On Tue, Jun 30, 2015 at 8:25 PM, Rafael J. Wysocki <raf...@kernel.org> wrote: > Hi Al, > > On Tue, Jun 30, 2015 at 7:29 PM, Al Stone <a...@redhat.com> wrote: >> On 06/30/2015 11:07 AM, Sudeep Holla wrote: >>> Hi Al, >>> >>> On 18/06/15 23:36, 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. >>>> >>> >>> We need to get this series or a patch to remove the check(similar to >>> ia64) based on what Rafael prefers. Without that, platforms using ACPI >>> on ARM64 fails to boot with latest mainline. This blocks any testing on >>> ARM64/ACPI systems. >>> >>> Regards, >>> Sudeep >> >> I have not received any other feedback than some Reviewed-bys from >> Hanjun and an ACK from Will for the arm64 patch. >> >> And absolutely agreed: this is a blocker for arm64/ACPI, starting with >> the ACPICA 20150515 patches which appear to have gone in with 4.2-rc1. >> >> Rafael? Ping? > > I overlooked the fact that this was needed to fix a recent regression, > sorry about that. > > Actually, if your patch fixes an error introduced by a specific > commit, it is good to use the Fixes: tag to indicate that. Which I > still would like to do, so which commit is fixed by this? > >> Do we need these to go through your tree or the arm64 >> tree? Without this series (or an ia64-like solution), we have ACPI >> systems in the field that cannot boot. > > I'm not quite sure why the definition of BAD_MADT_GICC_ENTRY has to go > into include/linux/acpi.h. Why is it necessary in there?
Like what about defining it in linux/irqchip/arm-gic-acpi.h for example? Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
