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=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 8B32EC433E6 for ; Sun, 7 Mar 2021 15:25:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5032265115 for ; Sun, 7 Mar 2021 15:25:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231363AbhCGPY7 (ORCPT ); Sun, 7 Mar 2021 10:24:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:60128 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230488AbhCGPYe (ORCPT ); Sun, 7 Mar 2021 10:24:34 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6801765004; Sun, 7 Mar 2021 15:24:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615130674; bh=v6Hpp6iOc56BzTgKF0Lqlq7f36GA6UOn7qkPYeygLDs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=o6t0vl1XcJjABVvkwrDtqIn65aMIJLWlZ+nmr8ab6DZR/FskYnSQHoMXgM8bYpvjx aZzeCCIQLPLclXQ3vkrCVeCGbCdrBobrVFuIXY6mpG4qype9tqbCEHi/HhV8e0kUtz Wb1TJoCLJL4EHeel7y0nywBZMkfJV7jxGcYYBULw= Date: Sun, 7 Mar 2021 16:24:31 +0100 From: Greg KH To: Nicolas Saenz Julienne Cc: Jing Xiangfeng , catalin.marinas@arm.com, will@kernel.org, akpm@linux-foundation.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, rppt@kernel.org, lorenzo.pieralisi@arm.com, guohanjun@huawei.com, sudeep.holla@arm.com, rjw@rjwysocki.net, lenb@kernel.org, song.bao.hua@hisilicon.com, ardb@kernel.org, anshuman.khandual@arm.com, bhelgaas@google.com, guro@fb.com, robh+dt@kernel.org, stable@vger.kernel.org, linux-arm-kernel@lists.infradead.org, frowand.list@gmail.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, wangkefeng.wang@huawei.com Subject: Re: [PATCH stable v5.10 0/7] arm64: Default to 32-bit wide ZONE_DMA Message-ID: References: <20210303073319.2215839-1-jingxiangfeng@huawei.com> <9bc396116372de5b538d71d8f9ae9c3259f1002e.camel@suse.de> <827b317d7f5da6e048806922098291faacdb19f9.camel@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <827b317d7f5da6e048806922098291faacdb19f9.camel@suse.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 04, 2021 at 04:09:28PM +0100, Nicolas Saenz Julienne wrote: > On Thu, 2021-03-04 at 15:17 +0100, Greg KH wrote: > > On Thu, Mar 04, 2021 at 03:05:32PM +0100, Nicolas Saenz Julienne wrote: > > > Hi Greg. > > > > > > On Thu, 2021-03-04 at 14:46 +0100, Greg KH wrote: > > > > On Wed, Mar 03, 2021 at 03:33:12PM +0800, Jing Xiangfeng wrote: > > > > > Using two distinct DMA zones turned out to be problematic. Here's an > > > > > attempt go back to a saner default. > > > > > > > > What problem does this solve? How does this fit into the stable kernel > > > > rules? > > > > > > We changed the way we setup memory zones in arm64 in order to cater for > > > Raspberry Pi 4's weird DMA constraints: ZONE_DMA spans the lower 1GB of memory > > > and ZONE_DMA32 the rest of the 32bit address space. Since you can't allocate > > > memory that crosses zone boundaries, this broke crashkernel allocations on big > > > machines. This series fixes all this by parsing the HW description and checking > > > for DMA constrained buses. When not found, the unnecessary zone creation is > > > skipped. > > > > What kernel/commit caused this "breakage"? > > 1a8e1cef7603 arm64: use both ZONE_DMA and ZONE_DMA32 Thanks for the info, all now queued up. greg k-h