Re: [PATCH v7] Introduce support for Systems Management Driver over WMI for Dell Systems
From: Hans de Goede
Date: Wed Oct 28 2020 - 18:00:28 EST
Hi,
On 10/27/20 2:49 PM, Divya Bharathi wrote:
> 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.
>
> Cc: Hans de Goede <hdegoede@xxxxxxxxxx>
> Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> Cc: mark gross <mgross@xxxxxxxxxxxxxxx>
>
> Co-developed-by: Mario Limonciello <mario.limonciello@xxxxxxxx>
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxxx>
> Co-developed-by: Prasanth KSR <prasanth.ksr@xxxxxxxx>
> Signed-off-by: Prasanth KSR <prasanth.ksr@xxxxxxxx>
> Signed-off-by: Divya Bharathi <divya.bharathi@xxxxxxxx>
Thank you for your patch, I've applied this patch to my review-hans
branch:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans
Note I've made 2 small changes while applying this:
1. I've added a missing "This attribute is mandatory." to the docs for
the /sys/class/firmware-attributes/*/authentication/*/is_enabled
sysfs file.
2. You did a direct return after the ACPI object type check, in
the various current_value_show functions:
if (obj->package.elements[CURRENT_VAL].type != ACPI_TYPE_STRING)
return -EINVAL;
This leaks the object returned by get_wmiobj_pointer() I've added the
missing kfree() call like this:
--- a/drivers/platform/x86/dell-wmi-sysman/enum-attributes.c
+++ b/drivers/platform/x86/dell-wmi-sysman/enum-attributes.c
@@ -23,8 +23,10 @@ static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *a
obj = get_wmiobj_pointer(instance_id, DELL_WMI_BIOS_ENUMERATION_ATTRIBUTE_GUID);
if (!obj)
return -EIO;
- if (obj->package.elements[CURRENT_VAL].type != ACPI_TYPE_STRING)
+ if (obj->package.elements[CURRENT_VAL].type != ACPI_TYPE_STRING) {
+ kfree(obj);
return -EINVAL;
+ }
ret = snprintf(buf, PAGE_SIZE, "%s\n", obj->package.elements[CURRENT_VAL].string.pointer);
kfree(obj);
return ret;
And I did the same for all the other cases.
Once I've run some tests on my review-hans branch the patches there will
be added to the platform-drivers-x86/for-next branch and eventually
will be included in the pdx86 pull-request to Linus for the next
merge-window.
Regards,
Hans
> ---
>
> Changes from v6 to v7:
> - Set current_value to rw only for root user
> - Correct spacing in sysfs documentation
> - Make some more attributes mandatory
> - Remove cap_sys_admin check
> - add extra check for -ENOMEM for attribute_property_store
> - Add dereferencing check for data types read
> - Adjust passobj bounds check by 1
> - Add extra check for -ENOMEM in new_password_store
> - Clear current password properly
> - Simplify reset_bios_store
> - Adjust helper functions per Hans' suggestions
> - Correct integer handling abusing ACPI core
>
> Changes from v5 to v6:
> - Fixed Mutex bug in set_bios_defaults
> - Adjust wrapping for enum-attributes.c description
> - Adjust wrapping for int-attributes.c comparison
> - Make current_password mandatory for mechanism == password
> - Move strlen of admin check into populate_security_password
> - Use correct device for dev_err calls (bios_attr_wdev)
> - Remove type from structs and add type-string directly in show functions
> - Remove unneeded macro definition (make function static)
> - Make calls to get_*_instance_id error handling match kernel style
> - Adjust -AE_ERROR to -EIO
> - Adjust validate_integer_input to propagate errors
> - Make current_password_store return -EIO for an unknown type
> - Don't store current_value, read dynamically every time
> - Move kobject_uevents to class_dev
> - Update all kernel doc comments with standard termination '*/'
> - Correct dereferences in alloc_*_data()
> - Make value_modifier and value_modifier_count local
> - Remove is_enabled from po
> - Fix current_password_store const char* handling
> - Propagate error value from get_po_instance_id() in is_enabled_show()
> - Adjust validate_str_input
> - Cleanups to reset_bios_store to use sysfs_match_string
> - Adjust set_bios_defaults
> - Rename create_reset_bios
> - strlcpy_attr handling
> - Check number of kset_unregister calls in error path
> - Make teardown order match error order
> - Pass password into calculate_security_buffer
> - Correct handling of const char * values in macros
> - Add new function for populating string buffers
> - Switch strncasecmp to strcasecmp
> + This wasn't strictly necessary (the firmware rejected invalid strings)
> + However, by doing it in the kernel we can send a more sensbile error -EINVAL
>
> Changes from v4 to v5:
> - Correct Kconfig description to not use "WMI" twice.
> - s/is_authentication_set/is_enabled/
> - Specify that all attributes are optional and take UTF8
> - Change authentication type to "role" and "mechanism"
> - Explain what semicolons are
> - Adjust whitespace of documentation
>
> Changes from v3 to v4:
> - Create a firmware-attributes class and tie ksets to a virtual device in it
> - Make modifier and value_modifier "dell only" attributes.
> - Correct some errors caught by kernel build bot around missing prototypes
> - Remove mutexes from populate_* functions and put in init_dell_bios_attrib_wmi instead
> - Move all code into a subdirectory drivers/platform/x86/dell-wmi-sysman and remove dell-wmi-*
> prefix on files
> - Move all data structures into shared struct
> - In alloc functions instead of kzalloc use kcalloc and check that there is no overflow
> + Same check for other alloc_foo-data functions
> - populate_*: Move sysfs_create_group to end of the function to prevent race conditions
> - Save kernel object into each data instance and only remove that rather than sysfs_remove_group
> - Document in sysfs file what causes change uevents to come through
> - Only notify with change uevent one time on multiple settings modifications
> - Adjust lots of string handling
> - Make more objects static
> - Various whitespace corrections
> - Document map_wmi_error properly
> - Bump version to 5.11 (February 2021)
>
> Changes from v2 to v3:
> - Fix a possible NULL pointer error in init
> - Add missing newlines to all dev_err/dev_dbg/pr_err/pr_debug statements
> - Correct updating passwords when both Admin and System password are set
> - Correct the WMI driver name
> - Correct some namespace clashing when compiled into the kernel (Reported by Mark Gross)
> - Correct some comment typos
> - Adopt suggestions made by Hans:
> + Use single global mutex
> + Clarify reason for uevents with a comment
> + Remove functions for set and get current password
> + Rename lower_bound to min_value and upper_bound to max_value
> + Rename possible_value to possible_values
> + Remove references to float
> + Build a separate passwords directory again since it behaves differently from the other
> attributes
> + Move more calls from pr_err -> dev_err
> - Documentation cleanups (see v2 patch feedback)
> + Grouping types
> + Syntax of `modifier` output
>
> Changes from v1 to v2:
> - use pr_fmt instead of pr_err(DRIVER_NAME
> - re-order variables reverse xmas tree order
> - correct returns of -1 to error codes
> - correct usage of {} on some split line statements
> - Refine all documentation deficiencies suggested by Hans
> - Merge all attributes to a single directory
> - Overhaul WMI interface interaction as suggested by Hans
> * Move WMI driver registration to start of module
> * Remove usage of lists that only use first entry for WMI interfaces
> * Create a global structure shared across interface source files
> * Make get_current_password function static
> * Remove get_pending changes function, shared across global structure now.
