Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754005AbbBTN55 (ORCPT ); Fri, 20 Feb 2015 08:57:57 -0500 Received: from pandora.arm.linux.org.uk ([78.32.30.218]:52542 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751148AbbBTN54 (ORCPT ); Fri, 20 Feb 2015 08:57:56 -0500 Date: Fri, 20 Feb 2015 13:57:44 +0000 From: Russell King - ARM Linux To: Rob Herring Cc: Dinh Nguyen , Dinh Nguyen , Arnd Bergmann , "linux-kernel@vger.kernel.org" , Olof Johansson , "linux-arm-kernel@lists.infradead.org" Subject: Re: [RESEND PATCH 2/2] arm: socfpga: Set share override bit of the l2 cache controller Message-ID: <20150220135744.GH8656@n2100.arm.linux.org.uk> References: <1424365606-19964-1-git-send-email-dinguyen@opensource.altera.com> <1424365606-19964-2-git-send-email-dinguyen@opensource.altera.com> <54E6DF09.9060505@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1248 Lines: 27 On Fri, Feb 20, 2015 at 07:53:50AM -0600, Rob Herring wrote: > On Fri, Feb 20, 2015 at 1:15 AM, Dinh Nguyen wrote: > > Can I ask what is your reasoning for doing this in the bootloader? It's > > seems like this is such a nice mechanism to do it here. > > Primarily, this register is secure only and we try to avoid secure > mode setup in the kernel. > > Russell also has had a patch to do this generically in his patch queue > forever. If we want this in the kernel, then we should apply that. I discarded it. In general, we want boot loaders or firmware to configure the basic properties of the caches, rather than having the kernel do it for exactly the reasons you say above. Yes, there are some cache features which can only be enabled in combination with CPU features, and those the kernel _has_ to know about, but the basic setup should be done outside the kernel. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/