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 46A97CA101F for ; Fri, 12 Sep 2025 13:29:46 +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=YECl72xE9QuU/KWNETQfkcJY72c7uevrw0XNZU4bZyI=; b=i92Ny/cDn6F+wSf7K4xMsJZT+9 4HhcJwq+x3Bf0w9jGk29UiGdlbo7uKlPQ2b2GYZHBDKQdRYKmmWEUN+JIcGq9JC+sI85W4R/iQffZ JRK3gm3oX6vTEXB7Uup6nyDQLiw9YGZo/GuPHBR9N8QuYSmH6BbLOCWxk3xuQgRz/gT1OQdz72xYp 7s/ncHnF51Vo9k/tvQHIEQho9qm8eFado8RSyuP/gJdmMu9VjUiWIhF7d3WXSjYRbLbhaap6gxZEe YJA4UsMF7apoJD049DfjIBR+PrJZgyYlORtIlv4HpUgifZmVfhAajjZH5uou8aEE3IxSebhbdpwMV ceAbRSBg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1ux3qO-00000009ZQ3-2sTi; Fri, 12 Sep 2025 13:29:40 +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 1ux3qM-00000009ZPb-2BnP for linux-arm-kernel@lists.infradead.org; Fri, 12 Sep 2025 13:29:39 +0000 Received: from mail.maildlp.com (unknown [172.18.186.31]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4cNZxV2v9Zz6GDFh; Fri, 12 Sep 2025 21:28:14 +0800 (CST) Received: from frapeml500008.china.huawei.com (unknown [7.182.85.71]) by mail.maildlp.com (Postfix) with ESMTPS id 9916F1401F4; Fri, 12 Sep 2025 21:29:32 +0800 (CST) Received: from localhost (10.203.177.15) by frapeml500008.china.huawei.com (7.182.85.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Fri, 12 Sep 2025 15:29:31 +0200 Date: Fri, 12 Sep 2025 14:29:29 +0100 From: Jonathan Cameron To: James Morse CC: , , , D Scott Phillips OS , , , , , , Jamie Iles , Xin Hao , , , , David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , , , Rob Herring , Rohit Mathew , "Rafael Wysocki" , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , "Will Deacon" , Greg Kroah-Hartman , Danilo Krummrich , Ben Horgan Subject: Re: [PATCH v2 26/29] arm_mpam: Use long MBWU counters if supported Message-ID: <20250912142929.00003cff@huawei.com> In-Reply-To: <20250910204309.20751-27-james.morse@arm.com> References: <20250910204309.20751-1-james.morse@arm.com> <20250910204309.20751-27-james.morse@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: [10.203.177.15] X-ClientProxiedBy: lhrpeml500005.china.huawei.com (7.191.163.240) To frapeml500008.china.huawei.com (7.182.85.71) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250912_062938_711036_10813738 X-CRM114-Status: GOOD ( 10.10 ) 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 Wed, 10 Sep 2025 20:43:06 +0000 James Morse wrote: > From: Rohit Mathew > > If the 44 bit (long) or 63 bit (LWD) counters are detected on probing > the RIS, use long/LWD counter instead of the regular 31 bit mbwu > counter. > > Only 32bit accesses to the MSC are required to be supported by the > spec, but these registers are 64bits. The lower half may overflow > into the higher half between two 32bit reads. To avoid this, use > a helper that reads the top half multiple times to check for overflow. > > Signed-off-by: Rohit Mathew > [morse: merged multiple patches from Rohit] > Signed-off-by: James Morse > Reviewed-by: Ben Horgan Reviewed-by: Jonathan Cameron