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=-12.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 138F6C47088 for ; Wed, 26 May 2021 15:53:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E792D613E6 for ; Wed, 26 May 2021 15:53:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235431AbhEZPzE (ORCPT ); Wed, 26 May 2021 11:55:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:37248 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232769AbhEZPzE (ORCPT ); Wed, 26 May 2021 11:55:04 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 063E7611CD; Wed, 26 May 2021 15:53:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622044412; bh=OnL/4Jq+LKq6vWvDBS0xA9CvVYxTMOTBjml/zh+3Ar0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=B4UuFsxu1r3HigmEjVwQF/otX4DrMd38lSSUyIbdumWlwAz4mqWFVwTfX3tV+cLTK ezumxJCPuSoiNTejbR/1l7Q+EyQuGnIdMF026YW9wZDBrp0Etki3m3VqLD3t52Z+ML aIGQuwBPRYJXDmtAfPisyQiC2L9qX6xiRg823CR+7DK1ZJFKUWOyliFfy6nu3kEBra 72iE6bgTyqyaVJ438e+wldUwZTA5bJjB+laj7DX9kULouD8NbVtF/6oVvQWdjQCza8 vTg4CtjTc7cs0vgmNuLf7hWhlxI/bnFdiE1zs5zIETRjnoBXmZKSOwwvGM2DpAYygJ B11ILWs8v9zvg== Date: Wed, 26 May 2021 16:53:21 +0100 From: Will Deacon To: Claire Chang Cc: Rob Herring , mpe@ellerman.id.au, Joerg Roedel , Frank Rowand , Konrad Rzeszutek Wilk , boris.ostrovsky@oracle.com, jgross@suse.com, Christoph Hellwig , Marek Szyprowski , benh@kernel.crashing.org, paulus@samba.org, "list@263.net:IOMMU DRIVERS" , sstabellini@kernel.org, Robin Murphy , grant.likely@arm.com, xypron.glpk@gmx.de, Thierry Reding , mingo@kernel.org, bauerman@linux.ibm.com, peterz@infradead.org, Greg KH , Saravana Kannan , "Rafael J . Wysocki" , heikki.krogerus@linux.intel.com, Andy Shevchenko , Randy Dunlap , Dan Williams , Bartosz Golaszewski , linux-devicetree , lkml , linuxppc-dev@lists.ozlabs.org, xen-devel@lists.xenproject.org, Nicolas Boichat , Jim Quinlan , tfiga@chromium.org, bskeggs@redhat.com, bhelgaas@google.com, chris@chris-wilson.co.uk, daniel@ffwll.ch, airlied@linux.ie, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, jani.nikula@linux.intel.com, jxgao@google.com, joonas.lahtinen@linux.intel.com, linux-pci@vger.kernel.org, maarten.lankhorst@linux.intel.com, matthew.auld@intel.com, rodrigo.vivi@intel.com, thomas.hellstrom@linux.intel.com Subject: Re: [PATCH v7 14/15] dt-bindings: of: Add restricted DMA pool Message-ID: <20210526155321.GA19633@willie-the-truck> References: <20210518064215.2856977-1-tientzu@chromium.org> <20210518064215.2856977-15-tientzu@chromium.org> <20210526121322.GA19313@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210526121322.GA19313@willie-the-truck> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Wed, May 26, 2021 at 01:13:22PM +0100, Will Deacon wrote: > On Tue, May 18, 2021 at 02:42:14PM +0800, Claire Chang wrote: > > @@ -138,4 +160,9 @@ one for multimedia processing (named multimedia-memory@77000000, 64MiB). > > memory-region = <&multimedia_reserved>; > > /* ... */ > > }; > > + > > + pcie_device: pcie_device@0,0 { > > + memory-region = <&restricted_dma_mem_reserved>; > > + /* ... */ > > + }; > > I still don't understand how this works for individual PCIe devices -- how > is dev->of_node set to point at the node you have above? > > I tried adding the memory-region to the host controller instead, and then > I see it crop up in dmesg: > > | pci-host-generic 40000000.pci: assigned reserved memory node restricted_dma_mem_reserved > > but none of the actual PCI devices end up with 'dma_io_tlb_mem' set, and > so the restricted DMA area is not used. In fact, swiotlb isn't used at all. > > What am I missing to make this work with PCIe devices? Aha, looks like we're just missing the logic to inherit the DMA configuration. The diff below gets things working for me. Will --->8 diff --git a/drivers/of/address.c b/drivers/of/address.c index c562a9ff5f0b..bf499fdd6e93 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -1113,25 +1113,25 @@ bool of_dma_is_coherent(struct device_node *np) } EXPORT_SYMBOL_GPL(of_dma_is_coherent); -int of_dma_set_restricted_buffer(struct device *dev) +int of_dma_set_restricted_buffer(struct device *dev, struct device_node *np) { - struct device_node *node; int count, i; - if (!dev->of_node) + if (!np) return 0; - count = of_property_count_elems_of_size(dev->of_node, "memory-region", + count = of_property_count_elems_of_size(np, "memory-region", sizeof(phandle)); for (i = 0; i < count; i++) { - node = of_parse_phandle(dev->of_node, "memory-region", i); + struct device_node *node; + + node = of_parse_phandle(np, "memory-region", i); /* There might be multiple memory regions, but only one - * restriced-dma-pool region is allowed. + * restricted-dma-pool region is allowed. */ if (of_device_is_compatible(node, "restricted-dma-pool") && of_device_is_available(node)) - return of_reserved_mem_device_init_by_idx( - dev, dev->of_node, i); + return of_reserved_mem_device_init_by_idx(dev, np, i); } return 0; diff --git a/drivers/of/device.c b/drivers/of/device.c index d8d865223e51..2defdca418ec 100644 --- a/drivers/of/device.c +++ b/drivers/of/device.c @@ -166,7 +166,7 @@ int of_dma_configure_id(struct device *dev, struct device_node *np, arch_setup_dma_ops(dev, dma_start, size, iommu, coherent); if (!iommu) - return of_dma_set_restricted_buffer(dev); + return of_dma_set_restricted_buffer(dev, np); return 0; } diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h index 9fc874548528..8fde97565d11 100644 --- a/drivers/of/of_private.h +++ b/drivers/of/of_private.h @@ -163,14 +163,15 @@ struct bus_dma_region; #if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_HAS_DMA) int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map); -int of_dma_set_restricted_buffer(struct device *dev); +int of_dma_set_restricted_buffer(struct device *dev, struct device_node *np); #else static inline int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map) { return -ENODEV; } -static inline int of_dma_set_restricted_buffer(struct device *dev) +static inline int of_dma_set_restricted_buffer(struct device *dev, + struct device_node *np) { return -ENODEV; }