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 154DEFD5F79 for ; Wed, 8 Apr 2026 11:15:47 +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=LhgFpSeQmIt9/Bn9B2tb3GS8hG4UzUV5QUAvyGcMwrE=; b=0WpWLiyWEPPmkOkrpYoJiFgLVN umRWtW9r3yDiJ8NppSvwnGhFhae5/cMTydTYEftEsh0BgfizWJtXkU+O8Qo4IXhDFx9vdzgSjOvQr rFyEDdnOPp6qRombi5gX1gvI2XFOsmfl7LL9i0zzUt3DtL5E/dtGDHR6EXBPlkct6kDNLkzdbdBXf eUCvY3KklmFT/TddtIeAYZRTpKvhAZkhKr27OS/E7poEHacc8yA5igIyakizvMSTKuvSn1pIOwkzt wGRjulTiq3vJxHltNhKmcrQrZ+Dql+jAa9bMObarrMEQRBfQKGuK0vrdea+jHoLu9MLmYCCGBKXIU XP6RJ5TQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wAQsn-00000008jV4-41xt; Wed, 08 Apr 2026 11:15:41 +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 1wAQsl-00000008jUi-3SM1 for linux-arm-kernel@lists.infradead.org; Wed, 08 Apr 2026 11:15:41 +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 7A5603161; Wed, 8 Apr 2026 04:15:31 -0700 (PDT) Received: from [10.57.86.179] (unknown [10.57.86.179]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 65DE03F641; Wed, 8 Apr 2026 04:15:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1775646937; bh=igR4tf9tvQIXuyv1BNumq6EyMN3XRctwsRk0w2FJVXM=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=vmSjwA7DZY/mrvzmHWRHTxc8XRQEDtjI/NSPo+eCaom6KcIlEdJNksO3Ug2p32frD bmssI77hNNjyHZbmiXYcj6Z+SnjoN3yx4TSxtECLlBIK9kTaVScZIcg+SWNq9WCl9l ei7sqx3WBZdUfzeW3vdvTzF2MEUrE172T8LpGmog= Message-ID: <2c1a1694-9597-400d-b441-714225b5377b@arm.com> Date: Wed, 8 Apr 2026 12:15:31 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/3] arm-smmu-v3: Add PMCG child support and update PMU MMIO mapping To: "Peng Fan (OSS)" , Will Deacon , Joerg Roedel , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Mark Rutland Cc: linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Peng Fan References: <20260408-smmu-perf-v1-0-d75dac96e828@nxp.com> From: Robin Murphy Content-Language: en-GB In-Reply-To: <20260408-smmu-perf-v1-0-d75dac96e828@nxp.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260408_041539_934066_63002794 X-CRM114-Status: GOOD ( 16.77 ) 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 On 2026-04-08 8:51 am, Peng Fan (OSS) wrote: > This patch series adds proper support for describing and probing the > Arm SMMU v3 PMCG (Performance Monitor Control Group) as a child node of > the SMMU in Devicetree, and updates the relevant drivers accordingly. > > The SMMU v3 architecture allows an optional PMCG block, typically > associated with TCUs, to be implemented within the SMMU register > address space. For example, mmu700 PMCG is at the offset 0x2000 of the > TCU page 0. But what's wrong with the existing binding? Especially given that it even has an upstream user already: https://git.kernel.org/torvalds/c/aef9703dcbf8 > Patch 1 updates the SMMU v3 Devicetree binding to allow PMCG child nodes, > referencing the existing arm,smmu-v3-pmcg binding. > > Patch 2 updates the arm-smmu-v3 driver to populate platform devices for > child nodes described in DT once the SMMU probe succeeds. > > Patch 3 updates the SMMUv3 PMU driver to correctly handle MMIO mapping when > PMCG is described as a child node. The PMCG registers occupy a sub-region > of the parent SMMU MMIO window, which is already requested by the SMMU That has not been the case since 52f3fab0067d ("iommu/arm-smmu-v3: Don't reserve implementation defined register space") nearly 6 years ago, where the whole purpose was to support Arm's PMCG implementation properly. What kernel is this based on? Thanks, Robin. > Signed-off-by: Peng Fan > --- > Peng Fan (3): > dt-bindings: iommu: arm-smmu-v3: Allow PMU child nodes > iommu/arm-smmu-v3: Populate PMU child devices from Devicetree > perf/arm-smmuv3: Avoid double-requesting shared SMMU MMIO for PMCG > > .../devicetree/bindings/iommu/arm,smmu-v3.yaml | 10 ++++++++++ > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 3 +++ > drivers/perf/arm_smmuv3_pmu.c | 19 ++++++++++++++++--- > 3 files changed, 29 insertions(+), 3 deletions(-) > --- > base-commit: f3e6330d7fe42b204af05a2dbc68b379e0ad179e > change-id: 20260408-smmu-perf-754367fe66c8 > > Best regards,