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 D1EF6C982D6 for ; Thu, 17 Sep 2026 14:57:03 +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=uaruAprQnKNGgAKG2ptX65xfypwitP7tXcad0wF0ZmM=; b=kRWEpmHyD6qri05T4zNVZunCJh 8HotfW7+VcTLZYv9KjZLNxmerX1UziIKziwR3TnK8l2R/pgFrbS8jFHlf0LKPBazk6Wm4tLcyG5F0 WM8Afe2m/faaRxE2+IOcw1FqR64Yboh+LAlsXL1glFGH/d2flFTa9WaXh+5guz0DLCTym6zBMfuao xgatraAGkzkfOSKL7Yn9wT5jdbq/4YFJqztdC0AmwABUZszuRI5AIXf53AjZh7O4IeXwNpLKiX3zR 3MJ+h33oT12YTyuhlea3LTOqsoG5PijuiCSrny7ftyPvfSobSM+om9lgNnkg3HNLk48TPKuJVB2PR zDaPoPPA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x7DXe-0000000BbHC-1bL0; Thu, 17 Sep 2026 14:56:50 +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 1x7DXZ-0000000BbBO-0z7x for linux-arm-kernel@lists.infradead.org; Thu, 17 Sep 2026 14:56:46 +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 8A1C11476; Thu, 17 Sep 2026 07:56:40 -0700 (PDT) Received: from e134344.cambridge.arm.com (unknown [10.2.212.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B27F83F86F; Thu, 17 Sep 2026 07:56:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1789657004; bh=RpO8zOr6jZcL27MkYikOaNk4efDL6B/6X8Hi1ZdtHW4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RX3NAQJ0exD9uuKhKEmGyYyBarHOBOm6jXMVcpW4qKypNCf+oC51ZYTS2oWr9i8mM YhDlcEtzy7C559IwRUVmxfNTHYkAVXzGFCw/0ds4Ll1l/S5LC614axefrxOzgieozW W8QVDlmV9qsvb5VVc9Ouwt2dY9+LgBsUwMEB1mfQ= From: Ben Horgan To: ben.horgan@arm.com Cc: james.morse@arm.com, reinette.chatre@intel.com, fenghuay@nvidia.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, dave.martin@arm.com, andre.przywara@arm.com, Gavin Shan Subject: [PATCH v2 10/12] arm_mpam: Don't loop forever if there is the maximum possible amount of PARTIDs Date: Thu, 17 Sep 2026 15:56:15 +0100 Message-ID: <20260917145617.2202986-11-ben.horgan@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260917145617.2202986-1-ben.horgan@arm.com> References: <20260917145617.2202986-1-ben.horgan@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260917_075645_318631_8DABC87C X-CRM114-Status: GOOD ( 10.89 ) 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 a theoretical platform with the maximum possible number of usable PARTIDs, 0XFFFF, the loops iterating over PARTID in mpam_reset_ris() and mpam_reprogram_ris() will never reach their termination condition leading to a system hang when register the cpu hotplug handlers when MPAM is enabling. Fix these loops. Fixes: f188a36ca241 ("arm_mpam: Reset MSC controls from cpuhp callbacks") Fixes: 09b89d2a72f3 ("arm_mpam: Allow configuration to be applied and restored during cpu online") Signed-off-by: Ben Horgan Tested-by: Gavin Shan --- drivers/resctrl/mpam_devices.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index cdc2d9d19e19..10fc5168699b 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -1754,7 +1754,7 @@ static int mpam_save_mbwu_state(void *arg) */ static int mpam_reset_ris(void *arg) { - u16 partid, partid_max; + u16 partid_max; struct mpam_config reset_cfg = {}; struct mpam_msc_ris *ris = arg; @@ -1764,7 +1764,7 @@ static int mpam_reset_ris(void *arg) spin_lock(&partid_max_lock); partid_max = mpam_partid_max; spin_unlock(&partid_max_lock); - for (partid = 0; partid <= partid_max; partid++) + for (u32 partid = 0; partid <= partid_max; partid++) mpam_reprogram_ris_partid(ris, partid, &reset_cfg); return 0; @@ -1811,7 +1811,6 @@ static int __write_config(void *arg) static void mpam_reprogram_msc(struct mpam_msc *msc) { - u16 partid; bool reset; struct mpam_config *cfg; struct mpam_msc_ris *ris; @@ -1835,7 +1834,7 @@ static void mpam_reprogram_msc(struct mpam_msc *msc) arg.comp = ris->vmsc->comp; arg.ris = ris; reset = true; - for (partid = 0; partid <= mpam_partid_max; partid++) { + for (u32 partid = 0; partid <= mpam_partid_max; partid++) { cfg = &ris->vmsc->comp->cfg[partid]; if (!bitmap_empty(cfg->features, MPAM_FEATURE_LAST)) reset = false; -- 2.43.0