Merge tag 'iommu-fixes-v5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull iommu fixes from Joerg Roedel:

 - Fix for a potential NULL-ptr dereference in IOMMU core code

 - Two resource leak fixes

 - Cache flush fix in the Intel VT-d driver

* tag 'iommu-fixes-v5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/vt-d: Fix incomplete cache flush in intel_pasid_tear_down_entry()
  iommu/vt-d: Fix PASID reference leak
  iommu: Check if group is NULL before remove device
  iommu/dma: Fix leak in non-contiguous API

5 files changed, 20 insertions, 3 deletions

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 98ba927aee1a..6f0df629353f 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -768,6 +768,7 @@ static void iommu_dma_free_noncontiguous(struct device *dev, size_t size,
 	__iommu_dma_unmap(dev, sgt->sgl->dma_address, size);
 	__iommu_dma_free_pages(sh->pages, PAGE_ALIGN(size) >> PAGE_SHIFT);
 	sg_free_table(&sh->sgt);
+	kfree(sh);
 }
 #endif /* CONFIG_DMA_REMAP */
 
diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index c6cf44a6c923..9ec374e17469 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -511,7 +511,7 @@ void intel_pasid_tear_down_entry(struct intel_iommu *iommu, struct device *dev,
 				 u32 pasid, bool fault_ignore)
 {
 	struct pasid_entry *pte;
-	u16 did;
+	u16 did, pgtt;
 
 	pte = intel_pasid_get_entry(dev, pasid);
 	if (WARN_ON(!pte))
@@ -521,13 +521,19 @@ void intel_pasid_tear_down_entry(struct intel_iommu *iommu, struct device *dev,
 		return;
 
 	did = pasid_get_domain_id(pte);
+	pgtt = pasid_pte_get_pgtt(pte);
+
 	intel_pasid_clear_entry(dev, pasid, fault_ignore);
 
 	if (!ecap_coherent(iommu->ecap))
 		clflush_cache_range(pte, sizeof(*pte));
 
 	pasid_cache_invalidation_with_pasid(iommu, did, pasid);
-	qi_flush_piotlb(iommu, did, pasid, 0, -1, 0);
+
+	if (pgtt == PASID_ENTRY_PGTT_PT || pgtt == PASID_ENTRY_PGTT_FL_ONLY)
+		qi_flush_piotlb(iommu, did, pasid, 0, -1, 0);
+	else
+		iommu->flush.flush_iotlb(iommu, did, 0, 0, DMA_TLB_DSI_FLUSH);
 
 	/* Device IOTLB doesn't need to be flushed in caching mode. */
 	if (!cap_caching_mode(iommu->cap))
diff --git a/drivers/iommu/intel/pasid.h b/drivers/iommu/intel/pasid.h
index 5ff61c3d401f..c11bc8b833b8 100644
--- a/drivers/iommu/intel/pasid.h
+++ b/drivers/iommu/intel/pasid.h
@@ -99,6 +99,12 @@ static inline bool pasid_pte_is_present(struct pasid_entry *pte)
 	return READ_ONCE(pte->val[0]) & PASID_PTE_PRESENT;
 }
 
+/* Get PGTT field of a PASID table entry */
+static inline u16 pasid_pte_get_pgtt(struct pasid_entry *pte)
+{
+	return (u16)((READ_ONCE(pte->val[0]) >> 6) & 0x7);
+}
+
 extern unsigned int intel_pasid_max_id;
 int intel_pasid_alloc_table(struct device *dev);
 void intel_pasid_free_table(struct device *dev);
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 9b0f22bc0514..4b9b3f35ba0e 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -675,7 +675,6 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid)
 			kfree_rcu(sdev, rcu);
 
 			if (list_empty(&svm->devs)) {
-				intel_svm_free_pasid(mm);
 				if (svm->notifier.ops) {
 					mmu_notifier_unregister(&svm->notifier, mm);
 					/* Clear mm's pasid. */
@@ -690,6 +689,8 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid)
 				kfree(svm);
 			}
 		}
+		/* Drop a PASID reference and free it if no reference. */
+		intel_svm_free_pasid(mm);
 	}
 out:
 	return ret;
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 5419c4b9f27a..63f0af10c403 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -924,6 +924,9 @@ void iommu_group_remove_device(struct device *dev)
 	struct iommu_group *group = dev->iommu_group;
 	struct group_device *tmp_device, *device = NULL;
 
+	if (!group)
+		return;
+
 	dev_info(dev, "Removing from iommu group %d\n", group->id);
 
 	/* Pre-notify listeners that a device is being removed. */