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 C80E2C79FAD for ; Mon, 5 Jan 2026 17:10:12 +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:MIME-Version:References:In-Reply-To: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=qN/f7HSJrrR3qiCeXEbDCd05WOKoZQ1xYHqGZhh2v5o=; b=pbXJ1Y3VJY4YsI8QF6jLZYZ6F6 AvRnsl7UWTHxr2FLWLdQq6oBneOAO9UmerAR5kjSRF0c9kVLm4W691LxubixNtHCr/MJtX1lwoLiG 2E6kVQVsZw/KiJlsretwTOhRfGXDZvAw0Co5UcRZUoBIINYJO+CqwyG25wgv98qUJPC3A0+WJVz8E rqz+J9uA3Da3VJB5QO46Bq32NOoSXMea9063/7t4YI5ZsPwFH1I4SZxH64TmwDqEe/eLXxXTF9xdl d6W5XlVliprmIB6kZ9yPTpHOmMcFNvEGe5RxpN/JEk2viL4kiiAOy+qjHtJBwatoLBxJmXug3tX3H BtSDe1/A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vco5m-0000000BmrU-3pAQ; Mon, 05 Jan 2026 17:10:06 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vco5k-0000000Bmpl-0JrL for linux-arm-kernel@lists.infradead.org; Mon, 05 Jan 2026 17:10:05 +0000 Received: from mail.maildlp.com (unknown [172.18.224.150]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4dlLQK2BlRzJ4687; Tue, 6 Jan 2026 01:10:01 +0800 (CST) Received: from dubpeml100005.china.huawei.com (unknown [7.214.146.113]) by mail.maildlp.com (Postfix) with ESMTPS id 871764056A; Tue, 6 Jan 2026 01:10:01 +0800 (CST) Received: from localhost (10.126.174.38) by dubpeml100005.china.huawei.com (7.214.146.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Mon, 5 Jan 2026 17:09:59 +0000 Date: Mon, 5 Jan 2026 17:09:58 +0000 From: Jonathan Cameron To: Ben Horgan CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH v2 10/45] arm64: mpam: Add cpu_pm notifier to restore MPAM sysregs Message-ID: <20260105170958.00007c32@huawei.com> In-Reply-To: <20251219181147.3404071-11-ben.horgan@arm.com> References: <20251219181147.3404071-1-ben.horgan@arm.com> <20251219181147.3404071-11-ben.horgan@arm.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.126.174.38] X-ClientProxiedBy: lhrpeml500012.china.huawei.com (7.191.174.4) To dubpeml100005.china.huawei.com (7.214.146.113) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260105_091004_282047_CF5BE11F X-CRM114-Status: UNSURE ( 9.74 ) X-CRM114-Notice: Please train this message. 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 Fri, 19 Dec 2025 18:11:12 +0000 Ben Horgan wrote: > From: James Morse > > The MPAM system registers will be lost if the CPU is reset during PSCI's > CPU_SUSPEND. > > Add a PM notifier to restore them. > > mpam_thread_switch(current) can't be used as this won't make any changes if > the in-memory copy says the register already has the correct value. In > reality the system register is UNKNOWN out of reset. > > Signed-off-by: James Morse > Signed-off-by: Ben Horgan Reviewed-by: Jonathan Cameron