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 D1FB8C43602 for ; Fri, 3 Jul 2026 08:48:05 +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:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=6lNDvIQ7jr/5I8vOfe3/aTA/gi15hpihcfMyZ4YJxSo=; b=kj94UqceyIt4r0ZOxZ4dF7OpWT xCm08CpghHl/C0YHChqfHyqNI0iYobK7VH/fTcGGy2TJpEzrETU6n0Pw4iQbBPqNeWx4BPZvrfWR2 m9cj2TMfjZTvxi19KNypiSk+CodfmKeZ6GKHYNt6CqUD+NPvZt+FuOuRijCIAk9ct+i/aFqgUqo+2 /L3DRObEx4ZTSK/BGCWd0FwwE+yT1IEyjrMqoJQbpinOCckx1HiCA6rEpXK1BuRA7JbU9HyjDUOdG Bqp5aj8cEeU2CUjQUBO55CBhC0c17/fNqQmvvOMk5eUSRZdfkdZXFhO/882Xdzl86EPLEZTZxcfv9 Azq5Ogjg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wfZZ1-00000006PRa-09zf; Fri, 03 Jul 2026 08:47:59 +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 1wfZYy-00000006PQw-0ejb for linux-arm-kernel@lists.infradead.org; Fri, 03 Jul 2026 08:47:57 +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 173D71F60; Fri, 3 Jul 2026 01:47:51 -0700 (PDT) Received: from [10.211.55.3] (unknown [10.57.73.238]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 838AB3F905; Fri, 3 Jul 2026 01:47:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1783068475; bh=NpBlximhQAzmFuW3CbHn1JpI2uwh8kzm6k5+vboRqUE=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=W1IwFSYrEGjHolem5ODtotNpxmIVDuvNmasOo0DB4mk02ya/vhK2hqF5pDAqkyJPY f7Nz8dcjGapUxlgcFQ2ecuhpIfwuUM3rWrriheS9EfeTle7rARIatAguCVWbGI/GRL IqNb48GIqNV0t1PszcjooZmlYIA/1mxJEsEUK8GI= Message-ID: <717a2f77-7caa-4cf5-acd5-c2f86686e34e@arm.com> Date: Wed, 1 Jul 2026 21:06:26 +0100 MIME-Version: 1.0 User-Agent: Thunderbird Daily Subject: Re: [PATCH v2 04/15] arm_mpam: propagate MSC read errors for mpam_msc_read_mbwu_l() To: Andre Przywara , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , "Rafael J . Wysocki" , Len Brown , James Morse , Reinette Chatre , Fenghua Yu Cc: Jonathan Cameron , Srivathsa L Rao , Ganapatrao Kulkarni , Trilok Soni , Srinivas Ramana , Niyas Sait , linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20260702162229.4008659-1-andre.przywara@arm.com> <20260702162229.4008659-5-andre.przywara@arm.com> Content-Language: en-US From: Ben Horgan In-Reply-To: <20260702162229.4008659-5-andre.przywara@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260703_014756_237185_A61F20BA X-CRM114-Status: GOOD ( 15.43 ) 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 Hi Andre, On 7/2/26 17:22, Andre Przywara wrote: > Allow the mpam_msc_read_mbwu_l() function to return an error, and > propagate read errors from the lower level up. > > Signed-off-by: Andre Przywara > --- > drivers/resctrl/mpam_devices.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c > index 011d1e3544d7..1d06902fb970 100644 > --- a/drivers/resctrl/mpam_devices.c > +++ b/drivers/resctrl/mpam_devices.c > @@ -1106,6 +1106,7 @@ static bool mpam_ris_has_mbwu_long_counter(struct mpam_msc_ris *ris) > > static u64 mpam_msc_read_mbwu_l(struct mpam_msc *msc) Now that your changing the other helpers to return an error and pass a pointer to hold the register value it would seem more consistent for this call to follow the same pattern. Thanks, Ben > { > + int ret; > int retry = 3; > u32 mbwu_l_low; > u32 mbwu_l_high1, mbwu_l_high2; > @@ -1115,11 +1116,17 @@ static u64 mpam_msc_read_mbwu_l(struct mpam_msc *msc) > WARN_ON_ONCE((MSMON_MBWU_L + sizeof(u64)) > msc->mapped_hwpage_sz); > WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(), &msc->accessibility)); > > - __mpam_read_reg(msc, MSMON_MBWU_L + 4, &mbwu_l_high2); > + ret = __mpam_read_reg(msc, MSMON_MBWU_L + 4, &mbwu_l_high2); > + if (ret) > + return MSMON___L_NRDY; > + > do { > mbwu_l_high1 = mbwu_l_high2; > - __mpam_read_reg(msc, MSMON_MBWU_L, &mbwu_l_low); > - __mpam_read_reg(msc, MSMON_MBWU_L + 4, &mbwu_l_high2); > + ret = __mpam_read_reg(msc, MSMON_MBWU_L, &mbwu_l_low); > + if (!ret) > + ret = __mpam_read_reg(msc, MSMON_MBWU_L + 4, &mbwu_l_high2); > + if (ret) > + return MSMON___L_NRDY; > > retry--; > } while (mbwu_l_high1 != mbwu_l_high2 && retry > 0);