Re: [Xen-devel] [PATCH v3 24/62] arm: Introduce a generic way to use a device from acpi

[Shannon Zhao <zhaoshenglong@xxxxxxxxxx>]

On 2015/11/17 22:25, Julien Grall wrote:
> On 17/11/15 13:21, Shannon Zhao wrote:
>>> AFAICT, it does only works for SPCR table used for UART device. For the
>>> GIC you've hardcoded the value and I can't find any version number in
>>> the table.
>>>
>> No, I didn't hardcode the GIC version. Since ACPI 6.0 introduces GIC
>> version in generic distributor table, it could get the version from
>> that. Please see [PATCH v3 28/62].
> 
> +    if ( dist->version == ACPI_MADT_GIC_VERSION_V2 )
> +        rc = acpi_device_init(DEVICE_GIC, NULL, GIC_V2);
> +    else if ( dist->version == ACPI_MADT_GIC_VERSION_V3 )
> +        rc = acpi_device_init(DEVICE_GIC, NULL, GIC_V3);
> 
> Every single time a new GIC version will be added, we will had to add
> another else if. I'm sorry but it's what I call hardcoding.
> 

Oh, I see. If it uses the enum acpi_madt_gic_version for ACPI GIC not
the enum gic_version, it could match 1:1. Something like below:

It uses ACPI_MADT_GIC_VERSION_V2 for GICv2.

ACPI_DEVICE_START(agicv2, "GICv2", DEVICE_GIC)
        .class_type = ACPI_MADT_GIC_VERSION_V2,
        .init = acpi_gicv2_preinit,
ACPI_DEVICE_END

Then get the GIC version from MADT table and call

acpi_device_init(DEVICE_GIC, NULL, dist->version);

How about this way?

Thanks,
-- 
Shannon


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel