From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752066AbeENKA7 (ORCPT ); Mon, 14 May 2018 06:00:59 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:38734 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751219AbeENKA6 (ORCPT ); Mon, 14 May 2018 06:00:58 -0400 Date: Mon, 14 May 2018 11:00:53 +0100 From: Dave Martin To: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org, marc.zyngier@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, linux@dominikbrodowski.net, james.morse@arm.com, viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 02/18] arm64: move SCTLR_EL{1,2} assertions to Message-ID: <20180514100053.GX7753@e103592.cambridge.arm.com> References: <20180514094640.27569-1-mark.rutland@arm.com> <20180514094640.27569-3-mark.rutland@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180514094640.27569-3-mark.rutland@arm.com> 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 On Mon, May 14, 2018 at 10:46:24AM +0100, Mark Rutland wrote: > Currently we assert that the SCTLR_EL{1,2}_{SET,CLEAR} bits are > self-consistent with an assertion in config_sctlr_el1(). This is a bit > unusual, since config_sctlr_el1() doesn't make use of these definitions, > and is far away from the definitions themselves. > > We can use the CPP #error directive to have equivalent assertions in > , next to the definitions of the set/clear bits, which is > a bit clearer and simpler. > > Signed-off-by: Mark Rutland > Cc: Catalin Marinas > Cc: James Morse > Cc: Will Deacon > --- > arch/arm64/include/asm/sysreg.h | 14 ++++++-------- > 1 file changed, 6 insertions(+), 8 deletions(-) > > diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h > index 6171178075dc..bd1d1194a5e7 100644 > --- a/arch/arm64/include/asm/sysreg.h > +++ b/arch/arm64/include/asm/sysreg.h > @@ -452,9 +452,9 @@ > SCTLR_ELx_SA | SCTLR_ELx_I | SCTLR_ELx_WXN | \ > ENDIAN_CLEAR_EL2 | SCTLR_EL2_RES0) > > -/* Check all the bits are accounted for */ > -#define SCTLR_EL2_BUILD_BUG_ON_MISSING_BITS BUILD_BUG_ON((SCTLR_EL2_SET ^ SCTLR_EL2_CLEAR) != ~0) > - > +#if (SCTLR_EL2_SET ^ SCTLR_EL2_CLEAR) != 0xffffffff > +#error "Inconsistent SCTLR_EL2 set/clear bits" > +#endif Can we have a comment on the != 0xffffffff versus != ~0 here? The subtle differences in evaluation semantics between #if and other contexts here may well trip people up during maintenance... With that, Reviewed-by: Dave Martin Cheers ---Dave > > /* SCTLR_EL1 specific flags. */ > #define SCTLR_EL1_UCI (1 << 26) > @@ -492,8 +492,9 @@ > SCTLR_EL1_UMA | SCTLR_ELx_WXN | ENDIAN_CLEAR_EL1 |\ > SCTLR_EL1_RES0) > > -/* Check all the bits are accounted for */ > -#define SCTLR_EL1_BUILD_BUG_ON_MISSING_BITS BUILD_BUG_ON((SCTLR_EL1_SET ^ SCTLR_EL1_CLEAR) != ~0) > +#if (SCTLR_EL1_SET ^ SCTLR_EL1_CLEAR) != 0xffffffff > +#error "Inconsistent SCTLR_EL1 set/clear bits" > +#endif > > /* id_aa64isar0 */ > #define ID_AA64ISAR0_TS_SHIFT 52 > @@ -732,9 +733,6 @@ static inline void config_sctlr_el1(u32 clear, u32 set) > { > u32 val; > > - SCTLR_EL2_BUILD_BUG_ON_MISSING_BITS; > - SCTLR_EL1_BUILD_BUG_ON_MISSING_BITS; > - > val = read_sysreg(sctlr_el1); > val &= ~clear; > val |= set; > -- > 2.11.0 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave.Martin@arm.com (Dave Martin) Date: Mon, 14 May 2018 11:00:53 +0100 Subject: [PATCH 02/18] arm64: move SCTLR_EL{1,2} assertions to In-Reply-To: <20180514094640.27569-3-mark.rutland@arm.com> References: <20180514094640.27569-1-mark.rutland@arm.com> <20180514094640.27569-3-mark.rutland@arm.com> Message-ID: <20180514100053.GX7753@e103592.cambridge.arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, May 14, 2018 at 10:46:24AM +0100, Mark Rutland wrote: > Currently we assert that the SCTLR_EL{1,2}_{SET,CLEAR} bits are > self-consistent with an assertion in config_sctlr_el1(). This is a bit > unusual, since config_sctlr_el1() doesn't make use of these definitions, > and is far away from the definitions themselves. > > We can use the CPP #error directive to have equivalent assertions in > , next to the definitions of the set/clear bits, which is > a bit clearer and simpler. > > Signed-off-by: Mark Rutland > Cc: Catalin Marinas > Cc: James Morse > Cc: Will Deacon > --- > arch/arm64/include/asm/sysreg.h | 14 ++++++-------- > 1 file changed, 6 insertions(+), 8 deletions(-) > > diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h > index 6171178075dc..bd1d1194a5e7 100644 > --- a/arch/arm64/include/asm/sysreg.h > +++ b/arch/arm64/include/asm/sysreg.h > @@ -452,9 +452,9 @@ > SCTLR_ELx_SA | SCTLR_ELx_I | SCTLR_ELx_WXN | \ > ENDIAN_CLEAR_EL2 | SCTLR_EL2_RES0) > > -/* Check all the bits are accounted for */ > -#define SCTLR_EL2_BUILD_BUG_ON_MISSING_BITS BUILD_BUG_ON((SCTLR_EL2_SET ^ SCTLR_EL2_CLEAR) != ~0) > - > +#if (SCTLR_EL2_SET ^ SCTLR_EL2_CLEAR) != 0xffffffff > +#error "Inconsistent SCTLR_EL2 set/clear bits" > +#endif Can we have a comment on the != 0xffffffff versus != ~0 here? The subtle differences in evaluation semantics between #if and other contexts here may well trip people up during maintenance... With that, Reviewed-by: Dave Martin Cheers ---Dave > > /* SCTLR_EL1 specific flags. */ > #define SCTLR_EL1_UCI (1 << 26) > @@ -492,8 +492,9 @@ > SCTLR_EL1_UMA | SCTLR_ELx_WXN | ENDIAN_CLEAR_EL1 |\ > SCTLR_EL1_RES0) > > -/* Check all the bits are accounted for */ > -#define SCTLR_EL1_BUILD_BUG_ON_MISSING_BITS BUILD_BUG_ON((SCTLR_EL1_SET ^ SCTLR_EL1_CLEAR) != ~0) > +#if (SCTLR_EL1_SET ^ SCTLR_EL1_CLEAR) != 0xffffffff > +#error "Inconsistent SCTLR_EL1 set/clear bits" > +#endif > > /* id_aa64isar0 */ > #define ID_AA64ISAR0_TS_SHIFT 52 > @@ -732,9 +733,6 @@ static inline void config_sctlr_el1(u32 clear, u32 set) > { > u32 val; > > - SCTLR_EL2_BUILD_BUG_ON_MISSING_BITS; > - SCTLR_EL1_BUILD_BUG_ON_MISSING_BITS; > - > val = read_sysreg(sctlr_el1); > val &= ~clear; > val |= set; > -- > 2.11.0 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel