1 files changed, 18 insertions, 6 deletions

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 6b0760dafb3e..f7cdd2ab7f11 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -140,10 +140,14 @@ static struct lock_class_key reserved_rbtree_key;
 static inline int match_hid_uid(struct device *dev,
 				struct acpihid_map_entry *entry)
 {
+	struct acpi_device *adev = ACPI_COMPANION(dev);
 	const char *hid, *uid;
 
-	hid = acpi_device_hid(ACPI_COMPANION(dev));
-	uid = acpi_device_uid(ACPI_COMPANION(dev));
+	if (!adev)
+		return -ENODEV;
+
+	hid = acpi_device_hid(adev);
+	uid = acpi_device_uid(adev);
 
 	if (!hid || !(*hid))
 		return -ENODEV;
@@ -2604,7 +2608,12 @@ static int map_sg(struct device *dev, struct scatterlist *sglist,
 
 	/* Everything is mapped - write the right values into s->dma_address */
 	for_each_sg(sglist, s, nelems, i) {
-		s->dma_address += address + s->offset;
+		/*
+		 * Add in the remaining piece of the scatter-gather offset that
+		 * was masked out when we were determining the physical address
+		 * via (sg_phys(s) & PAGE_MASK) earlier.
+		 */
+		s->dma_address += address + (s->offset & ~PAGE_MASK);
 		s->dma_length   = s->length;
 	}
 
@@ -3160,21 +3169,24 @@ static void amd_iommu_get_resv_regions(struct device *dev,
 		return;
 
 	list_for_each_entry(entry, &amd_iommu_unity_map, list) {
+		int type, prot = 0;
 		size_t length;
-		int prot = 0;
 
 		if (devid < entry->devid_start || devid > entry->devid_end)
 			continue;
 
+		type   = IOMMU_RESV_DIRECT;
 		length = entry->address_end - entry->address_start;
 		if (entry->prot & IOMMU_PROT_IR)
 			prot |= IOMMU_READ;
 		if (entry->prot & IOMMU_PROT_IW)
 			prot |= IOMMU_WRITE;
+		if (entry->prot & IOMMU_UNITY_MAP_FLAG_EXCL_RANGE)
+			/* Exclusion range */
+			type = IOMMU_RESV_RESERVED;
 
 		region = iommu_alloc_resv_region(entry->address_start,
-						 length, prot,
-						 IOMMU_RESV_DIRECT);
+						 length, prot, type);
 		if (!region) {
 			dev_err(dev, "Out of memory allocating dm-regions\n");
 			return;