From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1A8064519BA; Fri, 31 Jul 2026 16:32:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785515539; cv=none; b=TFZ4ZWtNwmUDX9CNv99VBtM1Kgvlk04R1f4LPt9phdMEE4M+Git+gB8Ho+dNDScNXI7YAOvVtlADJoD1boaSwUOlMJJWVzKoTq76iohVwb8Ns34Uy3cZiRGS2T7mErP0lHKHkJE9xE5i5tUoyUSsU4aaKPM4WRbs10T2JmZq22E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785515539; c=relaxed/simple; bh=VbxlaKfrlvVQz4HJBJtoAZXt2oWQTXMKrfRAQCHlrvA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=YYCrvW0UzRsCoU1NZaxVMqAE/dZGlHdVvmSor5RsOONFP/MNHbTmml+PqLNXEAyda+C+QhmotSJvDfL9VbXKxIXk/Km0IS503pos/yznm0q1bDND3GDmQSrGzZpvWiAlBycMLEd09ZcrnG3TRIosJOsA56k/iOBZr6ENtxlyRjU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=hPN34vbp; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="hPN34vbp" 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 2E4B1204C; Fri, 31 Jul 2026 09:32:12 -0700 (PDT) Received: from [192.168.178.24] (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 71A233F86F; Fri, 31 Jul 2026 09:32:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1785515536; bh=VbxlaKfrlvVQz4HJBJtoAZXt2oWQTXMKrfRAQCHlrvA=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=hPN34vbp4F+JtFjYjq6NM52DmQeW5hEDr6P+aePDLP9XQTBQlk/4DQFEiSoKV7i9C 9tODQZM7wZhedQAcGCLw4TeprZtegBAK6FHBJmda9baR/SbeWQElXQPVb/B+u6elaV RDBrh+ctknoQg4I+hoR4xBAtYGanTZKVFUFlZhpc= Message-ID: <771b0fb7-7689-49dd-a06f-8bef174e432d@arm.com> Date: Fri, 31 Jul 2026 18:32:06 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 00/10] arm_mpam: Add MPAM-Fb firmware support To: Ben Horgan , 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 , Lee Trager , Ritwick Sharma , linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20260730152539.2712312-1-andre.przywara@arm.com> Content-Language: en-GB From: Andre Przywara In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Ben, On 7/30/26 19:10, Ben Horgan wrote: > Hi Andre, > > On 7/30/26 16:25, Andre Przywara wrote: > [...] >> The first six patches rework all MSC access wrappers to propagate error >> information. Pure MMIO based MSC accesses would never fail, but the >> MPAM-Fb access can go wrong in multiple ways. The patches have been split >> up purely for reviewing reasons, if the number is a problem, we could as >> well squash them. Please note that until the very last patch of this series >> any MSC accesses would always only return 0, it's only the final enablement >> of MPAM-Fb that could possibly introduce errors. Hence all former patches >> can add error handling gradually, those code paths wouldn't be triggered >> before patch 10/10. > > I had a go at injecting some errors and noticed that at least some aren't getting to user space. > When writing the schemata file any MPAM-Fb error is not propagated to the user. The > resctrl_arch_update_domains() continues to return 0 as there are some missing links in the chain > down to the writes, e.g. __write_config() always returns 0. Ah yeah, that's true. With the write functions using a compatible prototype (just ignoring the new return value) this is harder to check, since the compiler is just fine with it. So I propagate all MSC access errors now in mpam_reprogram_ris_partid(), and the depending mpam_apply_config(), __write_config and mpam_reset_ris() functions. From my quick analysis I'd say that covers all functions now that mpam_devices.c exports. That will be a new patch 07/11. Cheers, Andre