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 8D76DC87FCB for ; Tue, 5 Aug 2025 17:24:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=b5kmbRAuNZg97lrzvCdhz4qukIVom32WBnnKidnOwhY=; b=WCTWLORJFlorP1qoyColVnQ5bL mMzsB4dOcYMytcRTtVnrJUVqFe21FaWcdeFQzLY6kieMxFv7wuR9H/TSfTnA8vB0WQHH2oSxQbxMI cfuYk3yaxlPJgVlt7k+udKgA5dlnvUMDFeZXP8EuWRqx0Fhqjk56zYwYV0+YCDptP5P9TH/gWaX9y QUER/NfaVTfmzRO8wdG5272cCXupB+pda3jE62MwC/FYrv17IZgXvAQw5srOFezQaGCuBM4oXRfH2 N1L1zGNuZxhzZ4U6UTREtJXM+WErtWY5qLvYlTMa49hToqC13JzU4viGfWJ25kMDuIHgEAWBurknJ 70XJtUbA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1ujLOY-0000000DQXs-1oNc; Tue, 05 Aug 2025 17:24:14 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1ujL7d-0000000DNTq-3BZe for linux-arm-kernel@lists.infradead.org; Tue, 05 Aug 2025 17:06:47 +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 59C84150C; Tue, 5 Aug 2025 10:06:34 -0700 (PDT) Received: from [10.1.197.43] (eglon.cambridge.arm.com [10.1.197.43]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B337F3F673; Tue, 5 Aug 2025 10:06:38 -0700 (PDT) Message-ID: <46248371-9a86-4653-8a06-4e1778808daa@arm.com> Date: Tue, 5 Aug 2025 18:06:37 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 07/36] ACPI / PPTT: Find cache level by cache-id To: Ben Horgan , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Rob Herring , Rohit Mathew , Shanker Donthineni , Zeng Heng , Lecopzer Chen , Carl Worth , shameerali.kolothum.thodi@huawei.com, D Scott Phillips OS , lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Rex Nie , Dave Martin , Koba Ko , Sudeep Holla References: <20250711183648.30766-1-james.morse@arm.com> <20250711183648.30766-8-james.morse@arm.com> Content-Language: en-GB From: James Morse In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250805_100645_840135_ED8395A5 X-CRM114-Status: UNSURE ( 9.14 ) X-CRM114-Notice: Please train this message. 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Ben, On 14/07/2025 12:42, Ben Horgan wrote: > On 7/11/25 19:36, James Morse wrote: >> The MPAM table identifies caches by id. The MPAM driver also wants to know >> the cache level to determine if the platform is of the shape that can be >> managed via resctrl. Cacheinfo has this information, but only for CPUs that >> are online. >> >> Waiting for all CPUs to come online is a problem for platforms where >> CPUs are brought online late by user-space. >> >> Add a helper that walks every possible cache, until it finds the one >> identified by cache-id, then return the level. >> >> acpi_count_levels() expects its levels parameter to be initialised to >> zero as it passes it to acpi_find_cache_level() as starting_level. >> The existing callers do this. Document it. > This paragraph is stale. You dealt with this in the previous commit. Fixed, thanks. James