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 X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B10E1C43381 for ; Sat, 23 Mar 2019 17:24:27 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 7F65D20879 for ; Sat, 23 Mar 2019 17:24:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="SIuio9jd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7F65D20879 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=zFLPmgq9kfAKrNVTr6pdRiLKJmjyfe8ThIKdpBqHzoE=; b=SIuio9jdleG8/E jpI14bZEKi98fyBp36MXmK2D0VKK2y8CvgQYhBgYcIIad8XrlcoWKg7LYxG3xdcmzBqGM9W1VeogE 5Q9wbBJjb0TAhyIp2eXYh+LBOWnyCucwym/gJdaH/hosdnZU5rw5TC2ra+QQyqiFI9cGHlTS+BcqN QoAKSDNVWnhko9eXdCU73ijtJ9WtKjLqhlGmWBtmp2iknzlOyb0zhL5d/+Pl9Sjfe2a7nKdHUh3TF fpl4X8DziBAHIAXdOg5zZA7yrgzTnhH+kbA921Ob5ltyvBJYk8CW0XzTeBeC96YPg62zZTjZ645vr +VkyxmhkVHYDC2quofQQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1h7kNb-0003jZ-0e; Sat, 23 Mar 2019 17:24:23 +0000 Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1h7kNZ-0003jE-92; Sat, 23 Mar 2019 17:24:21 +0000 Date: Sat, 23 Mar 2019 10:24:21 -0700 From: Christoph Hellwig To: Mike Rapoport Subject: Re: [PATCH v2 3/5] RISC-V: Allow booting kernel from any 4KB aligned address Message-ID: <20190323172421.GA14080@infradead.org> References: <20190321094710.16552-1-anup.patel@wdc.com> <20190321094710.16552-4-anup.patel@wdc.com> <20190323154012.GA25149@rapoport-lnx> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190323154012.GA25149@rapoport-lnx> User-Agent: Mutt/1.9.2 (2017-12-15) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Palmer Dabbelt , Anup Patel , "linux-kernel@vger.kernel.org" , Christoph Hellwig , Atish Patra , Albert Ou , Paul Walmsley , "linux-riscv@lists.infradead.org" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org On Sat, Mar 23, 2019 at 05:40:12PM +0200, Mike Rapoport wrote: > I have no general objection, but I presume the patch will be significantly > simplified if the addition of 4K pages support will follow the removal of > the trampoline_pd_dir. > > That said, I didn't look into the details, since they will change > substantially, only some comments on the Kconfig part. > > On the high level, have you considered using large pages in setup_vm() and > the remapping everything with 4K pages in setup_vm_final()? This might > save you the whole ops-> churn. That would be a great start. That being said the current tiny memory RISC-V devices don't even have a MMU, so the kernel pagetable mapping isn't even relevant for them. I'm just not sure adding more complexity in the early boot path for a borderline case (MMU and tiny memory with a tiny kernel image) is reall worth all the complexity. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv