Re: [PATCH v2 09/18] ACPI / processor: Make it possible to get CPU hardware ID via GICC

From: Hanjun Guo
Date: Tue Aug 19 2014 - 04:39:20 EST


On 2014-8-18 22:27, Catalin Marinas wrote:
> On Mon, Aug 04, 2014 at 04:28:16PM +0100, Hanjun Guo wrote:
>> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
>> index 022f4ad..a81898d 100644
>> --- a/arch/arm64/include/asm/acpi.h
>> +++ b/arch/arm64/include/asm/acpi.h
>> @@ -12,6 +12,8 @@
>> #ifndef _ASM_ACPI_H
>> #define _ASM_ACPI_H
>>
>> +#include <asm/smp_plat.h>
>> +
>> /* Basic configuration for ACPI */
>> #ifdef CONFIG_ACPI
>> /*
>> @@ -59,6 +61,18 @@ static inline void disable_acpi(void)
>> acpi_noirq = 1;
>> }
>>
>> +u32 pack_mpidr_into_32_bits(u64 mpidr);
>
> I would define this as a static inline function here.

ok, will update it.

>
>> diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
>> index e32321c..4007313 100644
>> --- a/drivers/acpi/processor_core.c
>> +++ b/drivers/acpi/processor_core.c
>> @@ -64,6 +64,38 @@ static int map_lsapic_id(struct acpi_subtable_header *entry,
>> return 0;
>> }
>>
>> +/*
>> + * On ARM platform, MPIDR value is the hardware ID as apic ID
>> + * on Intel platforms
>> + */
>> +static int map_gicc_mpidr(struct acpi_subtable_header *entry,
>> + int device_declaration, u32 acpi_id, int *mpidr)
>> +{
>> + struct acpi_madt_generic_interrupt *gicc =
>> + container_of(entry, struct acpi_madt_generic_interrupt, header);
>> +
>> + if (!(gicc->flags & ACPI_MADT_ENABLED))
>> + return -ENODEV;
>> +
>> + /* In the GIC interrupt model, logical processors are
>> + * required to have a Processor Device object in the DSDT,
>> + * so we should check device_declaration here
>> + */
>> + if (device_declaration && (gicc->uid == acpi_id)) {
>> + /*
>> + * Only bits [0:7] Aff0, bits [8:15] Aff1, bits [16:23] Aff2
>> + * and bits [32:39] Aff3 are meaningful, so pack the Affx
>> + * fields into a single 32 bit identifier to accommodate the
>> + * acpi processor drivers.
>> + */
>> + *mpidr = ((gicc->arm_mpidr & 0xff00000000) >> 8)
>> + | gicc->arm_mpidr;
>
> You can use pack_mpidr_into_32_bits().

processor_core.c will be used by x86 and ia64 too, it will cause
compile error on !ARM64 platforms.

Thanks
Hanjun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/