Re: [RFC part2 PATCH 2/9] ARM64 / ACPI: Prefill cpu possible/present maps and map logical cpu id to APIC id

Rob Herring
2013-12-04T15:40:07Z

On Wed, Dec 4, 2013 at 8:21 AM, Hanjun Guo <hanjun.guo@linaro.org> wrote:
> On 2013年12月04日 00:57, One Thousand Gnomes wrote:
>>>
>>> diff --git a/drivers/acpi/plat/arm-core.c b/drivers/acpi/plat/arm-core.c
>>> index 45ff625..8527ecc 100644
>>> --- a/drivers/acpi/plat/arm-core.c
>>> +++ b/drivers/acpi/plat/arm-core.c
>>> @@ -58,6 +58,13 @@ EXPORT_SYMBOL(acpi_pci_disabled);
>>> */
>>> static u64 acpi_lapic_addr __initdata;
>>> +/* available_cpus here means enabled cpu in MADT */
>>> +int available_cpus;
>>> +
>>> +/* Map logic cpu id to physical GIC id. */
>>> +int arm_cpu_to_apicid[NR_CPUS] = { [0 ... NR_CPUS-1] = -1 };
>>> +int boot_cpu_apic_id = -1;
>>> +
>>
>> static ?
>>
>> Really shouldn't be leaking names like "available_cpus" out of ACPI into
>> the global namespace
>
>
> Ok, will update in next version.
>
>
>
>>> +#ifdef CONFIG_SMP
>>> + if (available_cpus == 0) {
>>> + pr_info(PREFIX "Found 0 CPUs; assuming 1\n");
>>> + /* FIXME: should be the real GIC id read from hardware */
>>> + arm_cpu_to_apicid[available_cpus] = 0;
>>> + available_cpus = 1; /* We've got at least one of
>>> these */
>>> + }
>>> +#endif
>>
>> Isn't this true uniprocessor (by definition in fact)
>
>
> This code is intend to handle some buggy firmware I think.

Really? We have production firmware already that we need to
work-around? That's impressive given there is no production h/w.

Rob