1 files changed, 68 insertions, 0 deletions

diff --git a/drivers/iommu/amd/io_pgtable.c b/drivers/iommu/amd/io_pgtable.c
index 2892aa1b4dc1..6c0621f6f572 100644
--- a/drivers/iommu/amd/io_pgtable.c
+++ b/drivers/iommu/amd/io_pgtable.c
@@ -486,6 +486,73 @@ static phys_addr_t iommu_v1_iova_to_phys(struct io_pgtable_ops *ops, unsigned lo
 	return (__pte & ~offset_mask) | (iova & offset_mask);
 }
 
+static bool pte_test_and_clear_dirty(u64 *ptep, unsigned long size,
+				     unsigned long flags)
+{
+	bool test_only = flags & IOMMU_DIRTY_NO_CLEAR;
+	bool dirty = false;
+	int i, count;
+
+	/*
+	 * 2.2.3.2 Host Dirty Support
+	 * When a non-default page size is used , software must OR the
+	 * Dirty bits in all of the replicated host PTEs used to map
+	 * the page. The IOMMU does not guarantee the Dirty bits are
+	 * set in all of the replicated PTEs. Any portion of the page
+	 * may have been written even if the Dirty bit is set in only
+	 * one of the replicated PTEs.
+	 */
+	count = PAGE_SIZE_PTE_COUNT(size);
+	for (i = 0; i < count && test_only; i++) {
+		if (test_bit(IOMMU_PTE_HD_BIT, (unsigned long *)&ptep[i])) {
+			dirty = true;
+			break;
+		}
+	}
+
+	for (i = 0; i < count && !test_only; i++) {
+		if (test_and_clear_bit(IOMMU_PTE_HD_BIT,
+				       (unsigned long *)&ptep[i])) {
+			dirty = true;
+		}
+	}
+
+	return dirty;
+}
+
+static int iommu_v1_read_and_clear_dirty(struct io_pgtable_ops *ops,
+					 unsigned long iova, size_t size,
+					 unsigned long flags,
+					 struct iommu_dirty_bitmap *dirty)
+{
+	struct amd_io_pgtable *pgtable = io_pgtable_ops_to_data(ops);
+	unsigned long end = iova + size - 1;
+
+	do {
+		unsigned long pgsize = 0;
+		u64 *ptep, pte;
+
+		ptep = fetch_pte(pgtable, iova, &pgsize);
+		if (ptep)
+			pte = READ_ONCE(*ptep);
+		if (!ptep || !IOMMU_PTE_PRESENT(pte)) {
+			pgsize = pgsize ?: PTE_LEVEL_PAGE_SIZE(0);
+			iova += pgsize;
+			continue;
+		}
+
+		/*
+		 * Mark the whole IOVA range as dirty even if only one of
+		 * the replicated PTEs were marked dirty.
+		 */
+		if (pte_test_and_clear_dirty(ptep, pgsize, flags))
+			iommu_dirty_bitmap_record(dirty, iova, pgsize);
+		iova += pgsize;
+	} while (iova < end);
+
+	return 0;
+}
+
 /*
  * ----------------------------------------------------
  */
@@ -527,6 +594,7 @@ static struct io_pgtable *v1_alloc_pgtable(struct io_pgtable_cfg *cfg, void *coo
 	pgtable->iop.ops.map_pages    = iommu_v1_map_pages;
 	pgtable->iop.ops.unmap_pages  = iommu_v1_unmap_pages;
 	pgtable->iop.ops.iova_to_phys = iommu_v1_iova_to_phys;
+	pgtable->iop.ops.read_and_clear_dirty = iommu_v1_read_and_clear_dirty;
 
 	return &pgtable->iop;
 }