platform/x86: hp-bioscfg: enum-attributes
authorJorge Lopez <jorge.lopez2@hp.com>
Thu, 8 Jun 2023 16:33:11 +0000 (11:33 -0500)
committerHans de Goede <hdegoede@redhat.com>
Mon, 10 Jul 2023 12:41:28 +0000 (14:41 +0200)
Add enumeration 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@hp.com>
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20230608163319.18934-6-jorge.lopez2@hp.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c [new file with mode: 0644]

diff --git a/drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c
new file mode 100644 (file)
index 0000000..b1b241f
--- /dev/null
@@ -0,0 +1,447 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions corresponding to enumeration type attributes under
+ * BIOS Enumeration GUID for use with hp-bioscfg driver.
+ *
+ * Copyright (c) 2022 HP Development Company, L.P.
+ */
+
+#include "bioscfg.h"
+
+GET_INSTANCE_ID(enumeration);
+
+static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+       int instance_id = get_enumeration_instance_id(kobj);
+
+       if (instance_id < 0)
+               return -EIO;
+
+       return sysfs_emit(buf, "%s\n",
+                        bioscfg_drv.enumeration_data[instance_id].current_value);
+}
+
+/**
+ * validate_enumeration_input() -
+ * Validate input of current_value against possible values
+ *
+ * @instance_id: The instance on which input is validated
+ * @buf: Input value
+ */
+static int validate_enumeration_input(int instance_id, const char *buf)
+{
+       int i;
+       int found = 0;
+       struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
+
+       /* Is it a read only attribute */
+       if (enum_data->common.is_readonly)
+               return -EIO;
+
+       for (i = 0; i < enum_data->possible_values_size && !found; i++)
+               if (!strcmp(enum_data->possible_values[i], buf))
+                       found = 1;
+
+       if (!found)
+               return -EINVAL;
+
+       return 0;
+}
+
+static void update_enumeration_value(int instance_id, char *attr_value)
+{
+       struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
+
+       strscpy(enum_data->current_value,
+               attr_value,
+               sizeof(enum_data->current_value));
+}
+
+ATTRIBUTE_S_COMMON_PROPERTY_SHOW(display_name, enumeration);
+static struct kobj_attribute enumeration_display_name =
+               __ATTR_RO(display_name);
+
+ATTRIBUTE_PROPERTY_STORE(current_value, enumeration);
+static struct kobj_attribute enumeration_current_val =
+               __ATTR_RW(current_value);
+
+ATTRIBUTE_VALUES_PROPERTY_SHOW(possible_values, enumeration, SEMICOLON_SEP);
+static struct kobj_attribute enumeration_poss_val =
+               __ATTR_RO(possible_values);
+
+static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
+                        char *buf)
+{
+       return sysfs_emit(buf, "enumeration\n");
+}
+
+static struct kobj_attribute enumeration_type =
+               __ATTR_RO(type);
+
+static struct attribute *enumeration_attrs[] = {
+       &common_display_langcode.attr,
+       &enumeration_display_name.attr,
+       &enumeration_current_val.attr,
+       &enumeration_poss_val.attr,
+       &enumeration_type.attr,
+       NULL
+};
+
+static const struct attribute_group enumeration_attr_group = {
+       .attrs = enumeration_attrs,
+};
+
+int hp_alloc_enumeration_data(void)
+{
+       bioscfg_drv.enumeration_instances_count =
+               hp_get_instance_count(HP_WMI_BIOS_ENUMERATION_GUID);
+
+       bioscfg_drv.enumeration_data = kcalloc(bioscfg_drv.enumeration_instances_count,
+                                              sizeof(*bioscfg_drv.enumeration_data), GFP_KERNEL);
+       if (!bioscfg_drv.enumeration_data) {
+               bioscfg_drv.enumeration_instances_count = 0;
+               return -ENOMEM;
+       }
+       return 0;
+}
+
+/* Expected Values types associated with each element */
+static const acpi_object_type expected_enum_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,
+       [ENUM_CURRENT_VALUE] = ACPI_TYPE_STRING,
+       [ENUM_SIZE] = ACPI_TYPE_INTEGER,
+       [ENUM_POSSIBLE_VALUES] = ACPI_TYPE_STRING,
+};
+
+static int hp_populate_enumeration_elements_from_package(union acpi_object *enum_obj,
+                                                        int enum_obj_count,
+                                                        int instance_id)
+{
+       char *str_value = NULL;
+       int value_len;
+       u32 size = 0;
+       u32 int_value;
+       int elem = 0;
+       int reqs;
