Messages in this thread | | | Date | Fri, 3 Jul 2015 15:06:01 +0100 | From | Catalin Marinas <> | Subject | Re: [PATCH v3 2/3] ACPI / ARM64: add BAD_MADT_GICC_ENTRY() macro |
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On Thu, Jul 02, 2015 at 05:48:35PM -0600, Al Stone wrote: > diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h > index 39248d3..a3c26a4 100644 > --- a/arch/arm64/include/asm/acpi.h > +++ b/arch/arm64/include/asm/acpi.h > @@ -19,6 +19,17 @@ > #include <asm/psci.h> > #include <asm/smp_plat.h> > > +/* Macros for consistency checks of the GICC subtable of MADT */ > +#define ACPI_MADT_GICC_51_LENGTH 76 > +#define ACPI_MADT_GICC_60_LENGTH 80 > + > +#define BAD_MADT_GICC_ENTRY(entry, end) ( \ > + (!entry) || (unsigned long)entry + sizeof(*entry) > end || \ > + ((ACPI_FADT_SPEC_VERSION == ACPI_FADT_SPEC_VERSION_51) && \ > + (entry->header.length != ACPI_MADT_GICC_51_LENGTH)) || \ > + ((ACPI_FADT_SPEC_VERSION == ACPI_FADT_SPEC_VERSION_60) && \ > + (entry->header.length != ACPI_MADT_GICC_60_LENGTH)))
This looks ugly but, well, we could live with this.
However, I'd like to avoid having to extend this macro every time we get a new spec released, like 6.1 defining another 80 or 84 etc. So, how about we only update this when there is an actual change in the length? Something like:
#define ACPI_MADT_GICC_LENGTH ({ \ u8 length; \ if (ACPI_FADT_SPEC_VERSION < ACPI_FADT_SPEC_VERSION_6_0) \ length = 76; \ else \ length = 80; \ length; \ })
or just:
#define ACPI_MADT_GICC_LENGTH \ (ACPI_FADT_SPEC_VERSION < ACPI_FADT_SPEC_VERSION_6_0 ? 76 : 80)
(the latter is simpler but may not look nice if we change it again in 6.1; though we could re-write this macro when needed, not a problem)
-- Catalin
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