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 3FABC105F7AE for ; Fri, 13 Mar 2026 14:46:45 +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: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=7hmrc7E4N1O33Dgmjo3wpHwaqQJ3tUam2wicpgCLnlA=; b=L2m0vqCkBXe/J5fT61+du/H7TJ Dfq80BeSmnIcJD8ore7hF8hJsxNBanEwjB82V3btczk9XAgXwdIYnsEutwXkICQESegOeXzdSuPOl nl+woNbO3efqahwKq9PUncMlta58YEYihAPHCfqKDF4iuXI6p9zEIcn+cWX6Zl4PH5bzoFPPo/hJT V7c8zwV3m5Q2TvRwFRQ15gzi5cPB6R/HTFbplTpzrfrPdmiCQ2TIbn7LugBZ6awEjtYwDlQwws101 XnkOrQDM5b7SZ/EuVk5CHo38gHWVtCq7OCnLNyAAIso9ucfO+Hh8l5eoUTe+UR3HGC1orR0kh7DD3 9A7XhEnA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w13mi-00000000QLE-32t6; Fri, 13 Mar 2026 14:46:40 +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 1w13mf-00000000QJf-1mGl for linux-arm-kernel@lists.infradead.org; Fri, 13 Mar 2026 14:46:38 +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 3B1D91E7D; Fri, 13 Mar 2026 07:46:30 -0700 (PDT) Received: from e134344.cambridge.arm.com (e134344.arm.com [10.1.196.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 861153F7BD; Fri, 13 Mar 2026 07:46:32 -0700 (PDT) From: Ben Horgan To: ben.horgan@arm.com 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, catalin.marinas@arm.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, zengheng4@huawei.com, linux-doc@vger.kernel.org Subject: [PATCH v6 01/40] arm_mpam: Ensure in_reset_state is false after applying configuration Date: Fri, 13 Mar 2026 14:45:38 +0000 Message-ID: <20260313144617.3420416-2-ben.horgan@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260313144617.3420416-1-ben.horgan@arm.com> References: <20260313144617.3420416-1-ben.horgan@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260313_074637_512516_8165908D X-CRM114-Status: UNSURE ( 9.77 ) 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 From: Zeng Heng The per-RIS flag, in_reset_state, indicates whether or not the MSC registers are in reset state, and allows avoiding resetting when they are already in reset state. However, when mpam_apply_config() updates the configuration it doesn't update the in_reset_state flag and so even after the configuration update in_reset_state can be true and mpam_reset_ris() will skip the actual register restoration on subsequent resets. Once resctrl has a MPAM backend it will use resctrl_arch_reset_all_ctrls() to reset the MSC configuration on unmount and, if the in_reset_state flag is bogusly true, fail to reset the MSC configuration. The resulting non-reset MSC configuration can lead to persistent performance restrictions even after resctrl is unmounted. Fix by clearing in_reset_state to false immediately after successful configuration application, ensuring that the next reset operation properly restores MSC register defaults. Fixes: 09b89d2a72f3 ("arm_mpam: Allow configuration to be applied and restored during cpu online") Signed-off-by: Zeng Heng Acked-by: Ben Horgan [Horgan: rewrite commit message to not be specific to resctrl unmount] Signed-off-by: Ben Horgan --- Subject was originally: arm_mpam: Fix MPAM reset on resctrl unmount by clearing in_reset_state --- drivers/resctrl/mpam_devices.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 1eebc2602187..0fd6590a9b5c 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -2692,6 +2692,7 @@ int mpam_apply_config(struct mpam_component *comp, u16 partid, srcu_read_lock_held(&mpam_srcu)) { arg.ris = ris; mpam_touch_msc(msc, __write_config, &arg); + ris->in_reset_state = false; } mutex_unlock(&msc->cfg_lock); } -- 2.43.0