[PATCH 1/3] iommu/vt-d: Remove redundant IOTLB flush

From: Jacob Pan
Date: Fri Mar 20 2020 - 00:27:03 EST


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

Cc: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
---
drivers/iommu/intel-svm.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 8f42d717d8d7..1483f1845762 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -268,10 +268,9 @@ 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);
- intel_flush_svm_range_dev(svm, sdev, 0, -1, 0);
- }
+
rcu_read_unlock();

}
@@ -731,7 +730,6 @@ int intel_svm_unbind_mm(struct device *dev, int pasid)
* 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);
kfree_rcu(sdev, rcu);

if (list_empty(&svm->devs)) {
--
2.7.4