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-rw-r--r--drivers/platform/wmi/Kconfig37
-rw-r--r--drivers/platform/wmi/Makefile11
-rw-r--r--drivers/platform/wmi/core.c1612
-rw-r--r--drivers/platform/wmi/internal.h18
-rw-r--r--drivers/platform/wmi/marshalling.c251
-rw-r--r--drivers/platform/wmi/string.c92
-rw-r--r--drivers/platform/wmi/tests/Kconfig27
-rw-r--r--drivers/platform/wmi/tests/Makefile11
-rw-r--r--drivers/platform/wmi/tests/marshalling_kunit.c472
-rw-r--r--drivers/platform/wmi/tests/string_kunit.c296
10 files changed, 2827 insertions, 0 deletions
diff --git a/drivers/platform/wmi/Kconfig b/drivers/platform/wmi/Kconfig
new file mode 100644
index 000000000..d62f51ff3
--- /dev/null
+++ b/drivers/platform/wmi/Kconfig
@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# ACPI WMI Core
+#
+
+menuconfig ACPI_WMI
+ tristate "ACPI-WMI support"
+ depends on ACPI && X86
+ select NLS
+ help
+ This option enables support for the ACPI-WMI driver core.
+
+ The ACPI-WMI interface is a proprietary extension of ACPI allowing
+ the platform firmware to expose WMI (Windows Management Instrumentation)
+ objects used for managing various aspects of the underlying system.
+ Mapping between ACPI control methods and WMI objects happens through
+ special mapper devices (PNP0C14) defined inside the ACPI tables.
+
+ Enabling this option is necessary for building the vendor specific
+ ACPI-WMI client drivers for Acer, Dell an HP machines (among others).
+
+ It is safe to enable this option even for machines that do not contain
+ any ACPI-WMI mapper devices at all.
+
+if ACPI_WMI
+
+config ACPI_WMI_LEGACY_DEVICE_NAMES
+ bool "Use legacy WMI device naming scheme"
+ help
+ Say Y here to force the WMI driver core to use the old WMI device naming
+ scheme when creating WMI devices. Doing so might be necessary for some
+ userspace applications but will cause the registration of WMI devices with
+ the same GUID to fail in some corner cases.
+
+source "drivers/platform/wmi/tests/Kconfig"
+
+endif # ACPI_WMI
diff --git a/drivers/platform/wmi/Makefile b/drivers/platform/wmi/Makefile
new file mode 100644
index 000000000..2feff94a5
--- /dev/null
+++ b/drivers/platform/wmi/Makefile
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Makefile for linux/drivers/platform/wmi
+# ACPI WMI core
+#
+
+wmi-y := core.o marshalling.o string.o
+obj-$(CONFIG_ACPI_WMI) += wmi.o
+
+# Unit tests
+obj-y += tests/
diff --git a/drivers/platform/wmi/core.c b/drivers/platform/wmi/core.c
new file mode 100644
index 000000000..529825dcf
--- /dev/null
+++ b/drivers/platform/wmi/core.c
@@ -0,0 +1,1612 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ACPI-WMI mapping driver
+ *
+ * Copyright (C) 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk>
+ *
+ * GUID parsing code from ldm.c is:
+ * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
+ * Copyright (c) 2001-2007 Anton Altaparmakov
+ * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
+ *
+ * WMI bus infrastructure by Andrew Lutomirski and Darren Hart:
+ * Copyright (C) 2015 Andrew Lutomirski
+ * Copyright (C) 2017 VMware, Inc. All Rights Reserved.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/acpi.h>
+#include <linux/bits.h>
+#include <linux/build_bug.h>
+#include <linux/device.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/limits.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/rwsem.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+#include <linux/uuid.h>
+#include <linux/wmi.h>
+#include <linux/fs.h>
+
+#include "internal.h"
+
+MODULE_AUTHOR("Carlos Corbacho");
+MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
+MODULE_LICENSE("GPL");
+
+struct guid_block {
+ guid_t guid;
+ union {
+ char object_id[2];
+ struct {
+ unsigned char notify_id;
+ unsigned char reserved;
+ };
+ };
+ u8 instance_count;
+ u8 flags;
+} __packed;
+static_assert(sizeof(typeof_member(struct guid_block, guid)) == 16);
+static_assert(sizeof(struct guid_block) == 20);
+static_assert(__alignof__(struct guid_block) == 1);
+
+enum { /* wmi_block flags */
+ WMI_READ_TAKES_NO_ARGS,
+ WMI_GUID_DUPLICATED,
+ WMI_NO_EVENT_DATA,
+};
+
+struct wmi_block {
+ struct wmi_device dev;
+ struct guid_block gblock;
+ struct acpi_device *acpi_device;
+ struct rw_semaphore notify_lock; /* Protects notify callback add/remove */
+ wmi_notify_handler handler;
+ void *handler_data;
+ bool driver_ready;
+ unsigned long flags;
+};
+
+struct wmi_guid_count_context {
+ const guid_t *guid;
+ int count;
+};
+
+static DEFINE_IDA(wmi_ida);
+
+/*
+ * If the GUID data block is marked as expensive, we must enable and
+ * explicitily disable data collection.
+ */
+#define ACPI_WMI_EXPENSIVE BIT(0)
+#define ACPI_WMI_METHOD BIT(1) /* GUID is a method */
+#define ACPI_WMI_STRING BIT(2) /* GUID takes & returns a string */
+#define ACPI_WMI_EVENT BIT(3) /* GUID is an event */
+
+static const struct acpi_device_id wmi_device_ids[] = {
+ {"PNP0C14", 0},
+ {"pnp0c14", 0},
+ { }
+};
+MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
+
+#define dev_to_wblock(__dev) container_of_const(__dev, struct wmi_block, dev.dev)
+
+/*
+ * GUID parsing functions
+ */
+
+static bool guid_parse_and_compare(const char *string, const guid_t *guid)
+{
+ guid_t guid_input;
+
+ if (guid_parse(string, &guid_input))
+ return false;
+
+ return guid_equal(&guid_input, guid);
+}
+
+static const void *find_guid_context(struct wmi_block *wblock,
+ struct wmi_driver *wdriver)
+{
+ const struct wmi_device_id *id;
+
+ id = wdriver->id_table;
+ if (!id)
+ return NULL;
+
+ while (*id->guid_string) {
+ if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
+ return id->context;
+ id++;
+ }
+ return NULL;
+}
+
+#define WMI_ACPI_METHOD_NAME_SIZE 5
+
+static inline void get_acpi_method_name(const struct wmi_block *wblock,
+ const char method,
+ char buffer[static WMI_ACPI_METHOD_NAME_SIZE])
+{
+ static_assert(ARRAY_SIZE(wblock->gblock.object_id) == 2);
+ static_assert(WMI_ACPI_METHOD_NAME_SIZE >= 5);
+
+ buffer[0] = 'W';
+ buffer[1] = method;
+ buffer[2] = wblock->gblock.object_id[0];
+ buffer[3] = wblock->gblock.object_id[1];
+ buffer[4] = '\0';
+}
+
+static int wmidev_match_guid(struct device *dev, const void *data)
+{
+ struct wmi_block *wblock = dev_to_wblock(dev);
+ const guid_t *guid = data;
+
+ /* Legacy GUID-based functions are restricted to only see
+ * a single WMI device for each GUID.
+ */
+ if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags))
+ return 0;
+
+ if (guid_equal(guid, &wblock->gblock.guid))
+ return 1;
+
+ return 0;
+}
+
+static const struct bus_type wmi_bus_type;
+
+static const struct device_type wmi_type_event;
+
+static const struct device_type wmi_type_method;
+
+static int wmi_device_enable(struct wmi_device *wdev, bool enable)
+{
+ struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
+ char method[WMI_ACPI_METHOD_NAME_SIZE];
+ acpi_handle handle;
+ acpi_status status;
+
+ if (wblock->dev.dev.type == &wmi_type_method)
+ return 0;
+
+ if (wblock->dev.dev.type == &wmi_type_event) {
+ /*
+ * Windows always enables/disables WMI events, even when they are
+ * not marked as being expensive. We follow this behavior for
+ * compatibility reasons.
