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Subject: Re: [PATCH] Introduce support for Systems Management Driver over WMI
 for Dell Systems
To:     Divya Bharathi <divya27392@gmail.com>, dvhart@infradead.org
Cc:     LKML <linux-kernel@vger.kernel.org>,
        platform-driver-x86@vger.kernel.org,
        Divya Bharathi <divya.bharathi@dell.com>,
        Mario Limonciello <mario.limonciello@dell.com>,
        Prasanth KSR <prasanth.ksr@dell.com>
References: <20200730143122.10237-1-divya_bharathi@dell.com>
From:   Hans de Goede <hdegoede@redhat.com>
Message-ID: <aa23d8b8-6c6b-b6f2-e916-1defff8a9b26@redhat.com>
Date:   Tue, 1 Sep 2020 12:09:12 +0200
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Hi,

I promised a second review focussed on the code, but first a bit more
detailed review of the sysfs-files for the different attribute types...

On 7/30/20 4:31 PM, Divya Bharathi wrote:
> From: Divya Bharathi <divya.bharathi@dell.com>
> 
> The Dell WMI Systems Management Driver provides a sysfs
> interface for systems management to enable BIOS configuration
> capability on certain Dell Systems.
> 
> This driver allows user to configure Dell systems with a
> uniform common interface. To facilitate this, the patch
> introduces a generic way for driver to be able to create
> configurable BIOS Attributes available in Setup (F2) screen.
> 
> Co-developed-by: Mario Limonciello <mario.limonciello@dell.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
> Co-developed-by: Prasanth KSR <prasanth.ksr@dell.com>
> Signed-off-by: Prasanth KSR <prasanth.ksr@dell.com>
> Signed-off-by: Divya Bharathi <divya.bharathi@dell.com>
> ---
> NOTE: This patch series is intended to go on top of
> platform-drivers-x86 linux-next.
> 
>   .../testing/sysfs-platform-dell-wmi-sysman    | 201 ++++++
>   MAINTAINERS                                   |   9 +
>   drivers/platform/x86/Kconfig                  |  11 +
>   drivers/platform/x86/Makefile                 |   8 +
>   .../x86/dell-wmi-biosattr-interface.c         | 263 ++++++++
>   .../platform/x86/dell-wmi-enum-attributes.c   | 207 +++++++
>   .../platform/x86/dell-wmi-int-attributes.c    | 188 ++++++
>   .../x86/dell-wmi-passobj-attributes.c         | 161 +++++
>   .../x86/dell-wmi-passwordattr-interface.c     | 230 +++++++
>   .../platform/x86/dell-wmi-string-attributes.c | 170 ++++++
>   .../platform/x86/dell-wmi-sysman-attributes.c | 575 ++++++++++++++++++
>   .../platform/x86/dell-wmi-sysman-attributes.h | 125 ++++
>   12 files changed, 2148 insertions(+)
>   create mode 100644 Documentation/ABI/testing/sysfs-platform-dell-wmi-sysman
>   create mode 100644 drivers/platform/x86/dell-wmi-biosattr-interface.c
>   create mode 100644 drivers/platform/x86/dell-wmi-enum-attributes.c
>   create mode 100644 drivers/platform/x86/dell-wmi-int-attributes.c
>   create mode 100644 drivers/platform/x86/dell-wmi-passobj-attributes.c
>   create mode 100644 drivers/platform/x86/dell-wmi-passwordattr-interface.c
>   create mode 100644 drivers/platform/x86/dell-wmi-string-attributes.c
>   create mode 100644 drivers/platform/x86/dell-wmi-sysman-attributes.c
>   create mode 100644 drivers/platform/x86/dell-wmi-sysman-attributes.h
> 
> diff --git a/Documentation/ABI/testing/sysfs-platform-dell-wmi-sysman b/Documentation/ABI/testing/sysfs-platform-dell-wmi-sysman
> new file mode 100644
> index 000000000000..8ca3e502ed89
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-platform-dell-wmi-sysman
> @@ -0,0 +1,201 @@
> +What:		/sys/devices/platform/dell-wmi-sysman/attributes/
> +Date:		October 2020
> +KernelVersion:	5.9
> +Contact:	Divya Bharathi <Divya.Bharathi@Dell.com>,
> +		Mario Limonciello <mario.limonciello@dell.com>,
> +		Prasanth KSR <prasanth.ksr@dell.com>
> +Description:
> +		The Dell WMI Systems Management Driver provides a sysfs interface
> +		for systems management software to enable BIOS configuration
> +		capability on certain Dell systems. This directory exposes
> +		interfaces for interacting with BIOS attributes
> +
> +What:		/sys/devices/platform/dell-wmi-sysman/attributes/reset_bios
> +Date:		October 2020
> +KernelVersion:	5.9
> +Contact:	Divya Bharathi <Divya.Bharathi@Dell.com>,
> +		Mario Limonciello <mario.limonciello@dell.com>,
> +		Prasanth KSR <prasanth.ksr@dell.com>
> +Description:
> +		This attribute can be used to reset the BIOS Configuration.
> +		Specifically, it tells which type of reset BIOS configuration is being
> +		requested on the host.
> +
> +		Reading from it returns a list of supported options encoded as:
> +
> +			'builtinsafe' (Built in safe configuration profile)
> +			'lastknowngood' (Last known good saved configuration profile)
> +			'factory' (Default factory settings configuration profile)
> +			'custom' (Custom saved configuration profile)
> +
> +		The currently selected option is printed in square brackets as
> +		shown below:
> +
> +		# echo "factory" > sys/devices/platform/dell-wmi-sysman/attributes/reset_bios
> +
> +		# cat sys/devices/platform/dell-wmi-sysman/attributes/reset_bios
> +		# builtinsafe lastknowngood [factory] custom
> +
> +		Note that any changes to this attribute requires a reboot
> +		for changes to take effect.
> +
> +What:		/sys/devices/platform/dell-wmi-sysman/attributes/pending_reboot
> +Date:		October 2020
> +KernelVersion:	5.9
> +Contact:	Divya Bharathi <Divya.Bharathi@Dell.com>,
> +		Mario Limonciello <mario.limonciello@dell.com>,
> +		Prasanth KSR <prasanth.ksr@dell.com>
> +Description:
> +		A read-only attribute enumerating if a reboot is pending
> +		on any BIOS attribute change.
> +
> +			0:	No pending reboot
> +			1:	Pending reboot

"A read-only attribute enumerating if a reboot is pending on any BIOS attribute change."
does not really seem to make much sense. I guess what this is trying to say is:

"This read-only attribute reads 1 if a reboot is necessary to apply pending BIOS attribute changes"?

		0:	All BIOS attributes setting are current
		1:	A reboot is necessary to get pending pending BIOS attribute changes applied

Or some such. I'm not really happy with my own text either, but I think it better explains
what this attribute is about then the original text, right ?

> +
> +What:		/sys/devices/platform/dell-wmi-sysman/attributes/enumeration/<attr>/
> +Date:		October 2020
> +KernelVersion:	5.9
> +Contact:	Divya Bharathi <Divya.Bharathi@Dell.com>,
> +		Mario Limonciello <mario.limonciello@dell.com>,
> +		Prasanth KSR <prasanth.ksr@dell.com>
> +Description:
> +		This directory exposes interfaces for interaction with
> +		BIOS enumeration attributes.
> +
> +		Enumeration attributes are settings that accept set of
> +		pre-defined valid values.
> +
> +		current_value:	A file that can be read to obtain the current
> +		value of the <attr>
> +
> +		This file can also be written to in order to update
> +		the value of a <attr>
> +
> +		default_value:	A file that can be read to obtain the default
> +		value of the <attr>
> +
> +		display_name:	A file that can be read to obtain a user friendly
> +		description of the at <attr>
> +
> +		display_name_language_code:	A file that can be read to obtain
> +		the language code corresponding to the "display_name" of the <attr>

This needs to be specified better, e.g. this needs to say that this is an
ISO 639‑1 language code (or some other language-code specification)


> +
> +		modifier:	A file that can be read to obtain attribute-level
> +		dependency rule which has to be met to configure <attr>

What is the difference between modifier and value_modifier ? Also this need to
be specified in more detail.

> +
> +		possible_value:	A file that can be read to obtain the possible
> +		value of the <attr>

This is an enum, so possible value_s_ ?  I assume that for a enum this will list
all possible values, this also needs to specify how the possible values will be
separated (e.g. using semi-colons or newlines or ...).


> +
> +		value_modifier:	A file that can be read to obtain value-level
> +		dependency on a possible value which has to be met to configure <attr>
> +
> +What:		/sys/devices/platform/dell-wmi-sysman/attributes/integer/<attr>/
> +Date:		October 2020
> +KernelVersion:	5.9
> +Contact:	Divya Bharathi <Divya.Bharathi@Dell.com>,
> +		Mario Limonciello <mario.limonciello@dell.com>,
> +		Prasanth KSR <prasanth.ksr@dell.com>
> +Description:
> +		This directory exposes interfaces for interaction with
> +		BIOS integer attributes.
> +
> +		Integer attributes are settings that accept a range of
> +		numerical values for inputs. Each BIOS integer has a
> +		lower bound and an upper bound on the values that it can take.
> +
> +		current_value:	A file that can be read to obtain the current
> +		value of the <attr>
> +
> +		This file can also be written to in order to update
> +		the value of an <attr>.
> +
> +		default_value:	A file that can be read to obtain the default
> +		value of the <attr>
> +
> +		display_name:	A file that can be read to obtain a user friendly
> +		description of the at <attr>
> +
> +		display_name_language_code:	A file that can be read to obtain
> +		the language code corresponding to the "display_name" of the <attr>
> +
> +		lower_bound:	A file that can be read to obtain the lower
> +		bound value of the <attr>
> +
> +		modifier:	A file that can be read to obtain attribute-level
> +		dependency rule which has to be met to configure <attr>
> +
> +		scalar_increment:	A file that can be read to obtain the
> +		resolution of the incremental value this attribute accepts.
> +
> +		upper_bound:	A file that can be read to obtain the upper
> +		bound value of the <attr>

Are these integers or also possibly floats? I guess possibly also floats, right?
Then at a minimum this should specify which decimal-separator is used (I assume
we will go with the usual '.' as decimal separator).

> +
> +What:		/sys/devices/platform/dell-wmi-sysman/attributes/string/<attr>/
> +Date:		October 2020
> +KernelVersion:	5.9
> +Contact:	Divya Bharathi <Divya.Bharathi@Dell.com>,
> +		Mario Limonciello <mario.limonciello@dell.com>,
> +		Prasanth KSR <prasanth.ksr@dell.com>
> +Description:
> +		This directory exposes interfaces for interaction with
> +		BIOS string attributes.
> +
> +		String attributes are settings that accept a string for an input.
> +		Each BIOS string is characterized by the minimum length of the string,
> +		the maximum length of the string, and the type of the string.
> +
> +		current_value:	A file that can be read to obtain the current
> +		value of the <attr>
> +
> +		This file can also be written to in order to update
> +		the value of an <attr>.
> +
> +		default_value:	A file that can be read to obtain the default
> +		value of the <attr>
> +
> +		display_name:	A file that can be read to obtain a user friendly
> +		description of the at <attr>
> +
> +		display_name_language_code:	A file that can be read to obtain
> +		the language code corresponding to the "display_name" of the <attr>
> +
> +		max_length:	A file that can be read to obtain the maximum
> +		length value of the <attr>
> +
> +		min_length:	A file that can be read to obtain the minimum
> +		length value of the <attr>
> +
> +		modifier:	A file that can be read to obtain attribute-level
> +		dependency rule which has to be met to configure <attr>
> +
> +What:		/sys/devices/platform/dell-wmi-sysman/attributes/password/<attr>/
> +Date:		October 2020
> +KernelVersion:	5.9
> +Contact:	Divya Bharathi <Divya.Bharathi@Dell.com>,
> +		Mario Limonciello <mario.limonciello@dell.com>,
> +		Prasanth KSR <prasanth.ksr@dell.com>
> +Description:
> +		This directory exposes interfaces for interaction with
> +		BIOS password attributes.
> +
> +		BIOS Admin password and System Password can be set, reset or cleared
> +		using these attributes.
> +
> +		An "Admin" password is used for preventing modification to the BIOS settings.
> +		A "System" password is required to boot a machine.
> +
> +		is_password_set:	A file that can be read
> +		to obtain flag to see if a password is set on <attr>
> +
> +		max_password_length:	A file that can be read to obtain the
> +		maximum length of the Password
> +
> +		min_password_length:	A file that can be read to obtain the
> +		minimum length of the Password
> +
> +		current_password: A write only value used for privileged access
> +		such as setting attributes when a system or admin password is set
> +		or resetting to a new password
> +
> +		new_password: A write only value that when used in tandem with
> +		current_password will reset a system or admin password.

I'll send a third email for a review of the actual code for this.

