From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 558BDC433DB for ; Sun, 24 Jan 2021 16:21:58 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id CC12A22ADC for ; Sun, 24 Jan 2021 16:21:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CC12A22ADC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 23A9D4B35F; Sun, 24 Jan 2021 11:21:57 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id n7qMLVPtv8zl; Sun, 24 Jan 2021 11:21:55 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 5CBE14B35E; Sun, 24 Jan 2021 11:21:55 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id CAC444B35E for ; Sun, 24 Jan 2021 11:21:53 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id k6VlDaBnZyRz for ; Sun, 24 Jan 2021 11:21:52 -0500 (EST) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id AA6984B2BD for ; Sun, 24 Jan 2021 11:21:52 -0500 (EST) Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 94703229F0; Sun, 24 Jan 2021 16:21:51 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1l3i97-009kdA-Fk; Sun, 24 Jan 2021 16:21:49 +0000 Date: Sun, 24 Jan 2021 16:21:47 +0000 Message-ID: <87v9bmjof8.wl-maz@kernel.org> From: Marc Zyngier To: Catalin Marinas Subject: Re: [PATCH v4 12/21] arm64: cpufeature: Add an early command-line cpufeature override facility In-Reply-To: References: <20210118094533.2874082-1-maz@kernel.org> <20210118094533.2874082-13-maz@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, will@kernel.org, mark.rutland@arm.com, dbrazdil@google.com, alexandru.elisei@arm.com, ardb@kernel.org, jingzhangos@google.com, pajay@qti.qualcomm.com, psodagud@codeaurora.org, sramana@codeaurora.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Cc: Prasad Sodagudi , Srinivas Ramana , linux-kernel@vger.kernel.org, Ard Biesheuvel , Ajay Patil , kernel-team@android.com, Will Deacon , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Sat, 23 Jan 2021 13:43:52 +0000, Catalin Marinas wrote: > > On Mon, Jan 18, 2021 at 09:45:24AM +0000, Marc Zyngier wrote: > > +struct reg_desc { > > + const char * const name; > > + u64 * const val; > > + u64 * const mask; > > + struct { > > + const char * const name; > > + u8 shift; > > + } fields[]; > > +}; > > Sorry, I didn't see this earlier. Do we need to add all these consts > here? So you want the pointers to be const but why is 'shift' special > and not a const then? Is it modified later? > > Would this not work: > > struct reg_desc { > const char *name; > u64 *val; > u64 *mask; > struct { > const char *name; > u8 shift; > } fields[]; > }; > > > +static const struct reg_desc * const regs[] __initdata = { > > as we already declare the whole struct reg_desc pointers here as const. > I may have confused myself... It definitely is better. Specially given that we throw all of this away right after boot, there is no harm in keeping it simple. I've also renamed "reg_desc" to "ftr_set_desc", because we don't always describe a register (like for kaslr). Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81C96C433E0 for ; Sun, 24 Jan 2021 16:23:43 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3C99A2226A for ; Sun, 24 Jan 2021 16:23:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3C99A2226A Authentication-Results: mail.kernel.org; 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Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l3i9B-0007xX-SQ; Sun, 24 Jan 2021 16:21:53 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l3i9A-0007x8-HJ for linux-arm-kernel@lists.infradead.org; Sun, 24 Jan 2021 16:21:53 +0000 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 94703229F0; Sun, 24 Jan 2021 16:21:51 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1l3i97-009kdA-Fk; Sun, 24 Jan 2021 16:21:49 +0000 Date: Sun, 24 Jan 2021 16:21:47 +0000 Message-ID: <87v9bmjof8.wl-maz@kernel.org> From: Marc Zyngier To: Catalin Marinas Subject: Re: [PATCH v4 12/21] arm64: cpufeature: Add an early command-line cpufeature override facility In-Reply-To: References: <20210118094533.2874082-1-maz@kernel.org> <20210118094533.2874082-13-maz@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, will@kernel.org, mark.rutland@arm.com, dbrazdil@google.com, alexandru.elisei@arm.com, ardb@kernel.org, jingzhangos@google.com, pajay@qti.qualcomm.com, psodagud@codeaurora.org, sramana@codeaurora.