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Date:   Sun, 23 Apr 2023 14:55:22 +0200
From:   Thomas =?utf-8?Q?Wei=C3=9Fschuh?= <thomas@t-8ch.de>
To:     Jorge Lopez <jorgealtxwork@gmail.com>
Cc:     hdegoede@redhat.com, platform-driver-x86@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v11 09/14] HP BIOSCFG driver  - enum-attributes
Message-ID: <951adb9c-dd5c-4c40-a786-2025ebe1650f@t-8ch.de>
References: <20230420165454.9517-1-jorge.lopez2@hp.com>
 <20230420165454.9517-10-jorge.lopez2@hp.com>
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In-Reply-To: <20230420165454.9517-10-jorge.lopez2@hp.com>
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On 2023-04-20 11:54:49-0500, Jorge Lopez wrote:
>  .../x86/hp/hp-bioscfg/enum-attributes.c       | 543 ++++++++++++++++++
>  1 file changed, 543 insertions(+)
>  create mode 100644 drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c
> 
> 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
> index 000000000000..20defa92da6f
> --- /dev/null
> +++ b/drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c
> @@ -0,0 +1,543 @@
> +// 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 ret = 0;
> +	int found = 0;
> +	int i;
> +	int possible_values;
> +
> +	/* Is it a read only attribute */
> +	if (bioscfg_drv.enumeration_data[instance_id].common.is_readonly)
> +		return -EIO;
> +
> +	possible_values = bioscfg_drv.enumeration_data[instance_id].possible_values_size;
> +	for (i = 0; i < possible_values && !found; i++)
> +		if (!strcasecmp(bioscfg_drv.enumeration_data[instance_id].possible_values[i], buf))

Is this also intentionally case-insensitive?

> +			found = 1;
> +
> +	if (!found) {
> +		ret = -EINVAL;
> +		goto exit_enum_input;
> +	}
> +
> +	/*
> +	 * set pending reboot flag depending on
> +	 * "RequiresPhysicalPresence" value
> +	 */
> +	if (bioscfg_drv.enumeration_data[instance_id].common.requires_physical_presence)
> +		bioscfg_drv.pending_reboot = true;
> +
> +exit_enum_input:
> +	return ret;
> +}
> +
> +static void update_enumeration_value(int instance_id, char *attr_value)
> +{
> +	strscpy(bioscfg_drv.enumeration_data[instance_id].current_value,
> +		attr_value,
> +		sizeof(bioscfg_drv.enumeration_data[instance_id].current_value));
> +}
> +
> +ATTRIBUTE_S_COMMON_PROPERTY_SHOW(display_name_language_code, enumeration);
> +static struct kobj_attribute enumeration_display_langcode =
> +		__ATTR_RO(display_name_language_code);
> +
> +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_MODE(current_value, 0644);

0644 is the default for __ATTR_RW(), use that instead.

> +
> +ATTRIBUTE_N_COMMON_PROPERTY_SHOW(prerequisites_size, enumeration);
> +static struct kobj_attribute  enumeration_prerequisites_size_val =
> +		__ATTR_RO(prerequisites_size);
> +
> +ATTRIBUTE_V_COMMON_PROPERTY_SHOW(prerequisites, enumeration);
> +static struct kobj_attribute  enumeration_prerequisites_val =
> +		__ATTR_RO(prerequisites);
> +
> +ATTRIBUTE_N_PROPERTY_SHOW(possible_values_size, enumeration);
> +static struct kobj_attribute  enumeration_possible_values_size_val =
> +		__ATTR_RO(possible_values_size);
> +
> +ATTRIBUTE_VALUES_PROPERTY_SHOW(possible_values, enumeration);
> +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[] = {
> +	&enumeration_display_langcode.attr,
> +	&enumeration_display_name.attr,
> +	&enumeration_current_val.attr,
> +	&enumeration_prerequisites_size_val.attr,
> +	&enumeration_prerequisites_val.attr,
> +	&enumeration_possible_values_size_val.attr,
> +	&enumeration_poss_val.attr,
> +	&enumeration_type.attr,
> +	NULL
> +};
> +
> +static const struct attribute_group enumeration_attr_group = {
> +	.attrs = enumeration_attrs,
> +};
> +
> +int alloc_enumeration_data(void)
> +{
> +	int ret = 0;
> +
> +	bioscfg_drv.enumeration_instances_count =
> +		get_instance_count(HP_WMI_BIOS_ENUMERATION_GUID);
> +
> +	bioscfg_drv.enumeration_data = kcalloc(bioscfg_drv.enumeration_instances_count,
> +					       sizeof(struct enumeration_data), GFP_KERNEL);
> +	if (!bioscfg_drv.enumeration_data) {
> +		bioscfg_drv.enumeration_instances_count = 0;
> +		ret = -ENOMEM;
> +	}
> +	return ret;
> +}
> +
> +/* 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
> +};
> +
> +/*
> + * 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 populate_enumeration_package_data(union acpi_object *enum_obj,
> +				      int instance_id,
> +				      struct kobject *attr_name_kobj)
> +{
> +	bioscfg_drv.enumeration_data[instance_id].attr_name_kobj = attr_name_kobj;
> +
> +	populate_enumeration_elements_from_package(enum_obj,
> +						   enum_obj->package.count,
> +						   instance_id);
> +	update_attribute_permissions(bioscfg_drv.enumeration_data[instance_id].common.is_readonly,
> +				     &enumeration_current_val);
> +	/*
> +	 * Several attributes have names such "MONDAY".  Friendly
> +	 * user nane is generated to make the name more descriptive
> +	 */
> +	friendly_user_name_update(bioscfg_drv.enumeration_data[instance_id].common.path,
> +				  attr_name_kobj->name,
> +				  bioscfg_drv.enumeration_data[instance_id].common.display_name,
> +				  sizeof(bioscfg_drv.enumeration_data[instance_id].common.display_name));
> +	return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
> +}
> +
> +int 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;
> +
> +	strscpy(bioscfg_drv.enumeration_data[instance_id].common.display_name_language_code,
> +		LANG_CODE_STR,
> +		sizeof(bioscfg_drv.enumeration_data[instance_id].common.display_name_language_code));
> +
> +	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 = 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(bioscfg_drv.enumeration_data[instance_id].common.path, str_value,
> +				sizeof(bioscfg_drv.enumeration_data[instance_id].common.path));
> +			break;
> +		case IS_READONLY:
> +			bioscfg_drv.enumeration_data[instance_id].common.is_readonly = int_value;
> +			break;
> +		case DISPLAY_IN_UI:
> +			bioscfg_drv.enumeration_data[instance_id].common.display_in_ui = int_value;
> +			break;
> +		case REQUIRES_PHYSICAL_PRESENCE:
> +			bioscfg_drv.enumeration_data[instance_id].common.requires_physical_presence = int_value;
> +			break;
> +		case SEQUENCE:
> +			bioscfg_drv.enumeration_data[instance_id].common.sequence = int_value;
> +			break;
> +		case PREREQUISITES_SIZE:
> +			bioscfg_drv.enumeration_data[instance_id].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 = bioscfg_drv.enumeration_data[instance_id].common.prerequisites_size;
> +
> +			for (reqs = 0; reqs < size && reqs < MAX_PREREQUISITES_SIZE; reqs++) {
> +				if (elem >= enum_obj_count) {
> +					pr_err("Error enum-objects package is too small\n");
> +					return -EINVAL;
> +				}
> +
> +				ret = convert_hexstr_to_str(enum_obj[elem + reqs].string.pointer,
> +							    enum_obj[elem + reqs].string.length,
> +							    &str_value, &value_len);
> +
> +				if (ret)
> +					return -EINVAL;
> +
> +				strlcpy(bioscfg_drv.enumeration_data[instance_id].common.prerequisites[reqs],
> +					str_value,
> +					sizeof(bioscfg_drv.enumeration_data[instance_id].common.prerequisites[reqs]));
> +
> +				kfree(str_value);
> +			}
> +			break;
> +