+       int pos_values;
+       int ret;
+       int eloc;
+       struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
+
+       for (elem = 1, eloc = 1; elem < enum_obj_count; elem++, eloc++) {
+               /* ONLY look at the first ENUM_ELEM_CNT elements */
+               if (eloc == ENUM_ELEM_CNT)
+                       goto exit_enumeration_package;
+
+               switch (enum_obj[elem].type) {
+               case ACPI_TYPE_STRING:
+                       if (PREREQUISITES != elem && ENUM_POSSIBLE_VALUES != elem) {
+                               ret = hp_convert_hexstr_to_str(enum_obj[elem].string.pointer,
+                                                              enum_obj[elem].string.length,
+                                                              &str_value, &value_len);
+                               if (ret)
+                                       return -EINVAL;
+                       }
+                       break;
+               case ACPI_TYPE_INTEGER:
+                       int_value = (u32)enum_obj[elem].integer.value;
+                       break;
+               default:
+                       pr_warn("Unsupported object type [%d]\n", enum_obj[elem].type);
+                       continue;
+               }
+
+               /* Check that both expected and read object type match */
+               if (expected_enum_types[eloc] != enum_obj[elem].type) {
+                       pr_err("Error expected type %d for elem %d, but got type %d instead\n",
+                              expected_enum_types[eloc], elem, enum_obj[elem].type);
+                       return -EIO;
+               }
+
+               /* Assign appropriate element value to corresponding field */
+               switch (eloc) {
+               case NAME:
+               case VALUE:
+                       break;
+               case PATH:
+                       strscpy(enum_data->common.path, str_value,
+                               sizeof(enum_data->common.path));
+                       break;
+               case IS_READONLY:
+                       enum_data->common.is_readonly = int_value;
+                       break;
+               case DISPLAY_IN_UI:
+                       enum_data->common.display_in_ui = int_value;
+                       break;
+               case REQUIRES_PHYSICAL_PRESENCE:
+                       enum_data->common.requires_physical_presence = int_value;
+                       break;
+               case SEQUENCE:
+                       enum_data->common.sequence = int_value;
+                       break;
+               case PREREQUISITES_SIZE:
+                       enum_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, enum_data->common.prerequisites_size, MAX_PREREQUISITES_SIZE);
+                       for (reqs = 0; reqs < size; reqs++) {
+                               if (elem >= enum_obj_count) {
+                                       pr_err("Error enum-objects package is too small\n");
+                                       return -EINVAL;
+                               }
+
+                               ret = hp_convert_hexstr_to_str(enum_obj[elem + reqs].string.pointer,
+                                                              enum_obj[elem + reqs].string.length,
+                                                              &str_value, &value_len);
+
+                               if (ret)
+                                       return -EINVAL;
+
+                               strscpy(enum_data->common.prerequisites[reqs],
+                                       str_value,
+                                       sizeof(enum_data->common.prerequisites[reqs]));
+
+                               kfree(str_value);
+                       }
+                       break;
+
+               case SECURITY_LEVEL:
+                       enum_data->common.security_level = int_value;
+                       break;
+
+               case ENUM_CURRENT_VALUE:
+                       strscpy(enum_data->current_value,
+                               str_value, sizeof(enum_data->current_value));
+                       break;
+               case ENUM_SIZE:
+                       enum_data->possible_values_size = int_value;
+                       if (int_value > MAX_VALUES_SIZE)
+                               pr_warn("Possible number values 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. POSSIBLE_VALUES
+                        * object is omitted by BIOS when the size is zero.
