From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752910AbbATXsd (ORCPT ); Tue, 20 Jan 2015 18:48:33 -0500 Received: from pandora.arm.linux.org.uk ([78.32.30.218]:42301 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751645AbbATXsc (ORCPT ); Tue, 20 Jan 2015 18:48:32 -0500 Date: Tue, 20 Jan 2015 23:48:21 +0000 From: Russell King - ARM Linux To: Stefan Agner Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Mark Salter , Kees Cook , Laura Abbott , Arnd Bergmann , Rob Herring Subject: Re: [PATCH v2] ARM: early fixmap support for earlycon Message-ID: <20150120234821.GN26493@n2100.arm.linux.org.uk> References: <1421797064-2989-1-git-send-email-stefan@agner.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1421797064-2989-1-git-send-email-stefan@agner.ch> 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 On Wed, Jan 21, 2015 at 12:37:44AM +0100, Stefan Agner wrote: > Add early fixmap support, initially to support permanent, fixed > mapping support for early console. A temporary, early pte is > created which is migrated to a permanent mapping in paging_init. > This is also needed since the attributs may change as the memory > types are initialized. The 3MiB range of fixmap spans two pte > tables, but currently only one pte is created for early fixmap > support. I think this needs to be done more carefully - I think the entry(ies) should be removed, the TLBs flushed, and the new entry established. So: > +static void __init early_fixmap_shutdown(void) > +{ > + int i; > + > + pte_offset_fixmap = &pte_offset_late_fixmap; > + pmd_clear(fixmap_pmd(fix_to_virt(__end_of_permanent_fixed_addresses - 1))); I think you should flush tlbs here. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net.