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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 451AFC43219 for ; Fri, 26 Apr 2019 16:56:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 10DD4206E0 for ; Fri, 26 Apr 2019 16:56:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726299AbfDZQ4E (ORCPT ); Fri, 26 Apr 2019 12:56:04 -0400 Received: from mga05.intel.com ([192.55.52.43]:64090 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726154AbfDZQ4D (ORCPT ); Fri, 26 Apr 2019 12:56:03 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Apr 2019 09:56:03 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,398,1549958400"; d="scan'208";a="134668457" Received: from jacob-builder.jf.intel.com (HELO jacob-builder) ([10.7.199.155]) by orsmga007.jf.intel.com with ESMTP; 26 Apr 2019 09:56:03 -0700 Date: Fri, 26 Apr 2019 09:58:46 -0700 From: Jacob Pan To: Christoph Hellwig Cc: Jean-Philippe Brucker , "Tian, Kevin" , Raj Ashok , iommu@lists.linux-foundation.org, LKML , Alex Williamson , Andriy Shevchenko , David Woodhouse , "christian.koenig@amd.com" , jacob.jun.pan@linux.intel.com Subject: Re: [PATCH v2 06/19] drivers core: Add I/O ASID allocator Message-ID: <20190426095846.76a68f1f@jacob-builder> In-Reply-To: <20190426122115.GA29449@infradead.org> References: <1556062279-64135-1-git-send-email-jacob.jun.pan@linux.intel.com> <1556062279-64135-7-git-send-email-jacob.jun.pan@linux.intel.com> <20190424061903.GB30717@infradead.org> <20190425111912.0e15eb7d@jacob-builder> <856b0457-bd2f-c2af-fdeb-45fe0bd3136b@arm.com> <20190426122115.GA29449@infradead.org> Organization: OTC X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 26 Apr 2019 05:21:15 -0700 Christoph Hellwig wrote: > On Fri, Apr 26, 2019 at 12:47:43PM +0100, Jean-Philippe Brucker wrote: > > >> On Tue, Apr 23, 2019 at 04:31:06PM -0700, Jacob Pan wrote: > > >>> The allocator doesn't really belong in drivers/iommu because > > >>> some drivers would like to allocate PASIDs for devices that > > >>> aren't managed by an IOMMU, using the same ID space as IOMMU. > > >>> It doesn't really belong in drivers/pci either since platform > > >>> device also support PASID. Add the allocator in > > >>> drivers/base. > > >> > > >> I'd still add it to drivers/iommu, just selectable separately > > >> from the core iommu code.. > > > Perhaps I misunderstood. If a driver wants to use IOASIDs w/o > > > iommu subsystem even turned on, how could selecting from the core > > > iommu code help? Could you elaborate on "selectable"? > > > > How about doing the same as CONFIG_IOMMU_IOVA? The code is in > > drivers/iommu but can be selected by non-IOMMU_API users, > > independently of CONFIG_IOMMU_SUPPORT. It's true that this > > allocator will mostly be used by IOMMU drivers. > > That is exactly what I meant! Make sense, will do that in the next round. Thanks!