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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 DFBE5C433ED for ; Fri, 23 Apr 2021 13:36:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A2A2C61464 for ; Fri, 23 Apr 2021 13:36:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236752AbhDWNh3 (ORCPT ); Fri, 23 Apr 2021 09:37:29 -0400 Received: from foss.arm.com ([217.140.110.172]:35024 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235502AbhDWNgT (ORCPT ); Fri, 23 Apr 2021 09:36:19 -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 7FD1113A1; Fri, 23 Apr 2021 06:35:42 -0700 (PDT) Received: from [10.57.62.63] (unknown [10.57.62.63]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 492D03F73B; Fri, 23 Apr 2021 06:35:34 -0700 (PDT) Subject: Re: [PATCH v5 16/16] of: Add plumbing for restricted DMA pool To: Claire Chang , Joerg Roedel , Will Deacon , Frank Rowand , Konrad Rzeszutek Wilk , boris.ostrovsky@oracle.com, jgross@suse.com, Christoph Hellwig , Marek Szyprowski Cc: benh@kernel.crashing.org, paulus@samba.org, "list@263.net:IOMMU DRIVERS" , sstabellini@kernel.org, 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, nouveau@lists.freedesktop.org, rodrigo.vivi@intel.com, thomas.hellstrom@linux.intel.com References: <20210422081508.3942748-1-tientzu@chromium.org> <20210422081508.3942748-17-tientzu@chromium.org> From: Robin Murphy Message-ID: <03c5bc8a-3965-bf1d-01a4-97d074dfbe2b@arm.com> Date: Fri, 23 Apr 2021 14:35:32 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.10.0 MIME-Version: 1.0 In-Reply-To: <20210422081508.3942748-17-tientzu@chromium.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 2021-04-22 09:15, Claire Chang wrote: > If a device is not behind an IOMMU, we look up the device node and set > up the restricted DMA when the restricted-dma-pool is presented. > > Signed-off-by: Claire Chang > --- > drivers/of/address.c | 25 +++++++++++++++++++++++++ > drivers/of/device.c | 3 +++ > drivers/of/of_private.h | 5 +++++ > 3 files changed, 33 insertions(+) > > diff --git a/drivers/of/address.c b/drivers/of/address.c > index 54f221dde267..fff3adfe4986 100644 > --- a/drivers/of/address.c > +++ b/drivers/of/address.c > @@ -8,6 +8,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -1109,6 +1110,30 @@ 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) > +{ > + struct device_node *node; > + int count, i; > + > + if (!dev->of_node) > + return 0; > + > + count = of_property_count_elems_of_size(dev->of_node, "memory-region", > + sizeof(phandle)); > + for (i = 0; i < count; i++) { > + node = of_parse_phandle(dev->of_node, "memory-region", i); > + /* There might be multiple memory regions, but only one > + * restriced-dma-pool region is allowed. > + */ What's the use-case for having multiple regions if the restricted pool is by definition the only one accessible? Robin. > + 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 0; > +} > + > /** > * of_mmio_is_nonposted - Check if device uses non-posted MMIO > * @np: device node > diff --git a/drivers/of/device.c b/drivers/of/device.c > index c5a9473a5fb1..d8d865223e51 100644 > --- a/drivers/of/device.c > +++ b/drivers/of/device.c > @@ -165,6 +165,9 @@ 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 0; > } > EXPORT_SYMBOL_GPL(of_dma_configure_id); > diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h > index d717efbd637d..e9237f5eff48 100644 > --- a/drivers/of/of_private.h > +++ b/drivers/of/of_private.h > @@ -163,12 +163,17 @@ 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); > #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_get_restricted_buffer(struct device *dev) > +{ > + return -ENODEV; > +} > #endif > > #endif /* _LINUX_OF_PRIVATE_H */ >