Regards,

Hans


> diff --git a/MAINTAINERS b/MAINTAINERS
> index e64cdde81851..176311d712db 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -4879,6 +4879,15 @@ M:	Mario Limonciello <mario.limonciello@dell.com>
>   S:	Maintained
>   F:	drivers/platform/x86/dell-wmi-descriptor.c
>   
> +DELL WMI SYSMAN DRIVER
> +M:	Divya Bharathi <divya.bharathi@dell.com>
> +M:	Mario Limonciello <mario.limonciello@dell.com>
> +M:	Prasanth Ksr <prasanth.ksr@dell.com>
> +L:	platform-driver-x86@vger.kernel.org
> +S:	Maintained
> +F:	drivers/platform/x86/dell-wmi-*-attributes.*
> +F:	drivers/platform/x86/dell-wmi-*-interface.c
> +
>   DELL WMI NOTIFICATIONS DRIVER
>   M:	Matthew Garrett <mjg59@srcf.ucam.org>
>   M:	Pali Rohár <pali@kernel.org>
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index 0581a54cf562..de66373554c2 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -430,6 +430,17 @@ config DELL_WMI
>   	  To compile this driver as a module, choose M here: the module will
>   	  be called dell-wmi.
>   
> +config DELL_WMI_SYSMAN
> +	tristate "Dell WMI SYSMAN"
> +	depends on ACPI_WMI
> +	depends on DMI
> +	help
> +	  This driver allows changing BIOS settings on many Dell machines from
> +	  2018 and newer without the use of any additional software.
> +
> +	  To compile this driver as a module, choose M here: the module will
> +	  be called dell-wmi-sysman.
> +
>   config DELL_WMI_DESCRIPTOR
>   	tristate
>   	depends on ACPI_WMI
> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
> index 2b85852a1a87..bee03f1af28f 100644
> --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -47,6 +47,14 @@ obj-$(CONFIG_DELL_WMI)			+= dell-wmi.o
>   obj-$(CONFIG_DELL_WMI_DESCRIPTOR)	+= dell-wmi-descriptor.o
>   obj-$(CONFIG_DELL_WMI_AIO)		+= dell-wmi-aio.o
>   obj-$(CONFIG_DELL_WMI_LED)		+= dell-wmi-led.o
> +obj-$(CONFIG_DELL_WMI_SYSMAN)  += dell-wmi-sysman.o
> +dell-wmi-sysman-objs := dell-wmi-sysman-attributes.o \
> +				 dell-wmi-enum-attributes.o \
> +				 dell-wmi-int-attributes.o \
> +				 dell-wmi-string-attributes.o \
> +				 dell-wmi-passobj-attributes.o \
> +				 dell-wmi-passwordattr-interface.o \
> +				 dell-wmi-biosattr-interface.o
>   
>   # Fujitsu
>   obj-$(CONFIG_AMILO_RFKILL)	+= amilo-rfkill.o
> diff --git a/drivers/platform/x86/dell-wmi-biosattr-interface.c b/drivers/platform/x86/dell-wmi-biosattr-interface.c
> new file mode 100644
> index 000000000000..decf124d4388
> --- /dev/null
> +++ b/drivers/platform/x86/dell-wmi-biosattr-interface.c
> @@ -0,0 +1,263 @@
> +// 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-attributes.h"
> +
> +#define SETDEFAULTVALUES_METHOD_ID					0x02
> +#define SETBIOSDEFAULTS_METHOD_ID					0x03
> +#define SETATTRIBUTE_METHOD_ID						0x04
> +
> +static DEFINE_MUTEX(call_mutex);
> +static DEFINE_MUTEX(list_mutex);
> +
> +struct wmi_interface_priv {
> +	struct list_head list;
> +	struct wmi_device *wdev;
> +	struct device *child;
> +	bool pending_changes;
> +};
> +static LIST_HEAD(interface_list);
> +
> +static inline struct wmi_interface_priv *get_first_interface_priv(void)
> +{
> +	return list_first_entry_or_null(&interface_list,
> +					struct wmi_interface_priv,
> +					list);
> +}
> +
> +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;
> +
> +	kfree(output.pointer);
> +	kobject_uevent(&wdev->dev.kobj, KOBJ_CHANGE);
> +	return map_wmi_error(ret);
> +}
> +
> +/**
> + * get_pending_changes() - Fetch if any changes are pending
> + *
> + * Checks if any changes have been written that will be changed
> + * after a system reboot
> + **/
> +bool get_pending_changes(void)
> +{
> +	struct wmi_interface_priv *priv;
> +
> +	priv = get_first_interface_priv();
> +	if (priv)
> +		return priv->pending_changes;
> +	return 0;
> +}
> +
> +/**
> + * 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)
> +{
> +	int ret = -1;
> +	int i;
> +	u8 *name_len, *value_len;
> +	char *current_password, *attribute_name, *attribute_value;
> +	size_t security_area_size;
> +	size_t string_area_size;
> +	size_t buffer_size;
> +	struct wmi_interface_priv *priv;
> +	char *buffer;
> +
> +	/* look up if user set a password for the requests */
> +	current_password = get_current_password("Admin");
> +	if (!current_password)
> +		return -ENODEV;
> +
> +	/* password is set */
> +	if (strlen(current_password) > 0)
> +		security_area_size = (sizeof(u32) * 2) + strlen(current_password) +
> +					strlen(current_password) % 2;
> +	/* password not set */
> +	else
> +		security_area_size = sizeof(u32) * 2;
> +	string_area_size = (strlen(a_name) + strlen(a_value))*2;
> +	buffer_size = security_area_size + string_area_size + sizeof(u16) * 2;
> +
> +	buffer = kzalloc(buffer_size, GFP_KERNEL);
> +	if (!buffer)
> +		return -ENOMEM;
> +
> +	/* build security area */
> +	if (strlen(current_password) > 0)
> +		populate_security_buffer(buffer, current_password);
> +
> +	name_len = buffer + security_area_size;
> +	attribute_name = name_len + sizeof(u16);
> +	value_len = attribute_name + strlen(a_name)*2;
> +	attribute_value = value_len + sizeof(u16);
> +
> +	/* turn into UTF16 strings, no NULL terminator */
> +	*name_len = strlen(a_name)*2;
> +	*value_len = strlen(a_value)*2;
> +	for (i = 0; i < strlen(a_name); i++)
> +		attribute_name[i*2] = a_name[i];
> +	for (i = 0; i < strlen(a_value); i++)
> +		attribute_value[i*2] = a_value[i];
> +
> +	mutex_lock(&call_mutex);
> +	priv = get_first_interface_priv();
> +	if (!priv) {
> +		ret = -ENODEV;
> +		pr_err(DRIVER_NAME ": no WMI backend bound");
> +		goto out_set_attribute;
> +	}
> +
> +	ret = call_biosattributes_interface(priv->wdev, buffer, buffer_size,
> +						SETATTRIBUTE_METHOD_ID);
> +	if (ret == -EOPNOTSUPP)
> +		dev_err(&priv->wdev->dev, "admin password must be configured");
> +	else if (ret == -EACCES)
> +		dev_err(&priv->wdev->dev, "invalid password");
> +
> +	priv->pending_changes = 1;
> +out_set_attribute:
> +	kfree(buffer);
> +	mutex_unlock(&call_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)
> +{
> +	int ret = -1;
> +	u8 *defaultType;
> +	char *current_password, *buffer;
> +	size_t security_area_size;
> +	size_t integer_area_size = sizeof(u8);
> +	size_t buffer_size;
> +	struct wmi_interface_priv *priv;
> +
> +	/* look up if user set a password for the requests */
> +	current_password = get_current_password("Admin");
> +	if (!current_password)
> +		return -ENODEV;
> +
> +	/* password is set */
> +	if (strlen(current_password) > 0)
> +		security_area_size = (sizeof(u32) * 2) + strlen(current_password) +
> +					strlen(current_password) % 2;
> +	/* password not set */
> +	else
> +		security_area_size = sizeof(u32) * 2;
> +
> +	buffer_size = security_area_size + integer_area_size;
> +	buffer = kzalloc(buffer_size, GFP_KERNEL);
> +	if (!buffer)
> +		return -ENOMEM;
> +
> +	/* build security area */
> +	if (strlen(current_password) > 0)
> +		populate_security_buffer(buffer, current_password);
> +
> +	mutex_lock(&call_mutex);
> +	priv = get_first_interface_priv();
> +	if (!priv) {
> +		ret = -ENODEV;
> +		pr_err(DRIVER_NAME ": no WMI backend bound");
> +		goto out_bios_defaults;
> +	}
> +
> +	defaultType = buffer + security_area_size;
> +	*defaultType = deftype;
> +
> +	ret = call_biosattributes_interface(priv->wdev, buffer, buffer_size,
> +						SETBIOSDEFAULTS_METHOD_ID);
> +	if (ret)
> +		dev_err(&priv->wdev->dev, "reset BIOS defaults failed: %d", ret);
> +	priv->pending_changes = 1;
> +out_bios_defaults:
> +	kfree(buffer);
> +	mutex_unlock(&call_mutex);
> +
> +	return ret;
> +}
> +
> +static int dell_wmi_bios_attr_set_interface_probe(struct wmi_device *wdev, const void *context)
> +{
> +	struct wmi_interface_priv *priv;
> +
> +	priv = devm_kzalloc(&wdev->dev, sizeof(struct wmi_interface_priv),
> +			    GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +	priv->wdev = wdev;
> +	dev_set_drvdata(&wdev->dev, priv);
> +	mutex_lock(&list_mutex);
> +	list_add_tail(&priv->list, &interface_list);
> +	mutex_unlock(&list_mutex);
> +	return 0;
> +}
> +
> +static int dell_wmi_bios_attr_set_interface_remove(struct wmi_device *wdev)
> +{
> +	struct wmi_interface_priv *priv = dev_get_drvdata(&wdev->dev);
> +
> +	mutex_lock(&call_mutex);
> +	mutex_lock(&list_mutex);
> +	list_del(&priv->list);
> +	mutex_unlock(&list_mutex);
> +	mutex_unlock(&call_mutex);
> +	return 0;
> +}
> +
> +static const struct wmi_device_id dell_wmi_bios_attr_set_interface_id_table[] = {
> +	{ .guid_string = DELL_WMI_BIOS_ATTRIBUTES_INTERFACE_GUID },
> +	{ },
> +};
> +static struct wmi_driver dell_wmi_bios_attr_set_interface_driver = {
> +	.driver = {
> +		.name = DRIVER_NAME"-set"
> +	},
> +	.probe = dell_wmi_bios_attr_set_interface_probe,
> +	.remove = dell_wmi_bios_attr_set_interface_remove,
> +	.id_table = dell_wmi_bios_attr_set_interface_id_table,
> +};
> +
> +int init_dell_wmi_bios_attr_set_interface(void)
> +{
> +	return wmi_driver_register(&dell_wmi_bios_attr_set_interface_driver);
> +}
> +
> +void exit_dell_wmi_bios_attr_set_interface(void)
> +{
> +	wmi_driver_unregister(&dell_wmi_bios_attr_set_interface_driver);
> +}
> +
> +MODULE_DEVICE_TABLE(wmi, dell_wmi_bios_attr_set_interface_id_table);
> diff --git a/drivers/platform/x86/dell-wmi-enum-attributes.c b/drivers/platform/x86/dell-wmi-enum-attributes.c
> new file mode 100644
> index 000000000000..a2d8ae291d5c
> --- /dev/null
> +++ b/drivers/platform/x86/dell-wmi-enum-attributes.c
> @@ -0,0 +1,207 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Functions corresponding to enumeration type attributes under BIOS Enumeration GUID for use
> + * with dell-wmi-sysman
> + *
> + *  Copyright (c) 2020 Dell Inc.
> + */
> +
> +#include "dell-wmi-sysman-attributes.h"
> +
> +static DEFINE_MUTEX(call_mutex);
> +static DEFINE_MUTEX(list_mutex);
> +
> +/* kept variable names same as in sysfs file name for sysfs_show macro definition */
> +struct enumeration_data {
> +	char attribute_name[MAX_BUFF];
> +	char display_name_language_code[MAX_BUFF];
> +	char display_name[MAX_BUFF];
> +	char default_value[MAX_BUFF];
> +	char current_value[MAX_BUFF];
> +	char modifier[MAX_BUFF];
> +	int value_modifier_count;
