/*
* Copyright (c) 2014, 2016 embedded brains GmbH. All rights reserved.
*
* embedded brains GmbH
* Dornierstr. 4
* 82178 Puchheim
* Germany
* <rtems@embedded-brains.de>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#ifndef _RTEMS_SCORE_MRSPIMPL_H
#define _RTEMS_SCORE_MRSPIMPL_H
#include <rtems/score/mrsp.h>
#if defined(RTEMS_SMP)
#include <rtems/score/assert.h>
#include <rtems/score/chainimpl.h>
#include <rtems/score/resourceimpl.h>
#include <rtems/score/schedulerimpl.h>
#include <rtems/score/status.h>
#include <rtems/score/threadqimpl.h>
#include <rtems/score/watchdogimpl.h>
#include <rtems/score/wkspace.h>
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/**
* @addtogroup ScoreMRSP
*
* @{
*/
/**
* @brief Internal state used for MRSP_Rival::status to indicate that this
* rival waits for resource ownership.
*/
#define MRSP_WAIT_FOR_OWNERSHIP STATUS_MINUS_ONE
/*
* FIXME: Operations with the resource dependency tree are protected by the
* global scheduler lock. Since the scheduler lock should be scheduler
* instance specific in the future this will only work temporarily. A more
* sophisticated locking strategy is necessary.
*/
RTEMS_INLINE_ROUTINE void _MRSP_Giant_acquire( ISR_lock_Context *lock_context )
{
_ISR_lock_Acquire( &_Scheduler_Lock, lock_context );
}
RTEMS_INLINE_ROUTINE void _MRSP_Giant_release( ISR_lock_Context *lock_context )
{
_ISR_lock_Release( &_Scheduler_Lock, lock_context );
}
RTEMS_INLINE_ROUTINE void _MRSP_Acquire_critical(
MRSP_Control *mrsp,
Thread_queue_Context *queue_context
)
{
_Thread_queue_Acquire_critical( &mrsp->Wait_queue, queue_context );
}
RTEMS_INLINE_ROUTINE void _MRSP_Release(
MRSP_Control *mrsp,
Thread_queue_Context *queue_context
)
{
_Thread_queue_Release( &mrsp->Wait_queue, queue_context );
}
RTEMS_INLINE_ROUTINE Priority_Control _MRSP_Get_priority(
const MRSP_Control *mrsp,
const Scheduler_Control *scheduler
)
{
uint32_t scheduler_index;
scheduler_index = _Scheduler_Get_index( scheduler );
return mrsp->ceiling_priorities[ scheduler_index ];
}
RTEMS_INLINE_ROUTINE void _MRSP_Set_priority(
MRSP_Control *mrsp,
const Scheduler_Control *scheduler,
Priority_Control new_priority
)
{
uint32_t scheduler_index;
scheduler_index = _Scheduler_Get_index( scheduler );
mrsp->ceiling_priorities[ scheduler_index ] = new_priority;
}
RTEMS_INLINE_ROUTINE Status_Control _MRSP_Raise_priority(
MRSP_Control *mrsp,
Thread_Control *thread,
Priority_Node *priority_node,
Thread_queue_Context *queue_context
)
{
Status_Control status;
ISR_lock_Context lock_context;
const Scheduler_Control *scheduler;
Priority_Control ceiling_priority;
Scheduler_Node *own_node;
_Thread_queue_Context_clear_priority_updates( queue_context );
_Thread_Wait_acquire_default_critical( thread, &lock_context );
scheduler = _Scheduler_Get_own( thread );
own_node = _Thread_Scheduler_get_own_node( thread );
ceiling_priority = _MRSP_Get_priority( mrsp, scheduler );
if ( ceiling_priority <= own_node->Wait.Priority.Node.priority ) {
_Priority_Node_initialize( priority_node, ceiling_priority );
_Thread_Priority_add( thread, priority_node, queue_context );
status = STATUS_SUCCESSFUL;
} else {
