From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A28D0606A326 for ; Wed, 4 Nov 2026 11:08:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=xv1sbJo2; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=aY49vEqh 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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=Rlq0AlUVPysrDth/CxuMoGsaxPC731Hkjxmxyzg8dD8=; b=xv1sbJo2JkMjwd0ltSkWOtsT6h hbC/RYJAIQXE5nBNVn0pt4HeuIfnF/ddhu0bE530L5R7tjQvSyPY3BwqZMlBeFYdUliS6bfzeJAVl vWzs2mIaSMgOOlOUUItPqA4kRKBcUi6S4/LqFb5J07i36Jz0trxvTe94/mjenpKF02RpPKI5rbAQa BDIN2dz8GngSo3w+OygD/w8Lz+RcfGiXTdSb6QxDKWkpiGcoyXmvTVO4tKw0rMuMFRXMlZgT8aDkv UOmwMpFe4lx8KQZFHKh6uGt/BhW02k5c1ZeJ/PWcsiyyuEIU00RtJkEU0dMBvvL/Tx1G50JeNIq7M DawIZZXw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xOYqO-000000056hh-3zyx; Wed, 04 Nov 2026 11:07:52 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xOYqN-000000056h6-0YYE for linux-arm-kernel@lists.infradead.org; Wed, 04 Nov 2026 11:07:51 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 9562A4196E; Wed, 4 Nov 2026 11:07:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6F7C1F000C1; Wed, 4 Nov 2026 11:07:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793790470; bh=Rlq0AlUVPysrDth/CxuMoGsaxPC731Hkjxmxyzg8dD8=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=aY49vEqhN62ykjnMpkAIKjZ28H6cualZd/MRlIWKbcuXlUAiePZ7oko52CH53WrCf 5QLRqjDPRUepLCarInRwxW6dlhNi0IIus/ayByqiRUDFHfCKOXsjeHCgeowIJzJ1cI xRMQucEJ10m3Qj/A7AFs6sgZLNeJAmYQPdVllMYM8NBAUC8ir+4h7EoquEsRxeFmkT Txyxm2AT3QJJu5RtITSGjtJpUdDX6HQ170BhDfXKPERGoFiISmyb8tV7czHxrstT4C ocC2cwEBC52bCs/pAE9+oFZ+Z077xKs+5jgpR5JE0bH5Svk6OQhvb7WeoqTnVdG4k7 sfIhcA8/Y2LOg== Date: Wed, 4 Nov 2026 12:07:46 +0100 From: Thorsten Blum To: Ben Horgan Cc: Catalin Marinas , Will Deacon , Mark Rutland , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm64: cacheinfo: Simplify init_cache_level() Message-ID: References: <20261104083632.65715-2-blum@kernel.org> <0534c6f4-3bb8-4249-816c-502cf8ccb287@arm.com> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0534c6f4-3bb8-4249-816c-502cf8ccb287@arm.com> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-5.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 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. > 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." Thanks, Thorsten