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=-13.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 EA6F1ECE58D for ; Wed, 9 Oct 2019 10:56:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE8C820B7C for ; Wed, 9 Oct 2019 10:56:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731016AbfJIK4w (ORCPT ); Wed, 9 Oct 2019 06:56:52 -0400 Received: from foss.arm.com ([217.140.110.172]:59804 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725953AbfJIK4w (ORCPT ); Wed, 9 Oct 2019 06:56:52 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4999C28; Wed, 9 Oct 2019 03:56:51 -0700 (PDT) Received: from [10.37.12.37] (unknown [10.37.12.37]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E2B713F703; Wed, 9 Oct 2019 03:56:48 -0700 (PDT) Subject: Re: [PATCH v2] of: Make of_dma_get_range() work on bus nodes To: Rob Herring , devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Nicolas Saenz Julienne , Florian Fainelli , Stefan Wahren , Frank Rowand , Arnd Bergmann , Marek Vasut , Geert Uytterhoeven , Simon Horman , Lorenzo Pieralisi , Christoph Hellwig References: <20191008195239.12852-1-robh@kernel.org> From: Robin Murphy Message-ID: <597158a7-ce42-c4d0-62b0-5aab1ead8313@arm.com> Date: Wed, 9 Oct 2019 11:56:47 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <20191008195239.12852-1-robh@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019-10-08 8:52 pm, Rob Herring wrote: > From: Robin Murphy > > Since the "dma-ranges" property is only valid for a node representing a > bus, of_dma_get_range() currently assumes the node passed in is a leaf > representing a device, and starts the walk from its parent. In cases > like PCI host controllers on typical FDT systems, however, where the PCI > endpoints are probed dynamically the initial leaf node represents the > 'bus' itself, and this logic means we fail to consider any "dma-ranges" > describing the host bridge itself. Rework the logic such that > of_dma_get_range() also works correctly starting from a bus node > containing "dma-ranges". > > While this does mean "dma-ranges" could incorrectly be in a device leaf > node, there isn't really any way in this function to ensure that a leaf > node is or isn't a bus node. > > Signed-off-by: Robin Murphy > [robh: Allow for the bus child node to still be passed in] > Signed-off-by: Rob Herring > --- > Resending, hit send too quickly. > > v2: > - Ensure once we find dma-ranges, every parent has it. > - Only get the #{size,address}-cells after we find non-empty dma-ranges > - Add a check on the 'dma-ranges' length > > This is all that remains of the dma-ranges series. I've applied the rest > of the series prep and fixes. I dropped "of: Ratify of_dma_configure() > interface" as the assertions that the node pointer being the parent only > when struct device doesn't have a DT node pointer is not always > true. I'd still like to rework of_dma_configure() so that callers don't have to pass a redundant node in the common case, but that can wait. For now, this looks good enough to un-block the various 32-bit-PCI folks at least, and we can consider further improvements on top. For the changes: Reviewed-by: Robin Murphy Cheers, Robin. > I didn't include any tested-bys as this has changed a bit. A git branch > is here[1]. > > Rob > > [1] git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git dma-masks-v2 > > drivers/of/address.c | 44 ++++++++++++++++++-------------------------- > 1 file changed, 18 insertions(+), 26 deletions(-) > > diff --git a/drivers/of/address.c b/drivers/of/address.c > index 5ce69d026584..99c1b8058559 100644 > --- a/drivers/of/address.c > +++ b/drivers/of/address.c > @@ -930,47 +930,39 @@ int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *siz > const __be32 *ranges = NULL; > int len, naddr, nsize, pna; > int ret = 0; > + bool found_dma_ranges = false; > u64 dmaaddr; > > - if (!node) > - return -EINVAL; > - > - while (1) { > - struct device_node *parent; > - > - naddr = of_n_addr_cells(node); > - nsize = of_n_size_cells(node); > - > - parent = __of_get_dma_parent(node); > - of_node_put(node); > - > - node = parent; > - if (!node) > - break; > - > + while (node) { > ranges = of_get_property(node, "dma-ranges", &len); > > /* Ignore empty ranges, they imply no translation required */ > if (ranges && len > 0) > break; > > - /* > - * At least empty ranges has to be defined for parent node if > - * DMA is supported > - */ > - if (!ranges) > - break; > + /* Once we find 'dma-ranges', then a missing one is an error */ > + if (found_dma_ranges && !ranges) { > + ret = -ENODEV; > + goto out; > + } > + found_dma_ranges = true; > + > + node = of_get_next_dma_parent(node); > } > > - if (!ranges) { > + if (!node || !ranges) { > pr_debug("no dma-ranges found for node(%pOF)\n", np); > ret = -ENODEV; > goto out; > } > > - len /= sizeof(u32); > - > + naddr = of_bus_n_addr_cells(node); > + nsize = of_bus_n_size_cells(node); > pna = of_n_addr_cells(node); > + if ((len / sizeof(__be32)) % (pna + naddr + nsize)) { > + ret = -EINVAL; > + goto out; > + } > > /* dma-ranges format: > * DMA addr : naddr cells > @@ -978,7 +970,7 @@ int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *siz > * size : nsize cells > */ > dmaaddr = of_read_number(ranges, naddr); > - *paddr = of_translate_dma_address(np, ranges); > + *paddr = of_translate_dma_address(node, ranges + naddr); > if (*paddr == OF_BAD_ADDR) { > pr_err("translation of DMA address(%llx) to CPU address failed node(%pOF)\n", > dmaaddr, np); >