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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 785E7D18133 for ; Mon, 14 Oct 2024 17:26:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:References: List-Owner; bh=zvwon9aHAEFOWMSmexe4MQCtTgbqODjd8PrjKlBnOpg=; b=imOjz962Rfe2yp kP56LgmePBad1gT1ag0zrVlFsky1QqJfe5cxeJ2PobXIQpOyJaQvR+9mab41sfkk0m5KoLutpghz2 jy/ZdwdNN4VVruffpZHaOYC/UKD3fr2C2MBJlt/Us/UcG2+ZcjH+Z7gPlrOY/o35U1f9iNPmvD4Nq FXqRRjzPNMPH2hPfJKglqX2lKvbjv7yAH2BO1AuTMjAmEVU9r8EqyEKb5UZw4yeDPEMg9D6Gv5yu8 QhGbLbVy1PIqDp++YP586ShKlpk+7nwot8PwyZJSRfk+KJiZPSU/A3VRENyhhO8GrLqSXbsjVtANl K2s0sTlHrm/rkpyv5RFg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t0OqH-000000062sd-0KNU; Mon, 14 Oct 2024 17:26:49 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1t0Ooq-000000062i6-3qyi; Mon, 14 Oct 2024 17:25:22 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 8A6575C5803; Mon, 14 Oct 2024 17:25:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29EE6C4CEC3; Mon, 14 Oct 2024 17:25:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728926719; bh=bKEZkxrV5rlekK0yY/yIrhfg4Y/0zd9c8nRTKHHwPdM=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=Fq7hFbLKhGycRMTSATa7Gg+9Ilpd1/MFR7x0SDp2seTq6T4HBLyjMwwUlKTTXmdx1 S2rn4B87pHBXPmNBNzMYZb7vc9vTxnRftgd3kQkM1Rt8cyUIHvPoi0hAhzMD+dCosK 2iOH4cDDsU7pSfKOJaJBqYSE/oNVYEpj31NtmppC+X5lW9NOdgGUBLyzICiliRF/Se FPZoHQzQZfpsramf8AqPuWFGakFZIntFiV/6l3uLPtOjM0TvtvvtJxXKPKI2qRe7QL fQ9609kcYe4hBwptdxk2wVUhunm1aGgG74dHXd9sKYDQctOo2R0Q8986lbe+auR1xX Ua8DSX1Kcd6wQ== Date: Mon, 14 Oct 2024 12:25:17 -0500 From: Bjorn Helgaas To: Florian Fainelli Cc: Stanimir Varbanov , linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rpi-kernel@lists.infradead.org, linux-pci@vger.kernel.org, Broadcom internal kernel review list , Thomas Gleixner , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jim Quinlan , Nicolas Saenz Julienne , Bjorn Helgaas , Lorenzo Pieralisi , kw@linux.com, Philipp Zabel , Andrea della Porta , Phil Elwell , Jonathan Bell Subject: Re: [PATCH v3 04/11] PCI: brcmstb: Expand inbound size calculation helper Message-ID: <20241014172517.GA612835@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <69c2f4ac-896d-4cfc-8068-45bd58aef6dd@broadcom.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241014_102521_044293_A8AB93CA X-CRM114-Status: GOOD ( 16.83 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Oct 14, 2024 at 10:10:11AM -0700, Florian Fainelli wrote: > On 10/14/24 09:57, Bjorn Helgaas wrote: > > On Mon, Oct 14, 2024 at 04:07:03PM +0300, Stanimir Varbanov wrote: > > > BCM2712 memory map can supports up to 64GB of system > > > memory, thus expand the inbound size calculation in > > > helper function up to 64GB. > > > > The fact that the calculation is done in a helper isn't important > > here. Can you make the subject line say something about supporting > > DMA for up to 64GB of system memory? > > > > This is being done specifically for BCM2712, but I assume it's safe > > for *all* brcmstb devices, right? > > It is safe in the sense that all brcmstb devices with this PCIe controller > will adopt the same encoding of the size, all of the currently supported > brcmstb devices have a variety of limitations when it comes to the amount of > addressable DRAM however. Typically we have a hard limit at 4GB of DRAM per > memory controller, some devices can do 2GB x3, 4GB x2, or 4GB x1. > > Does that answer your question? I'd like something in the commit log to the effect that while we're doing this to support more system memory on BCM2712, this change is safe for other SoCs that don't support as much system memory.