On 09/15/2015 08:44 PM, Rafael J. Wysocki wrote: > On Tuesday, September 15, 2015 03:13:12 PM Al Stone wrote: >> On 09/09/2015 03:09 PM, Al Stone wrote: >>> Currently, the BAD_MADT_ENTRY macro is used to do a very simple sanity >>> check on the various subtables that are defined for the MADT. The check >>> compares the size of the subtable data structure as defined by ACPICA to >>> the length entry in the subtable. If they are not the same, the assumption >>> is that the subtable is incorrect. >>> >>> Over time, the ACPI spec has allowed for MADT subtables where this can >>> never be true (the local SAPIC subtable, for example). Or, more recently, >>> the spec has accumulated some minor flaws where there are three possible >>> sizes for a subtable, all of which are valid, but only for specific versions >>> of the spec (the GICC subtable). In both cases, BAD_MADT_ENTRY reports these >>> subtables as bad when they are not. In order to retain some sanity check >>> on the MADT subtables, we now have to special case these subtables. Of >>> necessity, these special cases have ended up in arch-dependent code (arm64) >>> or an arch has simply decided to forgo the check (ia64). >>> >>> This patch set replaces the BAD_MADT_ENTRY macro with a function called >>> bad_madt_entry(). This function uses a data set of details about the >>> subtables to provide more sanity checking than before: >>> >>> -- is the subtable legal for the version given in the FADT? >>> >>> -- is the subtable legal for the revision of the MADT in use? >>> >>> -- is the subtable of the proper length (including checking >>> on the one variable length subtable that is currently ignored), >>> given the FADT version and the MADT revision? >>> >>> Further, this patch set adds in the call to bad_madt_entry() from the >>> acpi_table_parse_madt() function, allowing it to be used consistently >>> by all architectures, for all subtables, and removing the need for each >>> of the subtable traversal callback functions to use BAD_MADT_ENTRY. >>> >>> In theory, as the ACPI specification changes, we would only have to add >>> additional information to the data set describing the MADT subtables in >>> order to continue providing sanity checks, even when new subtables are >>> added. >>> >>> These patches have been tested on an APM Mustang (arm64) and are known to >>> work there. They have also been cross-compiled for x86 and ia64 with no >>> known failures. >>> >>> Changes for v3: >>> -- Reviewed-and-tested-by from Sudeep Holla for arm64 parts >>> -- Clearer language in error messages (Graeme Gregory, Timur Tabi) >>> -- Double checked that inserting call to bad_madt_entry() into the >>> function acpi_parse_entries() does not impact current behavior >>> (Sudeep Holla) >>> >>> Changes for v2: >>> -- Acked-by on 2/5 from Marc Zyngier and Catalin Marinas for ARM >>> -- Correct faulty end of loop test found by Timur Tabi >>> >>> >>> Al Stone (5): >>> ACPI: add in a bad_madt_entry() function to eventually replace the >>> macro >>> ACPI / ARM64: remove usage of BAD_MADT_ENTRY/BAD_MADT_GICC_ENTRY >>> ACPI / IA64: remove usage of BAD_MADT_ENTRY >>> ACPI / X86: remove usage of BAD_MADT_ENTRY >>> ACPI: remove definition of BAD_MADT_ENTRY macro >>> >>> arch/arm64/include/asm/acpi.h | 8 -- >>> arch/arm64/kernel/smp.c | 2 - >>> arch/ia64/kernel/acpi.c | 20 ---- >>> arch/x86/kernel/acpi/boot.c | 27 ----- >>> drivers/acpi/tables.c | 245 +++++++++++++++++++++++++++++++++++++++++- >>> drivers/irqchip/irq-gic.c | 6 -- >>> include/linux/acpi.h | 4 - >>> 7 files changed, 244 insertions(+), 68 deletions(-) >>> >> >> Ping? Any additional comments on this version? I have only received >> feedback from arm64 reviewers so far, over three revisions, even though >> everyone that needs to be (ACPI, ia64, x86) has also been CCd. >> >> Anyone else before I fix a couple of things for v4 that the arm64 folks >> found? ACKs? NAKs? Please don't bother me, I'm in the merge window :)? > > The merge window is actually over, so why would you expect anything like that? I know. Merely a feeble attempt at humor.... > I'm going to apply this series if people have no problems with it. I do think > it is slightly overkill, but then as long as it works ... > > Thanks, > Rafael > Thanks, Rafael. -- ciao, al ----------------------------------- Al Stone Software Engineer Linaro Enterprise Group al.stone@xxxxxxxxxx ----------------------------------- -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