+ */
+ snprintf(method, sizeof(method), "WE%02X", wblock->gblock.notify_id);
+ } else {
+ if (!(wblock->gblock.flags & ACPI_WMI_EXPENSIVE))
+ return 0;
+
+ get_acpi_method_name(wblock, 'C', method);
+ }
+
+ /*
+ * Not all WMI devices marked as expensive actually implement the
+ * necessary ACPI method. Ignore this missing ACPI method to match
+ * the behaviour of the Windows driver.
+ */
+ status = acpi_get_handle(wblock->acpi_device->handle, method, &handle);
+ if (ACPI_FAILURE(status))
+ return 0;
+
+ status = acpi_execute_simple_method(handle, NULL, enable);
+ if (ACPI_FAILURE(status))
+ return -EIO;
+
+ return 0;
+}
+
+static struct wmi_device *wmi_find_device_by_guid(const char *guid_string)
+{
+ struct device *dev;
+ guid_t guid;
+ int ret;
+
+ ret = guid_parse(guid_string, &guid);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ dev = bus_find_device(&wmi_bus_type, NULL, &guid, wmidev_match_guid);
+ if (!dev)
+ return ERR_PTR(-ENODEV);
+
+ return to_wmi_device(dev);
+}
+
+static void wmi_device_put(struct wmi_device *wdev)
+{
+ put_device(&wdev->dev);
+}
+
+/*
+ * Exported WMI functions
+ */
+
+/**
+ * wmi_instance_count - Get number of WMI object instances
+ * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
+ *
+ * Get the number of WMI object instances.
+ *
+ * Returns: Number of WMI object instances or negative error code.
+ */
+int wmi_instance_count(const char *guid_string)
+{
+ struct wmi_device *wdev;
+ int ret;
+
+ wdev = wmi_find_device_by_guid(guid_string);
+ if (IS_ERR(wdev))
+ return PTR_ERR(wdev);
+
+ ret = wmidev_instance_count(wdev);
+ wmi_device_put(wdev);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(wmi_instance_count);
+
+/**
+ * wmidev_instance_count - Get number of WMI object instances
+ * @wdev: A wmi bus device from a driver
+ *
+ * Get the number of WMI object instances.
+ *
+ * Returns: Number of WMI object instances.
+ */
+u8 wmidev_instance_count(struct wmi_device *wdev)
+{
+ struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
+
+ return wblock->gblock.instance_count;
+}
+EXPORT_SYMBOL_GPL(wmidev_instance_count);
+
+/**
+ * wmi_evaluate_method - Evaluate a WMI method (deprecated)
+ * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
+ * @instance: Instance index
+ * @method_id: Method ID to call
+ * @in: Mandatory buffer containing input for the method call
+ * @out: Empty buffer to return the method results
+ *
+ * Call an ACPI-WMI method, the caller must free @out.
+ *
+ * Return: acpi_status signaling success or error.
+ */
+acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 method_id,
+ const struct acpi_buffer *in, struct acpi_buffer *out)
+{
+ struct wmi_device *wdev;
+ acpi_status status;
+
+ wdev = wmi_find_device_by_guid(guid_string);
+ if (IS_ERR(wdev))
+ return AE_ERROR;
+
+ status = wmidev_evaluate_method(wdev, instance, method_id, in, out);
+
+ wmi_device_put(wdev);
+
+ return status;
+}
+EXPORT_SYMBOL_GPL(wmi_evaluate_method);
+
+/**
+ * wmidev_evaluate_method - Evaluate a WMI method (deprecated)
+ * @wdev: A wmi bus device from a driver
+ * @instance: Instance index
+ * @method_id: Method ID to call
+ * @in: Mandatory buffer containing input for the method call
+ * @out: Empty buffer to return the method results
+ *
+ * Call an ACPI-WMI method, the caller must free @out.
+ *
+ * Return: acpi_status signaling success or error.
+ */
+acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 method_id,
+ const struct acpi_buffer *in, struct acpi_buffer *out)
+{
+ struct guid_block *block;
+ struct wmi_block *wblock;
+ acpi_handle handle;
+ struct acpi_object_list input;
+ union acpi_object params[3];
+ char method[WMI_ACPI_METHOD_NAME_SIZE];
+
+ wblock = container_of(wdev, struct wmi_block, dev);
+ block = &wblock->gblock;
+ handle = wblock->acpi_device->handle;
+
+ if (!in)
+ return AE_BAD_DATA;
+
+ if (!(block->flags & ACPI_WMI_METHOD))
+ return AE_BAD_DATA;
+
+ if (block->instance_count <= instance)
+ return AE_BAD_PARAMETER;
+
+ input.count = 3;
+ input.pointer = params;
+
+ params[0].type = ACPI_TYPE_INTEGER;
+ params[0].integer.value = instance;
+ params[1].type = ACPI_TYPE_INTEGER;
+ params[1].integer.value = method_id;
+
+ if (wblock->gblock.flags & ACPI_WMI_STRING) {
+ params[2].type = ACPI_TYPE_STRING;
+ params[2].string.length = in->length;
+ params[2].string.pointer = in->pointer;
+ } else {
+ params[2].type = ACPI_TYPE_BUFFER;
+ params[2].buffer.length = in->length;
+ params[2].buffer.pointer = in->pointer;
+ }
+
+ get_acpi_method_name(wblock, 'M', method);
+
+ return acpi_evaluate_object(handle, method, &input, out);
+}
+EXPORT_SYMBOL_GPL(wmidev_evaluate_method);
+
+/**
+ * wmidev_invoke_method - Invoke a WMI method that returns values
+ * @wdev: A wmi bus device from a driver
+ * @instance: Instance index
+ * @method_id: Method ID to call
+ * @in: Mandatory WMI buffer containing input for the method call
+ * @out: Mandatory WMI buffer to return the method results
+ * @min_size: Minimum size of the method result data in bytes
+ *
+ * Invoke a WMI method that returns values, the caller must free the resulting
+ * data inside @out using kfree(). Said data is guaranteed to be aligned on a
+ * 8-byte boundary. Use wmidev_invoke_procedure() for WMI methods that
+ * return no values.
+ *
+ * Return: 0 on success or negative error code on failure.
+ */
+int wmidev_invoke_method(struct wmi_device *wdev, u8 instance, u32 method_id,
+ const struct wmi_buffer *in, struct wmi_buffer *out, size_t min_size)
+{
+ struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
+ struct acpi_buffer aout = { ACPI_ALLOCATE_BUFFER, NULL };
+ struct acpi_buffer ain;
+ union acpi_object *obj;
+ acpi_status status;
+ int ret;
+
+ if (wblock->gblock.flags & ACPI_WMI_STRING) {
+ ret = wmi_marshal_string(in, &ain);
+ if (ret < 0)
+ return ret;
+ } else {
+ if (in->length > U32_MAX)
+ return -E2BIG;
+
+ ain.length = in->length;
+ ain.pointer = in->data;
+ }
+
+ status = wmidev_evaluate_method(wdev, instance, method_id, &ain, &aout);
+
+ if (wblock->gblock.flags & ACPI_WMI_STRING)
+ kfree(ain.pointer);
+
+ if (ACPI_FAILURE(status))
+ return -EIO;
+
+ obj = aout.pointer;
+ if (!obj) {
+ if (min_size != 0)
+ return -ENOMSG;
+
+ out->length = 0;
+ out->data = ZERO_SIZE_PTR;
+
+ return 0;
+ }
+
+ ret = wmi_unmarshal_acpi_object(obj, out, min_size);
+ kfree(obj);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(wmidev_invoke_method);
+
+/**
+ * wmidev_invoke_procedure - Invoke a WMI method that does not return values
+ * @wdev: A wmi bus device from a driver
+ * @instance: Instance index
+ * @method_id: Method ID to call
+ * @in: Mandatory WMI buffer containing input for the method call
+ *
+ * Invoke a WMI method that does not return any values. Use wmidev_invoke_method()
+ * for WMI methods that do return values.
+ *
+ * Return: 0 on success or negative error code on failure.