status = STATUS_MUTEX_CEILING_VIOLATED;
}
_Thread_Wait_release_default_critical( thread, &lock_context );
return status;
}
RTEMS_INLINE_ROUTINE void _MRSP_Remove_priority(
Thread_Control *thread,
Priority_Node *priority_node,
Thread_queue_Context *queue_context
)
{
ISR_lock_Context lock_context;
_Thread_queue_Context_clear_priority_updates( queue_context );
_Thread_Wait_acquire_default_critical( thread, &lock_context );
_Thread_Priority_remove( thread, priority_node, queue_context );
_Thread_Wait_release_default_critical( thread, &lock_context );
}
RTEMS_INLINE_ROUTINE void _MRSP_Replace_priority(
MRSP_Control *mrsp,
Thread_Control *thread,
MRSP_Rival *rival
)
{
ISR_lock_Context lock_context;
_Thread_Wait_acquire_default_critical( thread, &lock_context );
_Thread_Priority_replace(
thread,
&rival->Ceiling_priority,
&mrsp->Ceiling_priority
);
_Thread_Wait_release_default_critical( thread, &lock_context );
}
RTEMS_INLINE_ROUTINE Status_Control _MRSP_Claim_ownership(
MRSP_Control *mrsp,
Thread_Control *new_owner,
Thread_queue_Context *queue_context
)
{
Status_Control status;
Per_CPU_Control *cpu_self;
status = _MRSP_Raise_priority(
mrsp,
new_owner,
&mrsp->Ceiling_priority,
queue_context
);
if ( status != STATUS_SUCCESSFUL ) {
_MRSP_Release( mrsp, queue_context );
return status;
}
_Resource_Node_add_resource( &new_owner->Resource_node, &mrsp->Resource );
_Resource_Set_owner( &mrsp->Resource, &new_owner->Resource_node );
_Scheduler_Thread_change_help_state( new_owner, SCHEDULER_HELP_ACTIVE_OWNER );
cpu_self = _Thread_Dispatch_disable_critical(
&queue_context->Lock_context.Lock_context
);
_MRSP_Release( mrsp, queue_context );
_Thread_Priority_update( queue_context );
_Thread_Dispatch_enable( cpu_self );
return STATUS_SUCCESSFUL;
}
RTEMS_INLINE_ROUTINE Status_Control _MRSP_Initialize(
MRSP_Control *mrsp,
const Scheduler_Control *scheduler,
Priority_Control ceiling_priority,
Thread_Control *executing,
bool initially_locked
)
{
uint32_t scheduler_count = _Scheduler_Count;
uint32_t i;
if ( initially_locked ) {
return STATUS_INVALID_NUMBER;
}
mrsp->ceiling_priorities = _Workspace_Allocate(
sizeof( *mrsp->ceiling_priorities ) * scheduler_count
);
if ( mrsp->ceiling_priorities == NULL ) {
return STATUS_NO_MEMORY;
}
for ( i = 0 ; i < scheduler_count ; ++i ) {
const Scheduler_Control *scheduler_of_cpu;
scheduler_of_cpu = _Scheduler_Get_by_CPU_index( i );
if ( scheduler != scheduler_of_cpu ) {
mrsp->ceiling_priorities[ i ] =
_Scheduler_Map_priority( scheduler_of_cpu, 0 );
} else {
mrsp->ceiling_priorities[ i ] = ceiling_priority;
}
}
_Resource_Initialize( &mrsp->Resource );
_Chain_Initialize_empty( &mrsp->Rivals );
_Thread_queue_Initialize( &mrsp->Wait_queue );
return STATUS_SUCCESSFUL;
}
RTEMS_INLINE_ROUTINE void _MRSP_Timeout( Watchdog_Control *watchdog )
{
MRSP_Rival *rival;
MRSP_Control *mrsp;
Thread_Control *thread;
Thread_queue_Context queue_context;
rival = RTEMS_CONTAINER_OF( watchdog, MRSP_Rival, Watchdog );
mrsp = rival->resource;
thread = rival->thread;
_Thread_queue_Context_initialize( &queue_context );
_ISR_lock_ISR_disable( &queue_context.Lock_context.Lock_context );
_MRSP_Acquire_critical( mrsp, &queue_context );
if ( rival->status == MRSP_WAIT_FOR_OWNERSHIP ) {
ISR_lock_Context giant_lock_context;
_MRSP_Remove_priority( thread, &rival->Ceiling_priority, &queue_context );
_MRSP_Giant_acquire( &giant_lock_context );
_Chain_Extract_unprotected( &rival->Node );
_Resource_Node_extract( &thread->Resource_node );
_Resource_Node_set_dependency( &thread->Resource_node, NULL );
_Scheduler_Thread_change_help_state( thread, rival->initial_help_state );
_Scheduler_Thread_change_resource_root( thread, thread );
_MRSP_Giant_release( &giant_lock_context );
rival->status = STATUS_TIMEOUT;
_MRSP_Release( mrsp, &queue_context );
_Thread_Priority_update( &queue_context );
} else {
_MRSP_Release( mrsp, &queue_context );
}
}
RTEMS_INLINE_ROUTINE Status_Control _MRSP_Wait_for_ownership(
MRSP_Control *mrsp,
Resource_Node *owner,
Thread_Control *executing,
Thread_queue_Context *queue_context
)
{
Status_Control status;
MRSP_Rival rival;
Thread_Life_state life_state;
Per_CPU_Control *cpu_self;
ISR_lock_Context giant_lock_context;
ISR_Level level;
Watchdog_Interval timeout;
_Assert( queue_context->timeout_discipline == WATCHDOG_RELATIVE );
status = _MRSP_Raise_priority(
mrsp,
executing,
&rival.Ceiling_priority,
queue_context
);
if ( status != STATUS_SUCCESSFUL ) {
_MRSP_Release( mrsp, queue_context );
return status;
}
rival.thread = executing;
rival.resource = mrsp;
_Chain_Initialize_node( &rival.Node );
_MRSP_Giant_acquire( &giant_lock_context );
rival.initial_help_state =
_Scheduler_Thread_change_help_state( executing, SCHEDULER_HELP_ACTIVE_RIVAL );
rival.status = MRSP_WAIT_FOR_OWNERSHIP;
_Chain_Initialize_node( &rival.Node );
_Chain_Append_unprotected( &mrsp->Rivals, &rival.Node );
_Resource_Add_rival( &mrsp->Resource, &executing->Resource_node );
_Resource_Node_set_dependency( &executing->Resource_node, &mrsp->Resource );
_Scheduler_Thread_change_resource_root(
executing,
THREAD_RESOURCE_NODE_TO_THREAD( _Resource_Node_get_root( owner ) )
);
_MRSP_Giant_release( &giant_lock_context );
cpu_self = _Thread_Dispatch_disable_critical(
&queue_context->Lock_context.Lock_context
);
_MRSP_Release( mrsp, queue_context );
_Thread_Priority_update( queue_context );
timeout = (Watchdog_Interval) queue_context->timeout;
if ( timeout > 0 ) {
_Watchdog_Preinitialize( &rival.Watchdog, cpu_self );
_Watchdog_Initialize( &rival.Watchdog, _MRSP_Timeout );
_ISR_Local_disable( level );
_Watchdog_Per_CPU_insert_relative( &rival.Watchdog, cpu_self, timeout );
_ISR_Local_enable( level );
}
life_state = _Thread_Set_life_protection( THREAD_LIFE_PROTECTED );
_Thread_Dispatch_enable( cpu_self );
_Assert( _Debug_Is_thread_dispatching_allowed() );
/* Wait for state change */
do {
status = rival.status;
} while ( status == MRSP_WAIT_FOR_OWNERSHIP );
_Thread_Set_life_protection( life_state );
if ( timeout > 0 ) {
_ISR_Local_disable( level );
_Watchdog_Per_CPU_remove(
&rival.Watchdog,
cpu_self,
&cpu_self->Watchdog.Header[ PER_CPU_WATCHDOG_RELATIVE ]
);
_ISR_Local_enable( level );
}
return status;
}
RTEMS_INLINE_ROUTINE Status_Control _MRSP_Seize(
MRSP_Control *mrsp,
Thread_Control *executing,
bool wait,
Thread_queue_Context *queue_context