> - Overhaul use of mutexes
> * Make kset list mutex shared across source files
> * Remove unneeded dell-wmi-sysman call_mutex
> * Keep remaining call_mutexes in WMI functions
> - Move security area calculation into a function
> - Use NLS helper for utf8->utf16 conversion
>
> .../testing/sysfs-class-firmware-attributes | 223 +++++++
> MAINTAINERS | 8 +
> drivers/platform/x86/Kconfig | 12 +
> drivers/platform/x86/Makefile | 1 +
> drivers/platform/x86/dell-wmi-sysman/Makefile | 8 +
> .../x86/dell-wmi-sysman/biosattr-interface.c | 186 ++++++
> .../x86/dell-wmi-sysman/dell-wmi-sysman.h | 191 ++++++
> .../x86/dell-wmi-sysman/enum-attributes.c | 187 ++++++
> .../x86/dell-wmi-sysman/int-attributes.c | 171 +++++
> .../x86/dell-wmi-sysman/passobj-attributes.c | 192 ++++++
> .../dell-wmi-sysman/passwordattr-interface.c | 153 +++++
> .../x86/dell-wmi-sysman/string-attributes.c | 157 +++++
> drivers/platform/x86/dell-wmi-sysman/sysman.c | 625 ++++++++++++++++++
> 13 files changed, 2114 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-class-firmware-attributes
> create mode 100644 drivers/platform/x86/dell-wmi-sysman/Makefile
> create mode 100644 drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c
> create mode 100644 drivers/platform/x86/dell-wmi-sysman/dell-wmi-sysman.h
> create mode 100644 drivers/platform/x86/dell-wmi-sysman/enum-attributes.c
> create mode 100644 drivers/platform/x86/dell-wmi-sysman/int-attributes.c
> create mode 100644 drivers/platform/x86/dell-wmi-sysman/passobj-attributes.c
> create mode 100644 drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c
> create mode 100644 drivers/platform/x86/dell-wmi-sysman/string-attributes.c
> create mode 100644 drivers/platform/x86/dell-wmi-sysman/sysman.c
>
> diff --git a/Documentation/ABI/testing/sysfs-class-firmware-attributes b/Documentation/ABI/testing/sysfs-class-firmware-attributes
> new file mode 100644
> index 000000000000..feee3b860e5a
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-class-firmware-attributes
> @@ -0,0 +1,223 @@
> +What: /sys/class/firmware-attributes/*/attributes/*/
> +Date: February 2021
> +KernelVersion: 5.11
> +Contact: Divya Bharathi <Divya.Bharathi@xxxxxxxx>,
> + Mario Limonciello <mario.limonciello@xxxxxxxx>,
> + Prasanth KSR <prasanth.ksr@xxxxxxxx>
> +Description:
> + A sysfs interface for systems management software to enable
> + configuration capability on supported systems. This directory
> + exposes interfaces for interacting with configuration options.
> +
> + Unless otherwise specified in an attribute description all attributes are optional
> + and will accept UTF-8 input.
> +
> + type: A file that can be read to obtain the type of attribute. This attribute is
> + mandatory.
> +
> + The following are known types:
> + - enumeration: a set of pre-defined valid values
> + - integer: a range of numerical values
> + - string
> +
> + All attribute types support the following 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>
> +
> + This attribute is mandatory.
> +
> + 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 IETF language tag corresponding to the
> + "display_name" of the <attr>
> +
> + "enumeration"-type specific properties:
> +
> + possible_values: A file that can be read to obtain the possible
> + values of the <attr>. Values are separated using
> + semi-colon (``;``).
> +
> + "integer"-type specific properties:
> +
> + min_value: A file that can be read to obtain the lower
> + bound value of the <attr>
> +
> + max_value: A file that can be read to obtain the upper
> + bound value of the <attr>
> +
> + scalar_increment: A file that can be read to obtain the scalar value used for
> + increments of current_value this attribute accepts.
> +
> + "string"-type specific properties:
> +
> + 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>
> +
> + Dell specific class extensions
> + --------------------------
> +
> + On Dell systems the following additional attributes are available:
> +
> + dell_modifier: A file that can be read to obtain attribute-level
> + dependency rule. It says an attribute X will become read-only or
> + suppressed, if/if-not attribute Y is configured.
> +
> + modifier rules can be in following format:
> + [ReadOnlyIf:<attribute>=<value>]
> + [ReadOnlyIfNot:<attribute>=<value>]
> + [SuppressIf:<attribute>=<value>]
> + [SuppressIfNot:<attribute>=<value>]
> +
> + For example:
> + AutoOnFri/dell_modifier has value,
> + [SuppressIfNot:AutoOn=SelectDays]
> +
> + This means AutoOnFri will be suppressed in BIOS setup if AutoOn
> + attribute is not "SelectDays" and its value will not be effective
> + through sysfs until this rule is met.
> +
> + Enumeration attributes also support the following:
> +
> + dell_value_modifier: A file that can be read to obtain value-level dependency.
> + This file is similar to dell_modifier but here, an
> + attribute's current value will be forcefully changed based
> + dependent attributes value.
> +
> + dell_value_modifier rules can be in following format:
> + <value>[ForceIf:<attribute>=<value>]
> + <value>[ForceIfNot:<attribute>=<value>]
> +
> + For example,
> + LegacyOrom/dell_value_modifier has value:
> + Disabled[ForceIf:SecureBoot=Enabled]
> + This means LegacyOrom's current value will be forced to
> + "Disabled" in BIOS setup if SecureBoot is Enabled and its
> + value will not be effective through sysfs until this rule is
> + met.
> +
> +What: /sys/class/firmware-attributes/*/authentication/
> +Date: February 2021
> +KernelVersion: 5.11
> +Contact: Divya Bharathi <Divya.Bharathi@xxxxxxxx>,
> + Mario Limonciello <mario.limonciello@xxxxxxxx>,
> + Prasanth KSR <prasanth.ksr@xxxxxxxx>
> +
> + Devices support various authentication mechanisms which can be exposed
> + as a separate configuration object.
> +
> + For example a "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.
> +
> + Change in any of these two authentication methods will also generate an
> + uevent KOBJ_CHANGE.
> +
> + is_enabled: A file that can be read to obtain a 0/1 flag to see if
> + <attr> authentication is enabled.
> +
> + role: The type of authentication used.
> + This attribute is mandatory.
> + Known types:
> + bios-admin: Representing BIOS administrator password
> + power-on: Representing a password required to use
> + the system
> +
> + mechanism: The means of authentication. This attribute is mandatory.
> + Only supported type currently is "password".
> +
> + 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
> +
> + This attribute is mandatory when mechanism == "password".
> +
> + new_password: A write only value that when used in tandem with
> + current_password will reset a system or admin password.
> +
> + Note, password management is session specific. If Admin password is set,
> + same password must be written into current_password file (required for
> + password-validation) and must be cleared once the session is over.
> + For example:
> + echo "password" > current_password
> + echo "disabled" > TouchScreen/current_value
> + echo "" > current_password
> +
> + Drivers may emit a CHANGE uevent when a password is set or unset
> + userspace may check it again.
> +
> + On Dell systems, if Admin password is set, then all BIOS attributes
> + require password validation.
> +
> +What: /sys/class/firmware-attributes/*/attributes/pending_reboot
> +Date: February 2021
> +KernelVersion: 5.11
> +Contact: Divya Bharathi <Divya.Bharathi@xxxxxxxx>,
> + Mario Limonciello <mario.limonciello@xxxxxxxx>,
> + Prasanth KSR <prasanth.ksr@xxxxxxxx>
> +Description:
> + A read-only attribute reads 1 if a reboot is necessary to apply
> + pending BIOS attribute changes. Also, an uevent_KOBJ_CHANGE is
> + generated when it changes to 1.
> +
> + 0: All BIOS attributes setting are current
> + 1: A reboot is necessary to get pending BIOS attribute changes
> + applied
> +
> + Note, userspace applications need to follow below steps for efficient
> + BIOS management,
> + 1. Check if admin password is set. If yes, follow session method for
> + password management as briefed under authentication section above.
> + 2. Before setting any attribute, check if it has any modifiers
> + or value_modifiers. If yes, incorporate them and then modify
> + attribute.
> +
> + Drivers may emit a CHANGE uevent when this value changes and userspace
> + may check it again.
> +
> +What: /sys/class/firmware-attributes/*/attributes/reset_bios
> +Date: February 2021
> +KernelVersion: 5.11
> +Contact: Divya Bharathi <Divya.Bharathi@xxxxxxxx>,
> + Mario Limonciello <mario.limonciello@xxxxxxxx>,
> + Prasanth KSR <prasanth.ksr@xxxxxxxx>
> +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/class/firmware-attributes/*/device/attributes/reset_bios
> + # cat /sys/class/firmware-attributes/*/device/attributes/reset_bios
> + # builtinsafe lastknowngood [factory] custom
> +
> + Note that any changes to this attribute requires a reboot
> + for changes to take effect.