+ */
+int wmidev_invoke_procedure(struct wmi_device *wdev, u8 instance, u32 method_id,
+ const struct wmi_buffer *in)
+{
+ struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
+ struct acpi_buffer ain;
+ acpi_status status;
+ int ret;
+
+ if (wblock->gblock.flags & ACPI_WMI_STRING) {
+ ret = wmi_marshal_string(in, &ain);
+ if (ret < 0)
+ return ret;
+ } else {
+ if (in->length > U32_MAX)
+ return -E2BIG;
+
+ ain.length = in->length;
+ ain.pointer = in->data;
+ }
+
+ status = wmidev_evaluate_method(wdev, instance, method_id, &ain, NULL);
+
+ if (wblock->gblock.flags & ACPI_WMI_STRING)
+ kfree(ain.pointer);
+
+ if (ACPI_FAILURE(status))
+ return -EIO;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(wmidev_invoke_procedure);
+
+static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
+ struct acpi_buffer *out)
+{
+ struct guid_block *block;
+ acpi_handle handle;
+ struct acpi_object_list input;
+ union acpi_object wq_params[1];
+ char method[WMI_ACPI_METHOD_NAME_SIZE];
+
+ if (!out)
+ return AE_BAD_PARAMETER;
+
+ block = &wblock->gblock;
+ handle = wblock->acpi_device->handle;
+
+ if (block->instance_count <= instance)
+ return AE_BAD_PARAMETER;
+
+ /* Check GUID is a data block */
+ if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
+ return AE_ERROR;
+
+ input.count = 1;
+ input.pointer = wq_params;
+ wq_params[0].type = ACPI_TYPE_INTEGER;
+ wq_params[0].integer.value = instance;
+
+ if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags))
+ input.count = 0;
+
+ get_acpi_method_name(wblock, 'Q', method);
+
+ return acpi_evaluate_object(handle, method, &input, out);
+}
+
+/**
+ * wmi_query_block - Return contents of a WMI block (deprecated)
+ * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
+ * @instance: Instance index
+ * @out: Empty buffer to return the contents of the data block to
+ *
+ * Query a ACPI-WMI block, the caller must free @out.
+ *
+ * Return: ACPI object containing the content of the WMI block.
+ */
+acpi_status wmi_query_block(const char *guid_string, u8 instance,
+ struct acpi_buffer *out)
+{
+ struct wmi_block *wblock;
+ struct wmi_device *wdev;
+ acpi_status status;
+
+ wdev = wmi_find_device_by_guid(guid_string);
+ if (IS_ERR(wdev))
+ return AE_ERROR;
+
+ if (wmi_device_enable(wdev, true) < 0)
+ dev_warn(&wdev->dev, "Failed to enable device\n");
+
+ wblock = container_of(wdev, struct wmi_block, dev);
+ status = __query_block(wblock, instance, out);
+
+ if (wmi_device_enable(wdev, false) < 0)
+ dev_warn(&wdev->dev, "Failed to disable device\n");
+
+ wmi_device_put(wdev);
+
+ return status;
+}
+EXPORT_SYMBOL_GPL(wmi_query_block);
+
+/**
+ * wmidev_block_query - Return contents of a WMI block (deprectated)
+ * @wdev: A wmi bus device from a driver
+ * @instance: Instance index
+ *
+ * Query an ACPI-WMI block, the caller must free the result.
+ *
+ * Return: ACPI object containing the content of the WMI block.
+ */
+union acpi_object *wmidev_block_query(struct wmi_device *wdev, u8 instance)
+{
+ struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
+ struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
+
+ if (ACPI_FAILURE(__query_block(wblock, instance, &out)))
+ return NULL;
+
+ return out.pointer;
+}
+EXPORT_SYMBOL_GPL(wmidev_block_query);
+
+/**
+ * wmidev_query_block - Return contents of a WMI data block
+ * @wdev: A wmi bus device from a driver
+ * @instance: Instance index
+ * @out: WMI buffer to fill
+ * @min_size: Minimum size of the result data in bytes
+ *
+ * Query a WMI data block, the caller must free the resulting data inside @out
+ * using kfree(). Said data is guaranteed to be aligned on a 8-byte boundary.
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int wmidev_query_block(struct wmi_device *wdev, u8 instance, struct wmi_buffer *out,
+ size_t min_size)
+{
+ union acpi_object *obj;
+ int ret;
+
+ obj = wmidev_block_query(wdev, instance);
+ if (!obj)
+ return -EIO;
+
+ ret = wmi_unmarshal_acpi_object(obj, out, min_size);
+ kfree(obj);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(wmidev_query_block);
+
+/**
+ * wmi_set_block - Write to a WMI block (deprecated)
+ * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
+ * @instance: Instance index
+ * @in: Buffer containing new values for the data block
+ *
+ * Write the contents of the input buffer to an ACPI-WMI data block.
+ *
+ * Return: acpi_status signaling success or error.
+ */
+acpi_status wmi_set_block(const char *guid_string, u8 instance, const struct acpi_buffer *in)
+{
+ struct wmi_device *wdev;
+ acpi_status status;
+
+ wdev = wmi_find_device_by_guid(guid_string);
+ if (IS_ERR(wdev))
+ return AE_ERROR;
+
+ if (wmi_device_enable(wdev, true) < 0)
+ dev_warn(&wdev->dev, "Failed to enable device\n");
+
+ status = wmidev_block_set(wdev, instance, in);
+
+ if (wmi_device_enable(wdev, false) < 0)
+ dev_warn(&wdev->dev, "Failed to disable device\n");
+
+ wmi_device_put(wdev);
+
+ return status;
+}
+EXPORT_SYMBOL_GPL(wmi_set_block);
+
+/**
+ * wmidev_block_set - Write to a WMI block (deprecated)
+ * @wdev: A wmi bus device from a driver
+ * @instance: Instance index
+ * @in: Buffer containing new values for the data block
+ *
+ * Write contents of the input buffer to an ACPI-WMI data block.
+ *
+ * Return: acpi_status signaling success or error.
+ */
+acpi_status wmidev_block_set(struct wmi_device *wdev, u8 instance, const struct acpi_buffer *in)
+{
+ struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
+ acpi_handle handle = wblock->acpi_device->handle;
+ struct guid_block *block = &wblock->gblock;
+ char method[WMI_ACPI_METHOD_NAME_SIZE];
+ struct acpi_object_list input;
+ union acpi_object params[2];
+
+ if (!in)
+ return AE_BAD_DATA;
+
+ if (block->instance_count <= instance)
+ return AE_BAD_PARAMETER;
+
+ /* Check GUID is a data block */
+ if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD))
+ return AE_ERROR;
+
+ input.count = 2;
+ input.pointer = params;
+ params[0].type = ACPI_TYPE_INTEGER;
+ params[0].integer.value = instance;
+
+ if (wblock->gblock.flags & ACPI_WMI_STRING) {
+ params[1].type = ACPI_TYPE_STRING;
+ params[1].string.length = in->length;
+ params[1].string.pointer = in->pointer;
+ } else {
+ params[1].type = ACPI_TYPE_BUFFER;
+ params[1].buffer.length = in->length;
+ params[1].buffer.pointer = in->pointer;
+ }
+
+ get_acpi_method_name(wblock, 'S', method);
+
+ return acpi_evaluate_object(handle, method, &input, NULL);
+}
+EXPORT_SYMBOL_GPL(wmidev_block_set);
+
+/**
+ * wmidev_set_block - Write to a WMI data block
+ * @wdev: A wmi bus device from a driver
+ * @instance: Instance index
+ * @in: WMI buffer containing new values for the data block
+ *
+ * Write the content of @in into a WMI data block.
+ *
+ * Return: 0 on success or negative error code on failure.
+ */
+int wmidev_set_block(struct wmi_device *wdev, u8 instance, const struct wmi_buffer *in)
+{
+ struct wmi_block *wblock = container_of(wdev, struct wmi_block, dev);
+ struct acpi_buffer buffer;
+ acpi_status status;
+ int ret;
+
+ if (wblock->gblock.flags & ACPI_WMI_STRING) {
+ ret = wmi_marshal_string(in, &buffer);
+ if (ret < 0)
+ return ret;
+ } else {
+ if (in->length > U32_MAX)
+ return -E2BIG;
+
+ buffer.length = in->length;
+ buffer.pointer = in->data;
+ }
+
+ status = wmidev_block_set(wdev, instance, &buffer);
+ if (wblock->gblock.flags & ACPI_WMI_STRING)
+ kfree(buffer.pointer);
+
+ if (ACPI_FAILURE(status))
+ return -EIO;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(wmidev_set_block);
+
+/**
+ * wmi_install_notify_handler - Register handler for WMI events (deprecated)
+ * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
+ * @handler: Function to handle notifications
+ * @data: Data to be returned to handler when event is fired
+ *
+ * Register a handler for events sent to the ACPI-WMI mapper device.
+ *
+ * Return: acpi_status signaling success or error.
+ */
+acpi_status wmi_install_notify_handler(const char *guid,
+ wmi_notify_handler handler,
+ void *data)
+{
+ struct wmi_block *wblock;
+ struct wmi_device *wdev;
+ acpi_status status;
+
+ wdev = wmi_find_device_by_guid(guid);
+ if (IS_ERR(wdev))
+ return AE_ERROR;
+
+ wblock = container_of(wdev, struct wmi_block, dev);
+
+ down_write(&wblock->notify_lock);
+ if (wblock->handler) {
+ status = AE_ALREADY_ACQUIRED;
+ } else {
+ wblock->handler = handler;
+ wblock->handler_data = data;
+
+ if (wmi_device_enable(wdev, true) < 0)
+ dev_warn(&wblock->dev.dev, "Failed to enable device\n");
+
+ status = AE_OK;
+ }
+ up_write(&wblock->notify_lock);
+
+ wmi_device_put(wdev);
+
+ return status;
+}
+EXPORT_SYMBOL_GPL(wmi_install_notify_handler);
+
+/**
+ * wmi_remove_notify_handler - Unregister handler for WMI events (deprecated)
+ * @guid: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
+ *
+ * Unregister handler for events sent to the ACPI-WMI mapper device.
+ *
+ * Return: acpi_status signaling success or error.
+ */
+acpi_status wmi_remove_notify_handler(const char *guid)
+{
+ struct wmi_block *wblock;
+ struct wmi_device *wdev;
+ acpi_status status;
+
+ wdev = wmi_find_device_by_guid(guid);
+ if (IS_ERR(wdev))
+ return AE_ERROR;
+
+ wblock = container_of(wdev, struct wmi_block, dev);
+
+ down_write(&wblock->notify_lock);
+ if (!wblock->handler) {
+ status = AE_NULL_ENTRY;
+ } else {
+ if (wmi_device_enable(wdev, false) < 0)
+ dev_warn(&wblock->dev.dev, "Failed to disable device\n");
+
+ wblock->handler = NULL;
+ wblock->handler_data = NULL;
+
+ status = AE_OK;
+ }
+ up_write(&wblock->notify_lock);
+
+ wmi_device_put(wdev);
+
+ return status;
+}
+EXPORT_SYMBOL_GPL(wmi_remove_notify_handler);
+
+/**
+ * wmi_has_guid - Check if a GUID is available
+ * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
+ *
+ * Check if a given GUID is defined by _WDG.
+ *
+ * Return: True if GUID is available, false otherwise.
+ */
+bool wmi_has_guid(const char *guid_string)
+{
+ struct wmi_device *wdev;
+
+ wdev = wmi_find_device_by_guid(guid_string);
+ if (IS_ERR(wdev))
+ return false;
+
+ wmi_device_put(wdev);
+
+ return true;
+}
+EXPORT_SYMBOL_GPL(wmi_has_guid);
+
+/**
+ * wmi_get_acpi_device_uid() - Get _UID name of ACPI device that defines GUID (deprecated)
+ * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
+ *
+ * Find the _UID of ACPI device associated with this WMI GUID.
+ *
+ * Return: The ACPI _UID field value or NULL if the WMI GUID was not found.
+ */
+char *wmi_get_acpi_device_uid(const char *guid_string)
+{
+ struct wmi_block *wblock;
+ struct wmi_device *wdev;
+ char *uid;
+
+ wdev = wmi_find_device_by_guid(guid_string);
+ if (IS_ERR(wdev))
+ return NULL;
+
+ wblock = container_of(wdev, struct wmi_block, dev);
+ uid = acpi_device_uid(wblock->acpi_device);
+
+ wmi_device_put(wdev);
+
+ return uid;
+}
+EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid);
+
+/*
+ * sysfs interface
+ */
+static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct wmi_block *wblock = dev_to_wblock(dev);
+
+ return sysfs_emit(buf, "wmi:%pUL\n", &wblock->gblock.guid);
+}
+
+static const DEVICE_ATTR_RO(modalias);
+
+static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct wmi_block *wblock = dev_to_wblock(dev);
+
+ return sysfs_emit(buf, "%pUL\n", &wblock->gblock.guid);
+}
+
+static const DEVICE_ATTR_RO(guid);
+
+static ssize_t instance_count_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct wmi_block *wblock = dev_to_wblock(dev);
+
+ return sysfs_emit(buf, "%d\n", (int)wblock->gblock.instance_count);
+}
+
+static const DEVICE_ATTR_RO(instance_count);
+
+static ssize_t expensive_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct wmi_block *wblock = dev_to_wblock(dev);
+
+ return sysfs_emit(buf, "%d\n",
+ (wblock->gblock.flags & ACPI_WMI_EXPENSIVE) != 0);
+}
+
+static const DEVICE_ATTR_RO(expensive);
+
+static const struct attribute * const wmi_attrs[] = {
+ &dev_attr_modalias.attr,
+ &dev_attr_guid.attr,
+ &dev_attr_instance_count.attr,
+ &dev_attr_expensive.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(wmi);
+
+static ssize_t notify_id_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct wmi_block *wblock = dev_to_wblock(dev);
+
+ return sysfs_emit(buf, "%02X\n", (unsigned int)wblock->gblock.notify_id);
+}
+
+static const DEVICE_ATTR_RO(notify_id);
+
+static const struct attribute * const wmi_event_attrs[] = {
+ &dev_attr_notify_id.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(wmi_event);
+
+static ssize_t object_id_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct wmi_block *wblock = dev_to_wblock(dev);
+
+ return sysfs_emit(buf, "%c%c\n", wblock->gblock.object_id[0],
+ wblock->gblock.object_id[1]);
+}
+
+static const DEVICE_ATTR_RO(object_id);
+
+static ssize_t setable_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct wmi_device *wdev = to_wmi_device(dev);
+
+ return sysfs_emit(buf, "%d\n", (int)wdev->setable);
+}
+
+static const DEVICE_ATTR_RO(setable);
+
+static const struct attribute * const wmi_data_attrs[] = {
+ &dev_attr_object_id.attr,
+ &dev_attr_setable.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(wmi_data);
+
+static const struct attribute * const wmi_method_attrs[] = {
+ &dev_attr_object_id.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(wmi_method);
+
+static int wmi_dev_uevent(const struct device *dev, struct kobj_uevent_env *env)
+{
+ const struct wmi_block *wblock = dev_to_wblock(dev);
+
+ if (add_uevent_var(env, "MODALIAS=wmi:%pUL", &wblock->gblock.guid))
+ return -ENOMEM;
+
+ if (add_uevent_var(env, "WMI_GUID=%pUL", &wblock->gblock.guid))
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void wmi_dev_release(struct device *dev)
+{
+ struct wmi_block *wblock = dev_to_wblock(dev);
+
+ kfree(wblock);
+}
+
+static int wmi_dev_match(struct device *dev, const struct device_driver *driver)
+{
+ const struct wmi_driver *wmi_driver = to_wmi_driver(driver);
+ struct wmi_block *wblock = dev_to_wblock(dev);
+ const struct wmi_device_id *id = wmi_driver->id_table;
+ int ret;
+
+ /* When driver_override is set, only bind to the matching driver */
+ ret = device_match_driver_override(dev, driver);
+ if (ret >= 0)
+ return ret;
+
+ if (id == NULL)
+ return 0;
+
+ while (*id->guid_string) {
+ if (guid_parse_and_compare(id->guid_string, &wblock->gblock.guid))
+ return 1;
+
+ id++;
+ }
+
+ return 0;
+}
+
+static void wmi_dev_disable(void *data)
+{
+ struct device *dev = data;
+
+ if (wmi_device_enable(to_wmi_device(dev), false) < 0)
+ dev_warn(dev, "Failed to disable device\n");
+}
+
+static int wmi_dev_probe(struct device *dev)
+{
+ struct wmi_block *wblock = dev_to_wblock(dev);
+ struct wmi_driver *wdriver = to_wmi_driver(dev->driver);
+ int ret;
+
+ /* Some older WMI drivers will break if instantiated multiple times,
+ * so they are blocked from probing WMI devices with a duplicated GUID.
+ *
+ * New WMI drivers should support being instantiated multiple times.
