diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index d882bf87fa96..e0a95ba72371 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -74,7 +74,7 @@ struct acpi_memory_device {
 	unsigned short caching;	/* memory cache attribute */
 	unsigned short write_protect;	/* memory read/write attribute */
 	u64 start_addr;		/* Memory Range start physical addr */
-	u64 end_addr;		/* Memory Range end physical addr */
+	u64 length;		/* Memory Range length */
 };
 
 static int
@@ -97,12 +97,11 @@ acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
 	if (ACPI_SUCCESS(status)) {
 		if (address64.resource_type == ACPI_MEMORY_RANGE) {
 			/* Populate the structure */
-			mem_device->caching =
-			    address64.info.mem.caching;
+			mem_device->caching = address64.info.mem.caching;
 			mem_device->write_protect =
 			    address64.info.mem.write_protect;
 			mem_device->start_addr = address64.minimum;
-			mem_device->end_addr = address64.maximum;
+			mem_device->length = address64.address_length;
 		}
 	}
 
@@ -199,8 +198,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 	 * Tell the VM there is more memory here...
 	 * Note: Assume that this function returns zero on success
 	 */
-	result = add_memory(mem_device->start_addr,
-			    (mem_device->end_addr - mem_device->start_addr) + 1);
+	result = add_memory(mem_device->start_addr, mem_device->length);
 	if (result) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "\nadd_memory failed\n"));
 		mem_device->state = MEMORY_INVALID_STATE;
@@ -249,7 +247,7 @@ static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
 {
 	int result;
 	u64 start = mem_device->start_addr;
-	u64 len = mem_device->end_addr - start + 1;
+	u64 len = mem_device->length;
 
 	ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
 
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index ef140ebde117..07473cd84121 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -925,11 +925,8 @@ static acpi_status hpet_resources(struct acpi_resource *res, void *data)
 	status = acpi_resource_to_address64(res, &addr);
 
 	if (ACPI_SUCCESS(status)) {
-		unsigned long size;
-
-		size = addr.maximum - addr.minimum + 1;
 		hdp->hd_phys_address = addr.minimum;
-		hdp->hd_address = ioremap(addr.minimum, size);
+		hdp->hd_address = ioremap(addr.minimum, addr.address_length);
 
 		if (hpet_is_known(hdp)) {
 			printk(KERN_DEBUG "%s: 0x%lx is busy\n",