On Tue, Apr 22, 2014 at 10:16 AM, Gedare Bloom <ged...@rtems.org> wrote:
> What is the need/use for this optimization?
>
Rather, will it be useful anywhere other than SPARC which has so many
extra registers?
> On Tue, Apr 22, 2014 at 4:46 AM, Sebastian Huber
> <sebastian.hu...@embedded-brains.de> wrote:
>> Add optional method _CPU_Get_current_per_CPU_control() to obtain the
>> per-CPU control of the current processor.
>>
>> This is optional. Not every CPU port needs this. It is only an
>> optional optimization variant. In case this macro is undefined, the
>> default implementation using the current processor index will be used.
>> ---
>> cpukit/score/cpu/no_cpu/rtems/score/cpu.h | 18 ++++++++++++++++++
>> cpukit/score/include/rtems/score/percpu.h | 10 +++++++---
>> 2 files changed, 25 insertions(+), 3 deletions(-)
>>
>> diff --git a/cpukit/score/cpu/no_cpu/rtems/score/cpu.h
>> b/cpukit/score/cpu/no_cpu/rtems/score/cpu.h
>> index 5241b5b..959fb58 100644
>> --- a/cpukit/score/cpu/no_cpu/rtems/score/cpu.h
>> +++ b/cpukit/score/cpu/no_cpu/rtems/score/cpu.h
>> @@ -1462,6 +1462,24 @@ CPU_Counter_ticks _CPU_Counter_difference(
>> CPU_Counter_ticks first
>> );
>>
>> +/**
>> + * @brief Special register pointing to the per-CPU control of the current
>> + * processor.
>> + *
>> + * This is optional. Not every CPU port needs this. It is only an optional
>> + * optimization variant.
>> + */
>> +register struct Per_CPU_Control *_CPU_Per_CPU_current asm( "rX" );
>> +
>> +/**
>> + * @brief Optional method to obtain the per-CPU control of the current
>> processor.
>> + *
>> + * This is optional. Not every CPU port needs this. It is only an optional
>> + * optimization variant. In case this macro is undefined, the default
>> + * implementation using the current processor index will be used.
>> + */
>> +#define _CPU_Get_current_per_CPU_control() ( _CPU_Per_CPU_current )
>> +
>> #ifdef RTEMS_SMP
>> /**
>> * @brief Performs CPU specific SMP initialization in the context of the
>> boot
>> diff --git a/cpukit/score/include/rtems/score/percpu.h
>> b/cpukit/score/include/rtems/score/percpu.h
>> index afc3803..a1b0a38 100644
>> --- a/cpukit/score/include/rtems/score/percpu.h
>> +++ b/cpukit/score/include/rtems/score/percpu.h
>> @@ -235,7 +235,7 @@ typedef struct {
>> *
>> * This structure is used to hold per core state information.
>> */
>> -typedef struct {
>> +typedef struct Per_CPU_Control {
>> /**
>> * @brief CPU port specific control.
>> */
>> @@ -437,8 +437,12 @@ extern Per_CPU_Control_envelope _Per_CPU_Information[]
>> CPU_STRUCTURE_ALIGNMENT;
>> * we can use _Per_CPU_Get_snapshot()). All other places must use
>> * _Per_CPU_Get() so that we can add checks for RTEMS_DEBUG.
>> */
>> -#define _Per_CPU_Get_snapshot() \
>> - ( &_Per_CPU_Information[ _SMP_Get_current_processor() ].per_cpu )
>> +#if defined( _CPU_Get_current_per_CPU_control )
>> + #define _Per_CPU_Get_snapshot() _CPU_Get_current_per_CPU_control()
>> +#else
>> + #define _Per_CPU_Get_snapshot() \
>> + ( &_Per_CPU_Information[ _SMP_Get_current_processor() ].per_cpu )
>> +#endif
>>
>> #if defined( RTEMS_SMP )
>> static inline Per_CPU_Control *_Per_CPU_Get( void )
>> --
>> 1.7.7
>>
>> _______________________________________________
>> rtems-devel mailing list
>> rtems-devel@rtems.org
>> http://www.rtems.org/mailman/listinfo/rtems-devel
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