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

[Hanjun Guo <hanjun.guo@linaro.org>]

On 2015年02月04日 19:21, Catalin Marinas wrote:
> On Wed, Feb 04, 2015 at 09:48:05AM +0000, Hanjun Guo wrote:
>> On 2015年02月04日 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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