On Wed, 2008-10-22 at 13:10 -0600, Myron Stowe wrote:
> Len, Alexey:
>
> The following three item patch series fixes an issue with the introduction
> of > 256 processor declaration support: "Allow processor to be declared with
> the Device() instead of Processor()" (git SHA 11bf04c4).
>
> The root issue is in the lsapic mapping logic of drivers/acpi/processor_core.c.
> Currently, the logic tries both types of matches irregardless of declaration
> type and relies on one failing. According to the spec - lsapic mapping is
> dependent on how the processor object was declared: CPUs declared using the
> "Processor" statement should use the Local SAPIC's 'processor_id', and CPUs
> declared using the "Device" statement should use the 'uid'.
>
> Reference: Section 8.4 Declaring Processors; Section 5.2.11.13 Local SAPIC
> Structure. "Advanced Configuration and Power Interface Specification",
> Revision 3.0b, October 2006.
>
>
> [PATCH 1/3] disambiguates the processor declaration type that is currently
> conflated so that subsequent logic can behave based explicitly on the
> declaration's type. I expect the disambiguation this patch introduces will
> also be advantageous when extending the > 256 processor support for x86 via
> x2APIC.
In the patch the new HID("ACPI_CPU") for processor is introduced. Is it
required?
If there exists the _UID object under the scope of Processor, it won't
work well.
According to the spec the returned value of the _UID object for
processor/device can be numeric value or a string. If it is a numeric
value, we should match it with the ACPI_UID field of slapic table to get
the APIC id. If it is string, we should match it with the ACPI_UID
string field of slapic table get the APIC ID.
>
> [PATCH 2/3] addresses the root issue as stated above. With respect to this
> patch I'm ambivalent about the 'printk' introduced in "map_lsapic_id()" -
> perhaps it should be removed?
>
> [PATCH 3/3] is non-functional white space/spelling fixes in the related code.
>
>
> While the specific fix is ia64 focused the underlying code affected is common
> to both x86 and ia64. I have tested on the following platform/namespace
> combinations:
> ia64 with "Processor" type namespace processor declarations,
> ia64 with "Device" type namespace processor declarations,
> x86 with "Processor" type namespace processor declarations.
>
> Note that this patch series does *not* handle "Device" type processor
> declarations that contain a string type _UID object under the processor
> device's scope (I am currently not aware of any platforms that have such to
> test against).
>
> All comments welcome.
>
> Myron
>
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