)
{
Status_Control status;
Resource_Node *owner;
_MRSP_Acquire_critical( mrsp, queue_context );
owner = _Resource_Get_owner( &mrsp->Resource );
if ( owner == NULL ) {
status = _MRSP_Claim_ownership( mrsp, executing, queue_context );
} else if (
wait
&& _Resource_Node_get_root( owner ) != &executing->Resource_node
) {
status = _MRSP_Wait_for_ownership( mrsp, owner, executing, queue_context );
} else {
_MRSP_Release( mrsp, queue_context );
/* Not available, nested access or deadlock */
status = STATUS_UNAVAILABLE;
}
return status;
}
RTEMS_INLINE_ROUTINE Status_Control _MRSP_Surrender(
MRSP_Control *mrsp,
Thread_Control *executing,
Thread_queue_Context *queue_context
)
{
ISR_lock_Context giant_lock_context;
Per_CPU_Control *cpu_self;
if ( _Resource_Get_owner( &mrsp->Resource ) != &executing->Resource_node ) {
_ISR_lock_ISR_enable( &queue_context->Lock_context.Lock_context );
return STATUS_NOT_OWNER;
}
if (
!_Resource_Is_most_recently_obtained(
&mrsp->Resource,
&executing->Resource_node
)
) {
_ISR_lock_ISR_enable( &queue_context->Lock_context.Lock_context );
return STATUS_RELEASE_ORDER_VIOLATION;
}
_MRSP_Acquire_critical( mrsp, queue_context );
_MRSP_Remove_priority( executing, &mrsp->Ceiling_priority, queue_context );
_MRSP_Giant_acquire( &giant_lock_context );
_Resource_Extract( &mrsp->Resource );
if ( _Chain_Is_empty( &mrsp->Rivals ) ) {
_Resource_Set_owner( &mrsp->Resource, NULL );
} else {
MRSP_Rival *rival;
Thread_Control *new_owner;
rival = (MRSP_Rival *) _Chain_Get_first_unprotected( &mrsp->Rivals );
/*
* This must be inside the critical section since the status prevents a
* potential double extraction in _MRSP_Timeout().
*/
rival->status = STATUS_SUCCESSFUL;
new_owner = rival->thread;
_MRSP_Replace_priority( mrsp, new_owner, rival );
_Resource_Node_extract( &new_owner->Resource_node );
_Resource_Node_set_dependency( &new_owner->Resource_node, NULL );
_Resource_Node_add_resource( &new_owner->Resource_node, &mrsp->Resource );
_Resource_Set_owner( &mrsp->Resource, &new_owner->Resource_node );
_Scheduler_Thread_change_help_state( new_owner, SCHEDULER_HELP_ACTIVE_OWNER );
_Scheduler_Thread_change_resource_root( new_owner, new_owner );
}
if ( !_Resource_Node_owns_resources( &executing->Resource_node ) ) {
_Scheduler_Thread_change_help_state( executing, SCHEDULER_HELP_YOURSELF );
}
_MRSP_Giant_release( &giant_lock_context );
cpu_self = _Thread_Dispatch_disable_critical(
&queue_context->Lock_context.Lock_context
);
_MRSP_Release( mrsp, queue_context );
_Thread_Priority_update( queue_context );
_Thread_Dispatch_enable( cpu_self );
return STATUS_SUCCESSFUL;
}
RTEMS_INLINE_ROUTINE Status_Control _MRSP_Can_destroy( MRSP_Control *mrsp )
{
if ( _Resource_Get_owner( &mrsp->Resource ) != NULL ) {
return STATUS_RESOURCE_IN_USE;
}
return STATUS_SUCCESSFUL;
}
RTEMS_INLINE_ROUTINE void _MRSP_Destroy(
MRSP_Control *mrsp,
Thread_queue_Context *queue_context
)
{
_MRSP_Release( mrsp, queue_context );
_Thread_queue_Destroy( &mrsp->Wait_queue );
_Workspace_Free( mrsp->ceiling_priorities );
}
/** @} */
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* RTEMS_SMP */
#endif /* _RTEMS_SCORE_MRSPIMPL_H */