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e73636b75f29..e6e71444545a 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -4991,6 +4991,14 @@ M: Mario Limonciello <mario.limonciello@xxxxxxxx>
> S: Maintained
> F: drivers/platform/x86/dell-wmi-descriptor.c
>
> +DELL WMI SYSMAN DRIVER
> +M: Divya Bharathi <divya.bharathi@xxxxxxxx>
> +M: Mario Limonciello <mario.limonciello@xxxxxxxx>
> +M: Prasanth Ksr <prasanth.ksr@xxxxxxxx>
> +L: platform-driver-x86@xxxxxxxxxxxxxxx
> +S: Maintained
> +F: drivers/platform/x86/dell-wmi-syman/*
> +
> DELL WMI NOTIFICATIONS DRIVER
> M: Matthew Garrett <mjg59@xxxxxxxxxxxxx>
> M: Pali Rohár <pali@xxxxxxxxxx>
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index 0d91d136bc3b..7b6e90546b17 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -430,6 +430,18 @@ 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-based Systems management driver"
> + depends on ACPI_WMI
> + depends on DMI
> + select NLS
> + 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 5f823f7eff45..36ce38e80c8f 100644
> --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -47,6 +47,7 @@ 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-$(CONFIG_DELL_WMI_SYSMAN) += dell-wmi-sysman/
>
> # Fujitsu
> obj-$(CONFIG_AMILO_RFKILL) += amilo-rfkill.o
> diff --git a/drivers/platform/x86/dell-wmi-sysman/Makefile b/drivers/platform/x86/dell-wmi-sysman/Makefile
> new file mode 100644
> index 000000000000..825fb2fbeea8
> --- /dev/null
> +++ b/drivers/platform/x86/dell-wmi-sysman/Makefile
> @@ -0,0 +1,8 @@
> +obj-$(CONFIG_DELL_WMI_SYSMAN) += dell-wmi-sysman.o
> +dell-wmi-sysman-objs := sysman.o \
> + enum-attributes.o \
> + int-attributes.o \
> + string-attributes.o \
> + passobj-attributes.o \
> + biosattr-interface.o \
> + passwordattr-interface.o
> diff --git a/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c b/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c
> new file mode 100644
> index 000000000000..f95d8ddace5a
> --- /dev/null
> +++ b/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c
> @@ -0,0 +1,186 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Functions corresponding to SET methods under BIOS attributes interface GUID for use
> + * with dell-wmi-sysman
> + *
> + * Copyright (c) 2020 Dell Inc.
> + */
> +
> +#include <linux/wmi.h>
> +#include "dell-wmi-sysman.h"
> +
> +#define SETDEFAULTVALUES_METHOD_ID 0x02
> +#define SETBIOSDEFAULTS_METHOD_ID 0x03
> +#define SETATTRIBUTE_METHOD_ID 0x04
> +
> +static int call_biosattributes_interface(struct wmi_device *wdev, char *in_args, size_t size,
> + int method_id)
> +{
> + struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
> + struct acpi_buffer input;
> + union acpi_object *obj;
> + acpi_status status;
> + int ret = -EIO;
> +
> + input.length = (acpi_size) size;
> + input.pointer = in_args;
> + status = wmidev_evaluate_method(wdev, 0, method_id, &input, &output);
> + if (ACPI_FAILURE(status))
> + return -EIO;
> + obj = (union acpi_object *)output.pointer;
> + if (obj->type == ACPI_TYPE_INTEGER)
> + ret = obj->integer.value;
> +
> + if (wmi_priv.pending_changes == 0) {
> + wmi_priv.pending_changes = 1;
> + /* let userland know it may need to check reboot pending again */
> + kobject_uevent(&wmi_priv.class_dev->kobj, KOBJ_CHANGE);
> + }
> + kfree(output.pointer);
> + return map_wmi_error(ret);
> +}
> +
> +/**
> + * set_attribute() - Update an attribute value
> + * @a_name: The attribute name
> + * @a_value: The attribute value
> + *
> + * Sets an attribute to new value
> + */
> +int set_attribute(const char *a_name, const char *a_value)
> +{
> + size_t security_area_size, buffer_size;
> + size_t a_name_size, a_value_size;
> + char *buffer = NULL, *start;
> + int ret;
> +
> + mutex_lock(&wmi_priv.mutex);
> + if (!wmi_priv.bios_attr_wdev) {
> + ret = -ENODEV;
> + goto out;
> + }
> +
> + /* build/calculate buffer */
> + security_area_size = calculate_security_buffer(wmi_priv.current_admin_password);
> + a_name_size = calculate_string_buffer(a_name);
> + a_value_size = calculate_string_buffer(a_value);
> + buffer_size = security_area_size + a_name_size + a_value_size;
> + buffer = kzalloc(buffer_size, GFP_KERNEL);
> + if (!buffer) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + /* build security area */
> + populate_security_buffer(buffer, wmi_priv.current_admin_password);
> +
> + /* build variables to set */
> + start = buffer + security_area_size;
> + ret = populate_string_buffer(start, a_name_size, a_name);
> + if (ret < 0)
> + goto out;
> + start += ret;
> + ret = populate_string_buffer(start, a_value_size, a_value);
> + if (ret < 0)
> + goto out;
> +
> + print_hex_dump_bytes("set attribute data: ", DUMP_PREFIX_NONE, buffer, buffer_size);
> + ret = call_biosattributes_interface(wmi_priv.bios_attr_wdev,
> + buffer, buffer_size,
> + SETATTRIBUTE_METHOD_ID);
> + if (ret == -EOPNOTSUPP)
> + dev_err(&wmi_priv.bios_attr_wdev->dev, "admin password must be configured\n");
> + else if (ret == -EACCES)
> + dev_err(&wmi_priv.bios_attr_wdev->dev, "invalid password\n");
> +
> +out:
> + kfree(buffer);
> + mutex_unlock(&wmi_priv.mutex);
> + return ret;
> +}
> +
> +/**
> + * set_bios_defaults() - Resets BIOS defaults
> + * @deftype: the type of BIOS value reset to issue.
> + *
> + * Resets BIOS defaults
> + */
> +int set_bios_defaults(u8 deftype)
> +{
> + size_t security_area_size, buffer_size;
> + size_t integer_area_size = sizeof(u8);
> + char *buffer = NULL;
> + u8 *defaultType;
> + int ret;
> +
> + mutex_lock(&wmi_priv.mutex);
> + if (!wmi_priv.bios_attr_wdev) {
> + ret = -ENODEV;
> + goto out;
> + }
> +
> + security_area_size = calculate_security_buffer(wmi_priv.current_admin_password);
> + buffer_size = security_area_size + integer_area_size;
> + buffer = kzalloc(buffer_size, GFP_KERNEL);
> + if (!buffer) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + /* build security area */
> + populate_security_buffer(buffer, wmi_priv.current_admin_password);
> +
> + defaultType = buffer + security_area_size;
> + *defaultType = deftype;
> +
> + ret = call_biosattributes_interface(wmi_priv.bios_attr_wdev, buffer, buffer_size,
> + SETBIOSDEFAULTS_METHOD_ID);
> + if (ret)
> + dev_err(&wmi_priv.bios_attr_wdev->dev, "reset BIOS defaults failed: %d\n", ret);
> +
> + kfree(buffer);
> +out:
> + mutex_unlock(&wmi_priv.mutex);
> + return ret;
> +}
> +
> +static int bios_attr_set_interface_probe(struct wmi_device *wdev, const void *context)
> +{
> + mutex_lock(&wmi_priv.mutex);
> + wmi_priv.bios_attr_wdev = wdev;
> + mutex_unlock(&wmi_priv.mutex);
> + return 0;
> +}
> +
> +static int bios_attr_set_interface_remove(struct wmi_device *wdev)
> +{
> + mutex_lock(&wmi_priv.mutex);
> + wmi_priv.bios_attr_wdev = NULL;
> + mutex_unlock(&wmi_priv.mutex);
> + return 0;
> +}
> +
> +static const struct wmi_device_id bios_attr_set_interface_id_table[] = {
> + { .guid_string = DELL_WMI_BIOS_ATTRIBUTES_INTERFACE_GUID },
> + { },
> +};
> +static struct wmi_driver bios_attr_set_interface_driver = {
> + .driver = {
> + .name = DRIVER_NAME
> + },
> + .probe = bios_attr_set_interface_probe,
> + .remove = bios_attr_set_interface_remove,
> + .id_table = bios_attr_set_interface_id_table,
> +};
> +
> +int init_bios_attr_set_interface(void)
> +{
> + return wmi_driver_register(&bios_attr_set_interface_driver);
> +}
> +
> +void exit_bios_attr_set_interface(void)
> +{
> + wmi_driver_unregister(&bios_attr_set_interface_driver);
> +}
> +
> +MODULE_DEVICE_TABLE(wmi, bios_attr_set_interface_id_table);
> diff --git a/drivers/platform/x86/dell-wmi-sysman/dell-wmi-sysman.h b/drivers/platform/x86/dell-wmi-sysman/dell-wmi-sysman.h
> new file mode 100644
> index 000000000000..b80f2a62ea3f
> --- /dev/null
> +++ b/drivers/platform/x86/dell-wmi-sysman/dell-wmi-sysman.h
> @@ -0,0 +1,191 @@
