Re: [PATCH v8 14/21] ACPI / processor: Make it possible to get CPU hardware ID via GICC

[Catalin Marinas]

On Wed, Feb 04, 2015 at 09:48:05AM +0000, Hanjun Guo wrote:
> On 2015å02æ04æ 04:09, Catalin Marinas wrote:
> > diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
> > index ea4d2b35c57b..4fafd62b1b86 100644
> > --- a/arch/arm64/include/asm/acpi.h
> > +++ b/arch/arm64/include/asm/acpi.h
> > @@ -49,33 +49,12 @@ static inline void enable_acpi(void)
> >   	acpi_noirq = 0;
> >   }
> >
> > -/* MPIDR value provided in GICC structure is 64 bits, but the
> > - * existing phys_id (CPU hardware ID) using in acpi processor
> > - * driver is 32-bit, to conform to the same datatype we need
> > - * to repack the GICC structure MPIDR.
> > - *
> > - * bits other than following 32 bits are defined as 0, so it
> > - * will be no information lost after repacked.
> > - *
> > - * Bits [0:7] Aff0;
> > - * Bits [8:15] Aff1;
> > - * Bits [16:23] Aff2;
> > - * Bits [32:39] Aff3;
> > - */
> > -static inline u32 pack_mpidr(u64 mpidr)
> > -{
> > -	return (u32) ((mpidr & 0xff00000000) >> 8) | mpidr;
> > -}
> > -
> >   /*
> >    * The ACPI processor driver for ACPI core code needs this macro
> >    * to find out this cpu was already mapped (mapping from CPU hardware
> >    * ID to CPU logical ID) or not.
> > - *
> > - * cpu_logical_map(cpu) is the mapping of MPIDR and the logical cpu,
> > - * and MPIDR is the cpu hardware ID we needed to pack.
> >    */
> > -#define cpu_physical_id(cpu) pack_mpidr(cpu_logical_map(cpu))
> > +#define cpu_physical_id(cpu) cpu_logical_map(cpu)
> >
> >   /*
> >    * It's used from ACPI core in kdump to boot UP system with SMP kernel,
> > diff --git a/arch/arm64/include/asm/smp_plat.h b/arch/arm64/include/asm/smp_plat.h
> > index 59e282311b58..a492276e008d 100644
> > --- a/arch/arm64/include/asm/smp_plat.h
> > +++ b/arch/arm64/include/asm/smp_plat.h
> > @@ -40,4 +40,6 @@ static inline u32 mpidr_hash_size(void)
> >   extern u64 __cpu_logical_map[NR_CPUS];
> >   #define cpu_logical_map(cpu)    __cpu_logical_map[cpu]
> >
> > +typedef u64 cpuid_t;
> 
> I think cpuid_t is a little confused because people may recognize
> it as cpu logical id, its original meaning is the physical cpu ID,
> so how about:
> 
> typedef u64 phys_id_t; ?

I would keep "cpu" somewhere in the name as "phys" is too generic, maybe
phys_cpuid_t.

-- 
Catalin
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