4 files changed, 61 insertions, 26 deletions

diff --git a/drivers/acpi/acpica/acevents.h b/drivers/acpi/acpica/acevents.h
index ddd072cbc738..2133085deda7 100644
--- a/drivers/acpi/acpica/acevents.h
+++ b/drivers/acpi/acpica/acevents.h
@@ -191,6 +191,10 @@ void
 acpi_ev_execute_reg_methods(struct acpi_namespace_node *node,
 			    acpi_adr_space_type space_id, u32 function);
 
+void
+acpi_ev_execute_orphan_reg_method(struct acpi_namespace_node *node,
+				  acpi_adr_space_type space_id);
+
 acpi_status
 acpi_ev_execute_reg_method(union acpi_operand_object *region_obj, u32 function);
 
diff --git a/drivers/acpi/acpica/evregion.c b/drivers/acpi/acpica/evregion.c
index 18fdf2bc2d49..dc6004daf624 100644
--- a/drivers/acpi/acpica/evregion.c
+++ b/drivers/acpi/acpica/evregion.c
@@ -20,10 +20,6 @@ extern u8 acpi_gbl_default_address_spaces[];
 
 /* Local prototypes */
 
-static void
-acpi_ev_execute_orphan_reg_method(struct acpi_namespace_node *device_node,
-				  acpi_adr_space_type space_id);
-
 static acpi_status
 acpi_ev_reg_run(acpi_handle obj_handle,
 		u32 level, void *context, void **return_value);
@@ -818,7 +814,7 @@ acpi_ev_reg_run(acpi_handle obj_handle,
  *
  ******************************************************************************/
 
-static void
+void
 acpi_ev_execute_orphan_reg_method(struct acpi_namespace_node *device_node,
 				  acpi_adr_space_type space_id)
 {
diff --git a/drivers/acpi/acpica/evxfregn.c b/drivers/acpi/acpica/evxfregn.c
index 3197e6303c5b..624361a5f34d 100644
--- a/drivers/acpi/acpica/evxfregn.c
+++ b/drivers/acpi/acpica/evxfregn.c
@@ -306,3 +306,57 @@ acpi_execute_reg_methods(acpi_handle device, acpi_adr_space_type space_id)
 }
 
 ACPI_EXPORT_SYMBOL(acpi_execute_reg_methods)
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_execute_orphan_reg_method
+ *
+ * PARAMETERS:  device          - Handle for the device
+ *              space_id        - The address space ID
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Execute an "orphan" _REG method that appears under an ACPI
+ *              device. This is a _REG method that has no corresponding region
+ *              within the device's scope.
+ *
+ ******************************************************************************/
+acpi_status
+acpi_execute_orphan_reg_method(acpi_handle device, acpi_adr_space_type space_id)
+{
+	struct acpi_namespace_node *node;
+	acpi_status status;
+
+	ACPI_FUNCTION_TRACE(acpi_execute_orphan_reg_method);
+
+	/* Parameter validation */
+
+	if (!device) {
+		return_ACPI_STATUS(AE_BAD_PARAMETER);
+	}
+
+	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
+	if (ACPI_FAILURE(status)) {
+		return_ACPI_STATUS(status);
+	}
+
+	/* Convert and validate the device handle */
+
+	node = acpi_ns_validate_handle(device);
+	if (node) {
+
+		/*
+		 * If an "orphan" _REG method is present in the device's scope
+		 * for the given address space ID, run it.
+		 */
+
+		acpi_ev_execute_orphan_reg_method(node, space_id);
+	} else {
+		status = AE_BAD_PARAMETER;
+	}
+
+	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+	return_ACPI_STATUS(status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_execute_orphan_reg_method)
diff --git a/drivers/acpi/acpica/exregion.c b/drivers/acpi/acpica/exregion.c
index 8907b8bf4267..c49b9f8de723 100644
--- a/drivers/acpi/acpica/exregion.c
+++ b/drivers/acpi/acpica/exregion.c
@@ -44,7 +44,6 @@ acpi_ex_system_memory_space_handler(u32 function,
 	struct acpi_mem_mapping *mm = mem_info->cur_mm;
 	u32 length;
 	acpi_size map_length;
-	acpi_size page_boundary_map_length;
 #ifdef ACPI_MISALIGNMENT_NOT_SUPPORTED
 	u32 remainder;
 #endif
@@ -138,26 +137,8 @@ acpi_ex_system_memory_space_handler(u32 function,
 		map_length = (acpi_size)
 		    ((mem_info->address + mem_info->length) - address);
 
-		/*
-		 * If mapping the entire remaining portion of the region will cross
-		 * a page boundary, just map up to the page boundary, do not cross.
-		 * On some systems, crossing a page boundary while mapping regions
-		 * can cause warnings if the pages have different attributes
-		 * due to resource management.
-		 *
-		 * This has the added benefit of constraining a single mapping to
-		 * one page, which is similar to the original code that used a 4k
-		 * maximum window.
-		 */
-		page_boundary_map_length = (acpi_size)
-		    (ACPI_ROUND_UP(address, ACPI_DEFAULT_PAGE_SIZE) - address);
-		if (page_boundary_map_length == 0) {
-			page_boundary_map_length = ACPI_DEFAULT_PAGE_SIZE;
-		}
-
-		if (map_length > page_boundary_map_length) {
-			map_length = page_boundary_map_length;
-		}
+		if (map_length > ACPI_DEFAULT_PAGE_SIZE)
+			map_length = ACPI_DEFAULT_PAGE_SIZE;
 
 		/* Create a new mapping starting at the address given */