Re: [PATCH v7 04/16] ACPI: processor: Move checks and availability of acpi_processor earlier

[Hanjun Guo]

On 2024/4/25 1:18, Jonathan Cameron wrote:
> On Tue, 23 Apr 2024 19:53:34 +0800
> Hanjun Guo <guohanjun@xxxxxxxxxx> wrote:
>
> > > @@ -232,6 +263,7 @@ static int acpi_processor_get_info(struct acpi_device *device)
> > >    	acpi_status status = AE_OK;
> > >    	static int cpu0_initialized;
> > >    	unsigned long long value;
> > > +	int ret;
> > >    
> > >    	acpi_processor_errata();
> > >    
> > > @@ -316,10 +348,12 @@ static int acpi_processor_get_info(struct acpi_device *device)
> > >    	 *  because cpuid <-> apicid mapping is persistent now.
> > >    	 */
> > >    	if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) {
> > > -		int ret = acpi_processor_hotadd_init(pr);
> > > +		ret = acpi_processor_hotadd_init(pr, device);
> > >    
> > >    		if (ret)
> > > -			return ret;
> > > +			goto err;
> > > +	} else {
> > > +		acpi_processor_set_per_cpu(pr, device);
> > >    	}
> > >    
> > >    	/*
> > > @@ -357,6 +391,10 @@ static int acpi_processor_get_info(struct acpi_device *device)
> > >    		arch_fix_phys_package_id(pr->id, value);
> > >    
> > >    	return 0;
> > > +
> > > +err:
> > > +	per_cpu(processors, pr->id) = NULL;
> >
> > ...
> >
> > > +	return ret;
> > >    }
> > >    
> > >    /*
> > > @@ -365,8 +403,6 @@ static int acpi_processor_get_info(struct acpi_device *device)
> > >     * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
> > >     * Such things have to be put in and set up by the processor driver's .probe().
> > >     */
> > > -static DEFINE_PER_CPU(void *, processor_device_array);
> > > -
> > >    static int acpi_processor_add(struct acpi_device *device,
> > >    					const struct acpi_device_id *id)
> > >    {
> > > @@ -395,28 +431,6 @@ static int acpi_processor_add(struct acpi_device *device,
> > >    	if (result) /* Processor is not physically present or unavailable */
> > >    		return 0;
> > >    
> > > -	BUG_ON(pr->id >= nr_cpu_ids);
> > > -
> > > -	/*
> > > -	 * Buggy BIOS check.
> > > -	 * ACPI id of processors can be reported wrongly by the BIOS.
> > > -	 * Don't trust it blindly
> > > -	 */
> > > -	if (per_cpu(processor_device_array, pr->id) != NULL &&
> > > -	    per_cpu(processor_device_array, pr->id) != device) {
> > > -		dev_warn(&device->dev,
> > > -			"BIOS reported wrong ACPI id %d for the processor\n",
> > > -			pr->id);
> > > -		/* Give up, but do not abort the namespace scan. */
> > > -		goto err;
> > > -	}
> > > -	/*
> > > -	 * processor_device_array is not cleared on errors to allow buggy BIOS
> > > -	 * checks.
> > > -	 */
> > > -	per_cpu(processor_device_array, pr->id) = device;
> > > -	per_cpu(processors, pr->id) = pr;
> >
> > Nit: seems we need to remove the duplicated
> > per_cpu(processors, pr->id) = NULL; in acpi_processor_add():
> >
> > --- a/drivers/acpi/acpi_processor.c
> > +++ b/drivers/acpi/acpi_processor.c
> > @@ -446,7 +446,6 @@ static int acpi_processor_add(struct acpi_device
> > *device,
> >     err:
> >           free_cpumask_var(pr->throttling.shared_cpu_map);
> >           device->driver_data = NULL;
> > -       per_cpu(processors, pr->id) = NULL;
>
> I don't follow.  This path is used if processor_get_info() succeeded and
> we later fail.  I don't see where the the duplication is?

It is! Thanks for the clarification.

Thanks
Hanjun