+                        */
+                       if (int_value == 0)
+                               eloc++;
+                       break;
+
+               case ENUM_POSSIBLE_VALUES:
+                       size = enum_data->possible_values_size;
+
+                       for (pos_values = 0; pos_values < size && pos_values < MAX_VALUES_SIZE;
+                            pos_values++) {
+                               if (elem >= enum_obj_count) {
+                                       pr_err("Error enum-objects package is too small\n");
+                                       return -EINVAL;
+                               }
+
+                               ret = hp_convert_hexstr_to_str(enum_obj[elem + pos_values].string.pointer,
+                                                              enum_obj[elem + pos_values].string.length,
+                                                              &str_value, &value_len);
+
+                               if (ret)
+                                       return -EINVAL;
+
+                               /*
+                                * ignore strings when possible values size
+                                * is greater than MAX_VALUES_SIZE
+                                */
+                               if (size < MAX_VALUES_SIZE)
+                                       strscpy(enum_data->possible_values[pos_values],
+                                               str_value,
+                                               sizeof(enum_data->possible_values[pos_values]));
+                       }
+                       break;
+               default:
+                       pr_warn("Invalid element: %d found in Enumeration attribute or data may be malformed\n", elem);
+                       break;
+               }
+
+               kfree(str_value);
+       }
+
+exit_enumeration_package:
+       kfree(str_value);
+       return 0;
+}
+
+/**
+ * hp_populate_enumeration_package_data() -
+ * Populate all properties of an instance under enumeration attribute
+ *
+ * @enum_obj: ACPI object with enumeration data
+ * @instance_id: The instance to enumerate
+ * @attr_name_kobj: The parent kernel object
+ */
+int hp_populate_enumeration_package_data(union acpi_object *enum_obj,
+                                        int instance_id,
+                                        struct kobject *attr_name_kobj)
+{
+       struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
+
+       enum_data->attr_name_kobj = attr_name_kobj;
+
+       hp_populate_enumeration_elements_from_package(enum_obj,
+                                                     enum_obj->package.count,
+                                                     instance_id);
+       hp_update_attribute_permissions(enum_data->common.is_readonly,
+                                       &enumeration_current_val);
+       /*
+        * Several attributes have names such "MONDAY". Friendly
+        * user nane is generated to make the name more descriptive
+        */
+       hp_friendly_user_name_update(enum_data->common.path,
+                                    attr_name_kobj->name,
+                                    enum_data->common.display_name,
+                                    sizeof(enum_data->common.display_name));
+       return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
+}
+
+static int hp_populate_enumeration_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
+                                                       int instance_id)
+{
+       int values;
+       struct enumeration_data *enum_data = &bioscfg_drv.enumeration_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, enum_data->current_value,
+                                       sizeof(enum_data->current_value));
+       if (ret < 0)
+               goto buffer_exit;
+
+       // COMMON:
+       ret = hp_get_common_data_from_buffer(&buffer_ptr, buffer_size, &enum_data->common);
+       if (ret < 0)
+               goto buffer_exit;
+
+       // ENUM_CURRENT_VALUE:
+       ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size,
+                                       enum_data->current_value,
+                                       sizeof(enum_data->current_value));
+       if (ret < 0)
+               goto buffer_exit;
+
+       // ENUM_SIZE:
+       ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
+                                        &enum_data->possible_values_size);
+
+       if (enum_data->possible_values_size > MAX_VALUES_SIZE) {
+               /* Report a message and limit possible values size to maximum value */
+               pr_warn("Enum Possible size value exceeded the maximum number of elements supported or data may be malformed\n");
+               enum_data->possible_values_size = MAX_VALUES_SIZE;
+       }
+
+       // ENUM_POSSIBLE_VALUES:
+       for (values = 0; values < enum_data->possible_values_size; values++) {
+               ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size,
+                                               enum_data->possible_values[values],
+                                               sizeof(enum_data->possible_values[values]));
+               if (ret < 0)
+                       break;
+       }
+
+buffer_exit:
+       return ret;
+}
+
+/**
+ * hp_populate_enumeration_buffer_data() -
+ * Populate all properties of an instance under enumeration 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_enumeration_buffer_data(u8 *buffer_ptr, u32 *buffer_size,
+                                       int instance_id,
+                                       struct kobject *attr_name_kobj)
+{
+       struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
+       int ret = 0;
+
+       enum_data->attr_name_kobj = attr_name_kobj;
+
+       /* Populate enumeration elements */
+       ret = hp_populate_enumeration_elements_from_buffer(buffer_ptr, buffer_size,
+                                                          instance_id);
+       if (ret < 0)
+               return ret;
+
+       hp_update_attribute_permissions(enum_data->common.is_readonly,
+                                       &enumeration_current_val);
+       /*
+        * Several attributes have names such "MONDAY". A Friendlier
+        * user nane is generated to make the name more descriptive
+        */
+       hp_friendly_user_name_update(enum_data->common.path,
+                                    attr_name_kobj->name,
+                                    enum_data->common.display_name,
+                                    sizeof(enum_data->common.display_name));
+
+       return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
+}
+
+/**
+ * hp_exit_enumeration_attributes() - Clear all attribute data
+ *
+ * Clears all data allocated for this group of attributes
+ */
+void hp_exit_enumeration_attributes(void)
+{
+       int instance_id;
+
+       for (instance_id = 0; instance_id < bioscfg_drv.enumeration_instances_count;
+            instance_id++) {
+               struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
+               struct kobject *attr_name_kobj = enum_data->attr_name_kobj;
+
+               if (attr_name_kobj)
+                       sysfs_remove_group(attr_name_kobj, &enumeration_attr_group);
+       }
+       bioscfg_drv.enumeration_instances_count = 0;
+
+       kfree(bioscfg_drv.enumeration_data);
+       bioscfg_drv.enumeration_data = NULL;
+}