ACPI: introduce two helper functions for _EJ0 and _LCK

Introduce two helper functions, acpi_evaluate_ej0() and
acpi_evaluate_lck(), that will execute the _EJ0 and _LCK ACPI
control methods, respectively, and use them to simplify the
ACPI scan code.

[rjw: Changelog]
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/scan.c

@@ -193,8 +193,6 @@ static acpi_status acpi_bus_online_companions(acpi_handle handle, u32 lvl,
 static int acpi_scan_hot_remove(struct acpi_device *device)
 {
 	acpi_handle handle = device->handle;
-	struct acpi_object_list arg_list;
-	union acpi_object arg;
 	struct device *errdev;
 	acpi_status status;
 	unsigned long long sta;
@@ -257,32 +255,15 @@ static int acpi_scan_hot_remove(struct acpi_device *device)
 	put_device(&device->dev);
 	device = NULL;
 
-	if (acpi_has_method(handle, "_LCK")) {
-		arg_list.count = 1;
-		arg_list.pointer = &arg;
-		arg.type = ACPI_TYPE_INTEGER;
-		arg.integer.value = 0;
-		acpi_evaluate_object(handle, "_LCK", &arg_list, NULL);
-	}
-
-	arg_list.count = 1;
-	arg_list.pointer = &arg;
-	arg.type = ACPI_TYPE_INTEGER;
-	arg.integer.value = 1;
-
+	acpi_evaluate_lck(handle, 0);
 	/*
 	 * TBD: _EJD support.
 	 */
-	status = acpi_evaluate_object(handle, "_EJ0", &arg_list, NULL);
-	if (ACPI_FAILURE(status)) {
-		if (status == AE_NOT_FOUND) {
-			return -ENODEV;
-		} else {
-			acpi_handle_warn(handle, "Eject failed (0x%x)\n",
-								status);
-			return -EIO;
-		}
-	}
+	status = acpi_evaluate_ej0(handle);
+	if (status == AE_NOT_FOUND)
+		return -ENODEV;
+	else if (ACPI_FAILURE(status))
+		return -EIO;
 
 	/*
 	 * Verify if eject was indeed successful.  If not, log an error

drivers/acpi/utils.c

@@ -522,3 +522,46 @@ acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,
 	return acpi_evaluate_object(handle, method, &arg_list, NULL);
 }
 EXPORT_SYMBOL(acpi_execute_simple_method);
+
+/**
+ * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations
+ * @handle: ACPI device handle
+ *
+ * Evaluate device's _EJ0 method for hotplug operations.
+ */
+acpi_status acpi_evaluate_ej0(acpi_handle handle)
+{
+	acpi_status status;
+
+	status = acpi_execute_simple_method(handle, "_EJ0", 1);
+	if (status == AE_NOT_FOUND)
+		acpi_handle_warn(handle, "No _EJ0 support for device\n");
+	else if (ACPI_FAILURE(status))
+		acpi_handle_warn(handle, "Eject failed (0x%x)\n", status);
+
+	return status;
+}
+
+/**
+ * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device
+ * @handle: ACPI device handle
+ * @lock: lock device if non-zero, otherwise unlock device
+ *
+ * Evaluate device's _LCK method if present to lock/unlock device
+ */
+acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)
+{
+	acpi_status status;
+
+	status = acpi_execute_simple_method(handle, "_LCK", !!lock);
+	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+		if (lock)
+			acpi_handle_warn(handle,
+				"Locking device failed (0x%x)\n", status);
+		else
+			acpi_handle_warn(handle,
+				"Unlocking device failed (0x%x)\n", status);
+	}
+
+	return status;
+}

include/acpi/acpi_bus.h

@@ -60,6 +60,8 @@ acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld
 bool acpi_has_method(acpi_handle handle, char *name);
 acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,
 				       u64 arg);
+acpi_status acpi_evaluate_ej0(acpi_handle handle);
+acpi_status acpi_evaluate_lck(acpi_handle handle, int lock);
 
 #ifdef CONFIG_ACPI