From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 74EAF2853E3; Wed, 27 Aug 2025 10:46:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756291608; cv=none; b=RRhW/1c95C39oXFEgmvsymxhYTrkM8TLd2zzLr30WDfg/NMaXUwo/4F7Mqw66+KOWxXGdkyNabA+ZN02IToBpBcgsN6BgDt2pEyhZWdFJgS7XJcgA7CWGhINa/r4N6UXDq09h1Vm4O2MOIX3cpLYZwr5cUvU9E6aVXbAjJPkgRw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756291608; c=relaxed/simple; bh=NEeFWbxSjOhaJkreE/MdcTRInyZBXBYCV9SQqK9qwfs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=bK2B+H0EhiRNZJRW90d5mTY3EwFZGxoK5HQpdAMaxxcD7mPbNyDMxbEMVjCMScJ8+/vhXw/k/6ZviGoblpmOmetnbQEjHrdELJFWoWDVPwnupHxojnHFCX0w9jbcHUvm/ilf85DBg2Crq+M2DOdTIg29kEdSIEHxjQmUTI0ctO4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250822153048.2287-3-james.morse@arm.com> 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