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 1D74ACCFA13 for ; Thu, 30 Apr 2026 10:25:26 +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-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=3B2N4onJM6s/XddBOSTRq8Ip0ZeDZuU6wiv5gdBK0fY=; b=vPq8SQpXZDRZBO2vdZV+wDA1gT 3owhoHT9BlU5wOBNeRt0sLxfPruSPG6jkH8iVMiin74Wm84FFhB57BtRwIgypaZZieGeZb29s47og yhL9ZGtjaA5xXGW0MgVW2ezQd5N1koh1kM7+Uvz2JNxE82q97cBjKrpp8u2QLbwTPjZ4MuGfLXjFD bk/fXIdCI6VLIibw70/ZcshpyNltGaoQiZiaBEnii4VEPH/SXL8ccpCATkqHiLG4DdZpiZoBPMQbr XCZiicWf0A32EpZh9vIvPMspNLsZmKUbyC+7DN34utiX5Mjj0kDqgnuSuPqOMqNDuEQynFaYQfmft vGSRAWmA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wIOa9-00000005Bwo-00CY; Thu, 30 Apr 2026 10:25:21 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wIOa6-00000005BwK-0kiK for linux-arm-kernel@lists.infradead.org; Thu, 30 Apr 2026 10:25:19 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 85D0543E03; Thu, 30 Apr 2026 10:25:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B1A06C2BCB3; Thu, 30 Apr 2026 10:25:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777544717; bh=tMcr/ZNDm33BeUEJo0HZiE0/fFa3R/A1Oa5PdaowDp0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jO2eG3k+TD7SKH3f063YziHmLklRYcBOUMzewUdMjWcIV2LALhpDAffX/JjJ4h8TP AIRE8MkcqsfqjFNsgwigb//V3tYBoWFE9eY7ILSkNgWYiN/FyxRxIDZ+BNfu+Rzasp 0L4NyU69D21eZTQnN49/hp6Kdjnj0FTjSjEsa+R1Jb7daHQva3fc820Ue5tl3Vhusz eiuv7mMfhOAywMNOOB0Ta3+NJ0ETwGAxZyKGDstCaBo3yPhSnm28gtubg2yeukPPbK qCVNiOmpwVYJKJfYRt3DnBmMxj/DpsDT3n1ByOY6G0jpH5oHRxUgW2l3xOwgvwvWyY Eu4MEXZsF8H2w== Date: Thu, 30 Apr 2026 11:25:12 +0100 From: Sudeep Holla To: Andre Przywara Cc: Lorenzo Pieralisi , Hanjun Guo , Catalin Marinas , Sudeep Holla , Will Deacon , "Rafael J . Wysocki" , Len Brown , James Morse , Ben Horgan , Reinette Chatre , Fenghua Yu , Jonathan Cameron , linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 5/5] arm_mpam: detect and enable MPAM-Fb PCC support Message-ID: <20260430-chirpy-snobbish-pogona-58a9de@sudeepholla> References: <20260429141339.3171205-1-andre.przywara@arm.com> <20260429141339.3171205-6-andre.przywara@arm.com> <20260430-brave-hoatzin-of-fascination-e7d4ad@sudeepholla> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260430_032518_277108_0A90D71B X-CRM114-Status: GOOD ( 30.35 ) 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 Thu, Apr 30, 2026 at 11:20:42AM +0200, Andre Przywara wrote: > Hi Sudeep, > > thanks for having a look! > > On 4/30/26 10:35, Sudeep Holla wrote: > > On Wed, Apr 29, 2026 at 04:13:39PM +0200, Andre Przywara wrote: > > > The Arm MPAM-Fb specification [1] describes a protocol to access MSC > > > registers through a firmware interface. This requires a shared memory > > > region to hold the message, and a mailbox to trigger the access. > > > For ACPI this is wrapped as a PCC channel, described using existing > > > ACPI abstractions. > > > > > > Add code to parse those PCC table descriptions associated with an MSC, > > > and store the parsed information in the MSC struct. > > > This will be used by the MPAM-Fb access wrapper code. > > > > > > [1] https://developer.arm.com/documentation/den0144/latest > > > > > > Signed-off-by: Andre Przywara > > > --- > > > drivers/acpi/arm64/mpam.c | 2 ++ > > > drivers/resctrl/mpam_devices.c | 46 +++++++++++++++++++++++++++++++--- > > > 2 files changed, 45 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/acpi/arm64/mpam.c b/drivers/acpi/arm64/mpam.c > > > index 99c2bdbb3314..edb4d10e8dc3 100644 > > > --- a/drivers/acpi/arm64/mpam.c > > > +++ b/drivers/acpi/arm64/mpam.c > > > @@ -341,6 +341,8 @@ static struct platform_device * __init acpi_mpam_parse_msc(struct acpi_mpam_msc_ > > > } else if (iface == MPAM_IFACE_PCC) { > > > props[next_prop++] = PROPERTY_ENTRY_U32("pcc-channel", > > > tbl_msc->base_address); > > > + props[next_prop++] = PROPERTY_ENTRY_U32("msc-id", > > > + tbl_msc->identifier); > > > > I may be looking at the wrong documents, but neither DEN0065 nor DEN0144 carry > > any definitions of pcc-channel and msc-id for the device with HID > > "“ARMHAA5C". Since "pcc-channel" is already merged, I think I am looking at > > wrong documents, please point me to the right one. > > Please excuse my ignorance, but I was under the assumption that the strings > used here are just unique identifiers that need to match the property_get > calls in the MPAM code. Is there any requirement to match those > property_entry.name fields with the names given in some spec? And those > strings are kernel-internal only, right? But for DT would match exactly the > property names? > My bad, I missed to see that these are properties added to the software node created for ACPI. I assumed the ACPI code is expecting this property in the namespace device with HID 'ARMHAA5C'. Ignore my comment. -- Regards, Sudeep