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210124_112152_645613_50B411D2 X-CRM114-Status: GOOD ( 20.08 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Jing Zhang , Prasad Sodagudi , Srinivas Ramana , Suzuki K Poulose , Alexandru Elisei , linux-kernel@vger.kernel.org, Ard Biesheuvel , James Morse , Julien Thierry , Ajay Patil , kernel-team@android.com, David Brazdil , Will Deacon , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sat, 23 Jan 2021 13:43:52 +0000, Catalin Marinas wrote: > > On Mon, Jan 18, 2021 at 09:45:24AM +0000, Marc Zyngier wrote: > > +struct reg_desc { > > + const char * const name; > > + u64 * const val; > > + u64 * const mask; > > + struct { > > + const char * const name; > > + u8 shift; > > + } fields[]; > > +}; > > Sorry, I didn't see this earlier. Do we need to add all these consts > here? So you want the pointers to be const but why is 'shift' special > and not a const then? Is it modified later? > > Would this not work: > > struct reg_desc { > const char *name; > u64 *val; > u64 *mask; > struct { > const char *name; > u8 shift; > } fields[]; > }; > > > +static const struct reg_desc * const regs[] __initdata = { > > as we already declare the whole struct reg_desc pointers here as const. > I may have confused myself... It definitely is better. Specially given that we throw all of this away right after boot, there is no harm in keeping it simple. I've also renamed "reg_desc" to "ftr_set_desc", because we don't always describe a register (like for kaslr). Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ 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 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6DD31C433E0 for ; Sun, 24 Jan 2021 16:22:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2ED5A229F0 for ; Sun, 24 Jan 2021 16:22:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726494AbhAXQWm (ORCPT ); Sun, 24 Jan 2021 11:22:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:43134 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726292AbhAXQWf (ORCPT ); Sun, 24 Jan 2021 11:22:35 -0500 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 94703229F0; Sun, 24 Jan 2021 16:21:51 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1l3i97-009kdA-Fk; Sun, 24 Jan 2021 16:21:49 +0000 Date: Sun, 24 Jan 2021 16:21:47 +0000 Message-ID: <87v9bmjof8.wl-maz@kernel.org> From: Marc Zyngier To: Catalin Marinas Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, Will Deacon , Mark Rutland , David Brazdil , Alexandru Elisei , Ard Biesheuvel , Jing Zhang , Ajay Patil , Prasad Sodagudi , Srinivas Ramana , James Morse , Julien Thierry , Suzuki K Poulose , kernel-team@android.com Subject: Re: [PATCH v4 12/21] arm64: cpufeature: Add an early command-line cpufeature override facility In-Reply-To: References: <20210118094533.2874082-1-maz@kernel.org> <20210118094533.2874082-13-maz@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, will@kernel.org, mark.rutland@arm.com, dbrazdil@google.com, alexandru.elisei@arm.com, ardb@kernel.org, jingzhangos@google.com, pajay@qti.qualcomm.com, psodagud@codeaurora.org, sramana@codeaurora.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 23 Jan 2021 13:43:52 +0000, Catalin Marinas wrote: > > On Mon, Jan 18, 2021 at 09:45:24AM +0000, Marc Zyngier wrote: > > +struct reg_desc { > > + const char * const name; > > + u64 * const val; > > + u64 * const mask; > > + struct { > > + const char * const name; > > + u8 shift; > > + } fields[]; > > +}; > > Sorry, I didn't see this earlier. Do we need to add all these consts > here? So you want the pointers to be const but why is 'shift' special > and not a const then? Is it modified later? > > Would this not work: > > struct reg_desc { > const char *name; > u64 *val; > u64 *mask; > struct { > const char *name; > u8 shift; > } fields[]; > }; > > > +static const struct reg_desc * const regs[] __initdata = { > > as we already declare the whole struct reg_desc pointers here as const. > I may have confused myself... It definitely is better. Specially given that we throw all of this away right after boot, there is no harm in keeping it simple. I've also renamed "reg_desc" to "ftr_set_desc", because we don't always describe a register (like for kaslr). Thanks, M. -- Without deviation from the norm, progress is not possible.