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 6856BC531F9 for ; Tue, 28 Jul 2026 10:24:47 +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=TnZIBIfuAN65w+Kig7JAgaIcGU9jpuhp67GcExPOu88=; b=FKjQ2AIWVS3/kKxHtXsQ9sdQRe YgjzvyRtJ0EC6w8DvCuEpFpDQ7pkCJvdS11ZVO0J7HhvNAdvL77CDwexYWEibR2bECeW9feB3WeHy kApLB8j9sMAFmolAkSKpROi7bFNgCPMdNyHs2Sakza87EgX8R5YIRvmC0YqzR+xBSGizqQsv4+MCv Nc4LiXyg6zlKmJpp5dHMtwUgoTQy9GlC2K+qvhc80CbJNXHTk4hp5xovS9ZxZYe6WnW5EooEgDPoa 3f71/whbME3nqauuj8Ar7sKyDvpc9RY+vBj4EDs6QJZ8Gi5sPdmbFMGwubHxFKAUJvcsTMUrszv6p 66heoZoQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1woezB-00000004x9u-0qQh; Tue, 28 Jul 2026 10:24:33 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1woez9-00000004x9H-20K3 for linux-arm-kernel@lists.infradead.org; Tue, 28 Jul 2026 10:24:32 +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 0DE7D1A9A; Tue, 28 Jul 2026 03:24:26 -0700 (PDT) Received: from [192.168.178.24] (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 88F8A3F66F; Tue, 28 Jul 2026 03:24:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1785234270; bh=Qmp+S4jeEmSrfkFAfQ5zyR7lzd8T38ptAobQNxd/cuU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=SJoNAdegQ7YKgun3wquk6jCn/mdv9DajGXn+1hdsfPdT+pcXBg9qEg2yzQ6VpNyta yRKeNFrrELThJLda9OTQ2THOOTS49n5hTEam30QxUHBoHnctkdaAXmieiaC4TgUmV7 XmLOIkBrKGhWFoiXy/YoqSi8OyRf3fcUqsNrb8FY= Message-ID: <22434d15-7e7c-457d-8431-b77db9448cf0@arm.com> Date: Tue, 28 Jul 2026 12:24:25 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 08/10] arm_mpam: add MPAM-Fb MSC firmware access support To: Ritwick Sharma Cc: ben.horgan@arm.com, catalin.marinas@arm.com, fenghuay@nvidia.com, ganapatrao.kulkarni@oss.qualcomm.com, guohanjun@huawei.com, james.morse@arm.com, jic23@kernel.org, lee@trager.us, lenb@kernel.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, lpieralisi@kernel.org, rafael@kernel.org, reinette.chatre@intel.com, sramana@qti.qualcomm.com, srivathsa.rao@oss.qualcomm.com, sudeep.holla@kernel.org, tsoni@quicinc.com, will@kernel.org References: <20260723155454.1760823-9-andre.przywara@arm.com> <20260728100421.4047928-1-ritwick.sharma@arm.com> Content-Language: en-GB From: Andre Przywara In-Reply-To: <20260728100421.4047928-1-ritwick.sharma@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260728_032431_563771_159FCA09 X-CRM114-Status: GOOD ( 15.68 ) 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 Ritwick, On 7/28/26 12:04, Ritwick Sharma wrote: > On Thu, Jul 23, 2026 at 05:54:52PM +0200, Andre Przywara wrote: > >> - WARN_ON_ONCE((MSMON_MBWU_L + sizeof(u64)) > msc->mapped_hwpage_sz); >> + if (msc->iface == MPAM_IFACE_MMIO) >> + WARN_ON_ONCE((MSMON_MBWU_L + sizeof(u64)) > msc->mapped_hwpage_sz); > > I tested the MPAM-Fb series on an Arm AGI CPU. Many thanks for that, and for reporting on the list! > I think a similar MPAM_IFACE_MMIO check is needed in > mpam_msc_zero_mbwu_l(). Without this check, the mapped_hwpage_sz bounds > check is also performed for an MPAM-Fb MSC, which does not have an MMIO > mapping. I observed the following warning during testing: > > [ 50.638246] WARNING: drivers/resctrl/mpam_devices.c:1266 at mpam_msc_zero_mbwu_l+0x98/0xa8 Ouch, you are right, I missed that one. It seems my very limited testing didn't touch that code path. > There also appears to be an off-by-one issue in the calculation of > mapped_hwpage_sz: > > msc->mapped_hwpage_sz = msc_res->end - msc_res->start; > > The current calculation records a size that is one byte smaller than > the actual resource. I think this should use resource_size() instead: > > msc->mapped_hwpage_sz = resource_size(msc_res); Well spotted, I can make a separate patch for that, unless you beat me to it! Many thanks, Andre > > Thanks, > Ritwick