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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 062D3C31E5B for ; Tue, 18 Jun 2019 16:42:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DA5E92084B for ; Tue, 18 Jun 2019 16:42:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729970AbfFRQmy (ORCPT ); Tue, 18 Jun 2019 12:42:54 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:19040 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729319AbfFRQmy (ORCPT ); Tue, 18 Jun 2019 12:42:54 -0400 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id DB499F86BDB6E623D268; Wed, 19 Jun 2019 00:42:51 +0800 (CST) Received: from localhost (10.202.226.61) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.439.0; Wed, 19 Jun 2019 00:42:49 +0800 Date: Tue, 18 Jun 2019 17:42:37 +0100 From: Jonathan Cameron To: Jacob Pan CC: , LKML , Joerg Roedel , David Woodhouse , "Eric Auger" , Alex Williamson , Jean-Philippe Brucker , "Tian, Kevin" , Raj Ashok , Andriy Shevchenko Subject: Re: [PATCH v4 19/22] iommu/vt-d: Clean up for SVM device list Message-ID: <20190618174237.00000556@huawei.com> In-Reply-To: <1560087862-57608-20-git-send-email-jacob.jun.pan@linux.intel.com> References: <1560087862-57608-1-git-send-email-jacob.jun.pan@linux.intel.com> <1560087862-57608-20-git-send-email-jacob.jun.pan@linux.intel.com> Organization: Huawei X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; i686-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.226.61] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 9 Jun 2019 06:44:19 -0700 Jacob Pan wrote: > Use combined macro for_each_svm_dev() to simplify SVM device iteration. > > Suggested-by: Andy Shevchenko > Signed-off-by: Jacob Pan > Reviewed-by: Eric Auger > --- > drivers/iommu/intel-svm.c | 79 +++++++++++++++++++++++------------------------ > 1 file changed, 39 insertions(+), 40 deletions(-) > > diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c > index 9cbcc1f..66d98e1 100644 > --- a/drivers/iommu/intel-svm.c > +++ b/drivers/iommu/intel-svm.c > @@ -225,6 +225,9 @@ static const struct mmu_notifier_ops intel_mmuops = { > > static DEFINE_MUTEX(pasid_mutex); > static LIST_HEAD(global_svm_list); > +#define for_each_svm_dev() \ > + list_for_each_entry(sdev, &svm->devs, list) \ > + if (dev == sdev->dev) \ Could we make this macro less opaque and have it take the svm and dev as arguments? > > int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ops *ops) > { > @@ -271,15 +274,13 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ > goto out; > } > > - list_for_each_entry(sdev, &svm->devs, list) { > - if (dev == sdev->dev) { > - if (sdev->ops != ops) { > - ret = -EBUSY; > - goto out; > - } > - sdev->users++; > - goto success; > + for_each_svm_dev() { > + if (sdev->ops != ops) { > + ret = -EBUSY; > + goto out; > } > + sdev->users++; > + goto success; > } > > break; > @@ -409,40 +410,38 @@ int intel_svm_unbind_mm(struct device *dev, int pasid) > if (!svm) > goto out; > > - list_for_each_entry(sdev, &svm->devs, list) { > - if (dev == sdev->dev) { > - ret = 0; > - sdev->users--; > - if (!sdev->users) { > - list_del_rcu(&sdev->list); > - /* Flush the PASID cache and IOTLB for this device. > - * Note that we do depend on the hardware *not* using > - * the PASID any more. Just as we depend on other > - * devices never using PASIDs that they have no right > - * to use. We have a *shared* PASID table, because it's > - * large and has to be physically contiguous. So it's > - * hard to be as defensive as we might like. */ > - intel_pasid_tear_down_entry(iommu, dev, svm->pasid); > - intel_flush_svm_range_dev(svm, sdev, 0, -1, 0, !svm->mm); > - kfree_rcu(sdev, rcu); > - > - if (list_empty(&svm->devs)) { > - ioasid_free(svm->pasid); > - if (svm->mm) > - mmu_notifier_unregister(&svm->notifier, svm->mm); > - > - list_del(&svm->list); > - > - /* We mandate that no page faults may be outstanding > - * for the PASID when intel_svm_unbind_mm() is called. > - * If that is not obeyed, subtle errors will happen. > - * Let's make them less subtle... */ > - memset(svm, 0x6b, sizeof(*svm)); > - kfree(svm); > - } > + for_each_svm_dev() { > + ret = 0; > + sdev->users--; > + if (!sdev->users) { > + list_del_rcu(&sdev->list); > + /* Flush the PASID cache and IOTLB for this device. > + * Note that we do depend on the hardware *not* using > + * the PASID any more. Just as we depend on other > + * devices never using PASIDs that they have no right > + * to use. We have a *shared* PASID table, because it's > + * large and has to be physically contiguous. So it's > + * hard to be as defensive as we might like. */ > + intel_pasid_tear_down_entry(iommu, dev, svm->pasid); > + intel_flush_svm_range_dev(svm, sdev, 0, -1, 0, !svm->mm); > + kfree_rcu(sdev, rcu); > + > + if (list_empty(&svm->devs)) { > + ioasid_free(svm->pasid); > + if (svm->mm) > + mmu_notifier_unregister(&svm->notifier, svm->mm); > + > + list_del(&svm->list); > + > + /* We mandate that no page faults may be outstanding > + * for the PASID when intel_svm_unbind_mm() is called. > + * If that is not obeyed, subtle errors will happen. > + * Let's make them less subtle... */ > + memset(svm, 0x6b, sizeof(*svm)); > + kfree(svm); > } > - break; > } > + break; > } > out: > mutex_unlock(&pasid_mutex);