[PATCH v17 07/13] hp-bioscfg: order-list-attributes

[Jorge Lopez]

Add ordered list attributes support to hp-bioscfg.

HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.

Signed-off-by: Jorge Lopez <jorge.lopez2@xxxxxx>

---
Based on the latest platform-drivers-x86.git/for-next
---
 .../x86/hp/hp-bioscfg/order-list-attributes.c | 436 ++++++++++++++++++
 1 file changed, 436 insertions(+)
 create mode 100644 drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c

diff --git a/drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c
new file mode 100644
index 000000000000..7e49a8427c06
--- /dev/null
+++ b/drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c
@@ -0,0 +1,436 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions corresponding to ordered list type attributes under
+ * BIOS ORDERED LIST GUID for use with hp-bioscfg driver.
+ *
+ * Copyright (c) 2022 HP Development Company, L.P.
+ */
+
+#include "bioscfg.h"
+
+GET_INSTANCE_ID(ordered_list);
+
+static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+	int instance_id = get_ordered_list_instance_id(kobj);
+
+	if (instance_id < 0)
+		return -EIO;
+
+	return sysfs_emit(buf, "%s\n",
+			 bioscfg_drv.ordered_list_data[instance_id].current_value);
+}
+
+static int replace_char_str(u8 *buffer, char *repl_char, char *repl_with)
+{
+	char *src = buffer;
+	int buflen = strlen(buffer);
+	int item;
+
+	if (buflen < 1)
+		return -EINVAL;
+
+	for (item = 0; item < buflen; item++)
+		if (src[item] == *repl_char)
+			src[item] = *repl_with;
+
+	return 0;
+}
+
+/**
+ * validate_ordered_list_input() -
+ * Validate input of current_value against possible values
+ *
+ * @instance: The instance on which input is validated
+ * @buf: Input value
+ */
+static int validate_ordered_list_input(int instance, char *buf)
+{
+	/* validation is done by BIOS. This validation function will
+	 * convert semicolon to commas. BIOS uses commas as
+	 * separators when reporting ordered-list values.
+	 */
+	return replace_char_str(buf, SEMICOLON_SEP, COMMA_SEP);
+}
+
+static void update_ordered_list_value(int instance, char *attr_value)
+{
+	struct ordered_list_data *ordered_list_data = &bioscfg_drv.ordered_list_data[instance];
+
+	strscpy(ordered_list_data->current_value,
+		attr_value,
+		sizeof(ordered_list_data->current_value));
+}
+
+ATTRIBUTE_S_COMMON_PROPERTY_SHOW(display_name, ordered_list);
+static struct kobj_attribute ordered_list_display_name =
+	__ATTR_RO(display_name);
+
+ATTRIBUTE_PROPERTY_STORE(current_value, ordered_list);
+static struct kobj_attribute ordered_list_current_val =
+	__ATTR_RW_MODE(current_value, 0644);
+
+ATTRIBUTE_VALUES_PROPERTY_SHOW(elements, ordered_list, SEMICOLON_SEP);
+static struct kobj_attribute ordered_list_elements_val =
+	__ATTR_RO(elements);
+
+static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
+			 char *buf)
+{
+	return sysfs_emit(buf, "ordered-list\n");
+}
+
+static struct kobj_attribute ordered_list_type =
+	__ATTR_RO(type);
+
+static struct attribute *ordered_list_attrs[] = {
+	&common_display_langcode.attr,
+	&ordered_list_display_name.attr,
+	&ordered_list_current_val.attr,
+	&ordered_list_elements_val.attr,
+	&ordered_list_type.attr,
+	NULL
+};
+
+static const struct attribute_group ordered_list_attr_group = {
+	.attrs = ordered_list_attrs,
+};
+
+int hp_alloc_ordered_list_data(void)
+{
+	bioscfg_drv.ordered_list_instances_count =
+		hp_get_instance_count(HP_WMI_BIOS_ORDERED_LIST_GUID);
+	bioscfg_drv.ordered_list_data = kcalloc(bioscfg_drv.ordered_list_instances_count,
+						sizeof(*bioscfg_drv.ordered_list_data),
+						GFP_KERNEL);
+	if (!bioscfg_drv.ordered_list_data) {
+		bioscfg_drv.ordered_list_instances_count = 0;
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+/* Expected Values types associated with each element */
+static const acpi_object_type expected_order_types[] = {
+	[NAME]	= ACPI_TYPE_STRING,
+	[VALUE] = ACPI_TYPE_STRING,
+	[PATH] = ACPI_TYPE_STRING,
+	[IS_READONLY] = ACPI_TYPE_INTEGER,
+	[DISPLAY_IN_UI] = ACPI_TYPE_INTEGER,
+	[REQUIRES_PHYSICAL_PRESENCE] = ACPI_TYPE_INTEGER,
+	[SEQUENCE] = ACPI_TYPE_INTEGER,
+	[PREREQUISITES_SIZE] = ACPI_TYPE_INTEGER,
+	[PREREQUISITES] = ACPI_TYPE_STRING,
+	[SECURITY_LEVEL] = ACPI_TYPE_INTEGER,
+	[ORD_LIST_SIZE] = ACPI_TYPE_INTEGER,
+	[ORD_LIST_ELEMENTS] = ACPI_TYPE_STRING,
+};
+
+static int hp_populate_ordered_list_elements_from_package(union acpi_object *order_obj,
+							  int order_obj_count,
+							  int instance_id)
+{
+	char *str_value = NULL;
+	int value_len;
+	int ret;
+	u32 size;
+	u32 int_value;
+	int elem;
+	int reqs;
+	int eloc;
+	char *tmpstr = NULL;
+	char *part_tmp = NULL;
+	int tmp_len = 0;
+	char *part = NULL;
+	struct ordered_list_data *ordered_list_data = &bioscfg_drv.ordered_list_data[instance_id];
+
+	if (!order_obj)
+		return -EINVAL;
+
+	for (elem = 1, eloc = 1; elem < order_obj_count; elem++, eloc++) {
+		/* ONLY look at the first ORDERED_ELEM_CNT elements */
+		if (eloc == ORD_ELEM_CNT)
+			goto exit_list;
+
+		switch (order_obj[elem].type) {
+		case ACPI_TYPE_STRING:
+			if (elem != PREREQUISITES && elem != ORD_LIST_ELEMENTS) {
+				ret = hp_convert_hexstr_to_str(order_obj[elem].string.pointer,
+							       order_obj[elem].string.length,
+							       &str_value, &value_len);
+				if (ret)
+					continue;
+			}
+			break;
+		case ACPI_TYPE_INTEGER:
+			int_value = (u32)order_obj[elem].integer.value;
+			break;
+		default:
+			pr_warn("Unsupported object type [%d]\n", order_obj[elem].type);
+			continue;
+		}
+
+		/* Check that both expected and read object type match */
+		if (expected_order_types[eloc] != order_obj[elem].type) {
+			pr_err("Error expected type %d for elem %d, but got type %d instead\n",
+			       expected_order_types[eloc], elem, order_obj[elem].type);
+			return -EIO;
+		}
+
+		/* Assign appropriate element value to corresponding field*/
+		switch (eloc) {
+		case VALUE:
+			strscpy(ordered_list_data->current_value,
+				str_value, sizeof(ordered_list_data->current_value));
+			replace_char_str(ordered_list_data->current_value, COMMA_SEP, SEMICOLON_SEP);
+			break;
+		case PATH:
+			strscpy(ordered_list_data->common.path, str_value,
+				sizeof(ordered_list_data->common.path));
+			break;
+		case IS_READONLY:
+			ordered_list_data->common.is_readonly = int_value;
+			break;
+		case DISPLAY_IN_UI:
+			ordered_list_data->common.display_in_ui = int_value;
+			break;
+		case REQUIRES_PHYSICAL_PRESENCE:
+			ordered_list_data->common.requires_physical_presence = int_value;
+			break;
+		case SEQUENCE:
+			ordered_list_data->common.sequence = int_value;
+			break;
+		case PREREQUISITES_SIZE:
+			ordered_list_data->common.prerequisites_size = int_value;
+			if (int_value > MAX_PREREQUISITES_SIZE)
+				pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
+
+			/*
+			 * This HACK is needed to keep the expected
+			 * element list pointing to the right obj[elem].type
+			 * when the size is zero. PREREQUISITES
+			 * object is omitted by BIOS when the size is
+			 * zero.
+			 */
+			if (int_value == 0)
+				eloc++;
+			break;
+		case PREREQUISITES:
+			size = min_t(u32, ordered_list_data->common.prerequisites_size,
+				     MAX_PREREQUISITES_SIZE);
+			for (reqs = 0; reqs < size; reqs++) {
+				ret = hp_convert_hexstr_to_str(order_obj[elem + reqs].string.pointer,
+							       order_obj[elem + reqs].string.length,
+							       &str_value, &value_len);
+
+				if (ret)
+					continue;
+
+				strscpy(ordered_list_data->common.prerequisites[reqs],
+					str_value,
+					sizeof(ordered_list_data->common.prerequisites[reqs]));
+
+				kfree(str_value);
+			}
+			break;
+
+		case SECURITY_LEVEL:
+			ordered_list_data->common.security_level = int_value;
+			break;
+
+		case ORD_LIST_SIZE:
+			ordered_list_data->elements_size = int_value;
+			if (int_value > MAX_ELEMENTS_SIZE)
+				pr_warn("Ordered List size value exceeded the maximum number of elements supported or data may be malformed\n");
+			/*
+			 * This HACK is needed to keep the expected
+			 * element list pointing to the right obj[elem].type
+			 * when the size is zero. ORD_LIST_ELEMENTS
+			 * object is omitted by BIOS when the size is
+			 * zero.
+			 */
+			if (int_value == 0)
+				eloc++;
+			break;
+		case ORD_LIST_ELEMENTS:
+			size = ordered_list_data->elements_size;
+
+			/*
+			 * Ordered list data is stored in hex and comma separated format
+			 * Convert the data and split it to show each element
+			 */
+			ret = hp_convert_hexstr_to_str(str_value, value_len, &tmpstr, &tmp_len);
+			if (ret)
+				goto exit_list;
+
+			part_tmp = tmpstr;
+			part = strsep(&part_tmp, COMMA_SEP);
+			if (!part)
+				strscpy(ordered_list_data->elements[0],
+					tmpstr,
+					sizeof(ordered_list_data->elements[0]));
+
+			for (elem = 1; elem < MAX_ELEMENTS_SIZE && part; elem++) {
+				strscpy(ordered_list_data->elements[elem],
+					part,
+					sizeof(ordered_list_data->elements[elem]));
+				part = strsep(&part_tmp, SEMICOLON_SEP);
+			}
+
+			break;
+		default:
+			pr_warn("Invalid element: %d found in Ordered_List attribute or data may be malformed\n", elem);
+			break;
+		}
+		kfree(tmpstr);
+		kfree(str_value);
+	}
+
+exit_list:
+	kfree(tmpstr);
+	kfree(str_value);
+	return 0;
+}
+
+/**
+ * hp_populate_ordered_list_package_data() -
+ * Populate all properties of an instance under ordered_list attribute
+ *
+ * @order_obj: ACPI object with ordered_list data
+ * @instance_id: The instance to enumerate
+ * @attr_name_kobj: The parent kernel object
+ */
+int hp_populate_ordered_list_package_data(union acpi_object *order_obj, int instance_id,
+					  struct kobject *attr_name_kobj)
+{
+	struct ordered_list_data *ordered_list_data = &bioscfg_drv.ordered_list_data[instance_id];
+
+	ordered_list_data->attr_name_kobj = attr_name_kobj;
+
+	hp_populate_ordered_list_elements_from_package(order_obj,
+						       order_obj->package.count,
+						       instance_id);
+	hp_update_attribute_permissions(ordered_list_data->common.is_readonly,
+					&ordered_list_current_val);
+	hp_friendly_user_name_update(ordered_list_data->common.path,
+				     attr_name_kobj->name,
+				     ordered_list_data->common.display_name,
+				     sizeof(ordered_list_data->common.display_name));
+	return sysfs_create_group(attr_name_kobj, &ordered_list_attr_group);
+}
+
+static int hp_populate_ordered_list_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
+							 int instance_id)
+{
+	int values;
+	struct ordered_list_data *ordered_list_data = &bioscfg_drv.ordered_list_data[instance_id];
+	int ret = 0;
+
+	/*
+	 * Only data relevant to this driver and its functionality is
+	 * read. BIOS defines the order in which each * element is
+	 * read. Element 0 data is not relevant to this
+	 * driver hence it is ignored. For clarity, all element names
+	 * (DISPLAY_IN_UI) which defines the order in which is read
+	 * and the name matches the variable where the data is stored.
