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 7A342C54F51 for ; Wed, 29 Jul 2026 15:17:47 +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=LOPGeN0rKCz6mNY13kxCbWHtRpr8S9PGt80cMx45CS0=; b=aMdWERAMQ5PA6+mLjDEJxqjyzS XwcpxUhpiMd2BrXgvwMtrEjNwYx6N8DUWXJ6daOphTmElMyxDd8klQfqkfrQvIiBa72ExLwgCBP6p DNtlD0r2RN6ezIaby2j/IYdF7LgQHXBKgVb5St7vzsJCsJZtzeMTdWTEcxDSI9nNFMNROT+STrs4z 6t8cGLOJfu+1LPWZj/7izzDMsx+Qv4fZoo4F5UM79lctZ8B1IdNd0zyoSEeQqfweoeaafzzFVDB8Q eFQqw8/kTgBQtG/UITYBCxjNUr9lL6X+ui/mL2a9M9nRSxYy7j03qa5vCpE1JdQvmhGLBXb7Ozmkh MCEEmNEA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wp62J-00000008N0F-31yj; Wed, 29 Jul 2026 15:17:35 +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 1wp62G-00000008MzG-3fQ5 for linux-arm-kernel@lists.infradead.org; Wed, 29 Jul 2026 15:17:34 +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 07D1A1688; Wed, 29 Jul 2026 08:17:28 -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 73A4A3F763; Wed, 29 Jul 2026 08:17:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1785338252; bh=yxG2rPBIIwl247qKcaaMERIvGw6yJjMqKv6TJ9vu+Hw=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=ax5MADysoC/XxHv4h3VmFwFgWS3XYIyXGU7QVxjLPdu8sDanQ3XF5LaFknF1/YptF cP0EbCYt3MaeZYZKe62IeCpHab9sQBnFhanqVkI3k8eXdFCKhN5OjsCSRSMWu2/VWB +Tg9dTfl957zi0ZDyyV3bjMjvfwl2tUSHqfkacL8= Message-ID: <6266693e-61d1-41df-bbee-c761ecb47353@arm.com> Date: Wed, 29 Jul 2026 17:17:23 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 08/10] arm_mpam: add MPAM-Fb MSC firmware access support To: Ben Horgan , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , "Rafael J . Wysocki" , Len Brown , James Morse , Reinette Chatre , Fenghua Yu Cc: Jonathan Cameron , Srivathsa L Rao , Ganapatrao Kulkarni , Trilok Soni , Srinivas Ramana , Niyas Sait , Lee Trager , linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20260729134124.2506269-1-andre.przywara@arm.com> <20260729134124.2506269-9-andre.przywara@arm.com> <1da9895e-eaf8-45f0-bac8-c4304a3b4f6a@arm.com> Content-Language: en-GB From: Andre Przywara In-Reply-To: <1da9895e-eaf8-45f0-bac8-c4304a3b4f6a@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-20260729_081733_032051_AB2C01F0 X-CRM114-Status: GOOD ( 17.82 ) 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 Ben, thanks for having a look! On 7/29/26 16:51, Ben Horgan wrote: > Hi Andre, > > On 7/29/26 14:41, Andre Przywara wrote: >> The Arm MPAM Firmware-backed (Fb) Profile document[1] describes an >> alternative way of accessing the "Memory System Components" (MSC) in an >> MPAM enabled system. >> >> Normally the MSCs are MMIO mapped, but in some implementations this >> might not be possible (MSC located outside of the local socket, MSC >> mapped secure-only) or desirable (direct MMIO access too slow or needs >> to be mediated through a control processor). MPAM-fb standardises a >> protocol to abstract MSC accesses, building on the SCMI protocol. >> >> Add functions that do an MSC read or write access by redirecting the >> request through a firmware interface. For now this done via an ACPI >> PCC shared memory and mailbox combination. >> >> Since the protocol used is only a small subset of the full SCMI spec, >> and the SCMI protocol has no full ACPI support anyway, open-code the >> (simple) SCMI message generation, for just the fields we need. >> >> [1] https://developer.arm.com/documentation/den0144/latest >> >> Signed-off-by: Andre Przywara > > [...] > >> diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h >> index 2b81b6b0bf4e..a2193e7df57c 100644 >> --- a/drivers/resctrl/mpam_internal.h >> +++ b/drivers/resctrl/mpam_internal.h >> @@ -11,6 +11,7 @@ >> #include >> #include >> #include >> +#include >> #include >> #include >> #include >> @@ -57,6 +58,15 @@ struct mpam_garbage { >> struct platform_device *pdev; >> }; >> >> +struct mpam_pcc_chan { >> + struct list_head pcc_chans; >> + struct mbox_client pcc_cl; >> + struct pcc_mbox_chan *pcc_chan; >> + struct mutex pcc_chan_lock; /* only one message at a time */ >> + struct kref refcount; >> + int subspace_id; >> +}; >> + >> struct mpam_msc { >> /* member of mpam_all_msc */ >> struct list_head all_msc_list; >> @@ -66,6 +76,8 @@ struct mpam_msc { >> >> /* Not modified after mpam_is_enabled() becomes true */ >> enum mpam_msc_iface iface; >> + struct mpam_pcc_chan *pcc_chan; >> + int mpam_fb_msc_id; /* in its own name space */ > > This gets removed in patch 10 now. I guess you just edited the wrong patch. Argh, you are right, I squashed the fix into 10/10, but indeed the member is already introduced here. Good catch! Cheers, Andre