From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754381Ab2IXLus (ORCPT ); Mon, 24 Sep 2012 07:50:48 -0400 Received: from hqemgate04.nvidia.com ([216.228.121.35]:9264 "EHLO hqemgate04.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752890Ab2IXLuq convert rfc822-to-8bit (ORCPT ); Mon, 24 Sep 2012 07:50:46 -0400 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Mon, 24 Sep 2012 04:41:13 -0700 From: Hiroshi Doyu To: "m.szyprowski@samsung.com" CC: "James.Bottomley@HansenPartnership.com" , "swarren@wwwdotorg.org" , "joerg.roedel@amd.com" , "arnd@arndb.de" , Krishna Reddy , "linux@arm.linux.org.uk" , "minchan@kernel.org" , "chunsang.jeong@linaro.org" , "linux-kernel@vger.kernel.org" , "subashrp@gmail.com" , "linaro-mm-sig@lists.linaro.org" , "linux-mm@kvack.org" , "iommu@lists.linux-foundation.org" , "linux-tegra@vger.kernel.org" , "kyungmin.park@samsung.com" , "pullip.cho@samsung.com" , "linux-arm-kernel@lists.infradead.org" Date: Mon, 24 Sep 2012 13:50:14 +0200 Subject: Re: How to specify IOMMU'able devices in DT Thread-Topic: How to specify IOMMU'able devices in DT Thread-Index: Ac2aSsYb9RQ2QGYASjKk2Crlo6u6/Q== Message-ID: <20120924.145014.1452596970914043018.hdoyu@nvidia.com> References: <1348478881.2467.27.camel@dabdike><20120924124452.41070ed2ee9944d930cffffc@nvidia.com><054901cd9a45$db1a7ea0$914f7be0$%szyprowski@samsung.com> In-Reply-To: <054901cd9a45$db1a7ea0$914f7be0$%szyprowski@samsung.com> Accept-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-nvconfidentiality: public acceptlanguage: en-US Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Marek, Marek Szyprowski wrote @ Mon, 24 Sep 2012 13:14:51 +0200: > Hello, > > On Monday, September 24, 2012 11:45 AM Hiroshi Doyu wrote: > > > On Mon, 24 Sep 2012 11:28:01 +0200 > > James Bottomley wrote: > > > > > On Mon, 2012-09-24 at 12:04 +0300, Hiroshi Doyu wrote: > > > > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > > > > index a1a7225..9eae3be 100644 > > > > --- a/drivers/base/platform.c > > > > +++ b/drivers/base/platform.c > > > > @@ -21,6 +21,8 @@ > > > > #include > > > > #include > > > > > > > > +#include > > > > + > > > > #include "base.h" > > > > > > > > #define to_platform_driver(drv) (container_of((drv), struct > > > > platform_driver, \ > > > > @@ -305,8 +307,19 @@ int platform_device_add(struct platform_device > > > > *pdev) > > > > dev_name(&pdev->dev), dev_name(pdev->dev.parent)); > > > > > > > > ret = device_add(&pdev->dev); > > > > - if (ret == 0) > > > > - return ret; > > > > + if (ret) > > > > + goto failed; > > > > + > > > > +#ifdef CONFIG_PLATFORM_ENABLE_IOMMU > > > > + if (platform_bus_type.map && !pdev->dev.archdata.mapping) { > > > > + ret = arm_iommu_attach_device(&pdev->dev, > > > > + platform_bus_type.map); > > > > + if (ret) > > > > + goto failed; > > > > > > This is horrible ... you're adding an architecture specific callback > > > into our generic code; that's really a no-no. If the concept of > > > CONFIG_PLATFORM_ENABE_IOMMU is useful to more than just arm, then this > > > could become a generic callback. > > > > As mentioned in the original, this is a heck to explain what is > > needed. I am looking for some generic solution for how to specify > > IOMMU info for each platform devices. I'm guessing that some other SoC > > may have the similar requirements on the above. As you mentioned, this > > solution should be a generic, not arch specific. > > Please read more about bus notifiers. IMHO a good example is provided in > the following thread: > http://www.mail-archive.com/linux-samsung-soc@vger.kernel.org/msg12238.html This bus notifier seems enough flexible to afford the variation of IOMMU map info, like Tegra ASID, which could be platform-specific, and the other could be common too. There's already iommu_bus_notifier too. I'll try to implement something base on this. Thanks for the good info.