> +		case SECURITY_LEVEL:
> +			bioscfg_drv.enumeration_data[instance_id].common.security_level = int_value;
> +			break;
> +
> +		case ENUM_CURRENT_VALUE:
> +			strscpy(bioscfg_drv.enumeration_data[instance_id].current_value,
> +				str_value, sizeof(bioscfg_drv.enumeration_data[instance_id].current_value));
> +			break;
> +		case ENUM_SIZE:
> +			bioscfg_drv.enumeration_data[instance_id].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 = bioscfg_drv.enumeration_data[instance_id].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 = 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)
> +					strlcpy(bioscfg_drv.enumeration_data[instance_id].possible_values[pos_values],
> +						str_value,
> +						sizeof(bioscfg_drv.enumeration_data[instance_id].possible_values[pos_values]));
> +
> +				kfree(str_value);
> +			}
> +			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;
> +}
> +
> +/*
> + * populate_enumeration_buffer_data() -
> + * Populate all properties of an instance under enumeration attribute
> + *
> + * @buffer_ptr: Buffer pointer
> + * @buffer_size: Buffer size
> + * @enum_obj: ACPI object with enumeration data
> + * @instance_id: The instance to enumerate
> + * @attr_name_kobj: The parent kernel object
> + * @enumeration_property_count: Total properties count under enumeration type
> + */
> +int populate_enumeration_buffer_data(u8 *buffer_ptr, u32 *buffer_size,
> +				     int instance_id,
> +				     struct kobject *attr_name_kobj)
> +{
> +
> +	bioscfg_drv.enumeration_data[instance_id].attr_name_kobj = attr_name_kobj;
> +
> +	/* Populate enumeration elements */
> +	populate_enumeration_elements_from_buffer(buffer_ptr, buffer_size,
> +						  instance_id);
> +
> +	update_attribute_permissions(bioscfg_drv.enumeration_data[instance_id].common.is_readonly,
> +				     &enumeration_current_val);
> +	/*
> +	 * Several attributes have names such "MONDAY". A Friendlier
> +	 * user nane is generated to make the name more descriptive
> +	 */
> +	friendly_user_name_update(bioscfg_drv.enumeration_data[instance_id].common.path,
> +				  attr_name_kobj->name,
> +				  bioscfg_drv.enumeration_data[instance_id].common.display_name,
> +				  sizeof(bioscfg_drv.enumeration_data[instance_id].common.display_name));
> +
> +	return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
> +}
> +
> +int populate_enumeration_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
> +					      int instance_id)
> +{
> +	char *dst = NULL;
> +	int elem;
> +	int reqs;
> +	int integer;
> +	int size = 0;
> +	int values;
> +	int ret;
> +	int dst_size = *buffer_size / sizeof(u16);
> +
> +	dst = kcalloc(dst_size, sizeof(char), GFP_KERNEL);
> +	if (!dst)
> +		return -ENOMEM;
> +
> +	elem = 0;
> +
> +	strscpy(bioscfg_drv.enumeration_data[instance_id].common.display_name_language_code,
> +		LANG_CODE_STR,
> +		sizeof(bioscfg_drv.enumeration_data[instance_id].common.display_name_language_code));
> +
> +	for (elem = 1; elem < 3; elem++) {
> +
> +		ret = get_string_from_buffer(&buffer_ptr, buffer_size, dst, dst_size);
> +		/* Ignore. Zero length string values */
> +		if (ret < 0)
> +			continue;
> +
> +		switch (elem) {
> +		case VALUE:
> +			/* Skip 'Value' since 'CurrentValue' is reported. */
> +			break;
> +		case PATH:
> +			strscpy(bioscfg_drv.enumeration_data[instance_id].common.path,
> +				dst, sizeof(bioscfg_drv.enumeration_data[instance_id].common.path));
> +			break;
> +		default:
> +			pr_warn("Invalid element: %d found in Enumeration attribute or data may be malformed\n", elem);
> +			break;
> +		}
> +	}
> +
