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=-5.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 9771AC433E7 for ; Mon, 12 Oct 2020 08:49:23 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2103820773 for ; Mon, 12 Oct 2020 08:49:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="dWY/nHQQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2103820773 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=8LZobBNQI6GE9q0DW4g0sfo1t2CpnqIk2ytHfIF/psk=; b=dWY/nHQQ5753yUzMrolBTj3xN QSk0XxT5EblOjwd7vFMndwhEiUTmvhYdeIRFYdQPI6eu8P4Qzjy3ouLc1eNqEznOjhrocarRifSfT YIMgFH+txyqHRy0r9suxJJRiSbShwfNwd1oIWQJFV1UXCXCdPwot5gP+Xi+5LpUoLX6UkiuStquLb YUrWBOvufIJXTWdmXwLqj+6J0SfMFe3shSfJsnHRqv4GjlZK47ByEpActnuzIwbH5tIwTR84qV4Uy Dj8xEO+vv3dHxrcaiOR75PvueAyXiUhNJuml648ozz/4ATF7srzb/Om30auKR657aUNe8UDkE85iZ 0BDkJ9mww==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kRtUq-0005ME-MS; Mon, 12 Oct 2020 08:47:56 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kRtUo-0005LM-Eg; Mon, 12 Oct 2020 08:47:55 +0000 Received: from gaia (unknown [95.149.105.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DFCCE20773; Mon, 12 Oct 2020 08:47:49 +0000 (UTC) Date: Mon, 12 Oct 2020 09:47:47 +0100 From: Catalin Marinas To: Christoph Hellwig Subject: Re: [PATCH 1/4] of/fdt: Update zone_dma_bits when running in bcm2711 Message-ID: <20201012084746.GA9844@gaia> References: <20201002115541.GC7034@gaia> <12f33d487eabd626db4c07ded5a1447795eed355.camel@suse.de> <20201009071013.GA12208@lst.de> <513833810c15b5efeab7c3cbae1963a78c71a79f.camel@suse.de> <20201009152433.GA19953@e121166-lin.cambridge.arm.com> <20201009171051.GL23638@gaia> <20201012064715.GA2548@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201012064715.GA2548@lst.de> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201012_044754_564662_210D051C X-CRM114-Status: GOOD ( 18.69 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Linux ARM , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Lorenzo Pieralisi , Frank Rowand , Linux Kernel Mailing List , Linux Memory Management List , iommu@lists.linux-foundation.org, Rob Herring , linux-rpi-kernel@lists.infradead.org, Will Deacon , Ard Biesheuvel , Nicolas Saenz Julienne , Robin Murphy Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Oct 12, 2020 at 08:47:15AM +0200, Christoph Hellwig wrote: > On Fri, Oct 09, 2020 at 06:10:52PM +0100, Catalin Marinas wrote: > > kdump wants DMA-able memory and, > > DMAable by whom? The only way to guranteed DMAable memory is to use > the DMA memory allocator(s) and pass a specific device to them. Everyting > else is just fundamentally broken. Note that even when device is not > DMAable we can still use swiotlb to access it. What I meant is that the new kexec'ed kernel needs some memory in the ZONE_DMA range, currently set to the bottom 30-bit even for platforms that can cope with the whole 32-bit range (anything other than RPi4). The memory range available to the kdump kernels is limited to what reserve_crashkernel() allocated, which may not fit in the lower 1GB. There are two ongoing threads (complementary): 1. Change the arm64 reserve_crashkernel() similar to x86 which allocates memory above 4G with a small block in the ZONE_DMA range. 2. Allow zone_dma_bits to be 32 for arm64 platforms other than RPi4. The second point also fixes some regressions with CMA reservations that could no longer fit in the lower 1GB. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel