread_data, groups)) {
key = irq_lock();
func(thread_data->init_thread);
irq_unlock(key);
}
}
/*
* If the current thread is still in a ready state, then let the
* "unlock scheduler" code determine if any rescheduling is needed.
*/
if (_is_thread_ready(_current)) {
k_sched_unlock();
return;
}
/* The current thread is no longer in a ready state--reschedule. */
key = irq_lock();
_sched_unlock_no_reschedule();
_Swap(key);
}
void _k_thread_single_start(struct k_thread *thread)
{
_mark_thread_as_started(thread);
if (_is_thread_ready(thread)) {
_add_thread_to_ready_q(thread);
}
}
void _k_thread_single_suspend(struct k_thread *thread)
{
if (_is_thread_ready(thread)) {
_remove_thread_from_ready_q(thread);
}
_mark_thread_as_suspended(thread);
}
void _impl_k_thread_suspend(struct k_thread *thread)
{
unsigned int key = irq_lock();
_k_thread_single_suspend(thread);
if (thread == _current) {
_Swap(key);
} else {
irq_unlock(key);
}
}
#ifdef CONFIG_USERSPACE
_SYSCALL_HANDLER1_SIMPLE_VOID(k_thread_suspend, K_OBJ_THREAD, k_tid_t);
#endif
void _k_thread_single_resume(struct k_thread *thread)
{
_mark_thread_as_not_suspended(thread);
if (_is_thread_ready(thread)) {
_add_thread_to_ready_q(thread);
}
}
void _impl_k_thread_resume(struct k_thread *thread)
{
unsigned int key = irq_lock();
_k_thread_single_resume(thread);
_reschedule_threads(key);
}
#ifdef CONFIG_USERSPACE
_SYSCALL_HANDLER1_SIMPLE_VOID(k_thread_resume, K_OBJ_THREAD, k_tid_t);
#endif
void _k_thread_single_abort(struct k_thread *thread)
{
if (thread->fn_abort != NULL) {
thread->fn_abort();
}
if (_is_thread_ready(thread)) {
_remove_thread_from_ready_q(thread);
} else {
if (_is_thread_pending(thread)) {
_unpend_thread(thread);
}
if (_is_thread_timeout_active(thread)) {
_abort_thread_timeout(thread);
}
}
_mark_thread_as_dead(thread);
}
#ifdef CONFIG_MULTITHREADING
void _init_static_threads(void)
{
unsigned int key;
_FOREACH_STATIC_THREAD(thread_data) {
_setup_new_thread(
thread_data->init_thread,
thread_data->init_stack,
thread_data->init_stack_size,
thread_data->init_entry,
thread_data->init_p1,
thread_data->init_p2,
thread_data->init_p3,
thread_data->init_prio,
thread_data->init_options);
thread_data->init_thread->init_data = thread_data;
}
_sched_lock();
/*
* Non-legacy static threads may be started immediately or after a
* previously specified delay. Even though the scheduler is locked,
* ticks can still be delivered and processed. Lock interrupts so
* that the countdown until execution begins from the same tick.
*
* Note that static threads defined using the legacy API have a
* delay of K_FOREVER.
*/
key = irq_lock();
_FOREACH_STATIC_THREAD(thread_data) {
if (thread_data->init_delay != K_FOREVER) {
schedule_new_thread(thread_data->init_thread,
thread_data->init_delay);
}
}
irq_unlock(key);
k_sched_unlock();
}
#endif
void _init_thread_base(struct _thread_base *thread_base, int priority,
u32_t initial_state, unsigned int options)
{
/* k_q_node is initialized upon first insertion in a list */
thread_base->user_options = (u8_t)options;
thread_base->thread_state = (u8_t)initial_state;
thread_base->prio = priority;
thread_base->sched_locked = 0;
/* swap_data does not need to be initialized */
_init_thread_timeout(thread_base);
}
u32_t _k_thread_group_mask_get(struct k_thread *thread)
{
struct _static_thread_data *thread_data = thread->init_data;
return thread_data->init_groups;
}
void _k_thread_group_join(u32_t groups, struct k_thread *thread)
{
struct _static_thread_data *thread_data = thread->init_data;
thread_data->init_groups |= groups;
}
void _k_thread_group_leave(u32_t groups, struct k_thread *thread)
{
struct _static_thread_data *thread_data = thread->init_data;
thread_data->init_groups &= groups;
}
FUNC_NORETURN void k_thread_user_mode_enter(k_thread_entry_t entry,
void *p1, void *p2, void *p3)
{
_current->base.user_options |= K_USER;
_thread_essential_clear();
#ifdef CONFIG_USERSPACE
_arch_user_mode_enter(entry, p1, p2, p3);
#else
/* XXX In this case we do not reset the stack */
_thread_entry(entry, p1, p2, p3);
#endif
}