+ */
+ if (test_bit(WMI_GUID_DUPLICATED, &wblock->flags) && !wdriver->no_singleton) {
+ dev_warn(dev, "Legacy driver %s cannot be instantiated multiple times\n",
+ dev->driver->name);
+
+ return -ENODEV;
+ }
+
+ if (wdriver->notify || wdriver->notify_new) {
+ if (test_bit(WMI_NO_EVENT_DATA, &wblock->flags) && wdriver->min_event_size)
+ return -ENODEV;
+ }
+
+ if (wmi_device_enable(to_wmi_device(dev), true) < 0)
+ dev_warn(dev, "failed to enable device -- probing anyway\n");
+
+ /*
+ * We have to make sure that all devres-managed resources are released first because
+ * some might still want to access the underlying WMI device.
+ */
+ ret = devm_add_action_or_reset(dev, wmi_dev_disable, dev);
+ if (ret < 0)
+ return ret;
+
+ if (wdriver->probe) {
+ ret = wdriver->probe(to_wmi_device(dev),
+ find_guid_context(wblock, wdriver));
+ if (ret)
+ return ret;
+ }
+
+ down_write(&wblock->notify_lock);
+ wblock->driver_ready = true;
+ up_write(&wblock->notify_lock);
+
+ return 0;
+}
+
+static void wmi_dev_remove(struct device *dev)
+{
+ struct wmi_block *wblock = dev_to_wblock(dev);
+ struct wmi_driver *wdriver = to_wmi_driver(dev->driver);
+
+ down_write(&wblock->notify_lock);
+ wblock->driver_ready = false;
+ up_write(&wblock->notify_lock);
+
+ if (wdriver->remove)
+ wdriver->remove(to_wmi_device(dev));
+}
+
+static void wmi_dev_shutdown(struct device *dev)
+{
+ struct wmi_driver *wdriver;
+ struct wmi_block *wblock;
+
+ if (dev->driver) {
+ wdriver = to_wmi_driver(dev->driver);
+ wblock = dev_to_wblock(dev);
+
+ /*
+ * Some machines return bogus WMI event data when disabling
+ * the WMI event. Because of this we must prevent the associated
+ * WMI driver from receiving new WMI events before disabling it.
+ */
+ down_write(&wblock->notify_lock);
+ wblock->driver_ready = false;
+ up_write(&wblock->notify_lock);
+
+ if (wdriver->shutdown)
+ wdriver->shutdown(to_wmi_device(dev));
+
+ /*
+ * We still need to disable the WMI device here since devres-managed resources
+ * like wmi_dev_disable() will not be release during shutdown.
+ */
+ if (wmi_device_enable(to_wmi_device(dev), false) < 0)
+ dev_warn(dev, "Failed to disable device\n");
+ }
+}
+
+static const struct class wmi_bus_class = {
+ .name = "wmi_bus",
+};
+
+static const struct bus_type wmi_bus_type = {
+ .name = "wmi",
+ .dev_groups = wmi_groups,
+ .driver_override = true,
+ .match = wmi_dev_match,
+ .uevent = wmi_dev_uevent,
+ .probe = wmi_dev_probe,
+ .remove = wmi_dev_remove,
+ .shutdown = wmi_dev_shutdown,
+};
+
+static const struct device_type wmi_type_event = {
+ .name = "event",
+ .groups = wmi_event_groups,
+ .release = wmi_dev_release,
+};
+
+static const struct device_type wmi_type_method = {
+ .name = "method",
+ .groups = wmi_method_groups,
+ .release = wmi_dev_release,
+};
+
+static const struct device_type wmi_type_data = {
+ .name = "data",
+ .groups = wmi_data_groups,
+ .release = wmi_dev_release,
+};
+
+static int wmi_count_guids(struct device *dev, void *data)
+{
+ struct wmi_guid_count_context *context = data;
+ struct wmi_block *wblock = dev_to_wblock(dev);
+
+ if (guid_equal(&wblock->gblock.guid, context->guid))
+ context->count++;
+
+ return 0;
+}
+
+static int guid_count(const guid_t *guid)
+{
+ struct wmi_guid_count_context context = {
+ .guid = guid,
+ .count = 0,
+ };
+ int ret;
+
+ ret = bus_for_each_dev(&wmi_bus_type, NULL, &context, wmi_count_guids);
+ if (ret < 0)
+ return ret;
+
+ return context.count;
+}
+
+static int wmi_dev_set_name(struct wmi_block *wblock, int count)
+{
+ if (IS_ENABLED(CONFIG_ACPI_WMI_LEGACY_DEVICE_NAMES)) {
+ if (count)
+ return dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid,
+ count);
+ else
+ return dev_set_name(&wblock->dev.dev, "%pUL", &wblock->gblock.guid);
+ }
+
+ return dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, wblock->dev.dev.id);
+}
+
+static int wmi_create_device(struct device *wmi_bus_dev,
+ struct wmi_block *wblock,
+ struct acpi_device *device)
+{
+ char method[WMI_ACPI_METHOD_NAME_SIZE];
+ struct acpi_device_info *info;
+ acpi_handle method_handle;
+ acpi_status status;
+ int count, ret;
+
+ if (wblock->gblock.flags & ACPI_WMI_EVENT) {
+ wblock->dev.dev.type = &wmi_type_event;
+ goto out_init;
+ }
+
+ if (wblock->gblock.flags & ACPI_WMI_METHOD) {
+ get_acpi_method_name(wblock, 'M', method);
+ if (!acpi_has_method(device->handle, method)) {
+ dev_warn(wmi_bus_dev,
+ FW_BUG "%s method block execution control method not found\n",
+ method);
+
+ return -ENXIO;
+ }
+
+ wblock->dev.dev.type = &wmi_type_method;
+ goto out_init;
+ }
+
+ /*
+ * Data Block Query Control Method (WQxx by convention) is
+ * required per the WMI documentation. If it is not present,
+ * we ignore this data block.
+ */
+ get_acpi_method_name(wblock, 'Q', method);
+ status = acpi_get_handle(device->handle, method, &method_handle);
+ if (ACPI_FAILURE(status)) {
+ dev_warn(wmi_bus_dev,
+ FW_BUG "%s data block query control method not found\n",
+ method);
+
+ return -ENXIO;
+ }
+
+ status = acpi_get_object_info(method_handle, &info);
+ if (ACPI_FAILURE(status))
+ return -EIO;
+
+ wblock->dev.dev.type = &wmi_type_data;
+
+ /*
+ * The Microsoft documentation specifically states:
+ *
+ * Data blocks registered with only a single instance
+ * can ignore the parameter.
+ *
+ * ACPICA will get mad at us if we call the method with the wrong number
+ * of arguments, so check what our method expects. (On some Dell
+ * laptops, WQxx may not be a method at all.)
+ */
+ if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
+ set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
+
+ kfree(info);
+
+ get_acpi_method_name(wblock, 'S', method);
+ if (acpi_has_method(device->handle, method))
+ wblock->dev.setable = true;
+
+ out_init:
+ init_rwsem(&wblock->notify_lock);
+ wblock->driver_ready = false;
+ wblock->dev.dev.bus = &wmi_bus_type;
+ wblock->dev.dev.parent = wmi_bus_dev;
+
+ count = guid_count(&wblock->gblock.guid);
+ if (count < 0)
+ return count;
+
+ if (count)
+ set_bit(WMI_GUID_DUPLICATED, &wblock->flags);
+
+ ret = ida_alloc(&wmi_ida, GFP_KERNEL);
+ if (ret < 0)
+ return ret;
+
+ wblock->dev.dev.id = ret;
+ ret = wmi_dev_set_name(wblock, count);
+ if (ret < 0) {
+ ida_free(&wmi_ida, wblock->dev.dev.id);
+ return ret;
+ }
+
+ device_initialize(&wblock->dev.dev);
+
+ return 0;
+}
+
+static int wmi_add_device(struct platform_device *pdev, struct wmi_device *wdev)
+{
+ struct device_link *link;
+
+ /*
+ * Many aggregate WMI drivers do not use -EPROBE_DEFER when they
+ * are unable to find a WMI device during probe, instead they require
+ * all WMI devices associated with an platform device to become available
+ * at once. This device link thus prevents WMI drivers from probing until
+ * the associated platform device has finished probing (and has registered
+ * all discovered WMI devices).
+ */
+
+ link = device_link_add(&wdev->dev, &pdev->dev, DL_FLAG_AUTOREMOVE_SUPPLIER);
+ if (!link)
+ return -EINVAL;
+
+ return device_add(&wdev->dev);
+}
+
+/*
+ * Parse the _WDG method for the GUID data blocks
+ */
+static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
+{
+ struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
+ struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
+ const struct guid_block *gblock;
+ bool event_data_available;
+ struct wmi_block *wblock;
+ union acpi_object *obj;
+ acpi_status status;
+ u32 i, total;
+ int retval;
+
+ status = acpi_evaluate_object(device->handle, "_WDG", NULL, &out);
+ if (ACPI_FAILURE(status))
+ return -ENXIO;
+
+ obj = out.pointer;
+ if (!obj)
+ return -ENXIO;
+
+ if (obj->type != ACPI_TYPE_BUFFER) {
+ kfree(obj);
+ return -ENXIO;
+ }
+
+ event_data_available = acpi_has_method(device->handle, "_WED");
+ gblock = (const struct guid_block *)obj->buffer.pointer;
+ total = obj->buffer.length / sizeof(struct guid_block);
+
+ for (i = 0; i < total; i++) {
+ if (!gblock[i].instance_count) {
+ dev_info(wmi_bus_dev, FW_INFO "%pUL has zero instances\n", &gblock[i].guid);
+ continue;
+ }
+
+ wblock = kzalloc_obj(*wblock);
+ if (!wblock)
+ continue;
+
+ wblock->acpi_device = device;
+ wblock->gblock = gblock[i];
+ if (gblock[i].flags & ACPI_WMI_EVENT && !event_data_available)
+ set_bit(WMI_NO_EVENT_DATA, &wblock->flags);
+
+ retval = wmi_create_device(wmi_bus_dev, wblock, device);
+ if (retval) {
+ kfree(wblock);
+ continue;
+ }
+
+ retval = wmi_add_device(pdev, &wblock->dev);
+ if (retval) {
+ dev_err(wmi_bus_dev, "failed to register %pUL\n",
+ &wblock->gblock.guid);
+
+ ida_free(&wmi_ida, wblock->dev.dev.id);
+ put_device(&wblock->dev.dev);
+ }
+ }
+
+ kfree(obj);
+
+ return 0;
+}
+
+static int wmi_get_notify_data(struct wmi_block *wblock, union acpi_object **obj)
+{
+ struct acpi_buffer data = { ACPI_ALLOCATE_BUFFER, NULL };
+ union acpi_object param = {
+ .integer = {
+ .type = ACPI_TYPE_INTEGER,
+ .value = wblock->gblock.notify_id,
+ }
+ };
+ struct acpi_object_list input = {
+ .count = 1,
+ .pointer = &param,
+ };
+ acpi_status status;
+
+ status = acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, &data);
+ if (ACPI_FAILURE(status)) {
+ dev_warn(&wblock->dev.dev, "Failed to get event data\n");
+ return -EIO;
+ }
+
+ *obj = data.pointer;
+
+ return 0;
+}
+
+static void wmi_notify_driver(struct wmi_block *wblock, union acpi_object *obj)
+{
+ struct wmi_driver *driver = to_wmi_driver(wblock->dev.dev.driver);
+ struct wmi_buffer dummy = {
+ .length = 0,
+ .data = ZERO_SIZE_PTR,
+ };
+ struct wmi_buffer buffer;
+ int ret;
+
+ if (!obj && driver->min_event_size) {
+ dev_warn(&wblock->dev.dev, "Event contains no event data\n");
+ return;
+ }
+
+ if (driver->notify)
+ driver->notify(&wblock->dev, obj);
+
+ if (driver->notify_new) {
+ if (!obj) {
+ driver->notify_new(&wblock->dev, &dummy);
+ return;
+ }
+
+ ret = wmi_unmarshal_acpi_object(obj, &buffer, driver->min_event_size);
+ if (ret < 0) {
+ dev_warn(&wblock->dev.dev, "Failed to unmarshal event data: %d\n", ret);
+ return;
+ }
+
+ driver->notify_new(&wblock->dev, &buffer);
+ kfree(buffer.data);
+ }
+}
+
+static int wmi_notify_device(struct device *dev, void *data)
+{
+ struct wmi_block *wblock = dev_to_wblock(dev);
+ union acpi_object *obj = NULL;
+ u32 *event = data;
+ int ret;
+
+ if (!(wblock->gblock.flags & ACPI_WMI_EVENT && wblock->gblock.notify_id == *event))
+ return 0;
+
+ /* The ACPI WMI specification says that _WED should be
+ * evaluated every time an notification is received, even
+ * if no consumers are present.
+ *
+ * Some firmware implementations actually depend on this
+ * by using a queue for events which will fill up if the
+ * WMI driver core stops evaluating _WED due to missing
+ * WMI event consumers.
+ */
+ if (!test_bit(WMI_NO_EVENT_DATA, &wblock->flags)) {
+ ret = wmi_get_notify_data(wblock, &obj);
+ if (ret < 0)
+ return -EIO;
+ }
+
+ down_read(&wblock->notify_lock);
+
+ if (wblock->dev.dev.driver && wblock->driver_ready)
+ wmi_notify_driver(wblock, obj);
+
+ if (wblock->handler)
+ wblock->handler(obj, wblock->handler_data);
+
+ up_read(&wblock->notify_lock);
+
+ kfree(obj);
+
+ acpi_bus_generate_netlink_event("wmi", acpi_dev_name(wblock->acpi_device), *event, 0);
+
+ return -EBUSY;
+}
+
+static void acpi_wmi_notify_handler(acpi_handle handle, u32 event, void *context)
+{
+ struct device *wmi_bus_dev = context;
+
+ device_for_each_child(wmi_bus_dev, &event, wmi_notify_device);
+}
+
+static int wmi_remove_device(struct device *dev, void *data)
+{
+ int id = dev->id;
+
+ device_unregister(dev);
+ ida_free(&wmi_ida, id);
+
+ return 0;
+}
+
+static void acpi_wmi_remove(struct platform_device *device)
+{
+ struct device *wmi_bus_device = dev_get_drvdata(&device->dev);
+
+ device_for_each_child_reverse(wmi_bus_device, NULL, wmi_remove_device);
+}
+
+static void acpi_wmi_remove_notify_handler(void *data)
+{
+ struct acpi_device *acpi_device = data;
+
+ acpi_remove_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY, acpi_wmi_notify_handler);
+}
+
+static void acpi_wmi_remove_bus_device(void *data)
+{
+ struct device *wmi_bus_dev = data;
+
+ device_unregister(wmi_bus_dev);
+}
+
+static int acpi_wmi_probe(struct platform_device *device)
+{
+ struct acpi_device *acpi_device;
+ struct device *wmi_bus_dev;
+ acpi_status status;
+ int error;
+
+ acpi_device = ACPI_COMPANION(&device->dev);
+ if (!acpi_device) {
+ dev_err(&device->dev, "ACPI companion is missing\n");
+ return -ENODEV;
+ }
+
+ wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0), NULL, "wmi_bus-%s",
+ dev_name(&device->dev));
+ if (IS_ERR(wmi_bus_dev))
+ return PTR_ERR(wmi_bus_dev);
+
+ error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_bus_device, wmi_bus_dev);
+ if (error < 0)
+ return error;
+
+ dev_set_drvdata(&device->dev, wmi_bus_dev);
+
+ status = acpi_install_notify_handler(acpi_device->handle, ACPI_ALL_NOTIFY,
+ acpi_wmi_notify_handler, wmi_bus_dev);
+ if (ACPI_FAILURE(status)) {
+ dev_err(&device->dev, "Error installing notify handler\n");
+ return -ENODEV;
+ }
+ error = devm_add_action_or_reset(&device->dev, acpi_wmi_remove_notify_handler,
+ acpi_device);
+ if (error < 0)
+ return error;
+
+ error = parse_wdg(wmi_bus_dev, device);
+ if (error) {
+ dev_err(&device->dev, "Failed to parse _WDG method\n");
+ return error;
+ }
+
+ return 0;
+}
+
+int __must_check __wmi_driver_register(struct wmi_driver *driver,
+ struct module *owner)
+{
+ driver->driver.owner = owner;
+ driver->driver.bus = &wmi_bus_type;
+
+ return driver_register(&driver->driver);
+}
+EXPORT_SYMBOL(__wmi_driver_register);
+
+/**
+ * wmi_driver_unregister() - Unregister a WMI driver
+ * @driver: WMI driver to unregister
+ *
+ * Unregisters a WMI driver from the WMI bus.
