From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Wed, 30 Nov 2016 11:04:56 +0000 Subject: [PATCH 5/9] arm64: cpufeature: Define helpers for sys_reg id In-Reply-To: <1479994809-9081-6-git-send-email-suzuki.poulose@arm.com> References: <1479994809-9081-1-git-send-email-suzuki.poulose@arm.com> <1479994809-9081-6-git-send-email-suzuki.poulose@arm.com> Message-ID: <20161130110455.GD2724@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Nov 24, 2016 at 01:40:05PM +0000, Suzuki K Poulose wrote: > Define helper macros to extract op0, op1, CRn, CRm & op2 > for a given sys_reg id. > > Cc: Catalin Marinas > Cc: Mark Rutland > Cc: Will Deacon > Signed-off-by: Suzuki K Poulose > --- > arch/arm64/include/asm/sysreg.h | 21 ++++++++++++++++++++- > 1 file changed, 20 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h > index 6c80b36..488b939 100644 > --- a/arch/arm64/include/asm/sysreg.h > +++ b/arch/arm64/include/asm/sysreg.h > @@ -34,8 +34,27 @@ > * [11-8] : CRm > * [7-5] : Op2 > */ > +#define Op0_shift 19 > +#define Op0_mask 0x3 > +#define Op1_shift 16 > +#define Op1_mask 0x7 > +#define CRn_shift 12 > +#define CRn_mask 0xf > +#define CRm_shift 8 > +#define CRm_mask 0xf > +#define Op2_shift 5 > +#define Op2_mask 0x7 > + > #define sys_reg(op0, op1, crn, crm, op2) \ > - ((((op0)&3)<<19)|((op1)<<16)|((crn)<<12)|((crm)<<8)|((op2)<<5)) > + ((((op0) & Op0_mask) << Op0_shift) | \ > + ((op1) << Op1_shift) | ((crn) << CRn_shift) | \ > + ((crm) << CRm_shift) | ((op2) << Op2_shift)) You're preserving the current behaviour here, but why do we care so much about masking op0 but then not bother masking any of the other fields? Will From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757289AbcK3LFF (ORCPT ); Wed, 30 Nov 2016 06:05:05 -0500 Received: from foss.arm.com ([217.140.101.70]:42686 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751227AbcK3LE5 (ORCPT ); Wed, 30 Nov 2016 06:04:57 -0500 Date: Wed, 30 Nov 2016 11:04:56 +0000 From: Will Deacon To: Suzuki K Poulose Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, dave.martin@arm.com, aph@redhat.com, ryan.arnold@linaro.org, sid@reserved-bit.com, adhemerval.zanella@linaro.org, mark.rutland@arm.com, marc.zyngier@arm.com Subject: Re: [PATCH 5/9] arm64: cpufeature: Define helpers for sys_reg id Message-ID: <20161130110455.GD2724@arm.com> References: <1479994809-9081-1-git-send-email-suzuki.poulose@arm.com> <1479994809-9081-6-git-send-email-suzuki.poulose@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1479994809-9081-6-git-send-email-suzuki.poulose@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 Thu, Nov 24, 2016 at 01:40:05PM +0000, Suzuki K Poulose wrote: > Define helper macros to extract op0, op1, CRn, CRm & op2 > for a given sys_reg id. > > Cc: Catalin Marinas > Cc: Mark Rutland > Cc: Will Deacon > Signed-off-by: Suzuki K Poulose > --- > arch/arm64/include/asm/sysreg.h | 21 ++++++++++++++++++++- > 1 file changed, 20 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h > index 6c80b36..488b939 100644 > --- a/arch/arm64/include/asm/sysreg.h > +++ b/arch/arm64/include/asm/sysreg.h > @@ -34,8 +34,27 @@ > * [11-8] : CRm > * [7-5] : Op2 > */ > +#define Op0_shift 19 > +#define Op0_mask 0x3 > +#define Op1_shift 16 > +#define Op1_mask 0x7 > +#define CRn_shift 12 > +#define CRn_mask 0xf > +#define CRm_shift 8 > +#define CRm_mask 0xf > +#define Op2_shift 5 > +#define Op2_mask 0x7 > + > #define sys_reg(op0, op1, crn, crm, op2) \ > - ((((op0)&3)<<19)|((op1)<<16)|((crn)<<12)|((crm)<<8)|((op2)<<5)) > + ((((op0) & Op0_mask) << Op0_shift) | \ > + ((op1) << Op1_shift) | ((crn) << CRn_shift) | \ > + ((crm) << CRm_shift) | ((op2) << Op2_shift)) You're preserving the current behaviour here, but why do we care so much about masking op0 but then not bother masking any of the other fields? Will