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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,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 384F3C5CFE7 for ; Wed, 11 Jul 2018 02:45:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E670420BEC for ; Wed, 11 Jul 2018 02:45:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E670420BEC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732436AbeGKCrS (ORCPT ); Tue, 10 Jul 2018 22:47:18 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:45784 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1732292AbeGKCrR (ORCPT ); Tue, 10 Jul 2018 22:47:17 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2AFB5401DED0; Wed, 11 Jul 2018 02:45:15 +0000 (UTC) Received: from xz-mi (ovpn-12-41.pek2.redhat.com [10.72.12.41]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A4D1D2026D6B; Wed, 11 Jul 2018 02:45:09 +0000 (UTC) Date: Wed, 11 Jul 2018 10:45:06 +0800 From: Peter Xu To: Lu Baolu Cc: Joerg Roedel , David Woodhouse , ashok.raj@intel.com, sanjay.k.kumar@intel.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, yi.y.sun@intel.com, jacob.jun.pan@intel.com Subject: Re: [PATCH v4 9/9] iommu/vt-d: Remove the obsolete per iommu pasid tables Message-ID: <20180711024506.GB2359@xz-mi> References: <1531113778-28238-1-git-send-email-baolu.lu@linux.intel.com> <1531113778-28238-10-git-send-email-baolu.lu@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1531113778-28238-10-git-send-email-baolu.lu@linux.intel.com> User-Agent: Mutt/1.10.0 (2018-05-17) X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Wed, 11 Jul 2018 02:45:15 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Wed, 11 Jul 2018 02:45:15 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'peterx@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 09, 2018 at 01:22:58PM +0800, Lu Baolu wrote: > The obsolete per iommu pasid tables are no longer used. Hence, > clean up them. > > Cc: Ashok Raj > Cc: Jacob Pan > Cc: Kevin Tian > Cc: Liu Yi L > Signed-off-by: Lu Baolu > Reviewed-by: Liu Yi L > --- > drivers/iommu/intel-iommu.c | 6 +++--- > drivers/iommu/intel-svm.c | 17 ++--------------- > include/linux/intel-iommu.h | 5 ++--- > 3 files changed, 7 insertions(+), 21 deletions(-) > > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c > index f8609b5..9a88081 100644 > --- a/drivers/iommu/intel-iommu.c > +++ b/drivers/iommu/intel-iommu.c > @@ -1755,7 +1755,7 @@ static void free_dmar_iommu(struct intel_iommu *iommu) > if (pasid_enabled(iommu)) { > if (ecap_prs(iommu->ecap)) > intel_svm_finish_prq(iommu); > - intel_svm_free_pasid_tables(iommu); > + intel_svm_exit(iommu); > } > #endif > } > @@ -3336,7 +3336,7 @@ static int __init init_dmars(void) > hw_pass_through = 0; > #ifdef CONFIG_INTEL_IOMMU_SVM > if (pasid_enabled(iommu)) > - intel_svm_alloc_pasid_tables(iommu); > + intel_svm_init(iommu); > #endif > } > > @@ -4330,7 +4330,7 @@ static int intel_iommu_add(struct dmar_drhd_unit *dmaru) > > #ifdef CONFIG_INTEL_IOMMU_SVM > if (pasid_enabled(iommu)) > - intel_svm_alloc_pasid_tables(iommu); > + intel_svm_init(iommu); > #endif > > if (dmaru->ignored) { > diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c > index a253cde..eb30836 100644 > --- a/drivers/iommu/intel-svm.c > +++ b/drivers/iommu/intel-svm.c > @@ -38,7 +38,7 @@ struct pasid_state_entry { > u64 val; > }; > > -int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu) > +int intel_svm_init(struct intel_iommu *iommu) > { > struct page *pages; > int order; > @@ -63,15 +63,6 @@ int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu) > iommu->pasid_max = 0x20000; > > order = get_order(sizeof(struct pasid_entry) * iommu->pasid_max); > - pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order); > - if (!pages) { > - pr_warn("IOMMU: %s: Failed to allocate PASID table\n", > - iommu->name); > - return -ENOMEM; > - } > - iommu->pasid_table = page_address(pages); > - pr_info("%s: Allocated order %d PASID table.\n", iommu->name, order); > - > if (ecap_dis(iommu->ecap)) { > /* Just making it explicit... */ > BUILD_BUG_ON(sizeof(struct pasid_entry) != sizeof(struct pasid_state_entry)); Then do we still need the so-called pasid state table? I tried to find out what it did before but I failed since I see that the bit 27 of the extended cap is marked as reserved now in the latest vt-d spec (then ecap_dis could be meaningless too). Asked since if we don't need both the per-iommu pasid table and the pasid state table, then maybe we don't need intel_svm_init() at all? > @@ -86,14 +77,10 @@ int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu) > return 0; > } > > -int intel_svm_free_pasid_tables(struct intel_iommu *iommu) > +int intel_svm_exit(struct intel_iommu *iommu) Same thing applies to this exit() function - after we removed the per-iommu idr, per-iommu pasid table, and (possibly obsolete) per-iommu pasid state table, do we need that at all? Thanks, > { > int order = get_order(sizeof(struct pasid_entry) * iommu->pasid_max); > > - if (iommu->pasid_table) { > - free_pages((unsigned long)iommu->pasid_table, order); > - iommu->pasid_table = NULL; > - } > if (iommu->pasid_state_table) { > free_pages((unsigned long)iommu->pasid_state_table, order); > iommu->pasid_state_table = NULL; > diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h > index e7901d4..3c43882 100644 > --- a/include/linux/intel-iommu.h > +++ b/include/linux/intel-iommu.h > @@ -453,7 +453,6 @@ struct intel_iommu { > * devices away to userspace processes (e.g. for DPDK) and don't > * want to trust that userspace will use *only* the PASID it was > * told to. But while it's all driver-arbitrated, we're fine. */ > - struct pasid_entry *pasid_table; > struct pasid_state_entry *pasid_state_table; > struct page_req_dsc *prq; > unsigned char prq_name[16]; /* Name for PRQ interrupt */ > @@ -526,8 +525,8 @@ int for_each_device_domain(int (*fn)(struct device_domain_info *info, > void *data), void *data); > > #ifdef CONFIG_INTEL_IOMMU_SVM > -extern int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu); > -extern int intel_svm_free_pasid_tables(struct intel_iommu *iommu); > +int intel_svm_init(struct intel_iommu *iommu); > +int intel_svm_exit(struct intel_iommu *iommu); > extern int intel_svm_enable_prq(struct intel_iommu *iommu); > extern int intel_svm_finish_prq(struct intel_iommu *iommu); > > -- > 2.7.4 > > _______________________________________________ > iommu mailing list > iommu@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu -- Peter Xu