Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751928AbbK1CTm (ORCPT ); Fri, 27 Nov 2015 21:19:42 -0500 Received: from szxga03-in.huawei.com ([119.145.14.66]:56798 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751337AbbK1CTk (ORCPT ); Fri, 27 Nov 2015 21:19:40 -0500 Subject: Re: [PATCH V5 RESEND 2/3] iommu/hisilicon: Add hi6220-SoC smmu driver To: Joerg Roedel References: <1447986309-47548-1-git-send-email-puck.chen@hisilicon.com> <1447986309-47548-3-git-send-email-puck.chen@hisilicon.com> <20151127120203.GI24300@8bytes.org> CC: , , , , , , , , , , , , From: chenfeng Message-ID: <56590F22.90105@hisilicon.com> Date: Sat, 28 Nov 2015 10:19:14 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <20151127120203.GI24300@8bytes.org> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.142.192.172] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A090203.56590F30.004E,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 75b59e4bd64c0c146c92870029b29713 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2045 Lines: 71 On 2015/11/27 20:02, Joerg Roedel wrote: > On Fri, Nov 20, 2015 at 10:25:08AM +0800, Chen Feng wrote: >> +config HI6220_IOMMU >> + bool "Hi6220 IOMMU Support" >> + depends on ARM64 >> + select IOMMU_API >> + select IOMMU_IOVA >> + help >> + Enable IOMMU Driver for hi6220 SoC. The IOMMU API and IOMMU IOVA >> + is also selected. > > The last sentence is of little help for the user. Better put the reasons > in here when a user should select this option. > >> + /*set axi id*/ > > Coding style nit: Please write these oneline comments with spaces, like > this: > > /* set axi id */ > learned,Thanks. >> +static int hi6220_smmu_attach_dev(struct iommu_domain *domain, >> + struct device *dev) >> +{ >> + dev->archdata.iommu = &iova_allocator; >> + >> + return 0; >> +} >> + >> +static void hi6220_smmu_detach_dev(struct iommu_domain *domain, >> + struct device *dev) >> +{ >> + dev->archdata.iommu = NULL; >> +} > > This basically means that this driver only supports one domain, right? yes. > That is not compatible with the iommu-api requirements. > > You need to create an iommu-group per smmu in your system and put all > devices translated by this smmu in that group. And then you must change > your code to allow attaching/detaching this iommu-group to different > domains. > I read the code,I am confused about these concepts. In my opinion, IOMMU-Domain: The masters in one domain share the same iova space. Is that right? IOMMU-GROUP: As you mentioned up,all devices translated by this smmu should be into one group. I can do this. But if there is only on domain in the system, how can I attaching/detaching the group to different domains. I think I have something wrong with these concepts. Could you help to give me some suggestions. > > Joerg > > > . > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/