+ */
+void wmi_driver_unregister(struct wmi_driver *driver)
+{
+ driver_unregister(&driver->driver);
+}
+EXPORT_SYMBOL(wmi_driver_unregister);
+
+static struct platform_driver acpi_wmi_driver = {
+ .driver = {
+ .name = "acpi-wmi",
+ .acpi_match_table = wmi_device_ids,
+ },
+ .probe = acpi_wmi_probe,
+ .remove = acpi_wmi_remove,
+};
+
+static int __init acpi_wmi_init(void)
+{
+ int error;
+
+ if (acpi_disabled)
+ return -ENODEV;
+
+ error = class_register(&wmi_bus_class);
+ if (error)
+ return error;
+
+ error = bus_register(&wmi_bus_type);
+ if (error)
+ goto err_unreg_class;
+
+ error = platform_driver_register(&acpi_wmi_driver);
+ if (error) {
+ pr_err("Error loading mapper\n");
+ goto err_unreg_bus;
+ }
+
+ return 0;
+
+err_unreg_bus:
+ bus_unregister(&wmi_bus_type);
+
+err_unreg_class:
+ class_unregister(&wmi_bus_class);
+
+ return error;
+}
+
+static void __exit acpi_wmi_exit(void)
+{
+ platform_driver_unregister(&acpi_wmi_driver);
+ bus_unregister(&wmi_bus_type);
+ class_unregister(&wmi_bus_class);
+}
+
+subsys_initcall_sync(acpi_wmi_init);
+module_exit(acpi_wmi_exit);
diff --git a/drivers/platform/wmi/internal.h b/drivers/platform/wmi/internal.h
new file mode 100644
index 000000000..c02908694
--- /dev/null
+++ b/drivers/platform/wmi/internal.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Internal interfaces used by the WMI core.
+ *
+ * Copyright (C) 2025 Armin Wolf <W_Armin@gmx.de>
+ */
+
+#ifndef _WMI_INTERNAL_H_
+#define _WMI_INTERNAL_H_
+
+union acpi_object;
+struct wmi_buffer;
+
+int wmi_unmarshal_acpi_object(const union acpi_object *obj, struct wmi_buffer *buffer,
+ size_t min_size);
+int wmi_marshal_string(const struct wmi_buffer *buffer, struct acpi_buffer *out);
+
+#endif /* _WMI_INTERNAL_H_ */
diff --git a/drivers/platform/wmi/marshalling.c b/drivers/platform/wmi/marshalling.c
new file mode 100644
index 000000000..870918325
--- /dev/null
+++ b/drivers/platform/wmi/marshalling.c
@@ -0,0 +1,251 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ACPI-WMI buffer marshalling.
+ *
+ * Copyright (C) 2025 Armin Wolf <W_Armin@gmx.de>
+ */
+
+#include <linux/acpi.h>
+#include <linux/align.h>
+#include <linux/math.h>
+#include <linux/overflow.h>
+#include <linux/slab.h>
+#include <linux/unaligned.h>
+#include <linux/wmi.h>
+
+#include <kunit/visibility.h>
+
+#include "internal.h"
+
+static int wmi_adjust_buffer_length(size_t *length, const union acpi_object *obj)
+{
+ size_t alignment, size;
+
+ switch (obj->type) {
+ case ACPI_TYPE_INTEGER:
+ /*
+ * Integers are threated as 32 bit even if the ACPI DSDT
+ * declares 64 bit integer width.
+ */
+ alignment = 4;
+ size = sizeof(u32);
+ break;
+ case ACPI_TYPE_STRING:
+ /*
+ * Strings begin with a single little-endian 16-bit field containing
+ * the string length in bytes and are encoded as UTF-16LE with a terminating
+ * nul character.
+ */
+ if (obj->string.length + 1 > U16_MAX / 2)
+ return -EOVERFLOW;
+
+ alignment = 2;
+ size = struct_size_t(struct wmi_string, chars, obj->string.length + 1);
+ break;
+ case ACPI_TYPE_BUFFER:
+ /*
+ * Buffers are copied as-is.
+ */
+ alignment = 1;
+ size = obj->buffer.length;
+ break;
+ default:
+ return -EPROTO;
+ }
+
+ *length = size_add(ALIGN(*length, alignment), size);
+
+ return 0;
+}
+
+static int wmi_obj_get_buffer_length(const union acpi_object *obj, size_t *length)
+{
+ size_t total = 0;
+ int ret;
+
+ if (obj->type == ACPI_TYPE_PACKAGE) {
+ for (int i = 0; i < obj->package.count; i++) {
+ ret = wmi_adjust_buffer_length(&total, &obj->package.elements[i]);
+ if (ret < 0)
+ return ret;
+ }
+ } else {
+ ret = wmi_adjust_buffer_length(&total, obj);
+ if (ret < 0)
+ return ret;
+ }
+
+ *length = total;
+
+ return 0;
+}
+
+static int wmi_obj_transform_simple(const union acpi_object *obj, u8 *buffer, size_t *consumed)
+{
+ struct wmi_string *string;
+ size_t length;
+ __le32 value;
+ u8 *aligned;
+
+ switch (obj->type) {
+ case ACPI_TYPE_INTEGER:
+ aligned = PTR_ALIGN(buffer, 4);
+ length = sizeof(value);
+
+ value = cpu_to_le32(obj->integer.value);
+ memcpy(aligned, &value, length);
+ break;
+ case ACPI_TYPE_STRING:
+ aligned = PTR_ALIGN(buffer, 2);
+ string = (struct wmi_string *)aligned;
+ length = struct_size(string, chars, obj->string.length + 1);
+
+ /* We do not have to worry about unaligned accesses here as the WMI
+ * string will already be aligned on a two-byte boundary.
+ */
+ string->length = cpu_to_le16((obj->string.length + 1) * 2);
+ for (int i = 0; i < obj->string.length; i++)
+ string->chars[i] = cpu_to_le16(obj->string.pointer[i]);
+
+ /*
+ * The Windows WMI-ACPI driver always emits a terminating nul character,
+ * so we emulate this behavior here as well.
+ */
+ string->chars[obj->string.length] = '\0';
+ break;
+ case ACPI_TYPE_BUFFER:
+ aligned = buffer;
+ length = obj->buffer.length;
+
+ memcpy(aligned, obj->buffer.pointer, length);
+ break;
+ default:
+ return -EPROTO;
+ }
+
+ *consumed = (aligned - buffer) + length;
+
+ return 0;
+}
+
+static int wmi_obj_transform(const union acpi_object *obj, u8 *buffer)
+{
+ size_t consumed;
+ int ret;
+
+ if (obj->type == ACPI_TYPE_PACKAGE) {
+ for (int i = 0; i < obj->package.count; i++) {
+ ret = wmi_obj_transform_simple(&obj->package.elements[i], buffer,
+ &consumed);
+ if (ret < 0)
+ return ret;
+
+ buffer += consumed;
+ }
+ } else {
+ ret = wmi_obj_transform_simple(obj, buffer, &consumed);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+int wmi_unmarshal_acpi_object(const union acpi_object *obj, struct wmi_buffer *buffer,
+ size_t min_size)
+{
+ size_t length, alloc_length;
+ u8 *data;
+ int ret;
+
+ ret = wmi_obj_get_buffer_length(obj, &length);
+ if (ret < 0)
+ return ret;
+
+ if (length < min_size)
+ return -ENODATA;
+
+ if (ARCH_KMALLOC_MINALIGN < 8) {
+ /*
+ * kmalloc() guarantees that the alignment of the resulting memory allocation is at
+ * least the largest power-of-two divisor of the allocation size. The WMI buffer
+ * data needs to be aligned on a 8 byte boundary to properly support 64-bit WMI
+ * integers, so we have to round the allocation size to the next multiple of 8.