> +/* 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/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"
> +
> +struct enumeration_data {
> + struct kobject *attr_name_kobj;
> + char display_name_language_code[MAX_BUFF];
> + char dell_value_modifier[MAX_BUFF];
> + char possible_values[MAX_BUFF];
> + char attribute_name[MAX_BUFF];
> + char default_value[MAX_BUFF];
> + char dell_modifier[MAX_BUFF];
> + char display_name[MAX_BUFF];
> +};
> +
> +struct integer_data {
> + struct kobject *attr_name_kobj;
> + char display_name_language_code[MAX_BUFF];
> + char attribute_name[MAX_BUFF];
> + char dell_modifier[MAX_BUFF];
> + char display_name[MAX_BUFF];
> + int scalar_increment;
> + int default_value;
> + int min_value;
> + int max_value;
> +};
> +
> +struct str_data {
> + struct kobject *attr_name_kobj;
> + char display_name_language_code[MAX_BUFF];
> + char attribute_name[MAX_BUFF];
> + char display_name[MAX_BUFF];
> + char default_value[MAX_BUFF];
> + char dell_modifier[MAX_BUFF];
> + int min_length;
> + int max_length;
> +};
> +
> +struct po_data {
> + struct kobject *attr_name_kobj;
> + char attribute_name[MAX_BUFF];
> + int min_password_length;
> + int max_password_length;
> +};
> +
> +struct wmi_sysman_priv {
> + char current_admin_password[MAX_BUFF];
> + char current_system_password[MAX_BUFF];
> + struct wmi_device *password_attr_wdev;
> + struct wmi_device *bios_attr_wdev;
> + struct kset *authentication_dir_kset;
> + struct kset *main_dir_kset;
> + struct device *class_dev;
> + struct enumeration_data *enumeration_data;
> + int enumeration_instances_count;
> + struct integer_data *integer_data;
> + int integer_instances_count;
> + struct str_data *str_data;
> + int str_instances_count;
> + struct po_data *po_data;
> + int po_instances_count;
> + bool pending_changes;
> + struct mutex mutex;
> +};
> +
> +/* global structure used by multiple WMI interfaces */
> +extern struct wmi_sysman_priv wmi_priv;
> +
> +enum { ENUM, INT, STR, PO };
> +
> +enum {
> + ATTR_NAME,
> + DISPL_NAME_LANG_CODE,
> + DISPLAY_NAME,
> + DEFAULT_VAL,
> + CURRENT_VAL,
> + MODIFIER
> +};
> +
> +#define get_instance_id(type) \
> +static int get_##type##_instance_id(struct kobject *kobj) \
> +{ \
> + int i; \
> + for (i = 0; i <= wmi_priv.type##_instances_count; i++) { \
> + if (!(strcmp(kobj->name, wmi_priv.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", wmi_priv.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", wmi_priv.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, *buf_cp; \
> + int i, ret = -EIO; \
> + buf_cp = kstrdup(buf, GFP_KERNEL); \
> + if (!buf_cp) \
> + return -ENOMEM; \
> + p = memchr(buf_cp, '\n', count); \
> + \
> + if (p != NULL) \
> + *p = '\0'; \
> + i = get_##type##_instance_id(kobj); \
> + if (i >= 0) \
> + ret = validate_##type##_input(i, buf_cp); \
> + if (!ret) \
> + ret = set_attribute(kobj->name, buf_cp); \
> + kfree(buf_cp); \
> + 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 strlcpy_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(void);
> +
> +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(void);
> +
> +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(void);
> +
> +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(void);
> +
> +int set_attribute(const char *a_name, const char *a_value);
> +int set_bios_defaults(u8 defType);
> +
> +void exit_bios_attr_set_interface(void);
> +int init_bios_attr_set_interface(void);
> +int map_wmi_error(int error_code);
> +size_t calculate_string_buffer(const char *str);
> +size_t calculate_security_buffer(char *authentication);
> +void populate_security_buffer(char *buffer, char *authentication);
> +ssize_t populate_string_buffer(char *buffer, size_t buffer_len, const char *str);
> +int set_new_password(const char *password_type, const char *new);
> +int init_bios_attr_pass_interface(void);
> +void exit_bios_attr_pass_interface(void);
> +
> +#endif
> diff --git a/drivers/platform/x86/dell-wmi-sysman/enum-attributes.c b/drivers/platform/x86/dell-wmi-sysman/enum-attributes.c
> new file mode 100644
> index 000000000000..692c1f4777bf
> --- /dev/null
> +++ b/drivers/platform/x86/dell-wmi-sysman/enum-attributes.c
> @@ -0,0 +1,187 @@
> +// 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.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);
> + union acpi_object *obj;
> + ssize_t ret;
> +
> + if (instance_id < 0)
> + return instance_id;
> +
> + /* need to use specific instance_id and guid combination to get right data */
> + obj = get_wmiobj_pointer(instance_id, DELL_WMI_BIOS_ENUMERATION_ATTRIBUTE_GUID);
> + if (!obj)
> + return -EIO;
> + if (obj->package.elements[CURRENT_VAL].type != ACPI_TYPE_STRING)
> + return -EINVAL;
> + ret = snprintf(buf, PAGE_SIZE, "%s\n", obj->package.elements[CURRENT_VAL].string.pointer);
> + kfree(obj);
> + return ret;
> +}
> +
> +/**
> + * 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)
> +{
> + char *options, *tmp, *p;
> + int ret = -EINVAL;
> +
> + options = tmp = kstrdup(wmi_priv.enumeration_data[instance_id].possible_values,
> + GFP_KERNEL);
> + if (!options)
> + return -ENOMEM;
> +
> + while ((p = strsep(&options, ";")) != NULL) {
> + if (!*p)
> + continue;
> + if (!strcasecmp(p, buf)) {
> + 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);
> +static struct kobj_attribute displ_name =
> + __ATTR_RO(display_name);
> +
> +attribute_s_property_show(default_value, enumeration);
> +static struct kobj_attribute default_val =
> + __ATTR_RO(default_value);
> +
> +attribute_property_store(current_value, enumeration);
> +static struct kobj_attribute current_val =
> + __ATTR_RW_MODE(current_value, 0600);
> +
> +attribute_s_property_show(dell_modifier, enumeration);
> +static struct kobj_attribute modifier =
> + __ATTR_RO(dell_modifier);
> +
> +attribute_s_property_show(dell_value_modifier, enumeration);
> +static struct kobj_attribute value_modfr =
> + __ATTR_RO(dell_value_modifier);
> +
> +attribute_s_property_show(possible_values, enumeration);
> +static struct kobj_attribute poss_val =
> + __ATTR_RO(possible_values);
> +
> +static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
> + char *buf)
> +{
> + return sprintf(buf, "enumeration\n");
> +}
> +static struct kobj_attribute type =
> + __ATTR_RO(type);
> +
> +static struct attribute *enumeration_attrs[] = {
> + &displ_langcode.attr,
> + &displ_name.attr,
> + &default_val.attr,
> + ¤t_val.attr,
> + &modifier.attr,
> + &value_modfr.attr,
> + &poss_val.attr,
> + &type.attr,
> + NULL,
> +};
> +
> +static const struct attribute_group enumeration_attr_group = {
> + .attrs = enumeration_attrs,
> +};
> +
> +int alloc_enum_data(void)
> +{
> + int ret = 0;
> +
> + wmi_priv.enumeration_instances_count =
> + get_instance_count(DELL_WMI_BIOS_ENUMERATION_ATTRIBUTE_GUID);
> + wmi_priv.enumeration_data = kcalloc(wmi_priv.enumeration_instances_count,
> + sizeof(struct enumeration_data), GFP_KERNEL);
> + if (!wmi_priv.enumeration_data) {
> + wmi_priv.enumeration_instances_count = 0;
> + 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, value_modifier_count, possible_values_count;
> +
> + wmi_priv.enumeration_data[instance_id].attr_name_kobj = attr_name_kobj;
> + strlcpy_attr(wmi_priv.enumeration_data[instance_id].attribute_name,
> + enumeration_obj[ATTR_NAME].string.pointer);
> + strlcpy_attr(wmi_priv.enumeration_data[instance_id].display_name_language_code,
> + enumeration_obj[DISPL_NAME_LANG_CODE].string.pointer);
> + strlcpy_attr(wmi_priv.enumeration_data[instance_id].display_name,
> + enumeration_obj[DISPLAY_NAME].string.pointer);
> + strlcpy_attr(wmi_priv.enumeration_data[instance_id].default_value,
> + enumeration_obj[DEFAULT_VAL].string.pointer);
> + strlcpy_attr(wmi_priv.enumeration_data[instance_id].dell_modifier,
> + enumeration_obj[MODIFIER].string.pointer);
> +
> + next_obj = MODIFIER + 1;
> +
> + value_modifier_count = (uintptr_t)enumeration_obj[next_obj].string.pointer;
> +
> + for (i = 0; i < value_modifier_count; i++) {
> + strcat(wmi_priv.enumeration_data[instance_id].dell_value_modifier,
> + enumeration_obj[++next_obj].string.pointer);
> + strcat(wmi_priv.enumeration_data[instance_id].dell_value_modifier, ";");
> + }
> +
> + possible_values_count = (uintptr_t) enumeration_obj[++next_obj].string.pointer;
> +
> + for (i = 0; i < possible_values_count; i++) {
> + strcat(wmi_priv.enumeration_data[instance_id].possible_values,
> + enumeration_obj[++next_obj].string.pointer);
> + strcat(wmi_priv.enumeration_data[instance_id].possible_values, ";");
> + }
> +
> + return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
> +}
> +
> +/**
> + * exit_enum_attributes() - Clear all attribute data
> + *
> + * Clears all data allocated for this group of attributes
> + */
> +void exit_enum_attributes(void)
> +{
> + int instance_id;
> +
> + for (instance_id = 0; instance_id < wmi_priv.enumeration_instances_count; instance_id++) {
> + if (wmi_priv.enumeration_data[instance_id].attr_name_kobj)
> + sysfs_remove_group(wmi_priv.enumeration_data[instance_id].attr_name_kobj,
> + &enumeration_attr_group);
> + }
> + kfree(wmi_priv.enumeration_data);
> +}
> diff --git a/drivers/platform/x86/dell-wmi-sysman/int-attributes.c b/drivers/platform/x86/dell-wmi-sysman/int-attributes.c
> new file mode 100644
> index 000000000000..62cd7dbe57fe
> --- /dev/null
> +++ b/drivers/platform/x86/dell-wmi-sysman/int-attributes.c
> @@ -0,0 +1,171 @@
> +// 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.h"
> +
> +enum int_properties {MIN_VALUE = 6, MAX_VALUE, SCALAR_INCR};
> +
> +get_instance_id(integer);
> +
> +static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> +{
> + int instance_id = get_integer_instance_id(kobj);
> + union acpi_object *obj;
> + ssize_t ret;
> +
> + if (instance_id < 0)
> + return instance_id;
> +
> + /* need to use specific instance_id and guid combination to get right data */
> + obj = get_wmiobj_pointer(instance_id, DELL_WMI_BIOS_INTEGER_ATTRIBUTE_GUID);
> + if (!obj)
> + return -EIO;
> + if (obj->package.elements[CURRENT_VAL].type != ACPI_TYPE_INTEGER)
> + return -EINVAL;
> + ret = snprintf(buf, PAGE_SIZE, "%lld\n", obj->package.elements[CURRENT_VAL].integer.value);
> + kfree(obj);
> + return ret;
> +}
> +
> +/**
> + * 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
> + */
> +static int validate_integer_input(int instance_id, const char *buf)
> +{
> + int in_val;
> + int ret;
> +
> + ret = kstrtoint(buf, 0, &in_val);
> + if (ret)
> + return ret;
> + if (in_val < wmi_priv.integer_data[instance_id].min_value ||
> + in_val > wmi_priv.integer_data[instance_id].max_value)
> + return -EINVAL;
> +
> + 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);
> +static struct kobj_attribute integer_displ_name =
> + __ATTR_RO(display_name);
> +
> +attribute_n_property_show(default_value, integer);
> +static struct kobj_attribute integer_default_val =
> + __ATTR_RO(default_value);
> +
> +attribute_property_store(current_value, integer);
> +static struct kobj_attribute integer_current_val =
> + __ATTR_RW_MODE(current_value, 0600);
> +
> +attribute_s_property_show(dell_modifier, integer);
> +static struct kobj_attribute integer_modifier =
> + __ATTR_RO(dell_modifier);
> +
> +attribute_n_property_show(min_value, integer);
> +static struct kobj_attribute integer_lower_bound =
> + __ATTR_RO(min_value);
> +
> +attribute_n_property_show(max_value, integer);
> +static struct kobj_attribute integer_upper_bound =
> + __ATTR_RO(max_value);
> +
> +attribute_n_property_show(scalar_increment, integer);
> +static struct kobj_attribute integer_scalar_increment =
> + __ATTR_RO(scalar_increment);
> +
> +static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
> + char *buf)
> +{
> + return sprintf(buf, "integer\n");
> +}
> +static struct kobj_attribute integer_type =
> + __ATTR_RO(type);
> +
> +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,
> + &integer_type.attr,
> + NULL,
> +};
> +
> +static const struct attribute_group integer_attr_group = {
> + .attrs = integer_attrs,
> +};
> +
> +int alloc_int_data(void)
> +{
> + int ret = 0;
> +
> + wmi_priv.integer_instances_count = get_instance_count(DELL_WMI_BIOS_INTEGER_ATTRIBUTE_GUID);
> + wmi_priv.integer_data = kcalloc(wmi_priv.integer_instances_count,
> + sizeof(struct integer_data), GFP_KERNEL);
> + if (!wmi_priv.integer_data) {
> + wmi_priv.integer_instances_count = 0;
> + ret = -ENOMEM;
> + }
> + return ret;
> +}
> +
> +/**
> + * populate_int_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)
> +{
> + wmi_priv.integer_data[instance_id].attr_name_kobj = attr_name_kobj;
> + strlcpy_attr(wmi_priv.integer_data[instance_id].attribute_name,
> + integer_obj[ATTR_NAME].string.pointer);
> + strlcpy_attr(wmi_priv.integer_data[instance_id].display_name_language_code,
> + integer_obj[DISPL_NAME_LANG_CODE].string.pointer);
> + strlcpy_attr(wmi_priv.integer_data[instance_id].display_name,
> + integer_obj[DISPLAY_NAME].string.pointer);
> + wmi_priv.integer_data[instance_id].default_value =
> + (uintptr_t)integer_obj[DEFAULT_VAL].string.pointer;
> + strlcpy_attr(wmi_priv.integer_data[instance_id].dell_modifier,
> + integer_obj[MODIFIER].string.pointer);
> + wmi_priv.integer_data[instance_id].min_value =
> + (uintptr_t)integer_obj[MIN_VALUE].string.pointer;
> + wmi_priv.integer_data[instance_id].max_value =
> + (uintptr_t)integer_obj[MAX_VALUE].string.pointer;
> + wmi_priv.integer_data[instance_id].scalar_increment =
> + (uintptr_t)integer_obj[SCALAR_INCR].string.pointer;
> +
> + return sysfs_create_group(attr_name_kobj, &integer_attr_group);
> +}
> +
> +/**
> + * exit_int_attributes() - Clear all attribute data
> + *
> + * Clears all data allocated for this group of attributes
> + */
> +void exit_int_attributes(void)
> +{
> + int instance_id;
> +
> + for (instance_id = 0; instance_id < wmi_priv.integer_instances_count; instance_id++) {
> + if (wmi_priv.integer_data[instance_id].attr_name_kobj)
> + sysfs_remove_group(wmi_priv.integer_data[instance_id].attr_name_kobj,
> + &integer_attr_group);
> + }
> + kfree(wmi_priv.integer_data);
> +}
> diff --git a/drivers/platform/x86/dell-wmi-sysman/passobj-attributes.c b/drivers/platform/x86/dell-wmi-sysman/passobj-attributes.c
> new file mode 100644
> index 000000000000..0d11e48e2e63
> --- /dev/null
> +++ b/drivers/platform/x86/dell-wmi-sysman/passobj-attributes.c
> @@ -0,0 +1,192 @@
> +// 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.h"
> +
> +enum po_properties {IS_PASS_SET = 1, MIN_PASS_LEN, MAX_PASS_LEN};
> +
> +get_instance_id(po);
> +
> +static ssize_t is_enabled_show(struct kobject *kobj, struct kobj_attribute *attr,
> + char *buf)
> +{
> + int instance_id = get_po_instance_id(kobj);
> + union acpi_object *obj;
> + ssize_t ret;
> +
> + if (instance_id < 0)
> + return instance_id;
> +
> + /* need to use specific instance_id and guid combination to get right data */
> + obj = get_wmiobj_pointer(instance_id, DELL_WMI_BIOS_PASSOBJ_ATTRIBUTE_GUID);
> + if (!obj)
> + return -EIO;
> + if (obj->package.elements[IS_PASS_SET].type != ACPI_TYPE_INTEGER)
> + return -EINVAL;
> + ret = snprintf(buf, PAGE_SIZE, "%lld\n", obj->package.elements[IS_PASS_SET].integer.value);
> + kfree(obj);
> + return ret;
> +}
> +
> +struct kobj_attribute po_is_pass_set =
> + __ATTR_RO(is_enabled);
> +
> +static ssize_t current_password_store(struct kobject *kobj,
> + struct kobj_attribute *attr,
> + const char *buf, size_t count)
> +{
> + char *target = NULL;
> + int length;
> +
> + length = strlen(buf);
> + if (buf[length-1] == '\n')
> + length--;
> +
> + /* firmware does verifiation of min/max password length,
> + * hence only check for not exceeding MAX_BUFF here.
> + */
> + if (length >= MAX_BUFF)
> + return -EINVAL;
> +
> + if (strcmp(kobj->name, "Admin") == 0)
> + target = wmi_priv.current_admin_password;
> + else if (strcmp(kobj->name, "System") == 0)
> + target = wmi_priv.current_system_password;
> + if (!target)
> + return -EIO;
> + memcpy(target, buf, length);
> + target[length] = '\0';
> +
> + return 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, *buf_cp;
> + int ret;
> +
> + buf_cp = kstrdup(buf, GFP_KERNEL);
> + if (!buf_cp)
> + return -ENOMEM;
> + p = memchr(buf_cp, '\n', count);
> +
> + if (p != NULL)
> + *p = '\0';
> + if (strlen(buf_cp) > MAX_BUFF) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + ret = set_new_password(kobj->name, buf_cp);
> +
> +out:
> + kfree(buf_cp);
> + 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 ssize_t mechanism_show(struct kobject *kobj, struct kobj_attribute *attr,
> + char *buf)
> +{
> + return sprintf(buf, "password\n");
> +}
> +
> +struct kobj_attribute po_mechanism =
> + __ATTR_RO(mechanism);
> +
> +static ssize_t role_show(struct kobject *kobj, struct kobj_attribute *attr,
> + char *buf)
> +{
> + if (strcmp(kobj->name, "Admin") == 0)
> + return sprintf(buf, "bios-admin\n");
> + else if (strcmp(kobj->name, "System") == 0)
> + return sprintf(buf, "power-on\n");
> + return -EIO;
> +}
> +
> +struct kobj_attribute po_role =
> + __ATTR_RO(role);
> +
> +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,
> + &po_role.attr,
> + &po_mechanism.attr,
> + NULL,
> +};
> +
> +static const struct attribute_group po_attr_group = {
> + .attrs = po_attrs,
> +};
> +
> +int alloc_po_data(void)
> +{
> + int ret = 0;
> +
> + wmi_priv.po_instances_count = get_instance_count(DELL_WMI_BIOS_PASSOBJ_ATTRIBUTE_GUID);
> + wmi_priv.po_data = kcalloc(wmi_priv.po_instances_count, sizeof(struct po_data), GFP_KERNEL);
> + if (!wmi_priv.po_data) {
> + wmi_priv.po_instances_count = 0;
> + 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)
> +{
> + wmi_priv.po_data[instance_id].attr_name_kobj = attr_name_kobj;
> + strlcpy_attr(wmi_priv.po_data[instance_id].attribute_name,
> + po_obj[ATTR_NAME].string.pointer);
> + wmi_priv.po_data[instance_id].min_password_length =
> + (uintptr_t)po_obj[MIN_PASS_LEN].string.pointer;
> + wmi_priv.po_data[instance_id].max_password_length =
> + (uintptr_t) po_obj[MAX_PASS_LEN].string.pointer;
> +
> + return sysfs_create_group(attr_name_kobj, &po_attr_group);
> +}
> +
> +/**
> + * exit_po_attributes() - Clear all attribute data
> + *
> + * Clears all data allocated for this group of attributes
> + */
> +void exit_po_attributes(void)
> +{
> + int instance_id;
> +
> + for (instance_id = 0; instance_id < wmi_priv.po_instances_count; instance_id++) {
> + if (wmi_priv.po_data[instance_id].attr_name_kobj)
> + sysfs_remove_group(wmi_priv.po_data[instance_id].attr_name_kobj,
> + &po_attr_group);
> + }
> + kfree(wmi_priv.po_data);
> +}
> diff --git a/drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c b/drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c
> new file mode 100644
> index 000000000000..5780b4d94759
> --- /dev/null
> +++ b/drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c
> @@ -0,0 +1,153 @@
> +// 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.h"
> +
> +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);
> + /* let userland know it may need to check is_password_set again */
> + kobject_uevent(&wmi_priv.class_dev->kobj, KOBJ_CHANGE);
> + return map_wmi_error(ret);
> +}
> +
> +/**
> + * 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)
> +{
> + size_t password_type_size, current_password_size, new_size;
> + size_t security_area_size, buffer_size;
> + char *buffer = NULL, *start;
> + char *current_password;
> + int ret;
> +
> + mutex_lock(&wmi_priv.mutex);
> + if (!wmi_priv.password_attr_wdev) {
> + ret = -ENODEV;
> + goto out;
> + }
> + if (strcmp(password_type, "Admin") == 0) {
> + current_password = wmi_priv.current_admin_password;
> + } else if (strcmp(password_type, "System") == 0) {
> + current_password = wmi_priv.current_system_password;
> + } else {
> + ret = -EINVAL;
> + dev_err(&wmi_priv.password_attr_wdev->dev, "unknown password type %s\n",
> + password_type);
> + goto out;
> + }
> +
> + /* build/calculate buffer */
> + security_area_size = calculate_security_buffer(wmi_priv.current_admin_password);
> + password_type_size = calculate_string_buffer(password_type);
> + current_password_size = calculate_string_buffer(current_password);
> + new_size = calculate_string_buffer(new);
> + buffer_size = security_area_size + password_type_size + current_password_size + new_size;
> + buffer = kzalloc(buffer_size, GFP_KERNEL);
> + if (!buffer) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + /* build security area */
> + populate_security_buffer(buffer, wmi_priv.current_admin_password);
> +
> + /* build variables to set */
> + start = buffer + security_area_size;
> + ret = populate_string_buffer(start, password_type_size, password_type);
> + if (ret < 0)
> + goto out;
> +
> + start += ret;
> + ret = populate_string_buffer(start, current_password_size, current_password);
> + if (ret < 0)
> + goto out;
> +
> + start += ret;
> + ret = populate_string_buffer(start, new_size, new);
> + if (ret < 0)
> + goto out;
> +
> + print_hex_dump_bytes("set new password data: ", DUMP_PREFIX_NONE, buffer, buffer_size);
> + ret = call_password_interface(wmi_priv.password_attr_wdev, buffer, buffer_size);
> + /* clear current_password here and use user input from wmi_priv.current_password */
> + if (!ret)
> + memset(current_password, 0, MAX_BUFF);
> + /* explain to user the detailed failure reason */
> + else if (ret == -EOPNOTSUPP)
> + dev_err(&wmi_priv.password_attr_wdev->dev, "admin password must be configured\n");
> + else if (ret == -EACCES)
> + dev_err(&wmi_priv.password_attr_wdev->dev, "invalid password\n");
> +
> +out:
> + kfree(buffer);
> + mutex_unlock(&wmi_priv.mutex);
> +
> + return ret;
> +}
> +
> +static int bios_attr_pass_interface_probe(struct wmi_device *wdev, const void *context)
> +{
> + mutex_lock(&wmi_priv.mutex);
> + wmi_priv.password_attr_wdev = wdev;
> + mutex_unlock(&wmi_priv.mutex);
> + return 0;
> +}
> +
> +static int bios_attr_pass_interface_remove(struct wmi_device *wdev)
> +{
> + mutex_lock(&wmi_priv.mutex);
> + wmi_priv.password_attr_wdev = NULL;
> + mutex_unlock(&wmi_priv.mutex);
> + return 0;
> +}
> +
> +static const struct wmi_device_id bios_attr_pass_interface_id_table[] = {
> + { .guid_string = DELL_WMI_BIOS_PASSWORD_INTERFACE_GUID },
> + { },
> +};
> +static struct wmi_driver bios_attr_pass_interface_driver = {
> + .driver = {
> + .name = DRIVER_NAME"-password"
> + },
> + .probe = bios_attr_pass_interface_probe,
> + .remove = bios_attr_pass_interface_remove,
> + .id_table = bios_attr_pass_interface_id_table,
> +};
> +
> +int init_bios_attr_pass_interface(void)
> +{
> + return wmi_driver_register(&bios_attr_pass_interface_driver);
> +}
> +
> +void exit_bios_attr_pass_interface(void)
> +{
> + wmi_driver_unregister(&bios_attr_pass_interface_driver);
> +}
> +
> +MODULE_DEVICE_TABLE(wmi, bios_attr_pass_interface_id_table);
> diff --git a/drivers/platform/x86/dell-wmi-sysman/string-attributes.c b/drivers/platform/x86/dell-wmi-sysman/string-attributes.c
> new file mode 100644
> index 000000000000..3ff4a7f38469
> --- /dev/null
> +++ b/drivers/platform/x86/dell-wmi-sysman/string-attributes.c
> @@ -0,0 +1,157 @@
> +// 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.h"
> +
> +enum string_properties {MIN_LEN = 6, MAX_LEN};
> +
> +get_instance_id(str);
> +
> +static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> +{
> + int instance_id = get_str_instance_id(kobj);
> + union acpi_object *obj;
> + ssize_t ret;
