From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753776AbcDVNcR (ORCPT ); Fri, 22 Apr 2016 09:32:17 -0400 Received: from foss.arm.com ([217.140.101.70]:34313 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752473AbcDVNcO (ORCPT ); Fri, 22 Apr 2016 09:32:14 -0400 Date: Fri, 22 Apr 2016 14:32:09 +0100 From: Catalin Marinas To: Suzuki K Poulose Cc: linux-arm-kernel@lists.infradead.org, mark.rutland@arm.com, marc.zyngier@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, Vadim.Lomovtsev@caviumnetworks.com Subject: Re: [PATCH v4 2/5] arm64: Allow a capability to be checked on a single CPU Message-ID: <20160422133209.GJ2998@e104818-lin.cambridge.arm.com> References: <1461324335-5081-1-git-send-email-suzuki.poulose@arm.com> <1461324335-5081-3-git-send-email-suzuki.poulose@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1461324335-5081-3-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 Fri, Apr 22, 2016 at 12:25:32PM +0100, Suzuki K. Poulose wrote: > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -1005,6 +1005,24 @@ static void __init setup_feature_capabilities(void) > enable_cpu_capabilities(arm64_features); > } > > +/* > + * Check if the current CPU has a given feature capability. > + * Should be called from non-preemptible context. > + */ > +bool this_cpu_has_cap(unsigned int cap) > +{ > + const struct arm64_cpu_capabilities *caps = arm64_features; > + > + if (WARN_ON(preemptible())) > + return false; > + > + for (caps = arm64_features; caps->desc; caps++) > + if (caps->capability == cap && caps->matches) > + return caps->matches(caps, SCOPE_LOCAL_CPU); Nitpick: you don't need to initialise "caps" twice. Reviewed-by: Catalin Marinas