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'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 -- 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
