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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 5402DC43460 for ; Thu, 6 May 2021 12:43:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 064A6613D8 for ; Thu, 6 May 2021 12:43:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231327AbhEFMoi (ORCPT ); Thu, 6 May 2021 08:44:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229777AbhEFMoh (ORCPT ); Thu, 6 May 2021 08:44:37 -0400 Received: from mail-lj1-x22e.google.com (mail-lj1-x22e.google.com [IPv6:2a00:1450:4864:20::22e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB4EEC061763 for ; Thu, 6 May 2021 05:43:38 -0700 (PDT) Received: by mail-lj1-x22e.google.com with SMTP id o16so6876432ljp.3 for ; Thu, 06 May 2021 05:43:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=fbHWIIjNsb9wei3xXx6Otqpzu53zaXTIXIFKBmpNOgo=; b=Bgqg7sh9bCd5nshaNaWvRHui08dl/ZbqDnFZ0IJ97hliP13z/2GcIBrux/SLdwV0/i Km45HFsHhgWctbcGuGF6Ai0HvMZqIj6POZRSs6/PpSRACJl2PlFmLQU4hlC1yDovIWBg aoQtkENq3gxHz6laQ2nmHkKeFF5HDzsMB1hneI4Ds46GeucQ1zmRGYA3wLsnyxnSTV+p Db5TgOzJNR01i8q8ZcC7fzaKnTvJPicRUV9tY8zTJ3Fn3kGnBEhC16d3shmCkOArTBkz lLFzcth3mqWw7rRMzs4kvzsjIlgL1hnv1j22fv57T54QODE0L88yQ2jCksh+4ITE6+wH 5VGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=fbHWIIjNsb9wei3xXx6Otqpzu53zaXTIXIFKBmpNOgo=; b=K92eClfWreYBSi1EHnzI43vAtCtdowAw9ATXLIRCLpKa8OWQX/BqtUabKokATOorWs BBoix+S5SsAftC7enZMlgw/oBDRDxQMpUsMqO03foSXB4xvt4byYjHfFj9YrSwp89oEc QeQM7I5STPs4AbeEVB4ZVB/TCszX+U69cRpWubL+MH+c9QusSamTY3Mv3e77uKX8MDef jz8d3vGf8w2zSELTacy58FpQw4mo4LyFgwSQqY+jDsSFBLw9oit/d8PxrO54wRAbrVG5 97tfeTie7ee1NnO7JHcdVpdhWA569aS837mLhMO90N9ahU37YPSHSOUmIb1l0i3aqBDX DGkQ== X-Gm-Message-State: AOAM530ful2UmSXPy34IRW0AkZLN6tD0xHVSHtlC2J5WqnifvUPbSYpU FNbCR+XLuBSSUU2HCUhTufEydroSeja3Drbfk0I0zA== X-Google-Smtp-Source: ABdhPJz4optDOZiBZ3vSZcVI8Py60XPMQCZzXNInCGDBXfYIu467P3Ej4pt6DNl0kP7Ihy/ZCeYrBXG2yJQ/QYMK8Ng= X-Received: by 2002:a05:651c:503:: with SMTP id o3mr3172636ljp.368.1620305017299; Thu, 06 May 2021 05:43:37 -0700 (PDT) MIME-Version: 1.0 References: <20210317113130.2554368-1-geert+renesas@glider.be> In-Reply-To: <20210317113130.2554368-1-geert+renesas@glider.be> From: Linus Walleij Date: Thu, 6 May 2021 14:43:26 +0200 Message-ID: Subject: Re: [PATCH v3] ARM: Parse kdump DT properties To: Geert Uytterhoeven Cc: Russell King , Ard Biesheuvel , Nicolas Pitre , Marek Szyprowski , Dmitry Osipenko , Rob Herring , Simon Horman , Arnd Bergmann , Stephen Boyd , =?UTF-8?Q?Uwe_Kleine=2DK=C3=B6nig?= , Lukasz Stelmach , Linux ARM , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Linux-Renesas , linux-kernel , kexec@lists.infradead.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 17, 2021 at 12:31 PM Geert Uytterhoeven wrote: > Parse the following DT properties in the crash dump kernel, to provide a > modern interface between kexec and the crash dump kernel: > - linux,elfcorehdr: ELF core header segment, similar to the > "elfcorehdr=" kernel parameter. > - linux,usable-memory-range: Usable memory reserved for the crash dump > kernel. > This makes the memory reservation explicit. If present, Linux no > longer needs to mask the program counter, and rely on the "mem=" > kernel parameter to obtain the start and size of usable memory. > > For backwards compatibility, the traditional method to derive the start > of memory is still used if "linux,usable-memory-range" is absent, and > the "elfcorehdr=" and "mem=" kernel parameters are still parsed. > > Loosely based on the ARM64 version by Akashi Takahiro. > > Signed-off-by: Geert Uytterhoeven I like the approach overall. I see Rob has some comments that need adressing. The chosen.txt file needs an example of how to use this so people can intuitively get it right if they want to play with it, it was at least the first question in my head: how does that look in practice? Yours, Linus Walleij