From 49cab9d2b846bf69ef1164156ea2f4c7dec02f9f Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Tue, 31 Jan 2023 15:37:31 +0800 Subject: iommu/vt-d: Remove users from intel_svm_dev It was used as a reference counter of an existing bond between device and user application memory address. Commit be51b1d6bbff ("iommu/sva: Refactoring iommu_sva_bind/unbind_device()") has added this in iommu core. Remove it to avoid duplicate code. Reviewed-by: Kevin Tian Signed-off-by: Lu Baolu Link: https://lore.kernel.org/r/20230109014955.147068-4-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/intel/iommu.h | 1 - drivers/iommu/intel/svm.c | 62 ++++++++++++++++++++------------------------- 2 files changed, 27 insertions(+), 36 deletions(-) (limited to 'drivers') diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h index e7c732979364..2a1619ff0d79 100644 --- a/drivers/iommu/intel/iommu.h +++ b/drivers/iommu/intel/iommu.h @@ -762,7 +762,6 @@ struct intel_svm_dev { struct device *dev; struct intel_iommu *iommu; struct iommu_sva sva; - int users; u16 did; u16 sid, qdep; }; diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index d1e445f03aa6..c7dc53e40c26 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -333,13 +333,6 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu, } } - /* Find the matching device in svm list */ - sdev = svm_lookup_device_by_dev(svm, dev); - if (sdev) { - sdev->users++; - goto success; - } - sdev = kzalloc(sizeof(*sdev), GFP_KERNEL); if (!sdev) { ret = -ENOMEM; @@ -350,7 +343,6 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu, sdev->iommu = iommu; sdev->did = FLPT_DEFAULT_DID; sdev->sid = PCI_DEVID(info->bus, info->devfn); - sdev->users = 1; sdev->sva.dev = dev; init_rcu_head(&sdev->rcu); if (info->ats_enabled) { @@ -367,7 +359,7 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu, goto free_sdev; list_add_rcu(&sdev->list, &svm->devs); -success: + return &sdev->sva; free_sdev: @@ -401,32 +393,32 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid) mm = svm->mm; if (sdev) { - 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, false); - intel_svm_drain_prq(dev, svm->pasid); - kfree_rcu(sdev, rcu); - - if (list_empty(&svm->devs)) { - if (svm->notifier.ops) - mmu_notifier_unregister(&svm->notifier, mm); - pasid_private_remove(svm->pasid); - /* 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); - } + 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, false); + intel_svm_drain_prq(dev, svm->pasid); + kfree_rcu(sdev, rcu); + + if (list_empty(&svm->devs)) { + if (svm->notifier.ops) + mmu_notifier_unregister(&svm->notifier, mm); + pasid_private_remove(svm->pasid); + /* + * 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); } } out: -- cgit v1.2.3