From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp02.in.ibm.com (e28smtp02.in.ibm.com [122.248.162.2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 2D18C1A000E for ; Wed, 25 Jun 2014 15:28:05 +1000 (EST) Received: from /spool/local by e28smtp02.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 25 Jun 2014 10:58:03 +0530 Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id 3FA1A3940048 for ; Wed, 25 Jun 2014 10:58:01 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay04.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s5P5SGDG61997292 for ; Wed, 25 Jun 2014 10:58:16 +0530 Received: from d28av02.in.ibm.com (localhost [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s5P5RxXp008387 for ; Wed, 25 Jun 2014 10:58:00 +0530 Date: Wed, 25 Jun 2014 13:27:58 +0800 From: Wei Yang To: Alexey Kardashevskiy Subject: Re: [RFC PATCH V3 06/17] ppc/pnv: allocate pe->iommu_table dynamically Message-ID: <20140625052758.GA8873@richard> References: <1402365399-5121-1-git-send-email-weiyang@linux.vnet.ibm.com> <1402365399-5121-7-git-send-email-weiyang@linux.vnet.ibm.com> <53A94DA8.6020206@ozlabs.ru> <20140625011211.GA5785@richard> <53AA4C32.7060004@ozlabs.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <53AA4C32.7060004@ozlabs.ru> Cc: Wei Yang , benh@au1.ibm.com, linux-pci@vger.kernel.org, gwshan@linux.vnet.ibm.com, yan@linux.vnet.ibm.com, bhelgaas@google.com, qiudayu@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org Reply-To: Wei Yang List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Jun 25, 2014 at 02:12:34PM +1000, Alexey Kardashevskiy wrote: >On 06/25/2014 11:12 AM, Wei Yang wrote: >> On Tue, Jun 24, 2014 at 08:06:32PM +1000, Alexey Kardashevskiy wrote: >>> On 06/10/2014 11:56 AM, Wei Yang wrote: >>>> Current iommu_table of a PE is a static field. This will have a problem when >>>> iommu_free_table is called. >>> >>> What kind of problem? This table is per PE and PE is not going anywhere. >>> >> >> Yes, for Bus PE, they will always sit in the system. When VF PE introduced, >> they could be released on the fly. When they are released, so do the iommu >> table for the PE. > >iommu_table is a part of PE struct. When PE is released, iommu_table will >go with it as well. Why to make is a pointer? I would understand it if you >added reference counting there but no - iommu_table's lifetime is equal to >PE lifetime. > Yes, iommu_talbe's life time equals to PE lifetime, so when releasing a PE we need to release the iommu table. Currently, there is one function to release the iommu table, iommu_free_table() which takes a pointer of the iommu_table and release it. If the iommu table in PE is just a part of PE, it will have some problem to release it with iommu_free_table(). That's why I make it a pointer in PE structure. > > >-- >Alexey -- Richard Yang Help you, Help me