Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932156AbbGCOGM (ORCPT ); Fri, 3 Jul 2015 10:06:12 -0400 Received: from foss.arm.com ([217.140.101.70]:53442 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932169AbbGCOGG (ORCPT ); Fri, 3 Jul 2015 10:06:06 -0400 Date: Fri, 3 Jul 2015 15:06:01 +0100 From: Catalin Marinas To: Al Stone Cc: linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linaro-kernel@lists.linaro.org, jason@lakedaemon.net, linaro-acpi@lists.linaro.org, patches@linaro.org, rjw@rjwysocki.net, linux-kernel@vger.kernel.org, will.deacon@arm.com, tglx@linutronix.de, lenb@kernel.org Subject: Re: [PATCH v3 2/3] ACPI / ARM64: add BAD_MADT_GICC_ENTRY() macro Message-ID: <20150703140601.GL25907@e104818-lin.cambridge.arm.com> References: <1435880916-2153-1-git-send-email-al.stone@linaro.org> <1435880916-2153-3-git-send-email-al.stone@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1435880916-2153-3-git-send-email-al.stone@linaro.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1882 Lines: 51 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 > #include > > +/* 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/