[PATCH v5 5/5] iommu/vt-d: Remove redundant IOTLB flush

From: Lu Baolu
Date: Mon May 11 2020 - 20:56:50 EST


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@xxxxxxxxxxxxxxx>
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
---
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 84cc263cec47..d8e19486523f 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