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 99EB8D46607 for ; Thu, 15 Jan 2026 18:20:20 +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-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=lYiQAKUYsNXN3OMJD64PdDfVshj7F2/n/IikbQLw+5I=; b=NWpPVqXLssjqHIaLTQjBZIflbY Y2M/EtbaMgLFG91bsEvZTNeFEEiSbqZhjM5DvBSskzVjXLXlaTGHsnmdEaeda9pWnitY4/ztBZF+N 5EM5thdD7FjlQ0vLGx/LONW53YdivcNTrCVAvoDO0T4riQxnmxKPrek9n1CugrMEludZN4BiHtwVK btNUmN+v77maQpGhrbB87PtXYUuGTae/8cy8q8ICfmb7OCa49goEY0UrrElqhC7zf9eD9wouRAJsA WXn58y97J16CO6LQvVhXWBSXdeNr0U5booH7VgCCIsgRtvhlZTYl9Vh0W49B0I1C4nwpWWeO6rov+ Q3RiaPTQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vgRx8-0000000Cwvf-2gUN; Thu, 15 Jan 2026 18:20:14 +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 1vgRx6-0000000CwvH-0ORP for linux-arm-kernel@lists.infradead.org; Thu, 15 Jan 2026 18:20:13 +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 8C5691515; Thu, 15 Jan 2026 10:20:03 -0800 (PST) Received: from arm.com (arrakis.cambridge.arm.com [10.1.197.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DF1DC3F632; Thu, 15 Jan 2026 10:20:04 -0800 (PST) Date: Thu, 15 Jan 2026 18:20:02 +0000 From: Catalin Marinas To: Ben Horgan Cc: amitsinght@marvell.com, baisheng.gao@unisoc.com, baolin.wang@linux.alibaba.com, carl@os.amperecomputing.com, dave.martin@arm.com, david@kernel.org, dfustini@baylibre.com, fenghuay@nvidia.com, gshan@redhat.com, james.morse@arm.com, jonathan.cameron@huawei.com, kobak@nvidia.com, lcherian@marvell.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, peternewman@google.com, punit.agrawal@oss.qualcomm.com, quic_jiles@quicinc.com, reinette.chatre@intel.com, rohit.mathew@arm.com, scott@os.amperecomputing.com, sdonthineni@nvidia.com, tan.shaopeng@fujitsu.com, xhao@linux.alibaba.com, will@kernel.org, corbet@lwn.net, maz@kernel.org, oupton@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, kvmarm@lists.linux.dev Subject: Re: [PATCH v3 09/47] arm64: mpam: Add cpu_pm notifier to restore MPAM sysregs Message-ID: References: <20260112165914.4086692-1-ben.horgan@arm.com> <20260112165914.4086692-10-ben.horgan@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260112165914.4086692-10-ben.horgan@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260115_102012_199320_0BEC4CED X-CRM114-Status: GOOD ( 10.59 ) 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 Mon, Jan 12, 2026 at 04:58:36PM +0000, Ben Horgan wrote: > +static int mpam_pm_notifier(struct notifier_block *self, > + unsigned long cmd, void *v) > +{ > + u64 regval; > + int cpu = smp_processor_id(); > + > + switch (cmd) { > + case CPU_PM_EXIT: > + /* > + * Don't use mpam_thread_switch() as the system register > + * value has changed under our feet. > + */ > + regval = READ_ONCE(per_cpu(arm64_mpam_current, cpu)); > + write_sysreg_s(regval, SYS_MPAM1_EL1); > + isb(); > + > + write_sysreg_s(regval, SYS_MPAM0_EL1); > + > + return NOTIFY_OK; > + default: > + return NOTIFY_DONE; > + } > +} This looks fine unless we decide to save/restore them in the low-level suspend/resume functions. -- Catalin