[PATCH v4 5/5] iommu/vt-d: Remove redundant IOTLB flush

Lu Baolu baolu.lu at linux.intel.com
Thu May 7 00:55:34 UTC 2020


IOTLB flush already included in the PASID tear down and the page request
drain process. There is no need to flush again.

Signed-off-by: Jacob Pan <jacob.jun.pan at linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu at linux.intel.com>
---
 drivers/iommu/intel-svm.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 7256eb965cf6..5ff05adc96e9 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -209,11 +209,9 @@ static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
 	 * *has* to handle gracefully without affecting other processes.
 	 */
 	rcu_read_lock();
-	list_for_each_entry_rcu(sdev, &svm->devs, list) {
+	list_for_each_entry_rcu(sdev, &svm->devs, list)
 		intel_pasid_tear_down_entry(svm->iommu, sdev->dev,
 					    svm->pasid, true);
-		intel_flush_svm_range_dev(svm, sdev, 0, -1, 0);
-	}
 	rcu_read_unlock();
 
 }
@@ -407,7 +405,6 @@ int intel_svm_unbind_gpasid(struct device *dev, int pasid)
 			intel_pasid_tear_down_entry(iommu, dev,
 						    svm->pasid, false);
 			intel_svm_drain_prq(dev, svm->pasid);
-			intel_flush_svm_range_dev(svm, sdev, 0, -1, 0);
 			kfree_rcu(sdev, rcu);
 
 			if (list_empty(&svm->devs)) {
@@ -647,7 +644,6 @@ int intel_svm_unbind_mm(struct device *dev, int pasid)
 			intel_pasid_tear_down_entry(iommu, dev,
 						    svm->pasid, false);
 			intel_svm_drain_prq(dev, svm->pasid);
-			intel_flush_svm_range_dev(svm, sdev, 0, -1, 0);
 			kfree_rcu(sdev, rcu);
 
 			if (list_empty(&svm->devs)) {
-- 
2.17.1



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