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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E67E9C28CF5 for ; Wed, 26 Jan 2022 10:38:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=lzAA0bXUcpPNfBOfuCYtzS9MZmXuhNtGt5L1ZwT/9no=; b=2AE1b+5K+Dp0gl 6y68F6sKukeDjoiyEdpNlY4gK6kPMsfqDFBEzULl0fssOcSCMK0Fbkld4Kc6nKzC3HIXnoGXK9I9J x+POSaQatJ46iR1PJuvKTdK4kTV6qXJqBuurnjRVa5iu9cWDonOkV3/4LNb4jfgZqwwsniDVI5MVC UJimngYGU/pFVAzWCeqvGLzGvUKpkImmUMENwwDfw9N/Nbu+msfpykgYhIc0KoeK4Obt6KMKljnzI /JVZCVmbF8cby2ppGyZyh9GWHOEcVwFu9lNSsUzK1DJH3E5Etsk2Ls0vYvTBCiQ1uV4oULuIVMJPU Ea1V4muwl07lCkIEGE6g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nCffj-00BHca-Te; Wed, 26 Jan 2022 10:37:05 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nCffX-00BHaq-Pq for linux-arm-kernel@lists.infradead.org; Wed, 26 Jan 2022 10:36:53 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6AD6F1FB; Wed, 26 Jan 2022 02:36:50 -0800 (PST) Received: from bogus (unknown [10.57.39.189]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AE2C53F766; Wed, 26 Jan 2022 02:36:48 -0800 (PST) Date: Wed, 26 Jan 2022 10:36:14 +0000 From: Sudeep Holla To: Kohei Tarumizu Cc: catalin.marinas@arm.com, will@kernel.org, tglx@linutronix.de, Sudeep Holla , mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 5/8] arm64: Create cache sysfs directory without ACPI PPTT for hardware prefetch control Message-ID: <20220126103614.pcrcuc2kzklkq3xa@bogus> References: <20220125071414.811344-1-tarumizu.kohei@fujitsu.com> <20220125071414.811344-6-tarumizu.kohei@fujitsu.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220125071414.811344-6-tarumizu.kohei@fujitsu.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220126_023651_930598_9F2FE9C9 X-CRM114-Status: GOOD ( 11.99 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 Tue, Jan 25, 2022 at 04:14:11PM +0900, Kohei Tarumizu wrote: > This patch will create a cache sysfs directory without ACPI PPTT if > the CONFIG_HWPF_CONTROL is true. > > Hardware prefetch control driver need cache sysfs directory and cache > level/type information. In ARM processor, these information can be > obtained from the register even without PPTT. Therefore, we set the > cpu_map_populated to true to create cache sysfs directory if the > machine doesn't have PPTT. I am assuming this is ACPI enabled system. This looks bit hacky in my opinion. Before I explore better way of adding it, I would like to check if you have explored ways to add PPTT reading these registers from UEFI/EDK2 as PPTT has other topology information which you will need anyways. That would simplify handling of these cacheinfo sysfs in the kernel. Let me know what are your thoughts ? -- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel