Re: [PATCH 2/2] x86: Don't use BAD_APICID for non-APICID fields

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

On 03/24/2015 04:07 AM, Jan Beulich wrote:
>>>> On 23.03.15 at 20:54, <boris.ostrovsky@oracle.com> wrote:
>> BAD_APICID is used by cpuinfo_x86's phys_proc_id, cpu_core_id
>> and compute_unit_id even though these fields don't hold an APIC ID
>> itself but rather its derivative.
>>
>> Provide appropriate macros for each of those three (and make them
>> unsigned).
>>
>> This also fixes regression introduced by commit 2090f14c5cbd ("sysctl:
>> make XEN_SYSCTL_topologyinfo sysctl a little more efficient") which
>> leaked BAD_APICID into common code, breaking ARM.
>>
>> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
>> Reported-by: Julien Grall <julien.grall@linaro.org>
>> ---
>>
>> I left sysctl with
>>
>>      cputopo.core = cpu_to_core(i);
>>      if ( cputopo.core == INVALID_COREID )
>>          cputopo.core = XEN_INVALID_CORE_ID;
>>      cputopo.socket = cpu_to_socket(i);
>>      if ( cputopo.socket == INVALID_SOCKETID )
>>          cputopo.socket = XEN_INVALID_SOCKET_ID;
>>
>> since this is the only place that would use suggested inlines for external
>> (public) calls.
> But again - why did you not avoid the new #defines and use the
> XEN_-prefixed ones right away?

I did want to use XEN_* macros but then I realized that I need a new 
#define for cpuinfo_x86.compute_unit_id as well. This #define does not 
need to be public so for consistency I thought that having 
hypervisor-internal INVALID_* macros would be better.


-boris