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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 06544C433EF for ; Fri, 18 Feb 2022 21:29:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237998AbiBRVaA (ORCPT ); Fri, 18 Feb 2022 16:30:00 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:42400 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235638AbiBRV37 (ORCPT ); Fri, 18 Feb 2022 16:29:59 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9E671162; Fri, 18 Feb 2022 13:29:42 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5904961E5D; Fri, 18 Feb 2022 21:29:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 97463C340E9; Fri, 18 Feb 2022 21:29:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1645219781; bh=Yb49tcIy2xwRWN51tmn7o97oJJXUMsJ5zuFJFE4YTkk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tfhllptfUsOFf99hfb8EY55d2s//BYF5/fQLucehl6+UdHxjLDpDggJH7t1IJ1kNQ BBvaCTTLeIxaCAZKFvEXnegTi7yN2q/X4JBOVfpGctmXx36+D64dNyakHYdAbMcw+0 R1BIaxnUUfM3gs0Yve5RmMC2Y+Gz9Nh+8EeyVtw6LP14zBFxXVq/2dcgK0cWqP8ltO nhDyKaGvEXRsbXY5VmQV1eFciH7M0pP36YMzEUVJzk7X7t2z2llG0JN2NV99iX2LzU zKLer9NHb6ikUzjM/T+R0oI8ZEi8/5/R6Zy7mewx10r9D4L1MOdQxAJ6N9FXpFQoUe UULTaUOuKl6gA== Received: by pali.im (Postfix) id 348992BAE; Fri, 18 Feb 2022 22:29:39 +0100 (CET) Date: Fri, 18 Feb 2022 22:29:39 +0100 From: Pali =?utf-8?B?Um9ow6Fy?= To: Arnd Bergmann Cc: Gregory Clement , Andrew Lunn , Sebastian Hesselbarth , Rob Herring , Marek =?utf-8?B?QmVow7pu?= , Linux ARM , DTML , Linux Kernel Mailing List Subject: Re: [PATCH] arm64: dts: marvell: armada-37xx: Increase PCIe IO size from 64 KiB to 1 MiB Message-ID: <20220218212939.adfnbgx5fdita55m@pali> References: <20220113170755.11856-1-pali@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: NeoMutt/20180716 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Friday 18 February 2022 17:43:04 Arnd Bergmann wrote: > On Thu, Jan 13, 2022 at 6:07 PM Pali Rohár wrote: > > > > Commit 514ef1e62d65 ("arm64: dts: marvell: armada-37xx: Extend PCIe MEM > > space") increased size of PCIe MEM to 127 MiB, which is the maximal > > possible size for allocated 128 MiB PCIe window. PCIe IO size in that > > commit was unchanged. > > > > Armada 3720 PCIe controller supports 32-bit IO space mapping so it is > > possible to assign more than 64 KiB if address space for IO. > > > > Currently controller has assigned 127 MiB + 64 KiB memory and therefore > > there is 960 KiB of unused memory. So assign it to IO space by increasing > > IO window from 64 KiB to 1 MiB. > > > > DTS file armada-3720-turris-mox.dts already uses whole 128 MiB space, so > > only update comment about 32-bit IO space mapping. > > > > Signed-off-by: Pali Rohár > > Fixes: 514ef1e62d65 ("arm64: dts: marvell: armada-37xx: Extend PCIe MEM space") > > I just saw this is the fixes pull request, and it seems very odd. Does this > fix an actual bug? Note that Linux normally doesn't map more than 64KB > of I/O space per PCI domain, so it should not make a difference to us. > > Also, note that having a high bus address for the I/O space (0xefff0000, > as as the CPU physical address here) means that a lot of the older > devices that actually require I/O space won't work, because they need a > low bus address in the first few KB. > > Is this mapping a requirement from a broken bootloader, or can you change > the mapping of the I/O port window in the physical space to the usual > bus address 0? > > Arnd As we discussed on IRC changing mapping of I/O to bus address 0x0 is possible and together with recent changes of pci-aardvark.c driver should work out-of-the box. I sent patch which is changing I/O bus address to 0x0: https://lore.kernel.org/linux-arm-kernel/20220218212526.16021-1-pali@kernel.org/ Please look at it.