> +
> + if (instance_id < 0)
> + return -EIO;
> +
> + /* need to use specific instance_id and guid combination to get right data */
> + obj = get_wmiobj_pointer(instance_id, DELL_WMI_BIOS_STRING_ATTRIBUTE_GUID);
> + if (!obj)
> + return -EIO;
> + if (obj->package.elements[CURRENT_VAL].type != ACPI_TYPE_STRING)
> + return -EINVAL;
> + ret = snprintf(buf, PAGE_SIZE, "%s\n", obj->package.elements[CURRENT_VAL].string.pointer);
> + kfree(obj);
> + return ret;
> +}
> +
> +/**
> + * 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
> + */
> +static int validate_str_input(int instance_id, const char *buf)
> +{
> + int in_len = strlen(buf);
> +
> + if ((in_len < wmi_priv.str_data[instance_id].min_length) ||
> + (in_len > wmi_priv.str_data[instance_id].max_length))
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +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);
> +static struct kobj_attribute str_displ_name =
> + __ATTR_RO(display_name);
> +
> +attribute_s_property_show(default_value, str);
> +static struct kobj_attribute str_default_val =
> + __ATTR_RO(default_value);
> +
> +attribute_property_store(current_value, str);
> +static struct kobj_attribute str_current_val =
> + __ATTR_RW_MODE(current_value, 0600);
> +
> +attribute_s_property_show(dell_modifier, str);
> +static struct kobj_attribute str_modifier =
> + __ATTR_RO(dell_modifier);
> +
> +attribute_n_property_show(min_length, str);
> +static struct kobj_attribute str_min_length =
> + __ATTR_RO(min_length);
> +
> +attribute_n_property_show(max_length, str);
> +static struct kobj_attribute str_max_length =
> + __ATTR_RO(max_length);
> +
> +static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
> + char *buf)
> +{
> + return sprintf(buf, "string\n");
> +}
> +static struct kobj_attribute str_type =
> + __ATTR_RO(type);
> +
> +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,
> + &str_type.attr,
> + NULL,
> +};
> +
> +static const struct attribute_group str_attr_group = {
> + .attrs = str_attrs,
> +};
> +
> +int alloc_str_data(void)
> +{
> + int ret = 0;
> +
> + wmi_priv.str_instances_count = get_instance_count(DELL_WMI_BIOS_STRING_ATTRIBUTE_GUID);
> + wmi_priv.str_data = kcalloc(wmi_priv.str_instances_count,
> + sizeof(struct str_data), GFP_KERNEL);
> + if (!wmi_priv.str_data) {
> + wmi_priv.str_instances_count = 0;
> + ret = -ENOMEM;
> + }
> + return ret;
> +}
> +
> +/**
> + * populate_str_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)
> +{
> + wmi_priv.str_data[instance_id].attr_name_kobj = attr_name_kobj;
> + strlcpy_attr(wmi_priv.str_data[instance_id].attribute_name,
> + str_obj[ATTR_NAME].string.pointer);
> + strlcpy_attr(wmi_priv.str_data[instance_id].display_name_language_code,
> + str_obj[DISPL_NAME_LANG_CODE].string.pointer);
> + strlcpy_attr(wmi_priv.str_data[instance_id].display_name,
> + str_obj[DISPLAY_NAME].string.pointer);
> + strlcpy_attr(wmi_priv.str_data[instance_id].default_value,
> + str_obj[DEFAULT_VAL].string.pointer);
> + strlcpy_attr(wmi_priv.str_data[instance_id].dell_modifier,
> + str_obj[MODIFIER].string.pointer);
> + wmi_priv.str_data[instance_id].min_length = (uintptr_t)str_obj[MIN_LEN].string.pointer;
> + wmi_priv.str_data[instance_id].max_length = (uintptr_t) str_obj[MAX_LEN].string.pointer;
> +
> + return sysfs_create_group(attr_name_kobj, &str_attr_group);
> +}
> +
> +/**
> + * exit_str_attributes() - Clear all attribute data
> + *
> + * Clears all data allocated for this group of attributes
> + */
> +void exit_str_attributes(void)
> +{
> + int instance_id;
> +
> + for (instance_id = 0; instance_id < wmi_priv.str_instances_count; instance_id++) {
> + if (wmi_priv.str_data[instance_id].attr_name_kobj)
> + sysfs_remove_group(wmi_priv.str_data[instance_id].attr_name_kobj,
> + &str_attr_group);
> + }
> + kfree(wmi_priv.str_data);
> +}
> diff --git a/drivers/platform/x86/dell-wmi-sysman/sysman.c b/drivers/platform/x86/dell-wmi-sysman/sysman.c
> new file mode 100644
> index 000000000000..3842575a6c18
> --- /dev/null
> +++ b/drivers/platform/x86/dell-wmi-sysman/sysman.c
> @@ -0,0 +1,625 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Common methods for use with dell-wmi-sysman
> + *
> + * Copyright (c) 2020 Dell Inc.
> + */
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/fs.h>
> +#include <linux/dmi.h>
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/wmi.h>
> +#include "dell-wmi-sysman.h"
> +
> +#define MAX_TYPES 4
> +#include <linux/nls.h>
> +
> +static struct class firmware_attributes_class = {
> + .name = "firmware-attributes",
> +};
> +
> +struct wmi_sysman_priv wmi_priv = {
> + .mutex = __MUTEX_INITIALIZER(wmi_priv.mutex),
> +};
> +
> +/* reset bios to defaults */
> +static const char * const reset_types[] = {"builtinsafe", "lastknowngood", "factory", "custom"};
> +static int reset_option = -1;
> +
> +
> +/**
> + * populate_string_buffer() - populates a string buffer
> + * @buffer: the start of the destination buffer
> + * @buffer_len: length of the destination buffer
> + * @str: the string to insert into buffer
> + */
> +ssize_t populate_string_buffer(char *buffer, size_t buffer_len, const char *str)
> +{
> + u16 *length = (u16 *)buffer;
> + u16 *target = length + 1;
> + int ret;
> +
> + ret = utf8s_to_utf16s(str, strlen(str), UTF16_HOST_ENDIAN,
> + target, buffer_len - sizeof(u16));
> + if (ret < 0) {
> + dev_err(wmi_priv.class_dev, "UTF16 conversion failed\n");
> + return ret;
> + }
> +
> + if ((ret * sizeof(u16)) > U16_MAX) {
> + dev_err(wmi_priv.class_dev, "Error string too long\n");
> + return -ERANGE;
> + }
> +
> + *length = ret * sizeof(u16);
> + return sizeof(u16) + *length;
> +}
> +
> +/**
> + * calculate_string_buffer() - determines size of string buffer for use with BIOS communication
> + * @str: the string to calculate based upon
> + *
> + */
> +size_t calculate_string_buffer(const char *str)
> +{
> + /* u16 length field + one UTF16 char for each input char */
> + return sizeof(u16) + strlen(str) * sizeof(u16);
> +}
> +
> +/**
> + * calculate_security_buffer() - determines size of security buffer for authentication scheme
> + * @authentication: the authentication content
> + *
> + * Currently only supported type is Admin password
> + */
> +size_t calculate_security_buffer(char *authentication)
> +{
> + if (strlen(authentication) > 0) {
> + return (sizeof(u32) * 2) + strlen(authentication) +
> + strlen(authentication) % 2;
> + }
> + return sizeof(u32) * 2;
> +}
> +
> +/**
> + * 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)
> +{
> + char *auth = buffer + sizeof(u32) * 2;
> + u32 *sectype = (u32 *) buffer;
> + u32 *seclen = sectype + 1;
> +
> + *sectype = strlen(authentication) > 0 ? 1 : 0;
> + *seclen = strlen(authentication);
> +
> + /* plain text */
> + if (strlen(authentication) > 0)
> + memcpy(auth, authentication, *seclen);
> +}
> +
> +/**
> + * map_wmi_error() - map errors from WMI methods to kernel error codes
> + * @error_code: integer error code returned from Dell's firmware
> + */
> +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)
> +{
> + char *start = buf;
> + int i;
> +
> + 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 type = sysfs_match_string(reset_types, buf);
> + int ret;
> +
> + if (type < 0)
> + return type;
> +
> + ret = set_bios_defaults(type);
> + pr_debug("reset all attributes request type %d: %d\n", type, ret);
> + if (!ret) {
> + reset_option = type;
> + ret = count;
> + }
> +
> + 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", wmi_priv.pending_changes);
> +}
> +
> +static struct kobj_attribute reset_bios = __ATTR_RW(reset_bios);
> +static struct kobj_attribute pending_reboot = __ATTR_RO(pending_reboot);
> +
> +
> +/**
> + * create_attributes_level_sysfs_files() - Creates reset_bios and
