Re: [PATCH v2 2/3] ACPI / PPTT: fix build when CONFIG_ACPI_PPTT is not enabled

[Sudeep Holla <sudeep.holla@arm.com>]

On 05/06/18 16:00, Rafael J. Wysocki wrote:
> On Tue, Jun 5, 2018 at 4:35 PM, Sudeep Holla <sudeep.holla@arm.com> wrote:
>> Though CONFIG_ACPI_PPTT is selected by platforms and nor user visible,
>> it may be useful to support the build with CONFIG_ACPI_PPTT disabled.
>>
>> This patch adds the missing dummy/boiler plate implementation to fix
>> the build.
>>
>> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
>> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
>> ---
>>  include/linux/acpi.h      | 15 +++++++++++++++
>>  include/linux/cacheinfo.h |  2 +-
>>  2 files changed, 16 insertions(+), 1 deletion(-)
>>
>> Hi Rafael,
>>
>> If you are fine with this, can you provide Ack, so that we route this
>> through ARM64 tree where most of the ACPI PPTT support is present.
>>
>> Regards,
>> Sudeep
>>
>> v1->v2:
>>         - removed duplicate definition for acpi_find_last_cache_level
>>
>> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
>> index 8f2cdb0eca71..4b35a66383f9 100644
>> --- a/include/linux/acpi.h
>> +++ b/include/linux/acpi.h
>> @@ -1299,8 +1299,23 @@ static inline int lpit_read_residency_count_address(u64 *address)
>>  }
>>  #endif
>>
>> +#ifdef CONFIG_ACPI_PPTT
>>  int find_acpi_cpu_topology(unsigned int cpu, int level);
>>  int find_acpi_cpu_topology_package(unsigned int cpu);
>>  int find_acpi_cpu_cache_topology(unsigned int cpu, int level);
>> +#else
>> +static inline int find_acpi_cpu_topology(unsigned int cpu, int level)
>> +{
>> +       return -EINVAL;
> 
> Why -EINVAL?
> 

I am not sure either. I used to return -ENOTSUPP, but IIRC someone
suggested to use it only for syscalls. Also I just based it on other
existing functions in acpi.h

I am open for any alternatives if you think that is better here.
-- 
Regards,
Sudeep