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SubjectRe: [PATCH v2 0/3] Correct for ACPI 5.1->6.0 spec changes in MADT GICC entries
On 06/19/2015 06:36 AM, Al Stone wrote:
> In the ACPI 5.1 version of the spec, the struct for the GICC subtable
> (struct acpi_madt_generic_interrupt) of the MADT is 76 bytes long; in
> ACPI 6.0, the struct is 80 bytes long. But, there is only one definition
> in ACPICA for this struct -- and that is the 6.0 version. Hence, when
> BAD_MADT_ENTRY() compares the struct size to the length in the GICC
> subtable, it fails if 5.1 structs are in use, and there are systems in
> the wild that have them.
>
> Note that this was found in linux-next and these patches apply against
> that tree and the arm64 kernel tree; 4.1-rc8 does not appear to have this
> problem since it still has the 5.1 struct definition.
>
> Even though there is precendent in ia64 code for ignoring the changes in
> size, this patch set instead tries to verify correctness. The first patch
> in the set adds macros for easily using the ACPI spec version. The second
> patch adds the BAD_MADT_GICC_ENTRY() macro that uses the version macros to
> check the GICC subtable only, accounting for the difference in specification
> versions that are possible. The final patch replaces BAD_MADT_ENTRY usage
> with the BAD_MADT_GICC_ENTRY macro in arm64 code, which is currently the
> only architecture affected. The BAD_MADT_ENTRY() will continue to work as
> is for all other MADT subtables.
>
> I have tested these patches on an APM Mustang with version 1.15 firmware,
> where the problem was found, and they fix the problem.

I also tested on QEMU, it fixed the problem when I was using ACPICA 6.0
updates for MADT table,

Tested-by: Hanjun Guo <hanjun.guo@linaro.org>

Thanks
Hanjun

>
> Changes for v2:
> -- Replace magic constants with proper defines (Lorenzo)
> -- Minor syntax clean-up noted by checkpatch
> -- Send out CCs properly this time
> -- Minor clean-up of the paragraphs in this cover letter
>
>
> Al Stone (3):
> ACPI : introduce macros for using the ACPI specification version
> ACPI: add BAD_MADT_GICC_ENTRY() macro
> ACPI / ARM64 : use the new BAD_MADT_GICC_ENTRY macro
>
> arch/arm64/kernel/smp.c | 2 +-
> drivers/irqchip/irq-gic.c | 2 +-
> include/linux/acpi.h | 15 +++++++++++++++
> 3 files changed, 17 insertions(+), 2 deletions(-)
>
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