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

[Hanjun Guo]

On 2015å02æ04æ 19:21, Catalin Marinas wrote:
> 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.

This is pretty fine to me too :)

x86 and IA64 use 32 bit cpu phys_id (apic_id) everywhere in the arch
code, but I think I don't need to touch them in this patch.

Thanks
Hanjun
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