From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=217.140.110.172 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793791148; b=oGUp+d2tTXaNmBGb8lW+FBqGm4I5a/d2TW6xt+qPYMwTt3KsOLshLOtrBtW8Pijmieod KKQD0m2Kui+HOyH5bIgt049/ztufxESNHSBtiSs/jp3T4P7kAwBUrZWXbDbpV6WPQBk1C TzZHkvTjAM9mJ2fAcNUV7b8tH+z267yd2ai+EPk5vd1R19Qw+lFhYSc6hlRAvpFiLDebc aaL2FiNE8v54R7mBNQmcroqHkQyFv1ljo29KmLKK0bYznNSJ+9sRKWZP1y77zgdpTgg6O 4ok2aA4sYzJIAGXNkB9aJ3M95avQRTsTf/TzZCjYFwF5Kba8QamRC7bEiX2OmQyvoLg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793791148; h=DMARC-Filter:Received:Received:DKIM-Signature:Message-ID:Date: MIME-Version:User-Agent:Subject:To:Cc:References:Content-Language: From:In-Reply-To:Content-Type:Content-Transfer-Encoding; bh=XZJjulc9eC2Fef615j91pRgqzgY9in4xbBQCdTQZsjs=; b=Nmpte9S/S2WvcBoMk8GIJFAvyFQdLdZ3a2XCSdkSJ9rvIA/f8PpLibFlY5xdtqfTnLrR 9HdpxN6GUyGTzGl3hQLU9vKeFdaG0bLwphw+7+ZTRP63m+Gvxi+V1Bla4e/sG/YFnu75L zbt17EWQ9zu+5qUOkMSp/BVnAW3NcskCwOiZ+fpe82LlzZngrddXYBvHTvUOgyhoOokuQ af2bb+1gb3d55ECcaFzGIhs6e4mkK7MqE0PrBS4FAH9iwHAOes2hK57PKmlmO19lnedfq 3Eai1cZmFOn4I2tWKNoO62aDkCjyNrKvYBFvx0BCLwJ33eTQTR+9WtP4oWcJEpWufEA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=FmETS+WD; arc=none smtp.remote-ip=217.140.110.172 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7A6D5606A31B for ; Wed, 4 Nov 2026 11:19:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 7A6D5606A31B 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, unprotected) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=FmETS+WD 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 C362B1576; Wed, 4 Nov 2026 03:19:03 -0800 (PST) Received: from [10.2.212.8] (e134344.arm.com [10.2.212.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CE4FE3F632; Wed, 4 Nov 2026 03:19:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1793791146; bh=+Gg1IlVsuPqoi6TzyejboQL7M1kxWf7eEKSdkYy3a5s=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=FmETS+WDer/mEeQGarSpt9aR/XDxHyIfvyFacEqy3082LqIMho+elaQYjK8R593Cz vOpawPRQjb5wVQRnlV2ln2h8xIONCSwXdJCiBIXOF1tMYtEej+58eMz8h/UhCO7kOE IYIdz81lAl6tw1nsIzkZyG6iyBKSI6TlRNukN06U= Message-ID: <33d55cde-9dc1-4d61-8053-f1c1a2e95179@arm.com> Date: Wed, 4 Nov 2026 11:19:04 +0000 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] arm64: cacheinfo: Simplify init_cache_level() To: Thorsten Blum Cc: Catalin Marinas , Will Deacon , Mark Rutland , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20261104083632.65715-2-blum@kernel.org> <0534c6f4-3bb8-4249-816c-502cf8ccb287@arm.com> Content-Language: en-US From: Ben Horgan In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Thorsten, On 04/11/2026 11:07, Thorsten Blum wrote: > Hi Ben, > > On Wed, Nov 04, 2026 at 10:32:58AM +0000, Ben Horgan wrote: >> Hi Thorsten, >> >> On 04/11/2026 08:36, Thorsten Blum wrote: >>> acpi_get_cache_info() already sets fw_level to 0 on failure, so drop the >>> redundant check and the manual assignment. >> >> This doesn't seem to be the case when CONFIG_ACPI_PPTT is not defined. Can the dummy implementation >> in include/linux/cacheinfo.h be called from init_cache_level()? For the implementation in > > On arm64, ACPI_PPTT is selected when ACPI is enabled. When ACPI is > disabled, acpi_disabled = 1 and init_cache_level() won't call the stub. Ok, that's true. > >> drivers/acpi/pptt.c levels is documented as "Number of levels if success." and so would be good to >> mention what happens in the error case if it needs to be relied on. > > Below the parameter descriptions, it already says: > > "Errors caused by lack of a PPTT table, or otherwise, return 0 > indicating we didn't find any cache levels." Ah yes, I should have read on. Thanks, Ben > > Thanks, > Thorsten