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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 994FBC61DD8 for ; Fri, 13 Nov 2020 14:36:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5CEF62078B for ; Fri, 13 Nov 2020 14:36:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="PvtncT+D"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="WrTh6JnT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726621AbgKMOgK (ORCPT ); Fri, 13 Nov 2020 09:36:10 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:53134 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726443AbgKMOgJ (ORCPT ); Fri, 13 Nov 2020 09:36:09 -0500 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1605278168; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=/7H7cJ5j1JFx9OGMmbYXMDayFBipc1Odzd7yUdm50eQ=; b=PvtncT+DBe+snL/saZY+J1T9Q3NG/FTcri0yCZCHiRMzeRegVVIAuy5lwbugFDgCy3H1xs DN/R4SFpSCrlCdXtjWAPkGyLh4bDQ2hh5NdUs21MIGoe2Svy0ZPG/piECCNYM1Dc3MW9Si Ozzgg4cuzMedVodJa1AUg0OBqHEtUWBUByTscdSKS7+vuSUlFQ/u/yWWDRzYHI2+Jf98kb Tm20U4B32eyJfS2h13hFL7FCKrtYOitnUhXIwLS9jnY85WPUuhc4BDKjcVPwmxz51BClJ+ CMCzWuPiu0reZsavJEJQGX/FJ+IFU+VwhQK66Rm4FPzo9GgDqThUSJaJB493lg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1605278168; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=/7H7cJ5j1JFx9OGMmbYXMDayFBipc1Odzd7yUdm50eQ=; b=WrTh6JnTuXCGlQiWJQu2QtVRhUeab7lUfU1+4W28/LT8gg2CX5O1n/e8USHAOcqpo04T3U 2Lz6Dj2wlYCb0HBw== To: Max Filippov Cc: "open list\:TENSILICA XTENSA PORT \(xtensa\)" , Chris Zankel , LKML Subject: Re: [PATCH] highmem: fix highmem for xtensa In-Reply-To: References: <20201113122328.22942-1-jcmvbkbc@gmail.com> <87zh3ll6hw.fsf@nanos.tec.linutronix.de> Date: Fri, 13 Nov 2020 15:36:07 +0100 Message-ID: <87sg9dl3xk.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Max, On Fri, Nov 13 2020 at 05:50, Max Filippov wrote: > On Fri, Nov 13, 2020 at 5:40 AM Thomas Gleixner wrote: >> On Fri, Nov 13 2020 at 04:23, Max Filippov wrote: >> > Fixmap on xtensa grows upwards, i.e. bigger fixmap entry index >> > corresponds to a higher virtual address. This was lost in highmem >> > generalization resulting in the following runtime warnings: >> >> Sorry for not noticing. >> >> > Fix it by adding __ARCH_HAS_POSITIVE_FIXMAP macro and implementing >> > vaddr_in_fixmap and fixmap_pte primitives differently depending on >> > whether it is defined or not. >> >> What's wrong with just doing the obvious and making the fixmap defines >> the other way round? > > It becomes really awkward when we get to support high memory with > aliasing data cache: we must think about the actual virtual addresses > assigned to pages and it feels much simpler when it's done this way. Feeling are not really a technical argument. Is there any functional difference which matters? Thanks, tglx