diff --git a/drivers/acpi/nvs.c b/drivers/acpi/nvs.c
index fa5a1df42b79..096787b43c96 100644
--- a/drivers/acpi/nvs.c
+++ b/drivers/acpi/nvs.c
@@ -26,6 +26,7 @@ struct nvs_page {
 	unsigned int size;
 	void *kaddr;
 	void *data;
+	bool unmap;
 	struct list_head node;
 };
 
@@ -44,6 +45,9 @@ int suspend_nvs_register(unsigned long start, unsigned long size)
 {
 	struct nvs_page *entry, *next;
 
+	pr_info("PM: Registering ACPI NVS region at %lx (%ld bytes)\n",
+		start, size);
+
 	while (size > 0) {
 		unsigned int nr_bytes;
 
@@ -81,7 +85,13 @@ void suspend_nvs_free(void)
 			free_page((unsigned long)entry->data);
 			entry->data = NULL;
 			if (entry->kaddr) {
-				iounmap(entry->kaddr);
+				if (entry->unmap) {
+					iounmap(entry->kaddr);
+					entry->unmap = false;
+				} else {
+					acpi_os_unmap_memory(entry->kaddr,
+							     entry->size);
+				}
 				entry->kaddr = NULL;
 			}
 		}
@@ -115,8 +125,14 @@ int suspend_nvs_save(void)
 
 	list_for_each_entry(entry, &nvs_list, node)
 		if (entry->data) {
-			entry->kaddr = acpi_os_ioremap(entry->phys_start,
-						    entry->size);
+			unsigned long phys = entry->phys_start;
+			unsigned int size = entry->size;
+
+			entry->kaddr = acpi_os_get_iomem(phys, size);
+			if (!entry->kaddr) {
+				entry->kaddr = acpi_os_ioremap(phys, size);
+				entry->unmap = !!entry->kaddr;
+			}
 			if (!entry->kaddr) {
 				suspend_nvs_free();
 				return -ENOMEM;