[RFC] powerpc: add support for new hcall H_BEST_ENERGY

[Vaidyanathan Srinivasan]

* Dipankar Sarma <dipankar at in.ibm.com> [2010-03-06 00:48:11]:

> On Wed, Mar 03, 2010 at 11:48:22PM +0530, Vaidyanathan Srinivasan wrote:
> >  static void __init cpu_init_thread_core_maps(int tpc)
> > diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig
> > index c667f0f..b3dd108 100644
> > --- a/arch/powerpc/platforms/pseries/Kconfig
> > +++ b/arch/powerpc/platforms/pseries/Kconfig
> > @@ -33,6 +33,16 @@ config PSERIES_MSI
> >         depends on PCI_MSI && EEH
> >         default y
> > 
> > +config PSERIES_ENERGY
> > +	tristate "pseries energy management capabilities driver"
> > +	depends on PPC_PSERIES
> > +	default y
> > +	help
> > +	  Provides interface to platform energy management capabilities
> > +	  on supported PSERIES platforms.
> > +	  Provides: /sys/devices/system/cpu/pseries_(de)activation_hint_list
> > +	  and /sys/devices/system/cpu/cpuN/pseries_(de)activation_hint
> > +
> >  config SCANLOG
> >  	tristate "Scanlog dump interface"
> >  	depends on RTAS_PROC && PPC_PSERIES
> 
> .....
> 
> > +static int __init pseries_energy_init(void)
> > +{
> > +	int cpu, err;
> > +	struct sys_device *cpu_sys_dev;
> > +
> > +	/* Create the sysfs files */
> > +	err = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
> > +				&attr_cpu_activate_hint_list.attr);
> > +	if (!err)
> > +		err = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
> > +				&attr_cpu_deactivate_hint_list.attr);
> > +
> > +	for_each_possible_cpu(cpu) {
> > +		cpu_sys_dev = get_cpu_sysdev(cpu);
> > +		err = sysfs_create_file(&cpu_sys_dev->kobj,
> > +				&attr_percpu_activate_hint.attr);
> > +		if (err)
> > +			break;
> > +		err = sysfs_create_file(&cpu_sys_dev->kobj,
> > +				&attr_percpu_deactivate_hint.attr);
> > +		if (err)
> > +			break;
> > +	}
> > +	return err;
> > +
> > +}
> 
> Shouldn't we create this only for supported platforms ?

Hi Dipankar,

Yes we will need a check like
firmware_has_feature(FW_FEATURE_BEST_ENERGY) to avoid sysfs files in
unsupported platforms.  I will add that check in the next iteration.

Thanks,
Vaidy