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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 E828AECE58A for ; Tue, 1 Oct 2019 12:54:55 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id AEB2B21A4A for ; Tue, 1 Oct 2019 12:54:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="BOXfnlLN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AEB2B21A4A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5074D8E0006; Tue, 1 Oct 2019 08:54:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4DF038E0001; Tue, 1 Oct 2019 08:54:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3F5368E0006; Tue, 1 Oct 2019 08:54:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0068.hostedemail.com [216.40.44.68]) by kanga.kvack.org (Postfix) with ESMTP id 207538E0001 for ; Tue, 1 Oct 2019 08:54:55 -0400 (EDT) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id B8AF0758E for ; Tue, 1 Oct 2019 12:54:54 +0000 (UTC) X-FDA: 75995210508.19.wren00_47f11dcc71c47 X-HE-Tag: wren00_47f11dcc71c47 X-Filterd-Recvd-Size: 3159 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf37.hostedemail.com (Postfix) with ESMTP for ; Tue, 1 Oct 2019 12:54:54 +0000 (UTC) Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (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 C1ADF21872; Tue, 1 Oct 2019 12:54:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569934493; bh=4ZwqNMkLAQ6qVgwcsq/kPtYCFF46wZLCtAuZ+J9bA0E=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BOXfnlLNBAeHH+AHjQ/kdaxE6JUJFThHEvZ5AnHpcIJhKyHJiF59b0Nb3ywQH8RE5 78jm9cqaDGZLNS11Hdl09X2vIhhg0UGjXDBMZZPluuea7beLK4hgB694ALgyVuezxZ JS/+Y+lD4qfJINQObM0tYmWz7zzM3Gy1feo1XRN0= Date: Tue, 1 Oct 2019 13:54:47 +0100 From: Will Deacon To: Jia He Cc: Catalin Marinas , Mark Rutland , James Morse , Marc Zyngier , Matthew Wilcox , "Kirill A. Shutemov" , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Punit Agrawal , Thomas Gleixner , Andrew Morton , hejianet@gmail.com, Kaly Xin Subject: Re: [PATCH v10 1/3] arm64: cpufeature: introduce helper cpu_has_hw_af() Message-ID: <20191001125446.gknoofnm7az4wqf5@willie-the-truck> References: <20190930015740.84362-1-justin.he@arm.com> <20190930015740.84362-2-justin.he@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190930015740.84362-2-justin.he@arm.com> User-Agent: NeoMutt/20170113 (1.7.2) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Sep 30, 2019 at 09:57:38AM +0800, Jia He wrote: > We unconditionally set the HW_AFDBM capability and only enable it on > CPUs which really have the feature. But sometimes we need to know > whether this cpu has the capability of HW AF. So decouple AF from > DBM by new helper cpu_has_hw_af(). > > Signed-off-by: Jia He > Suggested-by: Suzuki Poulose > Reviewed-by: Catalin Marinas > --- > arch/arm64/include/asm/cpufeature.h | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h > index 9cde5d2e768f..949bc7c85030 100644 > --- a/arch/arm64/include/asm/cpufeature.h > +++ b/arch/arm64/include/asm/cpufeature.h > @@ -659,6 +659,16 @@ static inline u32 id_aa64mmfr0_parange_to_phys_shift(int parange) > default: return CONFIG_ARM64_PA_BITS; > } > } > + > +/* Check whether hardware update of the Access flag is supported */ > +static inline bool cpu_has_hw_af(void) > +{ > + if (IS_ENABLED(CONFIG_ARM64_HW_AFDBM)) > + return read_cpuid(ID_AA64MMFR1_EL1) & 0xf; 0xf? I think we should have a mask in sysreg.h for this constant. Will