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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 23AD7C43219 for ; Fri, 26 Apr 2019 12:21:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E02D72084F for ; Fri, 26 Apr 2019 12:21:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="IICgH3f0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726224AbfDZMVY (ORCPT ); Fri, 26 Apr 2019 08:21:24 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:58040 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725993AbfDZMVY (ORCPT ); Fri, 26 Apr 2019 08:21:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=6Fye5JDH7T/Xhdt3eo4IxCjOUBVE+iEQv5juCCRCrvE=; b=IICgH3f0uac3ZNFdH4gJzAMpj OpMP7U8L1FYek3lLPFxT09u/4AyzXHIfbxKQozyQh6L26IFJMYTFhXZlOj+A9JLsROxjwM8wsGQD1 UkYQyyVkRnW0VrbbBs6ju3ueYG3mUCrxkFFV6XtAwuy0G7URF2Mxb36IvFXHadnblmra4VOy5OrPr YfJkAg2actbLmBq38ve9wovlVAyAvAPot0ujRsM4mOXPw20pY/nuDtkDRkKPas2tRUJP2IN0E41PJ PcQaw1Vbc7Nezw6//33iNM+AVYHorggajqBMzU7zwymPsolX1Se9zI9i3Kqo6uK2DC3vH7t4/CkO9 IwwVktTwg==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1hJzqt-0007gd-8a; Fri, 26 Apr 2019 12:21:15 +0000 Date: Fri, 26 Apr 2019 05:21:15 -0700 From: Christoph Hellwig To: Jean-Philippe Brucker Cc: Jacob Pan , Christoph Hellwig , "Tian, Kevin" , Raj Ashok , iommu@lists.linux-foundation.org, LKML , Alex Williamson , Andriy Shevchenko , David Woodhouse , "christian.koenig@amd.com" Subject: Re: [PATCH v2 06/19] drivers core: Add I/O ASID allocator Message-ID: <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <856b0457-bd2f-c2af-fdeb-45fe0bd3136b@arm.com> User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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!