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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 EE305C433EC for ; Mon, 29 Mar 2021 09:31:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C862361960 for ; Mon, 29 Mar 2021 09:31:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232111AbhC2Jat (ORCPT ); Mon, 29 Mar 2021 05:30:49 -0400 Received: from elvis.franken.de ([193.175.24.41]:33842 "EHLO elvis.franken.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231572AbhC2JaX (ORCPT ); Mon, 29 Mar 2021 05:30:23 -0400 Received: from uucp (helo=alpha) by elvis.franken.de with local-bsmtp (Exim 3.36 #1) id 1lQoE1-0003qb-05; Mon, 29 Mar 2021 11:30:21 +0200 Received: by alpha.franken.de (Postfix, from userid 1000) id 1E866C1D90; Mon, 29 Mar 2021 11:26:07 +0200 (CEST) Date: Mon, 29 Mar 2021 11:26:07 +0200 From: Thomas Bogendoerfer To: Ilya Lipnitskiy Cc: John Crispin , Matthias Brugger , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Chuanhong Guo Subject: Re: [PATCH 2/2] MIPS: ralink: mt7621: add memory detection support Message-ID: <20210329092607.GE8484@alpha.franken.de> References: <20210327053840.471155-1-ilya.lipnitskiy@gmail.com> <20210327053840.471155-2-ilya.lipnitskiy@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210327053840.471155-2-ilya.lipnitskiy@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 26, 2021 at 10:38:40PM -0700, Ilya Lipnitskiy wrote: > From: Chuanhong Guo > > mt7621 has the following memory map: > 0x0-0x1c000000: lower 448m memory > 0x1c000000-0x2000000: peripheral registers > 0x20000000-0x2400000: higher 64m memory > > detect_memory_region in arch/mips/kernel/setup.c only adds the first > memory region and isn't suitable for 512m memory detection because > it may accidentally read the memory area for peripheral registers. > > This commit adds memory detection capability for mt7621: > 1. Add the highmem area when 512m is detected. > 2. Guard memcmp from accessing peripheral registers: > This only happens when a user decided to change kernel load address > to 256m or higher address. Since this is a quite unusual case, we > just skip 512m testing and return 256m as memory size. > > Signed-off-by: Chuanhong Guo > [Minor commit message reword, make mt7621_memory_detect static] > Signed-off-by: Ilya Lipnitskiy > --- > arch/mips/include/asm/mach-ralink/mt7621.h | 7 +++--- > arch/mips/ralink/common.h | 1 + > arch/mips/ralink/mt7621.c | 29 +++++++++++++++++++--- > arch/mips/ralink/of.c | 2 ++ > 4 files changed, 32 insertions(+), 7 deletions(-) applied to mips-next. Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]