Does it make sense to put the Giant Lock in its own files?
On Wed, Feb 19, 2014 at 8:42 AM, Sebastian Huber
<sebastian.hu...@embedded-brains.de> wrote:
> ---
> cpukit/score/include/rtems/score/threaddispatch.h | 12 ++++++++++++
> cpukit/score/src/smp.c | 8 ++++++++
> cpukit/score/src/threaddispatchdisablelevel.c | 13 +++++++++++++
> 3 files changed, 33 insertions(+), 0 deletions(-)
>
> diff --git a/cpukit/score/include/rtems/score/threaddispatch.h
> b/cpukit/score/include/rtems/score/threaddispatch.h
> index 2211662..4c2ecb0 100644
> --- a/cpukit/score/include/rtems/score/threaddispatch.h
> +++ b/cpukit/score/include/rtems/score/threaddispatch.h
> @@ -109,6 +109,18 @@ RTEMS_INLINE_ROUTINE void
> _Thread_Dispatch_initialization( void )
> void _Giant_Release( void );
>
> /**
> + * @brief Releases the giant lock completely if held by the executing
> processor.
> + *
> + * The thread dispatch disable level is not altered by this function.
> + *
> + * The only use case for this operation is in
> + * _SMP_Request_processors_to_shutdown().
> + *
> + * @param[in] self_cpu The current processor index.
> + */
> + void _Giant_Drop( uint32_t self_cpu );
> +
> + /**
> * @brief Sets thread dispatch level to the value passed in.
> *
> * This routine sets thread dispatch level to the
> diff --git a/cpukit/score/src/smp.c b/cpukit/score/src/smp.c
> index 445a56a..41787e3 100644
> --- a/cpukit/score/src/smp.c
> +++ b/cpukit/score/src/smp.c
> @@ -115,6 +115,14 @@ void _SMP_Request_processors_to_shutdown( void )
> _Per_CPU_Change_state( per_cpu, PER_CPU_STATE_SHUTDOWN );
> }
> }
> +
> + /*
> + * We have to drop the Giant lock here in order to give other processors
> the
> + * opportunity to receive the inter-processor interrupts issued previously.
> + * In case the executing thread still holds SMP locks, then other
> processors
> + * already waiting for this SMP lock will spin forever.
> + */
> + _Giant_Drop( self );
> }
>
> void _SMP_Send_message( uint32_t cpu, uint32_t message )
> diff --git a/cpukit/score/src/threaddispatchdisablelevel.c
> b/cpukit/score/src/threaddispatchdisablelevel.c
> index a3dec99..ec5ac81 100644
> --- a/cpukit/score/src/threaddispatchdisablelevel.c
> +++ b/cpukit/score/src/threaddispatchdisablelevel.c
> @@ -57,6 +57,19 @@ static void _Giant_Do_release( void )
> }
> }
>
> +void _Giant_Drop( uint32_t self_cpu )
> +{
> + Giant_Control *giant = &_Giant;
> +
> + _Assert( _ISR_Get_level() != 0 );
> +
> + if ( giant->owner_cpu == self_cpu ) {
> + giant->nest_level = 0;
> + giant->owner_cpu = NO_OWNER_CPU;
> + _SMP_lock_Release( &giant->lock );
> + }
> +}
> +
> uint32_t _Thread_Dispatch_increment_disable_level( void )
> {
> ISR_Level isr_level;
> --
> 1.7.7
>
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