> +	for (elem = 3; elem < ENUM_ELEM_CNT; elem++) {
> +		if (PREREQUISITES != elem && ENUM_CURRENT_VALUE != elem && ENUM_POSSIBLE_VALUES != elem) {
> +			ret = get_integer_from_buffer((int **)&buffer_ptr, buffer_size, (int *)&integer);
> +			if (ret < 0)
> +				continue;
> +		}
> +
> +		switch (elem) {
> +		case IS_READONLY:
> +			bioscfg_drv.enumeration_data[instance_id].common.is_readonly = integer;
> +			break;
> +		case DISPLAY_IN_UI:
> +			bioscfg_drv.enumeration_data[instance_id].common.display_in_ui = integer;
> +			break;
> +		case REQUIRES_PHYSICAL_PRESENCE:
> +			bioscfg_drv.enumeration_data[instance_id].common.requires_physical_presence = integer;
> +			break;
> +		case SEQUENCE:
> +			bioscfg_drv.enumeration_data[instance_id].common.sequence = integer;
> +			break;
> +		case PREREQUISITES_SIZE:
> +			bioscfg_drv.enumeration_data[instance_id].common.prerequisites_size = integer;
> +			if (integer > MAX_PREREQUISITES_SIZE)
> +				pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
> +
> +			// PREREQUISITES:
> +			elem++;
> +
> +			size = bioscfg_drv.enumeration_data[instance_id].common.prerequisites_size;
> +			for (reqs = 0; reqs < size && reqs < MAX_PREREQUISITES_SIZE; reqs++) {
> +				ret = get_string_from_buffer(&buffer_ptr, buffer_size, dst, dst_size);
> +				/* Ignore. expect zero length strings at the end of prerequisite values */
> +				if (ret < 0)
> +					continue;
> +
> +				strscpy(bioscfg_drv.enumeration_data[instance_id].common.prerequisites[reqs],
> +					dst,
> +					sizeof(bioscfg_drv.enumeration_data[instance_id].common.prerequisites[reqs]));
> +			}
> +			break;
> +		case SECURITY_LEVEL:
> +			bioscfg_drv.enumeration_data[instance_id].common.security_level = integer;
> +			break;
> +		case ENUM_CURRENT_VALUE:
> +			ret = get_string_from_buffer(&buffer_ptr, buffer_size, dst, dst_size);
> +			if (ret < 0)
> +				continue;
> +
> +			strscpy(bioscfg_drv.enumeration_data[instance_id].current_value,
> +				dst,
> +				sizeof(bioscfg_drv.enumeration_data[instance_id].current_value));
> +			break;
> +		case ENUM_SIZE:
> +			bioscfg_drv.enumeration_data[instance_id].possible_values_size = integer;
> +			if (integer > MAX_VALUES_SIZE)
> +				pr_warn("Possible size value exceeded the maximum number of elements supported or data may be malformed\n");
> +
> +			// ENUM_POSSIBLE_VALUES:
> +			elem++;
> +
> +			size = bioscfg_drv.enumeration_data[instance_id].possible_values_size;
> +			for (values = 0; values < size && values < MAX_VALUES_SIZE; values++) {
> +				ret = get_string_from_buffer(&buffer_ptr, buffer_size, dst, dst_size);
> +				/* Ignore expect zero size strings at the end of all possible values */
> +				if (ret < 0)
> +					continue;
> +
> +				strscpy(bioscfg_drv.enumeration_data[instance_id].possible_values[values],
> +					dst,
> +					sizeof(bioscfg_drv.enumeration_data[instance_id].possible_values[values]));
> +			}
> +			break;
> +		default:
> +			pr_warn("Invalid element: %d found in Enumeration attribute or data may be malformed\n", elem);
> +			break;
> +		}
> +	}
> +
> +	kfree(dst);
> +
> +	return 0;
> +}
> +
> +/**
> + * exit_enumeration_attributes() - Clear all attribute data
> + *
> + * Clears all data allocated for this group of attributes
> + */
> +void exit_enumeration_attributes(void)
> +{
> +	int instance_id;
> +
> +	for (instance_id = 0; instance_id < bioscfg_drv.enumeration_instances_count; instance_id++) {
> +		struct kobject *attr_name_kobj = bioscfg_drv.enumeration_data[instance_id].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;
> +}
> -- 
> 2.34.1
>