> + * pending_reboot attributes
> + */
> +static int create_attributes_level_sysfs_files(void)
> +{
> + int ret = sysfs_create_file(&wmi_priv.main_dir_kset->kobj, &reset_bios.attr);
> +
> + if (ret) {
> + pr_debug("could not create reset_bios file\n");
> + return ret;
> + }
> +
> + ret = sysfs_create_file(&wmi_priv.main_dir_kset->kobj, &pending_reboot.attr);
> + if (ret) {
> + pr_debug("could not create changing_pending_reboot file\n");
> + sysfs_remove_file(&wmi_priv.main_dir_kset->kobj, &reset_bios.attr);
> + }
> + return ret;
> +}
> +
> +static void release_reset_bios_data(void)
> +{
> + sysfs_remove_file(&wmi_priv.main_dir_kset->kobj, &reset_bios.attr);
> + sysfs_remove_file(&wmi_priv.main_dir_kset->kobj, &pending_reboot.attr);
> +}
> +
> +static ssize_t wmi_sysman_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 wmi_sysman_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 wmi_sysman_kobj_sysfs_ops = {
> + .show = wmi_sysman_attr_show,
> + .store = wmi_sysman_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 = &wmi_sysman_kobj_sysfs_ops,
> +};
> +
> +/**
> + * strlcpy_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 strlcpy_attr(char *dest, char *src)
> +{
> + size_t len = strlen(src) + 1;
> +
> + if (len > 1 && len <= MAX_BUFF)
> + strlcpy(dest, src, len);
> +
> + /*len can be zero because any property not-applicable to attribute can
> + * be empty so check only for too long buffers and log error
> + */
> + if (len > MAX_BUFF)
> + pr_err("Source string returned from BIOS is out of bound!\n");
> +}
> +
> +/**
> + * 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)
> +{
> + struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
> + acpi_status status;
> +
> + 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)
> +{
> + union acpi_object *wmi_obj = NULL;
> + int i = 0;
> +
> + 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;
> +
> + 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;
> + }
> +
> + 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;
> +
> + list_for_each_entry_safe(pos, next, &kset->list, entry) {
> + kobject_put(pos);
> + }
> +}
> +
> +/**
> + * release_attributes_data() - Clean-up all sysfs directories and files created
> + */
> +static void release_attributes_data(void)
> +{
> + release_reset_bios_data();
> +
> + mutex_lock(&wmi_priv.mutex);
> + exit_enum_attributes();
> + exit_int_attributes();
> + exit_str_attributes();
> + exit_po_attributes();
> + if (wmi_priv.authentication_dir_kset) {
> + destroy_attribute_objs(wmi_priv.authentication_dir_kset);
> + kset_unregister(wmi_priv.authentication_dir_kset);
> + wmi_priv.authentication_dir_kset = NULL;
> + }
> + if (wmi_priv.main_dir_kset) {
> + destroy_attribute_objs(wmi_priv.main_dir_kset);
> + kset_unregister(wmi_priv.main_dir_kset);
> + }
> + mutex_unlock(&wmi_priv.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)
> +{
> + struct kobject *attr_name_kobj; //individual attribute names
> + union acpi_object *obj = NULL;
> + union acpi_object *elements;
> + struct kset *tmp_set;
> +
> + /* instance_id needs to be reset for each type GUID
> + * also, instance IDs are unique within GUID but not across
> + */
> + int instance_id = 0;
> + int retval = 0;
> +
> + retval = alloc_attributes_data(attr_type);
> + if (retval)
> + return retval;
> + /* need to use specific instance_id and guid combination to get right data */
> + obj = get_wmiobj_pointer(instance_id, guid);
> + if (!obj)
> + return -ENODEV;
> + elements = obj->package.elements;
> +
> + mutex_lock(&wmi_priv.mutex);
> + while (elements) {
> + /* sanity checking */
> + if (strlen(elements[ATTR_NAME].string.pointer) == 0) {
> + pr_debug("empty attribute found\n");
> + goto nextobj;
> + }
> + if (attr_type == PO)
> + tmp_set = wmi_priv.authentication_dir_kset;
> + else
> + tmp_set = wmi_priv.main_dir_kset;
> +
> + if (kset_find_obj(tmp_set, elements[ATTR_NAME].string.pointer)) {
> + pr_debug("duplicate attribute name found - %s\n",
> + 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 = tmp_set;
> +
> + 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) {
> + pr_debug("failed to populate %s\n",
> + 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:
> + mutex_unlock(&wmi_priv.mutex);
> + return retval;
> +}
> +
> +static int __init sysman_init(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 = init_bios_attr_set_interface();
> + if (ret || !wmi_priv.bios_attr_wdev) {
> + pr_debug("failed to initialize set interface\n");
> + goto fail_set_interface;
> + }
> +
> + ret = init_bios_attr_pass_interface();
> + if (ret || !wmi_priv.password_attr_wdev) {
> + pr_debug("failed to initialize pass interface\n");
> + goto fail_pass_interface;
> + }
> +
> + ret = class_register(&firmware_attributes_class);
> + if (ret)
> + goto fail_class;
> +
> + wmi_priv.class_dev = device_create(&firmware_attributes_class, NULL, MKDEV(0, 0),
> + NULL, "%s", DRIVER_NAME);
> + if (IS_ERR(wmi_priv.class_dev)) {
> + ret = PTR_ERR(wmi_priv.class_dev);
> + goto fail_classdev;
> + }
> +
> + wmi_priv.main_dir_kset = kset_create_and_add("attributes", NULL,
> + &wmi_priv.class_dev->kobj);
> + if (!wmi_priv.main_dir_kset) {
> + ret = -ENOMEM;
> + goto fail_main_kset;
> + }
> +
> + wmi_priv.authentication_dir_kset = kset_create_and_add("authentication", NULL,
> + &wmi_priv.class_dev->kobj);
> + if (!wmi_priv.authentication_dir_kset) {
> + ret = -ENOMEM;
> + goto fail_authentication_kset;
> + }
> +
> + ret = create_attributes_level_sysfs_files();
> + if (ret) {
> + pr_debug("could not create reset BIOS attribute\n");
> + goto fail_reset_bios;
> + }
> +
> + ret = init_bios_attributes(ENUM, DELL_WMI_BIOS_ENUMERATION_ATTRIBUTE_GUID);
> + if (ret) {
> + pr_debug("failed to populate enumeration type attributes\n");
> + goto fail_create_group;
> + }
> +
> + ret = init_bios_attributes(INT, DELL_WMI_BIOS_INTEGER_ATTRIBUTE_GUID);
> + if (ret) {
> + pr_debug("failed to populate integer type attributes\n");
> + goto fail_create_group;
> + }
> +
> + ret = init_bios_attributes(STR, DELL_WMI_BIOS_STRING_ATTRIBUTE_GUID);
> + if (ret) {
> + pr_debug("failed to populate string type attributes\n");
> + goto fail_create_group;
> + }
> +
> + ret = init_bios_attributes(PO, DELL_WMI_BIOS_PASSOBJ_ATTRIBUTE_GUID);
> + if (ret) {
> + pr_debug("failed to populate pass object type attributes\n");
> + goto fail_create_group;
> + }
> +
> + return 0;
> +
> +fail_create_group:
> + release_attributes_data();
> +
> +fail_reset_bios:
> + if (wmi_priv.authentication_dir_kset) {
> + kset_unregister(wmi_priv.authentication_dir_kset);
> + wmi_priv.authentication_dir_kset = NULL;
> + }
> +
> +fail_authentication_kset:
> + if (wmi_priv.main_dir_kset) {
> + kset_unregister(wmi_priv.main_dir_kset);
> + wmi_priv.main_dir_kset = NULL;
> + }
> +
> +fail_main_kset:
> + device_destroy(&firmware_attributes_class, MKDEV(0, 0));
> +
> +fail_classdev:
> + class_unregister(&firmware_attributes_class);
> +
> +fail_class:
> + exit_bios_attr_pass_interface();
> +
> +fail_pass_interface:
> + exit_bios_attr_set_interface();
> +
> +fail_set_interface:
> + return ret;
> +}
> +
> +static void __exit sysman_exit(void)
> +{
> + release_attributes_data();
> + device_destroy(&firmware_attributes_class, MKDEV(0, 0));
> + class_unregister(&firmware_attributes_class);
> + exit_bios_attr_set_interface();
> + exit_bios_attr_pass_interface();
> +}
> +
> +module_init(sysman_init);
> +module_exit(sysman_exit);
> +
> +MODULE_AUTHOR("Mario Limonciello <mario.limonciello@xxxxxxxx>");
> +MODULE_AUTHOR("Prasanth Ksr <prasanth.ksr@xxxxxxxx>");
> +MODULE_AUTHOR("Divya Bharathi <divya.bharathi@xxxxxxxx>");
> +MODULE_DESCRIPTION("Dell platform setting control interface");
> +MODULE_LICENSE("GPL");
>