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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 C2176C32753 for ; Wed, 14 Aug 2019 15:49:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A2F3B2133F for ; Wed, 14 Aug 2019 15:49:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726585AbfHNPtT (ORCPT ); Wed, 14 Aug 2019 11:49:19 -0400 Received: from foss.arm.com ([217.140.110.172]:56360 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726166AbfHNPtT (ORCPT ); Wed, 14 Aug 2019 11:49:19 -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 E0B2328; Wed, 14 Aug 2019 08:49:17 -0700 (PDT) Received: from [10.1.197.57] (e110467-lin.cambridge.arm.com [10.1.197.57]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0A26C3F694; Wed, 14 Aug 2019 08:49:14 -0700 (PDT) Subject: Re: [PATCH 6/6] driver core: initialize a default DMA mask for platform device To: Christoph Hellwig , Greg Kroah-Hartman , Maxime Chevallier Cc: linux-arch@vger.kernel.org, Olav Kongas , Gavin Li , linuxppc-dev@lists.ozlabs.org, Mathias Nyman , Geoff Levand , Fabio Estevam , Sascha Hauer , linux-usb@vger.kernel.org, Michal Simek , linux-kernel@vger.kernel.org, Tony Prisk , iommu@lists.linux-foundation.org, Alan Stern , NXP Linux Team , Pengutronix Kernel Team , Minas Harutyunyan , Shawn Guo , Bin Liu , linux-arm-kernel@lists.infradead.org References: <20190811080520.21712-1-hch@lst.de> <20190811080520.21712-7-hch@lst.de> From: Robin Murphy Message-ID: Date: Wed, 14 Aug 2019 16:49:13 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190811080520.21712-7-hch@lst.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On 11/08/2019 09:05, Christoph Hellwig wrote: > We still treat devices without a DMA mask as defaulting to 32-bits for > both mask, but a few releases ago we've started warning about such > cases, as they require special cases to work around this sloppyness. > Add a dma_mask field to struct platform_object so that we can initialize s/object/device/ > the dma_mask pointer in struct device and initialize both masks to > 32-bits by default. Architectures can still override this in > arch_setup_pdev_archdata if needed. > > Note that the code looks a little odd with the various conditionals > because we have to support platform_device structures that are > statically allocated. This would be a good point to also get rid of the long-standing bodge in platform_device_register_full(). > Signed-off-by: Christoph Hellwig > --- > drivers/base/platform.c | 15 +++++++++++++-- > include/linux/platform_device.h | 1 + > 2 files changed, 14 insertions(+), 2 deletions(-) > > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > index ec974ba9c0c4..b216fcb0a8af 100644 > --- a/drivers/base/platform.c > +++ b/drivers/base/platform.c > @@ -264,6 +264,17 @@ struct platform_object { > char name[]; > }; > > +static void setup_pdev_archdata(struct platform_device *pdev) Bikeshed: painting the generic DMA API properties as "archdata" feels a bit off-target :/ > +{ > + if (!pdev->dev.coherent_dma_mask) > + pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32); > + if (!pdev->dma_mask) > + pdev->dma_mask = DMA_BIT_MASK(32); > + if (!pdev->dev.dma_mask) > + pdev->dev.dma_mask = &pdev->dma_mask; > + arch_setup_pdev_archdata(pdev); AFAICS m68k's implementation of that arch hook becomes entirely redundant after this change, so may as well go. That would just leave powerpc's actual archdata, which at a glance looks like it could probably be cleaned up with not *too* much trouble. Robin. > +}; > + > /** > * platform_device_put - destroy a platform device > * @pdev: platform device to free > @@ -310,7 +321,7 @@ struct platform_device *platform_device_alloc(const char *name, int id) > pa->pdev.id = id; > device_initialize(&pa->pdev.dev); > pa->pdev.dev.release = platform_device_release; > - arch_setup_pdev_archdata(&pa->pdev); > + setup_pdev_archdata(&pa->pdev); > } > > return pa ? &pa->pdev : NULL; > @@ -512,7 +523,7 @@ EXPORT_SYMBOL_GPL(platform_device_del); > int platform_device_register(struct platform_device *pdev) > { > device_initialize(&pdev->dev); > - arch_setup_pdev_archdata(pdev); > + setup_pdev_archdata(pdev); > return platform_device_add(pdev); > } > EXPORT_SYMBOL_GPL(platform_device_register); > diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h > index 9bc36b589827..a2abde2aef25 100644 > --- a/include/linux/platform_device.h > +++ b/include/linux/platform_device.h > @@ -24,6 +24,7 @@ struct platform_device { > int id; > bool id_auto; > struct device dev; > + u64 dma_mask; > u32 num_resources; > struct resource *resource; > >