1 files changed, 186 insertions, 0 deletions
diff --git a/drivers/platform/x86/dell/dell-wmi-sysman/biosattr-interface.c b/drivers/platform/x86/dell/dell-wmi-sysman/biosattr-interface.c
new file mode 100644
index 000000000000..f95d8ddace5a
--- /dev/null
+++ b/drivers/platform/x86/dell/dell-wmi-sysman/biosattr-interface.c
@@ -0,0 +1,186 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions corresponding to SET methods under BIOS attributes interface GUID for use
+ * with dell-wmi-sysman
+ *
+ *  Copyright (c) 2020 Dell Inc.
+ */
+
+#include <linux/wmi.h>
+#include "dell-wmi-sysman.h"
+
+#define SETDEFAULTVALUES_METHOD_ID					0x02
+#define SETBIOSDEFAULTS_METHOD_ID					0x03
+#define SETATTRIBUTE_METHOD_ID						0x04
+
+static int call_biosattributes_interface(struct wmi_device *wdev, char *in_args, size_t size,
+					int method_id)
+{
+	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
+	struct acpi_buffer input;
+	union acpi_object *obj;
+	acpi_status status;
+	int ret = -EIO;
+
+	input.length =  (acpi_size) size;
+	input.pointer = in_args;
+	status = wmidev_evaluate_method(wdev, 0, method_id, &input, &output);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+	obj = (union acpi_object *)output.pointer;
+	if (obj->type == ACPI_TYPE_INTEGER)
+		ret = obj->integer.value;
+
+	if (wmi_priv.pending_changes == 0) {
+		wmi_priv.pending_changes = 1;
+		/* let userland know it may need to check reboot pending again */
+		kobject_uevent(&wmi_priv.class_dev->kobj, KOBJ_CHANGE);
+	}
+	kfree(output.pointer);
+	return map_wmi_error(ret);
+}
+
+/**
+ * set_attribute() - Update an attribute value
+ * @a_name: The attribute name
+ * @a_value: The attribute value
+ *
+ * Sets an attribute to new value
+ */
+int set_attribute(const char *a_name, const char *a_value)
+{
+	size_t security_area_size, buffer_size;
+	size_t a_name_size, a_value_size;
+	char *buffer = NULL, *start;
+	int ret;
+
+	mutex_lock(&wmi_priv.mutex);
+	if (!wmi_priv.bios_attr_wdev) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	/* build/calculate buffer */
+	security_area_size = calculate_security_buffer(wmi_priv.current_admin_password);
+	a_name_size = calculate_string_buffer(a_name);
+	a_value_size = calculate_string_buffer(a_value);
+	buffer_size = security_area_size + a_name_size + a_value_size;
+	buffer = kzalloc(buffer_size, GFP_KERNEL);
+	if (!buffer) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/* build security area */
+	populate_security_buffer(buffer, wmi_priv.current_admin_password);
+
+	/* build variables to set */
+	start = buffer + security_area_size;
+	ret = populate_string_buffer(start, a_name_size, a_name);
+	if (ret < 0)
+		goto out;
+	start += ret;
+	ret = populate_string_buffer(start, a_value_size, a_value);
+	if (ret < 0)
+		goto out;
+
+	print_hex_dump_bytes("set attribute data: ", DUMP_PREFIX_NONE, buffer, buffer_size);
+	ret = call_biosattributes_interface(wmi_priv.bios_attr_wdev,
+					    buffer, buffer_size,
+					    SETATTRIBUTE_METHOD_ID);
+	if (ret == -EOPNOTSUPP)
+		dev_err(&wmi_priv.bios_attr_wdev->dev, "admin password must be configured\n");
+	else if (ret == -EACCES)
+		dev_err(&wmi_priv.bios_attr_wdev->dev, "invalid password\n");
+
+out:
+	kfree(buffer);
+	mutex_unlock(&wmi_priv.mutex);
+	return ret;
+}
+
+/**
+ * set_bios_defaults() - Resets BIOS defaults
+ * @deftype: the type of BIOS value reset to issue.
+ *
+ * Resets BIOS defaults
+ */
+int set_bios_defaults(u8 deftype)
+{
+	size_t security_area_size, buffer_size;
+	size_t integer_area_size = sizeof(u8);
+	char *buffer = NULL;
+	u8 *defaultType;
+	int ret;
+
+	mutex_lock(&wmi_priv.mutex);
+	if (!wmi_priv.bios_attr_wdev) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	security_area_size = calculate_security_buffer(wmi_priv.current_admin_password);
+	buffer_size = security_area_size + integer_area_size;
+	buffer = kzalloc(buffer_size, GFP_KERNEL);
+	if (!buffer) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/* build security area */
+	populate_security_buffer(buffer, wmi_priv.current_admin_password);
+
+	defaultType = buffer + security_area_size;
+	*defaultType = deftype;
+
+	ret = call_biosattributes_interface(wmi_priv.bios_attr_wdev, buffer, buffer_size,
+					    SETBIOSDEFAULTS_METHOD_ID);
+	if (ret)
+		dev_err(&wmi_priv.bios_attr_wdev->dev, "reset BIOS defaults failed: %d\n", ret);
+
+	kfree(buffer);
+out:
+	mutex_unlock(&wmi_priv.mutex);
+	return ret;
+}
+
+static int bios_attr_set_interface_probe(struct wmi_device *wdev, const void *context)
+{
+	mutex_lock(&wmi_priv.mutex);
+	wmi_priv.bios_attr_wdev = wdev;
+	mutex_unlock(&wmi_priv.mutex);
+	return 0;
+}
+
+static int bios_attr_set_interface_remove(struct wmi_device *wdev)
+{
+	mutex_lock(&wmi_priv.mutex);
+	wmi_priv.bios_attr_wdev = NULL;
+	mutex_unlock(&wmi_priv.mutex);
+	return 0;
+}
+
+static const struct wmi_device_id bios_attr_set_interface_id_table[] = {
+	{ .guid_string = DELL_WMI_BIOS_ATTRIBUTES_INTERFACE_GUID },
+	{ },
+};
+static struct wmi_driver bios_attr_set_interface_driver = {
+	.driver = {
+		.name = DRIVER_NAME
+	},
+	.probe = bios_attr_set_interface_probe,
+	.remove = bios_attr_set_interface_remove,
+	.id_table = bios_attr_set_interface_id_table,
+};
+
+int init_bios_attr_set_interface(void)
+{
+	return wmi_driver_register(&bios_attr_set_interface_driver);
+}
+
+void exit_bios_attr_set_interface(void)
+{
+	wmi_driver_unregister(&bios_attr_set_interface_driver);
+}
+
+MODULE_DEVICE_TABLE(wmi, bios_attr_set_interface_id_table);