+	 *
+	 * In earlier implementation, reported errors were ignored
+	 * causing the data to remain uninitialized. It is not
+	 * possible to determine if data read from BIOS is valid or
+	 * not. It is for this reason functions may return a error
+	 * without validating the data itself.
+	 */
+
+	// VALUE:
+	ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size, ordered_list_data->current_value,
+					sizeof(ordered_list_data->current_value));
+	if (ret < 0)
+		goto buffer_exit;
+
+	replace_char_str(ordered_list_data->current_value, COMMA_SEP, SEMICOLON_SEP);
+
+	// COMMON:
+	ret = hp_get_common_data_from_buffer(&buffer_ptr, buffer_size,
+					     &ordered_list_data->common);
+	if (ret < 0)
+		goto buffer_exit;
+
+	// ORD_LIST_SIZE:
+	ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+					 &ordered_list_data->elements_size);
+
+	if (ordered_list_data->elements_size > MAX_ELEMENTS_SIZE) {
+		/* Report a message and limit elements size to maximum value */
+		pr_warn("Ordered List size value exceeded the maximum number of elements supported or data may be malformed\n");
+		ordered_list_data->elements_size = MAX_ELEMENTS_SIZE;
+	}
+
+	// ORD_LIST_ELEMENTS:
+	for (values = 0; values < ordered_list_data->elements_size; values++) {
+		ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size,
+						ordered_list_data->elements[values],
+						sizeof(ordered_list_data->elements[values]));
+		if (ret < 0)
+			break;
+	}
+
+buffer_exit:
+	return ret;
+}
+
+/**
+ * hp_populate_ordered_list_buffer_data() - Populate all properties of an
+ * instance under ordered list attribute
+ *
+ * @buffer_ptr: Buffer pointer
+ * @buffer_size: Buffer size
+ * @instance_id: The instance to enumerate
+ * @attr_name_kobj: The parent kernel object
+ */
+int hp_populate_ordered_list_buffer_data(u8 *buffer_ptr, u32 *buffer_size, int instance_id,
+					 struct kobject *attr_name_kobj)
+{
+	struct ordered_list_data *ordered_list_data = &bioscfg_drv.ordered_list_data[instance_id];
+	int ret = 0;
+
+	ordered_list_data->attr_name_kobj = attr_name_kobj;
+
+	/* Populate ordered list elements */
+	ret = hp_populate_ordered_list_elements_from_buffer(buffer_ptr, buffer_size,
+							    instance_id);
+	if (ret < 0)
+		return ret;
+
+	hp_update_attribute_permissions(ordered_list_data->common.is_readonly,
+					&ordered_list_current_val);
+	hp_friendly_user_name_update(ordered_list_data->common.path,
+				     attr_name_kobj->name,
+				     ordered_list_data->common.display_name,
+				     sizeof(ordered_list_data->common.display_name));
+
+	return sysfs_create_group(attr_name_kobj, &ordered_list_attr_group);
+}
+
+/**
+ * hp_exit_ordered_list_attributes() - Clear all attribute data
+ *
+ * Clears all data allocated for this group of attributes
+ */
+void hp_exit_ordered_list_attributes(void)
+{
+	int instance_id;
+
+	for (instance_id = 0; instance_id < bioscfg_drv.ordered_list_instances_count;
+	     instance_id++) {
+		struct kobject *attr_name_kobj =
+			bioscfg_drv.ordered_list_data[instance_id].attr_name_kobj;
+
+		if (attr_name_kobj)
+			sysfs_remove_group(attr_name_kobj,
+					   &ordered_list_attr_group);
+	}
+	bioscfg_drv.ordered_list_instances_count = 0;
+
+	kfree(bioscfg_drv.ordered_list_data);
+	bioscfg_drv.ordered_list_data = NULL;
+}
-- 
2.34.1