> +	char value_modifier[MAX_BUFF];
> +	int possible_value_count;
> +	char possible_value[MAX_BUFF];
> +};
> +
> +static struct enumeration_data *enumeration_data;
> +static int enumeration_instances_count;
> +get_instance_id(enumeration);
> +
> +static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> +{
> +	int instance_id;
> +
> +	if (!capable(CAP_SYS_ADMIN))
> +		return -EPERM;
> +	instance_id = get_enumeration_instance_id(kobj);
> +	if (instance_id >= 0) {
> +		union acpi_object *obj;
> +
> +		obj = get_wmiobj_pointer(instance_id, DELL_WMI_BIOS_ENUMERATION_ATTRIBUTE_GUID);
> +		if (!obj)
> +			return -AE_ERROR;
> +		strncpy_attr(enumeration_data[instance_id].current_value,
> +		       obj->package.elements[CURRENT_VAL].string.pointer);
> +		kfree(obj);
> +		return sprintf(buf, "%s\n", enumeration_data[instance_id].current_value);
> +	}
> +	return -EIO;
> +}
> +
> +/**
> + * validate_enumeration_input() - Validate input of current_value against possible values
> + * @instance_id: The instance on which input is validated
> + * @buf: Input value
> + **/
> +int validate_enumeration_input(int instance_id, const char *buf)
> +{
> +	int ret = -EINVAL;
> +	char *options, *tmp, *p;
> +
> +	options = tmp = kstrdup((enumeration_data[instance_id].possible_value), GFP_KERNEL);
> +	if (!options)
> +		return -ENOMEM;
> +
> +	while ((p = strsep(&options, ";")) != NULL) {
> +		if (!*p)
> +			continue;
> +		if (!strncasecmp(p, buf, strlen(p))) {
> +			ret = 0;
> +			break;
> +		}
> +	}
> +
> +	kfree(tmp);
> +	return ret;
> +}
> +
> +attribute_s_property_show(display_name_language_code, enumeration);
> +static struct kobj_attribute displ_langcode =
> +		__ATTR_RO(display_name_language_code);
> +
> +attribute_s_property_show(display_name, enumeration);
> +struct kobj_attribute displ_name =
> +		__ATTR_RO(display_name);
> +
> +attribute_s_property_show(default_value, enumeration);
> +struct kobj_attribute default_val =
> +		__ATTR_RO(default_value);
> +
> +attribute_property_store(current_value, enumeration);
> +struct kobj_attribute current_val =
> +		__ATTR_RW(current_value);
> +
> +attribute_s_property_show(modifier, enumeration);
> +struct kobj_attribute modifier =
> +		__ATTR_RO(modifier);
> +
> +attribute_s_property_show(value_modifier, enumeration);
> +struct kobj_attribute value_modfr =
> +		__ATTR_RO(value_modifier);
> +
> +attribute_s_property_show(possible_value, enumeration);
> +struct kobj_attribute poss_val =
> +		__ATTR_RO(possible_value);
> +
> +static struct attribute *enumeration_attrs[] = {
> +	&displ_langcode.attr,
> +	&displ_name.attr,
> +	&default_val.attr,
> +	&current_val.attr,
> +	&modifier.attr,
> +	&value_modfr.attr,
> +	&poss_val.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group enumeration_attr_group = {
> +	.attrs = enumeration_attrs,
> +};
> +
> +int alloc_enum_data(void)
> +{
> +	int ret = 0;
> +
> +	enumeration_instances_count = get_instance_count(DELL_WMI_BIOS_ENUMERATION_ATTRIBUTE_GUID);
> +	enumeration_data = kzalloc((sizeof(struct enumeration_data) * enumeration_instances_count),
> +					GFP_KERNEL);
> +	if (!enumeration_data)
> +		ret = -ENOMEM;
> +	return ret;
> +}
> +
> +/**
> + * populate_enum_data() - Populate all properties of an instance under enumeration attribute
> + * @enumeration_obj: ACPI object with enumeration data
> + * @instance_id: The instance to enumerate
> + * @attr_name_kobj: The parent kernel object
> + **/
> +int populate_enum_data(union acpi_object *enumeration_obj, int instance_id,
> +			struct kobject *attr_name_kobj)
> +{
> +	int i, next_obj;
> +	int retval = sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
> +
> +	if (retval)
> +		goto out;
> +
> +	mutex_lock(&call_mutex);
> +	strncpy_attr(enumeration_data[instance_id].attribute_name,
> +		enumeration_obj[ATTR_NAME].string.pointer);
> +	strncpy_attr(enumeration_data[instance_id].display_name_language_code,
> +		enumeration_obj[DISPL_NAME_LANG_CODE].string.pointer);
> +	strncpy_attr(enumeration_data[instance_id].display_name,
> +		enumeration_obj[DISPLAY_NAME].string.pointer);
> +	strncpy_attr(enumeration_data[instance_id].default_value,
> +		enumeration_obj[DEFAULT_VAL].string.pointer);
> +	strncpy_attr(enumeration_data[instance_id].current_value,
> +		enumeration_obj[CURRENT_VAL].string.pointer);
> +	strncpy_attr(enumeration_data[instance_id].modifier,
> +		enumeration_obj[MODIFIER].string.pointer);
> +
> +	next_obj = MODIFIER + 1;
> +
> +	enumeration_data[instance_id].value_modifier_count =
> +		(uintptr_t)enumeration_obj[next_obj].string.pointer;
> +
> +	for (i = 0; i < enumeration_data[instance_id].value_modifier_count; i++) {
> +		strcat(enumeration_data[instance_id].value_modifier,
> +			enumeration_obj[++next_obj].string.pointer);
> +		strcat(enumeration_data[instance_id].value_modifier, ";");
> +	}
> +
> +	enumeration_data[instance_id].possible_value_count =
> +		(uintptr_t) enumeration_obj[++next_obj].string.pointer;
> +
> +	for (i = 0; i < enumeration_data[instance_id].possible_value_count; i++) {
> +		strcat(enumeration_data[instance_id].possible_value,
> +			enumeration_obj[++next_obj].string.pointer);
> +		strcat(enumeration_data[instance_id].possible_value, ";");
> +	}
> +	mutex_unlock(&call_mutex);
> +
> +out:
> +	return retval;
> +}
> +
> +/**
> + * exit_enum_attributes() - Clear all attribute data
> + * @kset: The kset to free
> + *
> + * Clears all data allocated for this group of attributes
> + **/
> +void exit_enum_attributes(struct kset *kset)
> +{
> +	struct kobject *pos, *next;
> +
> +	mutex_lock(&list_mutex);
> +	list_for_each_entry_safe(pos, next, &kset->list, entry) {
> +		sysfs_remove_group(pos, &enumeration_attr_group);
> +	}
> +	mutex_unlock(&list_mutex);
> +	mutex_lock(&call_mutex);
> +	kfree(enumeration_data);
> +	mutex_unlock(&call_mutex);
> +}
> diff --git a/drivers/platform/x86/dell-wmi-int-attributes.c b/drivers/platform/x86/dell-wmi-int-attributes.c
> new file mode 100644
> index 000000000000..222971be2b48
> --- /dev/null
> +++ b/drivers/platform/x86/dell-wmi-int-attributes.c
> @@ -0,0 +1,188 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Functions corresponding to integer type attributes under BIOS Integer GUID for use with
> + * dell-wmi-sysman
> + *
> + *  Copyright (c) 2020 Dell Inc.
> + */
> +
> +#include "dell-wmi-sysman-attributes.h"
> +
> +static DEFINE_MUTEX(call_mutex);
> +static DEFINE_MUTEX(list_mutex);
> +
> +enum int_properties {LOWER_BOUND = 6, UPPER_BOUND, SCALAR_INCR};
> +
> +/* kept variable names same as in sysfs file name for sysfs_show macro definition */
> +struct integer_data {
> +	char attribute_name[MAX_BUFF];
> +	char display_name_language_code[MAX_BUFF];
> +	char display_name[MAX_BUFF];
> +	int default_value;
> +	int current_value;
> +	char modifier[MAX_BUFF];
> +	int lower_bound;
> +	int upper_bound;
> +	int scalar_increment;
> +};
> +
> +static struct integer_data *integer_data;
> +static int integer_instances_count;
> +get_instance_id(integer);
> +
> +static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> +{
> +	int instance_id;
> +
> +	if (!capable(CAP_SYS_ADMIN))
> +		return -EPERM;
> +	instance_id = get_integer_instance_id(kobj);
> +	if (instance_id >= 0) {
> +		union acpi_object *obj;
> +
> +		obj = get_wmiobj_pointer(instance_id, DELL_WMI_BIOS_INTEGER_ATTRIBUTE_GUID);
> +		if (!obj)
> +			return -AE_ERROR;
> +		integer_data[instance_id].current_value =
> +			(uintptr_t)obj->package.elements[CURRENT_VAL].string.pointer;
> +		kfree(obj);
> +		return sprintf(buf, "%d\n", integer_data[instance_id].current_value);
> +	}
> +	return -EIO;
> +}
> +
> +/**
> + * validate_integer_input() - Validate input of current_value against lower and upper bound
> + * @instance_id: The instance on which input is validated
> + * @buf: Input value
> + **/
> +int validate_integer_input(int instance_id, const char *buf)
> +{
> +	int in_val;
> +	int ret = -EINVAL;
> +
> +	if (kstrtoint(buf, 0, &in_val))
> +		return -EINVAL;
> +	if ((in_val >= integer_data[instance_id].lower_bound) &&
> +	(in_val <= integer_data[instance_id].upper_bound))
> +		ret = 0;
> +
> +	return ret;
> +}
> +
> +attribute_s_property_show(display_name_language_code, integer);
> +static struct kobj_attribute integer_displ_langcode =
> +	__ATTR_RO(display_name_language_code);
> +
> +attribute_s_property_show(display_name, integer);
> +struct kobj_attribute integer_displ_name =
> +	__ATTR_RO(display_name);
> +
> +attribute_n_property_show(default_value, integer);
> +struct kobj_attribute integer_default_val =
> +	__ATTR_RO(default_value);
> +
> +attribute_property_store(current_value, integer);
> +struct kobj_attribute integer_current_val =
> +	__ATTR_RW(current_value);
> +
> +attribute_s_property_show(modifier, integer);
> +struct kobj_attribute integer_modifier =
> +	__ATTR_RO(modifier);
> +
> +attribute_n_property_show(lower_bound, integer);
> +struct kobj_attribute integer_lower_bound =
> +	__ATTR_RO(lower_bound);
> +
> +attribute_n_property_show(upper_bound, integer);
> +struct kobj_attribute integer_upper_bound =
> +	__ATTR_RO(upper_bound);
> +
> +attribute_n_property_show(scalar_increment, integer);
> +struct kobj_attribute integer_scalar_increment =
> +	__ATTR_RO(scalar_increment);
> +
> +static struct attribute *integer_attrs[] = {
> +	&integer_displ_langcode.attr,
> +	&integer_displ_name.attr,
> +	&integer_default_val.attr,
> +	&integer_current_val.attr,
> +	&integer_modifier.attr,
> +	&integer_lower_bound.attr,
> +	&integer_upper_bound.attr,
> +	&integer_scalar_increment.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group integer_attr_group = {
> +	.attrs = integer_attrs,
> +};
> +
> +int alloc_int_data(void)
> +{
> +	int ret = 0;
> +
> +	integer_instances_count = get_instance_count(DELL_WMI_BIOS_INTEGER_ATTRIBUTE_GUID);
> +	integer_data = kzalloc((sizeof(struct integer_data) * integer_instances_count), GFP_KERNEL);
> +	if (!integer_data)
> +		ret = -ENOMEM;
> +	return ret;
> +}
> +
> +/**
> + * populate_enum_data() - Populate all properties of an instance under integer attribute
> + * @integer_obj: ACPI object with integer data
> + * @instance_id: The instance to enumerate
> + * @attr_name_kobj: The parent kernel object
> + **/
> +int populate_int_data(union acpi_object *integer_obj, int instance_id,
> +			struct kobject *attr_name_kobj)
> +{
> +	int retval = sysfs_create_group(attr_name_kobj, &integer_attr_group);
> +
> +	if (retval)
> +		goto out;
> +
> +	mutex_lock(&call_mutex);
> +	strncpy_attr(integer_data[instance_id].attribute_name,
> +		integer_obj[ATTR_NAME].string.pointer);
> +	strncpy_attr(integer_data[instance_id].display_name_language_code,
> +		integer_obj[DISPL_NAME_LANG_CODE].string.pointer);
> +	strncpy_attr(integer_data[instance_id].display_name,
> +		integer_obj[DISPLAY_NAME].string.pointer);
> +	integer_data[instance_id].default_value =
> +		(uintptr_t)integer_obj[DEFAULT_VAL].string.pointer;
> +	integer_data[instance_id].current_value =
> +		(uintptr_t)integer_obj[CURRENT_VAL].string.pointer;
> +	strncpy_attr(integer_data[instance_id].modifier, integer_obj[MODIFIER].string.pointer);
> +	integer_data[instance_id].lower_bound =
> +		(uintptr_t)integer_obj[LOWER_BOUND].string.pointer;
> +	integer_data[instance_id].upper_bound =
> +		(uintptr_t)integer_obj[UPPER_BOUND].string.pointer;
> +	integer_data[instance_id].scalar_increment =
> +		(uintptr_t)integer_obj[SCALAR_INCR].string.pointer;
> +	mutex_unlock(&call_mutex);
> +
> +out:
> +	return retval;
> +}
> +
> +/**
> + * exit_int_attributes() - Clear all attribute data
> + * @kset: The kset to free
> + *
> + * Clears all data allocated for this group of attributes
> + **/
> +void exit_int_attributes(struct kset *kset)
> +{
> +	struct kobject *pos, *next;
> +
> +	mutex_lock(&list_mutex);
> +	list_for_each_entry_safe(pos, next, &kset->list, entry) {
> +		sysfs_remove_group(pos, &integer_attr_group);
> +	}
> +	mutex_unlock(&list_mutex);
> +	mutex_lock(&call_mutex);
> +	kfree(integer_data);
> +	mutex_unlock(&call_mutex);
> +}
> diff --git a/drivers/platform/x86/dell-wmi-passobj-attributes.c b/drivers/platform/x86/dell-wmi-passobj-attributes.c
> new file mode 100644
> index 000000000000..d430ecf2387b
> --- /dev/null
> +++ b/drivers/platform/x86/dell-wmi-passobj-attributes.c
> @@ -0,0 +1,161 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Functions corresponding to password object type attributes under BIOS Password Object GUID for
> + * use with dell-wmi-sysman
> + *
> + *  Copyright (c) 2020 Dell Inc.
> + */
> +
> +#include "dell-wmi-sysman-attributes.h"
> +
> +static DEFINE_MUTEX(call_mutex);
> +static DEFINE_MUTEX(list_mutex);
> +
> +enum po_properties {IS_PASS_SET = 1, MIN_PASS_LEN, MAX_PASS_LEN};
> +
> +/* kept variable names same as in sysfs file name for sysfs_show macro definition */
> +struct po_data {
> +	char attribute_name[MAX_BUFF];
> +	int is_password_set;
> +	int min_password_length;
> +	int max_password_length;
> +};
> +
> +static struct po_data *po_data;
> +static int po_instances_count;
> +get_instance_id(po);
> +
> +static ssize_t is_password_set_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> +{
> +	int instance_id = get_po_instance_id(kobj);
> +
> +	if (instance_id >= 0) {
> +		union acpi_object *obj;
> +
> +		obj = get_wmiobj_pointer(instance_id, DELL_WMI_BIOS_PASSOBJ_ATTRIBUTE_GUID);
> +		if (!obj)
> +			return -AE_ERROR;
> +		po_data[instance_id].is_password_set =
> +			(uintptr_t)obj->package.elements[IS_PASS_SET].string.pointer;
> +		kfree(obj);
> +		return sprintf(buf, "%d\n", po_data[instance_id].is_password_set);
> +	}
> +	return -EIO;
> +}
> +
> +struct kobj_attribute po_is_pass_set =
> +		__ATTR_RO(is_password_set);
> +
> +static ssize_t current_password_store(struct kobject *kobj,
> +				      struct kobj_attribute *attr,
> +				      const char *buf, size_t count)
> +{
> +	char *p = memchr(buf, '\n', count);
> +	int ret;
> +
> +	if (p != NULL)
> +		*p = '\0';
> +	if (strlen(buf) > MAX_BUFF)
> +		return -EINVAL;
> +
> +	ret = set_current_password(kobj->name, buf);
> +	return ret ? ret : count;
> +}
> +
> +struct kobj_attribute po_current_password =
> +		__ATTR_WO(current_password);
> +
> +static ssize_t new_password_store(struct kobject *kobj,
> +				  struct kobj_attribute *attr,
> +				  const char *buf, size_t count)
> +{
> +	char *p = memchr(buf, '\n', count);
> +	int ret;
> +
> +	if (p != NULL)
> +		*p = '\0';
> +	if (strlen(buf) > MAX_BUFF)
> +		return -EINVAL;
> +
> +	ret = set_new_password(kobj->name, buf);
> +	return ret ? ret : count;
> +}
> +
> +struct kobj_attribute po_new_password =
> +		__ATTR_WO(new_password);
> +
> +attribute_n_property_show(min_password_length, po);
> +struct kobj_attribute po_min_pass_length =
> +		__ATTR_RO(min_password_length);
> +
> +attribute_n_property_show(max_password_length, po);
> +struct kobj_attribute po_max_pass_length =
> +		__ATTR_RO(max_password_length);
> +
> +static struct attribute *po_attrs[] = {
> +	&po_is_pass_set.attr,
> +	&po_min_pass_length.attr,
> +	&po_max_pass_length.attr,
> +	&po_current_password.attr,
> +	&po_new_password.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group po_attr_group = {
> +	.attrs = po_attrs,
> +};
> +
> +int alloc_po_data(void)
> +{
> +	int ret = 0;
> +
> +	po_instances_count = get_instance_count(DELL_WMI_BIOS_PASSOBJ_ATTRIBUTE_GUID);
> +	po_data = kzalloc((sizeof(struct po_data) * po_instances_count), GFP_KERNEL);
> +	if (!po_data)
> +		ret = -ENOMEM;
> +	return ret;
> +}
> +
> +/**
> + * populate_po_data() - Populate all properties of an instance under password object attribute
> + * @po_obj: ACPI object with password object data
> + * @instance_id: The instance to enumerate
> + * @attr_name_kobj: The parent kernel object
> + **/
> +int populate_po_data(union acpi_object *po_obj, int instance_id, struct kobject *attr_name_kobj)
> +{
> +	int retval = sysfs_create_group(attr_name_kobj, &po_attr_group);
> +
> +	if (retval)
> +		goto out;
> +
> +	mutex_lock(&call_mutex);
> +	strncpy_attr(po_data[instance_id].attribute_name, po_obj[ATTR_NAME].string.pointer);
> +	po_data[instance_id].is_password_set = (uintptr_t)po_obj[IS_PASS_SET].string.pointer;
> +	po_data[instance_id].min_password_length = (uintptr_t)po_obj[MIN_PASS_LEN].string.pointer;
> +	po_data[instance_id].max_password_length = (uintptr_t) po_obj[MAX_PASS_LEN].string.pointer;
> +	mutex_unlock(&call_mutex);
> +
> +out:
> +	return retval;
> +}
> +
> +/**
> + * exit_po_attributes() - Clear all attribute data
> + * @kset: The kset to free
> + *
> + * Clears all data allocated for this group of attributes
> + **/
> +void exit_po_attributes(struct kset *kset)
> +{
> +	struct kobject *pos, *next;
> +
> +	mutex_lock(&list_mutex);
> +	list_for_each_entry_safe(pos, next, &kset->list, entry) {
> +		sysfs_remove_group(pos, &po_attr_group);
> +	}
> +	mutex_unlock(&list_mutex);
> +	mutex_lock(&call_mutex);
> +	kfree(po_data);
> +	mutex_unlock(&call_mutex);
> +}
> diff --git a/drivers/platform/x86/dell-wmi-passwordattr-interface.c b/drivers/platform/x86/dell-wmi-passwordattr-interface.c
> new file mode 100644
> index 000000000000..9d7ac36e232f
> --- /dev/null
> +++ b/drivers/platform/x86/dell-wmi-passwordattr-interface.c
> @@ -0,0 +1,230 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Functions corresponding to SET password methods under BIOS attributes interface GUID
> + *
> + *  Copyright (c) 2020 Dell Inc.
> + */
> +
> +#include <linux/wmi.h>
> +#include "dell-wmi-sysman-attributes.h"
> +
> +static DEFINE_MUTEX(call_mutex);
> +static DEFINE_MUTEX(list_mutex);
> +
> +struct wmi_interface_priv {
> +	struct list_head list;
> +	struct wmi_device *wdev;
> +	struct device *child;
> +	char current_admin_password[MAX_BUFF];
> +	char current_system_password[MAX_BUFF];
> +};
> +static LIST_HEAD(interface_list);
> +
> +static inline struct wmi_interface_priv *get_first_interface_priv(void)
> +{
> +	return list_first_entry_or_null(&interface_list,
> +					struct wmi_interface_priv,
> +					list);
> +}
> +
> +static int call_password_interface(struct wmi_device *wdev, char *in_args, size_t size)
> +{
> +	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, 1, &input, &output);
> +	if (ACPI_FAILURE(status))
> +		return -EIO;
> +	obj = (union acpi_object *)output.pointer;
> +	if (obj->type == ACPI_TYPE_INTEGER)
> +		ret = obj->integer.value;
> +
> +	kfree(output.pointer);
> +	kobject_uevent(&wdev->dev.kobj, KOBJ_CHANGE);
> +	return map_wmi_error(ret);
> +}
> +
> +/**
> + * get_current_password() - Get the current stored password value
> + * @password_type: The type of password to store
> + **/
> +char *get_current_password(const char *password_type)
> +{
> +	struct wmi_interface_priv *priv = get_first_interface_priv();
> +
> +	if (!priv) {
> +		pr_err(DRIVER_NAME ": no WMI backend bound");
> +		return NULL;
> +	}
> +	if (strcmp(password_type, "Admin") == 0)
> +		return priv->current_admin_password;
> +	if (strcmp(password_type, "System") == 0)
> +		return priv->current_system_password;
> +	dev_err(&priv->wdev->dev, "unknown password type %s", password_type);
> +	return NULL;
> +}
> +
> +/**
> + * set_current_password() - Store current password
> + * @password_type: The type of password to store
> + * @current: The current value
> + *
> + * Sets the current value of the password.
> + * This is used for:
> + *  - Resetting password
> + *  - Basis for any functions requiring password to execute
> + **/
> +int set_current_password(const char *password_type, const char *cur)
> +{
> +	char *current_password = get_current_password(password_type);
> +
> +	if (!current_password)
> +		return -ENODEV;
> +	strncpy(current_password, cur, (strlen(cur) + 1));
> +	return 0;
> +}
> +
> +/**
> + * set_new_password() - Sets a system admin password
> + * @password_type: The type of password to set
> + * @new: The new password
> + *
> + * Sets the password using plaintext interface
> + **/
> +int set_new_password(const char *password_type, const char *new)
> +{
> +	int ret = -1;
> +	int i;
> +	u8 *type_len, *old_len, *new_len;
> +	char *current_password, *type_value, *old_value, *new_value;
> +	size_t security_area_size;
