Commit 49cab9d2 authored by Lu Baolu's avatar Lu Baolu Committed by Joerg Roedel
Browse files

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 be51b1d6 ("iommu/sva:
Refactoring iommu_sva_bind/unbind_device()") has added this in iommu
core. Remove it to avoid duplicate code.

Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20230109014955.147068-4-baolu.lu@linux.intel.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 557abbd6

drivers/iommu/intel/iommu.h

+0 −1
Original line number Diff line number Diff line
@@ -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;

};

drivers/iommu/intel/svm.c

+27 −35
Original line number Diff line number Diff line
@@ -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:
@@ -401,18 +393,17 @@ 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.

		/*

		 * 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);

		 * 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);
@@ -420,15 +411,16 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid) 
			if (svm->notifier.ops)

				mmu_notifier_unregister(&svm->notifier, mm);

			pasid_private_remove(svm->pasid);

				/* We mandate that no page faults may be outstanding

			/*

			 * 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... */

			 * Let's make them less subtle...

			 */

			memset(svm, 0x6b, sizeof(*svm));

			kfree(svm);

		}

	}

	}

out:

	return ret;

}