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 4B5FFCA0EFF for ; Wed, 27 Aug 2025 11:29:38 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=jzT6lK+GCu9K2FLE5o7Ljy8OWdxNBrNhiRd9FVmZNLM=; b=ptfSZwe6stJC/BXs78kE6VIYz5 IQf3o3rrXRa+GgL9ziFm+3GS2VFos6/OhDZIaap1vZOGuG2k3z1ZR5kASpexw+ZnHUISQsDq1Euu8 fTle4I44cSiM3sfYAY3xBviWZ/vgzZkvNAJzHPzcIbfBl9q77FWBf89qvOq6MaXgNrkiwVdou//XU ADPdMyblqyRJN6Fkywy1KojM0N154nXf64CIguN1jwhI7595HiIsO/b4N0CLB0TmT1IPrDwS+jvLn kvIYBxoz8PYiLMnWh0DY8cTE+JF7b3gmQtD4Yqlm7KIqopdSbRJmavY4HOoLK2BgRGF30CpGz2w+0 GeCSikHg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1urELN-0000000FGkj-1BfT; Wed, 27 Aug 2025 11:29:33 +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 1urDfy-0000000F721-1CG3 for linux-arm-kernel@lists.infradead.org; Wed, 27 Aug 2025 10:46:47 +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 7A1D71688; Wed, 27 Aug 2025 03:46:37 -0700 (PDT) Received: from e133380.arm.com (e133380.arm.com [10.1.197.68]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0753D3F738; Wed, 27 Aug 2025 03:46:39 -0700 (PDT) Date: Wed, 27 Aug 2025 11:46:37 +0100 From: Dave Martin To: James Morse Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org, devicetree@vger.kernel.org, shameerali.kolothum.thodi@huawei.com, D Scott Phillips OS , carl@os.amperecomputing.com, 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 , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Krzysztof Kozlowski , Conor Dooley , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich Subject: Re: [PATCH 02/33] drivers: base: cacheinfo: Add helper to find the cache size from cpu+level Message-ID: References: <20250822153048.2287-1-james.morse@arm.com> <20250822153048.2287-3-james.morse@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250822153048.2287-3-james.morse@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250827_034646_365644_972A2A10 X-CRM114-Status: GOOD ( 22.20 ) 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, On Fri, Aug 22, 2025 at 03:29:43PM +0000, James Morse wrote: > MPAM needs to know the size of a cache associated with a particular CPU. > The DT/ACPI agnostic way of doing this is to ask cacheinfo. > > Add a helper to do this. > > Signed-off-by: James Morse > > --- > Changes since v1: > * Converted to kdoc. > * Simplified helper to use get_cpu_cacheinfo_level(). > --- > include/linux/cacheinfo.h | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/include/linux/cacheinfo.h b/include/linux/cacheinfo.h > index 2dcbb69139e9..e12d6f2c6a57 100644 > --- a/include/linux/cacheinfo.h > +++ b/include/linux/cacheinfo.h > @@ -148,6 +148,21 @@ static inline int get_cpu_cacheinfo_id(int cpu, int level) > return ci ? ci->id : -1; > } > > +/** > + * get_cpu_cacheinfo_size() - Get the size of the cache. > + * @cpu: The cpu that is associated with the cache. > + * @level: The level of the cache as seen by @cpu. > + * > + * Callers must hold the cpuhp lock. > + * Returns the cache-size on success, or 0 for an error. > + */ Nit: Maybe use the wording cpuhp lock must be held. in the kerneldoc here, to match the other helpers it sits alongside. Otherwise, looks reasonable. > +static inline unsigned int get_cpu_cacheinfo_size(int cpu, int level) > +{ > + struct cacheinfo *ci = get_cpu_cacheinfo_level(cpu, level); > + > + return ci ? ci->size : 0; > +} > + Orphaned function? Can fs/resctrl/rdtgroup.c:rdtgroup_cbm_to_size() be ported to use this? If so, this wouldn't just be dead code in this series. Cheers ---Dave