> +	size_t string_area_size;
> +	size_t buffer_size;
> +	struct wmi_interface_priv *priv;
> +	char *buffer;
> +
> +	mutex_lock(&call_mutex);
> +	priv = get_first_interface_priv();
> +	if (!priv) {
> +		ret = -ENODEV;
> +		pr_err(DRIVER_NAME ": no WMI backend bound");
> +		goto out_close_mutex;
> +	}
> +	current_password = get_current_password(password_type);
> +	if (!current_password) {
> +		ret = -ENODEV;
> +		goto out_close_mutex;
> +	}
> +	/* password is set */
> +	if (strlen(current_password) > 0)
> +		security_area_size = (sizeof(u32) * 2) + strlen(current_password) +
> +					strlen(current_password) % 2;
> +	/* password not set */
> +	else
> +		security_area_size = sizeof(u32) * 2;
> +	string_area_size = (strlen(password_type) + strlen(current_password) + strlen(new))*2;
> +	buffer_size = security_area_size + string_area_size + sizeof(u16) * 3;
> +
> +	buffer = kzalloc(buffer_size, GFP_KERNEL);
> +
> +	if (!buffer) {
> +		ret = -ENOMEM;
> +		goto out_close_mutex;
> +	}
> +
> +	/* build security area */
> +	if (strlen(current_password) > 0)
> +		populate_security_buffer(buffer, current_password);
> +
> +	type_len = buffer + security_area_size;
> +	type_value = type_len + sizeof(u16);
> +	old_len = type_value + strlen(password_type)*2;
> +	old_value = old_len + sizeof(u16);
> +	new_len = old_value + strlen(current_password)*2;
> +	new_value = new_len + sizeof(u16);
> +
> +	/* turn into UTF16 strings, no NULL terminator */
> +	*type_len = strlen(password_type)*2;
> +	*old_len = strlen(current_password)*2;
> +	*new_len = strlen(new)*2;
> +	for (i = 0; i < strlen(password_type); i++)
> +		type_value[i*2] = password_type[i];
> +	for (i = 0; i < strlen(current_password); i++)
> +		old_value[i*2] = current_password[i];
> +	for (i = 0; i < strlen(new); i++)
> +		new_value[i*2] = new[i];
> +
> +	ret = call_password_interface(priv->wdev, buffer, buffer_size);
> +	/* update current password so commands work after reset */
> +	if (!ret)
> +		ret = set_current_password(password_type, new);
> +	/* explain to user the detailed failure reason */
> +	else if (ret == -EOPNOTSUPP)
> +		dev_err(&priv->wdev->dev, "admin password must be configured");
> +	else if (ret == -EACCES)
> +		dev_err(&priv->wdev->dev, "invalid password");
> +	kfree(buffer);
> +
> +out_close_mutex:
> +	mutex_unlock(&call_mutex);
> +
> +	return ret;
> +}
> +
> +static int dell_wmi_bios_attr_pass_interface_probe(struct wmi_device *wdev, const void *context)
> +{
> +	struct wmi_interface_priv *priv;
> +
> +	priv = devm_kzalloc(&wdev->dev, sizeof(struct wmi_interface_priv),
> +			    GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +	priv->wdev = wdev;
> +	dev_set_drvdata(&wdev->dev, priv);
> +	mutex_lock(&list_mutex);
> +	list_add_tail(&priv->list, &interface_list);
> +	mutex_unlock(&list_mutex);
> +	return 0;
> +}
> +
> +static int dell_wmi_bios_attr_pass_interface_remove(struct wmi_device *wdev)
> +{
> +	struct wmi_interface_priv *priv = dev_get_drvdata(&wdev->dev);
> +
> +	mutex_lock(&call_mutex);
> +	mutex_lock(&list_mutex);
> +	list_del(&priv->list);
> +	mutex_unlock(&list_mutex);
> +	mutex_unlock(&call_mutex);
> +	return 0;
> +}
> +
> +static const struct wmi_device_id dell_wmi_bios_attr_pass_interface_id_table[] = {
> +	{ .guid_string = DELL_WMI_BIOS_PASSWORD_INTERFACE_GUID },
> +	{ },
> +};
> +static struct wmi_driver dell_wmi_bios_attr_pass_interface_driver = {
> +	.driver = {
> +		.name = DRIVER_NAME"-password"
> +	},
> +	.probe = dell_wmi_bios_attr_pass_interface_probe,
> +	.remove = dell_wmi_bios_attr_pass_interface_remove,
> +	.id_table = dell_wmi_bios_attr_pass_interface_id_table,
> +};
> +
> +int init_dell_wmi_bios_attr_pass_interface(void)
> +{
> +	return wmi_driver_register(&dell_wmi_bios_attr_pass_interface_driver);
> +}
> +
> +void exit_dell_wmi_bios_attr_pass_interface(void)
> +{
> +	wmi_driver_unregister(&dell_wmi_bios_attr_pass_interface_driver);
> +}
> +
> +MODULE_DEVICE_TABLE(wmi, dell_wmi_bios_attr_pass_interface_id_table);
> diff --git a/drivers/platform/x86/dell-wmi-string-attributes.c b/drivers/platform/x86/dell-wmi-string-attributes.c
> new file mode 100644
> index 000000000000..562d09055dd1
> --- /dev/null
> +++ b/drivers/platform/x86/dell-wmi-string-attributes.c
> @@ -0,0 +1,170 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Functions corresponding to string type attributes under BIOS String GUID for use with
> + * dell-wmi-sysman
> + *
> + *  Copyright (c) 2020 Dell Inc.
> + */
> +
> +#include "dell-wmi-sysman-attributes.h"
> +
> +static DEFINE_MUTEX(call_mutex);
> +static DEFINE_MUTEX(list_mutex);
> +
> +enum string_properties {MIN_LEN = 6, MAX_LEN};
> +
> +/* kept variable names same as in sysfs file name for sysfs_show macro definition */
> +struct str_data {
> +	char attribute_name[MAX_BUFF];
> +	char display_name_language_code[MAX_BUFF];
> +	char display_name[MAX_BUFF];
> +	char default_value[MAX_BUFF];
> +	char current_value[MAX_BUFF];
> +	char modifier[MAX_BUFF];
> +	int min_length;
> +	int max_length;
> +};
> +
> +static struct str_data *str_data;
> +static int str_instances_count;
> +get_instance_id(str);
> +
> +static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> +{
> +	int instance_id;
> +
> +	if (!capable(CAP_SYS_ADMIN))
> +		return -EPERM;
> +	instance_id = get_str_instance_id(kobj);
> +	if (instance_id >= 0) {
> +		union acpi_object *obj;
> +
> +		obj = get_wmiobj_pointer(instance_id, DELL_WMI_BIOS_STRING_ATTRIBUTE_GUID);
> +		if (!obj)
> +			return -AE_ERROR;
> +		strncpy_attr(str_data[instance_id].current_value,
> +			obj->package.elements[CURRENT_VAL].string.pointer);
> +		kfree(obj);
> +		return sprintf(buf, "%s\n", str_data[instance_id].current_value);
> +	}
> +	return -EIO;
> +}
> +
> +/**
> + * validate_str_input() - Validate input of current_value against min and max lengths
> + * @instance_id: The instance on which input is validated
> + * @buf: Input value
> + **/
> +int validate_str_input(int instance_id, const char *buf)
> +{
> +	int in_len = strlen(buf);
> +
> +	if ((in_len >= str_data[instance_id].min_length) &&
> +	(in_len <= str_data[instance_id].max_length))
> +		return 0;
> +
> +	return -EINVAL;
> +}
> +
> +attribute_s_property_show(display_name_language_code, str);
> +static struct kobj_attribute str_displ_langcode =
> +		__ATTR_RO(display_name_language_code);
> +
> +attribute_s_property_show(display_name, str);
> +struct kobj_attribute str_displ_name =
> +		__ATTR_RO(display_name);
> +
> +attribute_s_property_show(default_value, str);
> +struct kobj_attribute str_default_val =
> +		__ATTR_RO(default_value);
> +
> +attribute_property_store(current_value, str);
> +struct kobj_attribute str_current_val =
> +		__ATTR_RW(current_value);
> +
> +attribute_s_property_show(modifier, str);
> +struct kobj_attribute str_modifier =
> +		__ATTR_RO(modifier);
> +
> +attribute_n_property_show(min_length, str);
> +struct kobj_attribute str_min_length =
> +		__ATTR_RO(min_length);
> +
> +attribute_n_property_show(max_length, str);
> +struct kobj_attribute str_max_length =
> +		__ATTR_RO(max_length);
> +
> +static struct attribute *str_attrs[] = {
> +	&str_displ_langcode.attr,
> +	&str_displ_name.attr,
> +	&str_default_val.attr,
> +	&str_current_val.attr,
> +	&str_modifier.attr,
> +	&str_min_length.attr,
> +	&str_max_length.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group str_attr_group = {
> +	.attrs = str_attrs,
> +};
> +
> +int alloc_str_data(void)
> +{
> +	int ret = 0;
> +
> +	str_instances_count = get_instance_count(DELL_WMI_BIOS_STRING_ATTRIBUTE_GUID);
> +	str_data = kzalloc((sizeof(struct str_data) * str_instances_count), GFP_KERNEL);
> +	if (!str_data)
> +		ret = -ENOMEM;
> +	return ret;
> +}
> +
> +/**
> + * populate_enum_data() - Populate all properties of an instance under string attribute
> + * @str_obj: ACPI object with integer data
> + * @instance_id: The instance to enumerate
> + * @attr_name_kobj: The parent kernel object
> + **/
> +int populate_str_data(union acpi_object *str_obj, int instance_id, struct kobject *attr_name_kobj)
> +{
> +	int retval = sysfs_create_group(attr_name_kobj, &str_attr_group);
> +
> +	if (retval)
> +		goto out;
> +
> +	mutex_lock(&call_mutex);
> +	strncpy_attr(str_data[instance_id].attribute_name, str_obj[ATTR_NAME].string.pointer);
> +	strncpy_attr(str_data[instance_id].display_name_language_code,
> +		str_obj[DISPL_NAME_LANG_CODE].string.pointer);
> +	strncpy_attr(str_data[instance_id].display_name, str_obj[DISPLAY_NAME].string.pointer);
> +	strncpy_attr(str_data[instance_id].default_value, str_obj[DEFAULT_VAL].string.pointer);
> +	strncpy_attr(str_data[instance_id].current_value, str_obj[CURRENT_VAL].string.pointer);
> +	strncpy_attr(str_data[instance_id].modifier, str_obj[MODIFIER].string.pointer);
> +	str_data[instance_id].min_length = (uintptr_t)str_obj[MIN_LEN].string.pointer;
> +	str_data[instance_id].max_length = (uintptr_t) str_obj[MAX_LEN].string.pointer;
> +	mutex_unlock(&call_mutex);
> +
> +out:
> +	return retval;
> +}
> +
> +/**
> + * exit_str_attributes() - Clear all attribute data
> + * @kset: The kset to free
> + *
> + * Clears all data allocated for this group of attributes
> + **/
> +void exit_str_attributes(struct kset *kset)
> +{
> +	struct kobject *pos, *next;
> +
> +	mutex_lock(&list_mutex);
> +	list_for_each_entry_safe(pos, next, &kset->list, entry) {
> +		sysfs_remove_group(pos, &str_attr_group);
> +	}
> +	mutex_unlock(&list_mutex);
> +	mutex_lock(&call_mutex);
> +	kfree(str_data);
> +	mutex_unlock(&call_mutex);
> +}
> diff --git a/drivers/platform/x86/dell-wmi-sysman-attributes.c b/drivers/platform/x86/dell-wmi-sysman-attributes.c
> new file mode 100644
> index 000000000000..485545ab6c8b
> --- /dev/null
> +++ b/drivers/platform/x86/dell-wmi-sysman-attributes.c
> @@ -0,0 +1,575 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Common methods for use with dell-wmi-sysman
> + *
> + *  Copyright (c) 2020 Dell Inc.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/platform_device.h>
> +#include <linux/dmi.h>
> +#include <linux/wmi.h>
> +#include "dell-wmi-sysman-attributes.h"
> +
> +static DEFINE_MUTEX(call_mutex);
> +static DEFINE_MUTEX(list_mutex);
> +
> +#define MAX_TYPES  4
> +
> +static struct platform_device *platform_device;
> +
> +static struct platform_driver platform_driver = {
> +	.driver = {
> +		.name = DRIVER_NAME,
> +	},
> +};
> +
> +/* attribute directory under platform dev */
> +struct kset *main_dir_kset;
> +/* subtypes of attributes */
> +struct kset *type_dir_kset[MAX_TYPES];
> +
> +/* reset bios to defaults */
> +static const char * const reset_types[] = {"builtinsafe", "lastknowngood", "factory", "custom"};
> +static int reset_option = -1;
> +
> +/**
> + * populate_security_buffer() - builds a security buffer for authentication scheme
> + * @buffer: the buffer to populate
> + * @authentication: the authentication content
> + *
> + * Currently only supported type is PLAIN TEXT
> + **/
> +void populate_security_buffer(char *buffer, char *authentication)
> +{
> +	u32 *sectype = (u32 *) buffer;
> +	u32 *seclen = sectype + 1;
> +	char *auth = buffer + sizeof(u32)*2;
> +	/* plain text */
> +	*sectype = 1;
> +	*seclen = strlen(authentication);
> +	strncpy(auth, authentication, *seclen);
> +}
> +
> +/**
> + * map_wmi_error() - map errors from WMI methods to kernel error codes
> + **/
> +int map_wmi_error(int error_code)
> +{
> +	switch (error_code) {
> +	case 0:
> +		/* success */
> +		return 0;
> +	case 1:
> +		/* failed */
> +		return -EIO;
> +	case 2:
> +		/* invalid parameter */
> +		return -EINVAL;
> +	case 3:
> +		/* access denied */
> +		return -EACCES;
> +	case 4:
> +		/* not supported */
> +		return -EOPNOTSUPP;
> +	case 5:
> +		/* memory error */
> +		return -ENOMEM;
> +	case 6:
> +		/* protocol error */
> +		return -EPROTO;
> +	}
> +	/* unspecified error */
> +	return -EIO;
> +}
> +
> +/**
> + * reset_bios_show() - sysfs implementaton for read reset_bios
> + * @kobj: Kernel object for this attribute
> + * @attr: Kernel object attribute
> + * @buf: The buffer to display to userspace
> + **/
> +static ssize_t reset_bios_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> +{
> +	int i;
> +	char *start = buf;
> +
> +	for (i = 0; i < MAX_TYPES; i++) {
> +		if (i == reset_option)
> +			buf += sprintf(buf, "[%s] ", reset_types[i]);
> +		else
> +			buf += sprintf(buf, "%s ", reset_types[i]);
> +	}
> +	buf += sprintf(buf, "\n");
> +	return buf-start;
> +}
> +
> +/**
> + * reset_bios_store() - sysfs implementaton for write reset_bios
> + * @kobj: Kernel object for this attribute
> + * @attr: Kernel object attribute
> + * @buf: The buffer from userspace
> + * @count: the size of the buffer from userspace
> + **/
> +static ssize_t reset_bios_store(struct kobject *kobj,
> +				struct kobj_attribute *attr, const char *buf, size_t count)
> +{
> +	int len, ret, i;
> +	int type = -1;
> +	char *p;
> +
> +	p = memchr(buf, '\n', count);
> +	if (p != NULL)
> +		*p = '\0';
> +	len = p ? p - buf : count;
> +
> +	for (i = 0; i < MAX_TYPES; i++) {
> +		if (len == strlen(reset_types[i])
> +		    && !strncmp(buf, reset_types[i], len)) {
> +			type = i;
> +			break;
> +		}
> +	}
> +
> +	if (type < 0 || type >= MAX_TYPES) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	ret = set_bios_defaults(type);
> +	dev_dbg(&platform_device->dev, "reset all attributes request type %d: %d", type, ret);
> +	if (ret) {
> +		ret = -EINVAL;
> +	} else {
> +		reset_option = type;
> +		ret = count;
> +	}
> +
> +out:
> +	return ret;
> +}
> +
> +/**
> + * pending_reboot_show() - sysfs implementaton for read pending_reboot
> + * @kobj: Kernel object for this attribute
> + * @attr: Kernel object attribute
> + * @buf: The buffer to display to userspace
> + *
> + * Stores default value as 0
> + * When current_value is changed this attribute is set to 1 to notify reboot may be required
> + **/
> +static ssize_t pending_reboot_show(struct kobject *kobj, struct kobj_attribute *attr,
> +						char *buf)
> +{
> +	return sprintf(buf, "%d\n", get_pending_changes());
> +}
> +
> +static struct kobj_attribute reset_bios = __ATTR_RW(reset_bios);
> +static struct kobj_attribute pending_reboot = __ATTR_RO(pending_reboot);
> +
> +
> +/**
> + * create_reset_bios() - Creates reset_bios and pending_reboot attributes
> + **/
> +static int create_reset_bios(void)
> +{
> +	int ret = sysfs_create_file(&main_dir_kset->kobj, &reset_bios.attr);
> +
> +	if (ret) {
> +		dev_dbg(&platform_device->dev, "could not create reset_bios file");
> +		return ret;
> +	}
> +
> +	ret = sysfs_create_file(&main_dir_kset->kobj, &pending_reboot.attr);
> +	if (ret) {
> +		dev_dbg(&platform_device->dev, "could not create changing_pending_reboot file");
> +		sysfs_remove_file(&main_dir_kset->kobj, &reset_bios.attr);
> +	}
> +	return ret;
> +}
> +
> +static void release_reset_bios_data(void)
> +{
> +	sysfs_remove_file(&main_dir_kset->kobj, &reset_bios.attr);
> +	sysfs_remove_file(&main_dir_kset->kobj, &pending_reboot.attr);
> +}
> +
> +static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr,
> +			      char *buf)
> +{
> +	struct kobj_attribute *kattr;
> +	ssize_t ret = -EIO;
> +
> +	kattr = container_of(attr, struct kobj_attribute, attr);
> +	if (kattr->show)
> +		ret = kattr->show(kobj, kattr, buf);
> +	return ret;
> +}
> +
> +static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr,
> +			       const char *buf, size_t count)
> +{
> +	struct kobj_attribute *kattr;
> +	ssize_t ret = -EIO;
> +
> +	kattr = container_of(attr, struct kobj_attribute, attr);
> +	if (kattr->store)
> +		ret = kattr->store(kobj, kattr, buf, count);
> +	return ret;
> +}
> +
> +const struct sysfs_ops kobj_sysfs_ops = {
> +	.show	= kobj_attr_show,
> +	.store	= kobj_attr_store,
> +};
> +
> +static void attr_name_release(struct kobject *kobj)
> +{
> +	kfree(kobj);
> +}
> +
> +static struct kobj_type attr_name_ktype = {
> +	.release	= attr_name_release,
> +	.sysfs_ops	= &kobj_sysfs_ops,
> +};
> +
> +/**
> + * strncpy_attr - Copy a length-limited, NULL-terminated string with bound checks
> + * @dest: Where to copy the string to
> + * @src: Where to copy the string from
> + **/
> +void strncpy_attr(char *dest, char *src)
> +{
> +	size_t len = strlen(src) + 1;
> +
> +	if (len > 1 && len < MAX_BUFF)
> +		strncpy(dest, src, len);
> +}
> +
> +/**
> + * get_wmiobj_pointer() - Get Content of WMI block for particular instance
> + * @instance_id: WMI instance ID
> + * @guid_string: WMI GUID (in str form)
> + *
> + * Fetches the content for WMI block (instance_id) under GUID (guid_string)
> + * Caller must kfree the return
> + **/
> +union acpi_object *get_wmiobj_pointer(int instance_id, const char *guid_string)
> +{
> +	acpi_status status;
> +	struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
> +
> +	status = wmi_query_block(guid_string, instance_id, &out);
> +
> +	return ACPI_SUCCESS(status) ? (union acpi_object *)out.pointer : NULL;
> +}
> +
> +/**
> + * get_instance_count() - Compute total number of instances under guid_string
> + * @guid_string: WMI GUID (in string form)
> + **/
> +int get_instance_count(const char *guid_string)
> +{
> +	int i = 0;
> +	union acpi_object *wmi_obj = NULL;
> +
> +	do {
> +		kfree(wmi_obj);
> +		wmi_obj = get_wmiobj_pointer(i, guid_string);
> +		i++;
> +	} while (wmi_obj);
> +
> +	return (i-1);
> +}
> +
> +/**
> + * alloc_attributes_data() - Allocate attributes data for a particular type
> + * @attr_type: Attribute type to allocate
> + **/
> +static int alloc_attributes_data(int attr_type)
> +{
> +	int retval = 0;
> +	char *type[MAX_TYPES] = {"enumeration", "integer", "string", "password"};
> +
> +	type_dir_kset[attr_type] = kset_create_and_add(type[attr_type], NULL, &main_dir_kset->kobj);
> +	if (!type_dir_kset[attr_type])
> +		goto err_bios_attr;
> +
> +	switch (attr_type) {
> +	case ENUM:
> +		retval = alloc_enum_data();
> +		break;
> +	case INT:
> +		retval = alloc_int_data();
> +		break;
> +	case STR:
> +		retval = alloc_str_data();
> +		break;
> +	case PO:
> +		retval = alloc_po_data();
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	goto out;
> +
> +err_bios_attr:
> +	kset_unregister(main_dir_kset);
> +
> +out:
> +	return retval;
> +}
> +
> +/**
> + * destroy_attribute_objs() - Free a kset of kobjects
> + * @kset: The kset to destroy
> + *
> + * Fress kobjects created for each attribute_name under attribute type kset
> + **/
> +static void destroy_attribute_objs(struct kset *kset)
> +{
> +	struct kobject *pos, *next;
> +
> +	mutex_lock(&list_mutex);
> +	list_for_each_entry_safe(pos, next, &kset->list, entry) {
> +		kobject_put(pos);
> +	}
> +	mutex_unlock(&list_mutex);
> +}
> +
> +/**
> + * release_attributes_data() - Clean-up all sysfs directories and files created
> + **/
> +static void release_attributes_data(void)
> +{
> +	release_reset_bios_data();
> +
> +	exit_enum_attributes(type_dir_kset[ENUM]);
> +	exit_int_attributes(type_dir_kset[INT]);
> +	exit_str_attributes(type_dir_kset[STR]);
> +	exit_po_attributes(type_dir_kset[PO]);
> +
> +	mutex_lock(&call_mutex);
> +	if (main_dir_kset) {
> +		int i;
> +
> +		/* unregister all 4 types ENUM,INT,STR and PO */
> +		for (i = ENUM; i <= PO; i++) {
> +			destroy_attribute_objs(type_dir_kset[i]);
> +			kset_unregister(type_dir_kset[i]);
> +		}
> +		kset_unregister(main_dir_kset);
> +	}
> +	mutex_unlock(&call_mutex);
> +}
> +
> +/**
> + * init_bios_attributes() - Initialize all attributes for a type
> + * @attr_type: The attribute type to initialize
> + * @guid: The WMI GUID associated with this type to initialize
> + *
> + * Initialiaze all 4 types of attributes enumeration, integer, string and password object.
> + * Populates each attrbute typ's respective properties under sysfs files
> + **/
> +static int init_bios_attributes(int attr_type, const char *guid)
> +{
> +	union acpi_object *obj = NULL;
> +	union acpi_object *elements;
> +	int retval = 0;
> +	int instance_id = 0;
> +	struct kobject *attr_name_kobj; //individual attribute names
> +
> +	retval = alloc_attributes_data(attr_type);
> +	if (retval)
> +		return retval;
> +	obj = get_wmiobj_pointer(instance_id, guid);
> +	if (!obj)
> +		return -ENODEV;
> +	elements = obj->package.elements;
> +
> +	while (elements) {
> +		/* sanity checking */
> +		if (strlen(elements[ATTR_NAME].string.pointer) == 0) {
> +			dev_dbg(&platform_device->dev, "empty attribute found");
> +			goto nextobj;
> +		}
> +		if (kset_find_obj(type_dir_kset[attr_type], elements[ATTR_NAME].string.pointer)) {
> +			dev_dbg(&platform_device->dev, "duplicate attribute name found - %s",
> +				elements[ATTR_NAME].string.pointer);
> +			goto nextobj;
> +		}
> +
> +		/* build attribute */
> +		attr_name_kobj = kzalloc(sizeof(*attr_name_kobj), GFP_KERNEL);
> +		if (!attr_name_kobj)
> +			goto err_attr_init;
> +
> +		attr_name_kobj->kset = type_dir_kset[attr_type];
> +
> +		retval = kobject_init_and_add(attr_name_kobj, &attr_name_ktype, NULL, "%s",
> +						elements[ATTR_NAME].string.pointer);
> +		if (retval) {
> +			kobject_put(attr_name_kobj);
> +			goto err_attr_init;
> +		}
> +
> +		/* enumerate all of this attribute */
> +		switch (attr_type) {
> +		case ENUM:
> +			retval = populate_enum_data(elements, instance_id, attr_name_kobj);
> +			break;
> +		case INT:
> +			retval = populate_int_data(elements, instance_id, attr_name_kobj);
> +			break;
> +		case STR:
> +			retval = populate_str_data(elements, instance_id, attr_name_kobj);
> +			break;
> +		case PO:
> +			retval = populate_po_data(elements, instance_id, attr_name_kobj);
> +			break;
> +		default:
> +			break;
> +		}
> +
> +		if (retval) {
> +			dev_dbg(&platform_device->dev, "failed to populate %s",
> +				elements[ATTR_NAME].string.pointer);
> +			goto err_attr_init;
> +		}
> +
> +nextobj:
> +		kfree(obj);
> +		instance_id++;
> +		obj = get_wmiobj_pointer(instance_id, guid);
> +		elements = obj ? obj->package.elements : NULL;
> +	}
> +
> +	goto out;
> +
> +err_attr_init:
> +	release_attributes_data();
> +	kfree(obj);
> +out:
> +	return retval;
> +}
> +
> +static int __init init_dell_bios_attrib_wmi(void)
> +{
> +	int ret = 0;
> +
> +	if (!dmi_find_device(DMI_DEV_TYPE_OEM_STRING, "Dell System", NULL) &&
> +	    !dmi_find_device(DMI_DEV_TYPE_OEM_STRING, "www.dell.com", NULL)) {
> +		pr_err("Unable to run on non-Dell system\n");
> +		return -ENODEV;
> +	}
> +
> +	ret = platform_driver_register(&platform_driver);
> +	if (ret)
> +		goto fail_platform_driver;
> +
> +	platform_device = platform_device_alloc(DRIVER_NAME, -1);
> +	if (!platform_device) {
> +		ret = -ENOMEM;
> +		goto fail_platform_device_alloc;
> +	}
> +
> +	ret = platform_device_add(platform_device);
> +	if (ret)
> +		goto fail_platform_device_add;
> +
> +	main_dir_kset = kset_create_and_add("attributes", NULL, &platform_device->dev.kobj);
> +	if (!main_dir_kset) {
> +		ret = -ENOMEM;
> +		goto fail_platform_device_add;
> +	}
> +
> +	ret = init_dell_wmi_bios_attr_set_interface();
> +	if (ret) {
> +		dev_dbg(&platform_device->dev, "failed to initialize set interface");
> +		goto fail_kset;
> +	}
> +
> +	ret = init_dell_wmi_bios_attr_pass_interface();
> +	if (ret) {
> +		dev_dbg(&platform_device->dev, "failed to initialize pass interface");
> +		goto fail_set_interface;
> +	}
> +
> +	ret = create_reset_bios();
> +	if (ret) {
> +		dev_dbg(&platform_device->dev, "could not create reset BIOS attribute");
> +		goto fail_pass_interface;
> +	}
> +
> +	ret = init_bios_attributes(ENUM, DELL_WMI_BIOS_ENUMERATION_ATTRIBUTE_GUID);
> +	if (ret) {
> +		dev_dbg(&platform_device->dev, "failed to populate enumeration type attributes");
> +		goto fail_create_group;
> +	}
> +
> +	ret = init_bios_attributes(INT, DELL_WMI_BIOS_INTEGER_ATTRIBUTE_GUID);
> +	if (ret) {
> +		dev_dbg(&platform_device->dev, "failed to populate integer type attributes");
> +		goto fail_create_group;
> +	}
> +
> +	ret = init_bios_attributes(STR, DELL_WMI_BIOS_STRING_ATTRIBUTE_GUID);
> +	if (ret) {
> +		dev_dbg(&platform_device->dev, "failed to populate string type attributes");
> +		goto fail_create_group;
> +	}
> +
> +	ret = init_bios_attributes(PO, DELL_WMI_BIOS_PASSOBJ_ATTRIBUTE_GUID);
> +	if (ret) {
> +		dev_dbg(&platform_device->dev, "failed to populate pass object type attributes");
> +		goto fail_create_group;
> +	}
> +
> +	return 0;
> +
> +fail_create_group:
> +	release_attributes_data();
> +	platform_device_del(platform_device);
> +
> +fail_pass_interface:
> +	exit_dell_wmi_bios_attr_pass_interface();
> +
> +fail_set_interface:
> +	exit_dell_wmi_bios_attr_set_interface();
> +
> +fail_kset:
> +	kset_unregister(main_dir_kset);
> +
> +fail_platform_device_add:
> +	platform_device_put(platform_device);
> +
> +fail_platform_device_alloc:
> +	platform_driver_unregister(&platform_driver);
> +
> +fail_platform_driver:
> +	return ret;
> +}
> +
> +static void __exit exit_dell_bios_attrib_wmi(void)
> +{
> +	release_attributes_data();
> +	mutex_lock(&call_mutex);
> +	exit_dell_wmi_bios_attr_set_interface();
> +	exit_dell_wmi_bios_attr_pass_interface();
> +	if (platform_device) {
> +		platform_device_unregister(platform_device);
> +		platform_driver_unregister(&platform_driver);
> +	}
> +	mutex_unlock(&call_mutex);
> +}
> +
> +module_init(init_dell_bios_attrib_wmi);
> +module_exit(exit_dell_bios_attrib_wmi);
> +
> +MODULE_AUTHOR("Mario Limonciello <mario.limonciello@dell.com>");
> +MODULE_AUTHOR("Prasanth Ksr <prasanth.ksr@dell.com>");
> +MODULE_AUTHOR("Divya Bharathi <divya.bharathi@dell.com>");
> +MODULE_DESCRIPTION("Dell platform setting control interface");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/platform/x86/dell-wmi-sysman-attributes.h b/drivers/platform/x86/dell-wmi-sysman-attributes.h
> new file mode 100644
> index 000000000000..bb5053b91ec7
> --- /dev/null
> +++ b/drivers/platform/x86/dell-wmi-sysman-attributes.h
> @@ -0,0 +1,125 @@
> +/* SPDX-License-Identifier: GPL-2.0
> + * Definitions for kernel modules using Dell WMI System Management Driver
> + *
> + *  Copyright (c) 2020 Dell Inc.
> + */
> +
> +#ifndef _DELL_WMI_BIOS_ATTR_H_
> +#define _DELL_WMI_BIOS_ATTR_H_
> +
> +#include <linux/wmi.h>
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/platform_device.h>
> +#include <linux/capability.h>
> +
> +#define DRIVER_NAME					"dell-wmi-sysman"
> +#define MAX_BUFF  512
> +
> +#define DELL_WMI_BIOS_ENUMERATION_ATTRIBUTE_GUID	"F1DDEE52-063C-4784-A11E-8A06684B9BF5"
> +#define DELL_WMI_BIOS_INTEGER_ATTRIBUTE_GUID		"F1DDEE52-063C-4784-A11E-8A06684B9BFA"
> +#define DELL_WMI_BIOS_STRING_ATTRIBUTE_GUID		"F1DDEE52-063C-4784-A11E-8A06684B9BF9"
> +#define DELL_WMI_BIOS_PASSOBJ_ATTRIBUTE_GUID		"0894B8D6-44A6-4719-97D7-6AD24108BFD4"
> +#define DELL_WMI_BIOS_ATTRIBUTES_INTERFACE_GUID		"F1DDEE52-063C-4784-A11E-8A06684B9BF4"
> +#define DELL_WMI_BIOS_PASSWORD_INTERFACE_GUID		"70FE8229-D03B-4214-A1C6-1F884B1A892A"
> +
> +enum { ENUM, INT, STR, PO };
> +
> +enum {
> +	ATTR_NAME,
> +	DISPL_NAME_LANG_CODE,
> +	DISPLAY_NAME,
> +	DEFAULT_VAL,
> +	CURRENT_VAL,
> +	MODIFIER
> +};
> +
> +#define get_instance_id(type)							\
> +int get_##type##_instance_id(struct kobject *kobj)				\
> +{										\
> +	int i;									\
> +	for (i = 0; i <= type##_instances_count; i++) {				\
> +		if (!(strcmp(kobj->name, type##_data[i].attribute_name)))	\
> +			return i;						\
> +	}									\
> +	return -EIO;								\
> +}
> +
> +#define attribute_s_property_show(name, type)					\
> +static ssize_t name##_show(struct kobject *kobj, struct kobj_attribute *attr,	\
> +			   char *buf)						\
> +{										\
> +	int i = get_##type##_instance_id(kobj);					\
> +	if (i >= 0)								\
> +		return sprintf(buf, "%s\n", type##_data[i].name);		\
> +	return 0;								\
> +}
> +
> +#define attribute_n_property_show(name, type)					\
> +static ssize_t name##_show(struct kobject *kobj, struct kobj_attribute *attr,	\
> +			   char *buf)						\
> +{										\
> +	int i = get_##type##_instance_id(kobj);					\
> +	if (i >= 0)								\
> +		return sprintf(buf, "%d\n", type##_data[i].name);		\
> +	return 0;								\
> +}
> +
> +#define attribute_property_store(curr_val, type)				\
> +static ssize_t curr_val##_store(struct kobject *kobj,				\
> +				struct kobj_attribute *attr,			\
> +				const char *buf, size_t count)			\
> +{										\
> +	char *p = memchr(buf, '\n', count);					\
> +	int ret = -EIO;								\
> +	int i;									\
> +										\
> +	if (p != NULL)								\
> +		*p = '\0';							\
> +	i = get_##type##_instance_id(kobj);					\
> +	if (i >= 0)								\
> +		ret = validate_##type##_input(i, buf);				\
> +	if (!ret)								\
> +		ret = set_attribute(kobj->name, buf);				\
> +	return ret ? ret : count;						\
> +}
> +
> +union acpi_object *get_wmiobj_pointer(int instance_id, const char *guid_string);
> +int get_instance_count(const char *guid_string);
> +void strncpy_attr(char *dest, char *src);
> +
> +int populate_enum_data(union acpi_object *enumeration_obj, int instance_id,
> +			struct kobject *attr_name_kobj);
> +int alloc_enum_data(void);
> +void exit_enum_attributes(struct kset *kset);
> +
> +int populate_int_data(union acpi_object *integer_obj, int instance_id,
> +			struct kobject *attr_name_kobj);
> +int alloc_int_data(void);
> +void exit_int_attributes(struct kset *kset);
> +
> +int populate_str_data(union acpi_object *str_obj, int instance_id, struct kobject *attr_name_kobj);
> +int alloc_str_data(void);
> +void exit_str_attributes(struct kset *kset);
> +
> +int populate_po_data(union acpi_object *po_obj, int instance_id, struct kobject *attr_name_kobj);
> +int alloc_po_data(void);
> +void exit_po_attributes(struct kset *kset);
> +
> +int set_attribute(const char *a_name, const char *a_value);
> +int set_bios_defaults(u8 defType);
> +
> +void exit_dell_wmi_bios_attr_set_interface(void);
> +int init_dell_wmi_bios_attr_set_interface(void);
> +bool get_pending_changes(void);
> +int map_wmi_error(int error_code);
> +void populate_security_buffer(char *buffer, char *authentication);
> +
> +char *get_current_password(const char *password_type);
> +int set_current_password(const char *password_type, const char *cur);
> +int set_new_password(const char *password_type, const char *new);
> +int init_dell_wmi_bios_attr_pass_interface(void);
> +void exit_dell_wmi_bios_attr_pass_interface(void);
> +
> +#endif
>