[PATCH v9 14/21] ACPI / processor: Make it possible to get CPU hardware ID via GICC

[Rafael J. Wysocki]

On Thu, Mar 5, 2015 at 12:27 PM, Catalin Marinas
<catalin.marinas at arm.com> wrote:
> On Thu, Mar 05, 2015 at 04:03:21PM +0800, Hanjun Guo wrote:
>> On 2015/3/5 6:46, Rafael J. Wysocki wrote:
>> > IMO, you really need to define phys_cpuid_t in a common place or people will
>> > forget that it may be 64-bit, because they'll only be looking at their arch.
>>
>> Since x86 and ARM64 are using different types for phys_cpuid_t, we need to
>> introduce something like following if define it in common place:
>>
>> in linux/acpi.h,
>>
>> #if defined(CONFIG_X86) || defined(CONFIG_IA64)
>> typedef u32 phys_cpuid_t;
>> #define PHYS_CPUID_INVALID (phys_cpuid_t)(-1)
>> #else if defined(CONFIG_ARM64)
>> typedef u64 phys_cpuid_t;
>> #define PHYS_CPUID_INVALID INVALID_HWID
>> #endif
>>
>> I think it's awful, did I miss something?

Well, you can define the type and PHYS_CPUID_INVALID in the arch
code and then do this in a common header:

#ifndef PHYS_CPUID_INVALID
typedef u32 phys_cpuid_t;
#define PHYS_CPUID_INVALID (phys_cpuid_t)(-1)
#endif

That would allow you to avoid the need to duplicate the
definitions where it is not necessary.

> I also think that's awful. I'm rather in favour of a per-arch
> phys_cpuid_t.

OK, so what about the above?

Rafael