+ */
+ alloc_length = round_up(length, 8);
+ } else {
+ alloc_length = length;
+ }
+
+ data = kzalloc(alloc_length, GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ ret = wmi_obj_transform(obj, data);
+ if (ret < 0) {
+ kfree(data);
+ return ret;
+ }
+
+ buffer->length = length;
+ buffer->data = data;
+
+ return 0;
+}
+EXPORT_SYMBOL_IF_KUNIT(wmi_unmarshal_acpi_object);
+
+int wmi_marshal_string(const struct wmi_buffer *buffer, struct acpi_buffer *out)
+{
+ const struct wmi_string *string;
+ u16 length, value;
+ size_t chars;
+ char *str;
+
+ if (buffer->length < sizeof(*string))
+ return -ENODATA;
+
+ string = buffer->data;
+ length = get_unaligned_le16(&string->length);
+ if (buffer->length < sizeof(*string) + length)
+ return -ENODATA;
+
+ /* Each character needs to be 16 bits long */
+ if (length % 2)
+ return -EINVAL;
+
+ chars = length / 2;
+ str = kmalloc(chars + 1, GFP_KERNEL);
+ if (!str)
+ return -ENOMEM;
+
+ for (int i = 0; i < chars; i++) {
+ value = get_unaligned_le16(&string->chars[i]);
+
+ /* ACPI only accepts ASCII strings */
+ if (value > 0x7F) {
+ kfree(str);
+ return -EINVAL;
+ }
+
+ str[i] = value & 0xFF;
+
+ /*
+ * ACPI strings should only contain a single nul character at the end.
+ * Because of this we must not copy any padding from the WMI string.
+ */
+ if (!value) {
+ /* ACPICA wants the length of the string without the nul character */
+ out->length = i;
+ out->pointer = str;
+ return 0;
+ }
+ }
+
+ str[chars] = '\0';
+
+ out->length = chars;
+ out->pointer = str;
+
+ return 0;
+}
+EXPORT_SYMBOL_IF_KUNIT(wmi_marshal_string);
diff --git a/drivers/platform/wmi/string.c b/drivers/platform/wmi/string.c
new file mode 100644
index 000000000..0fc43218a
--- /dev/null
+++ b/drivers/platform/wmi/string.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * WMI string utility functions.
+ *
+ * Copyright (C) 2025 Armin Wolf <W_Armin@gmx.de>
+ */
+
+#include <linux/build_bug.h>
+#include <linux/compiler_types.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/nls.h>
+#include <linux/limits.h>
+#include <linux/types.h>
+#include <linux/wmi.h>
+
+#include <asm/byteorder.h>
+
+static_assert(sizeof(__le16) == sizeof(wchar_t));
+
+/**
+ * wmi_string_to_utf8s - Convert a WMI string into a UTF8 string.
+ * @str: WMI string representation
+ * @dst: Buffer to fill with UTF8 characters
+ * @length: Length of the destination buffer
+ *
+ * Convert as WMI string into a standard UTF8 string. The conversion will stop
+ * once a NUL character is detected or when the buffer is full. Any invalid UTF16
+ * characters will be ignored. The resulting UTF8 string will always be NUL-terminated
+ * when this function returns successfully.
+ *
+ * Return: Length of the resulting UTF8 string or negative errno code on failure.
+ */
+ssize_t wmi_string_to_utf8s(const struct wmi_string *str, u8 *dst, size_t length)
+{
+ /* Contains the maximum number of UTF16 code points to read */
+ int inlen = le16_to_cpu(str->length) / 2;
+ int ret;
+
+ if (length < 1)
+ return -EINVAL;
+
+ /* We must leave room for the NUL character at the end of the destination buffer */
+ ret = utf16s_to_utf8s((__force const wchar_t *)str->chars, inlen, UTF16_LITTLE_ENDIAN, dst,
+ length - 1);
+ if (ret < 0)
+ return ret;
+
+ dst[ret] = '\0';
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(wmi_string_to_utf8s);
+
+/**
+ * wmi_string_from_utf8s - Convert a UTF8 string into a WMI string.
+ * @str: WMI string representation
+ * @max_chars: Maximum number of UTF16 code points to store inside the WMI string
+ * @src: UTF8 string to convert
+ * @src_length: Length of the source string without any trailing NUL-characters
+ *
+ * Convert a UTF8 string into a WMI string. The conversion will stop when the WMI string is
+ * full. The resulting WMI string will always be NUL-terminated and have its length field set
+ * to and appropriate value when this function returns successfully.
+ *
+ * Return: Number of UTF16 code points inside the WMI string or negative errno code on failure.
+ */
+ssize_t wmi_string_from_utf8s(struct wmi_string *str, size_t max_chars, const u8 *src,
+ size_t src_length)
+{
+ size_t str_length;
+ int ret;
+
+ if (max_chars < 1)
+ return -EINVAL;
+
+ /* We must leave room for the NUL character at the end of the WMI string */
+ ret = utf8s_to_utf16s(src, src_length, UTF16_LITTLE_ENDIAN, (__force wchar_t *)str->chars,
+ max_chars - 1);
+ if (ret < 0)
+ return ret;
+
+ str_length = (ret + 1) * sizeof(u16);
+ if (str_length > U16_MAX)
+ return -EOVERFLOW;
+
+ str->length = cpu_to_le16(str_length);
+ str->chars[ret] = '\0';
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(wmi_string_from_utf8s);
diff --git a/drivers/platform/wmi/tests/Kconfig b/drivers/platform/wmi/tests/Kconfig
new file mode 100644
index 000000000..f7f0f3c54
--- /dev/null
+++ b/drivers/platform/wmi/tests/Kconfig
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# ACPI WMI KUnit tests
+#
+
+config ACPI_WMI_MARSHALLING_KUNIT_TEST
+ tristate "KUnit Test for ACPI-WMI marshalling" if !KUNIT_ALL_TESTS
+ depends on KUNIT
+ default KUNIT_ALL_TESTS
+ help
+ This builds unit tests for the ACPI-WMI marshalling code.
+
+ For more information on KUnit and unit tests in general, please refer
+ to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+ If unsure, say N.
+
+config ACPI_WMI_STRING_KUNIT_TEST
+ tristate "KUnit Test for ACPI-WMI string conversion" if !KUNIT_ALL_TESTS
+ depends on KUNIT
+ default KUNIT_ALL_TESTS
+ help
+ This builds unit tests for the ACPI-WMI string conversion code.
+ For more information on KUnit and unit tests in general, please refer
+ to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+ If unsure, say N.
diff --git a/drivers/platform/wmi/tests/Makefile b/drivers/platform/wmi/tests/Makefile
new file mode 100644
index 000000000..62c438e26
--- /dev/null
+++ b/drivers/platform/wmi/tests/Makefile
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Makefile for linux/drivers/platform/x86/wmi/tests
+# ACPI WMI KUnit tests
+#
+
+wmi_marshalling_kunit-y := marshalling_kunit.o
+obj-$(CONFIG_ACPI_WMI_MARSHALLING_KUNIT_TEST) += wmi_marshalling_kunit.o
+
+wmi_string_kunit-y := string_kunit.o
+obj-$(CONFIG_ACPI_WMI_STRING_KUNIT_TEST) += wmi_string_kunit.o
diff --git a/drivers/platform/wmi/tests/marshalling_kunit.c b/drivers/platform/wmi/tests/marshalling_kunit.c
new file mode 100644
index 000000000..471963076
--- /dev/null
+++ b/drivers/platform/wmi/tests/marshalling_kunit.c
@@ -0,0 +1,472 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * KUnit test for the ACPI-WMI marshalling code.
+ *
+ * Copyright (C) 2025 Armin Wolf <W_Armin@gmx.de>
+ */
+
+#include <linux/acpi.h>
+#include <linux/align.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/wmi.h>
+
+#include <kunit/resource.h>
+#include <kunit/test.h>
+
+#include "../internal.h"
+
+struct wmi_acpi_param {
+ const char *name;
+ const union acpi_object obj;
+ const struct wmi_buffer buffer;
+};
+
+struct wmi_string_param {
+ const char *name;
+ const char *string;
+ const struct wmi_buffer buffer;
+};
+
+struct wmi_invalid_acpi_param {
+ const char *name;
+ const union acpi_object obj;
+};
+
+struct wmi_invalid_string_param {
+ const char *name;
+ const struct wmi_buffer buffer;
+};
+
+/* 0xdeadbeef */
+static u8 expected_single_integer[] = {
+ 0xef, 0xbe, 0xad, 0xde,
+};
+
+/* "TEST" */
+static u8 expected_single_string[] = {
+ 0x0a, 0x00, 0x54, 0x00, 0x45, 0x00, 0x53, 0x00, 0x54, 0x00, 0x00, 0x00,
+};
+
+static u8 test_buffer[] = {
+ 0xab, 0xcd,
+};
+
+static u8 expected_single_buffer[] = {
+ 0xab, 0xcd,
+};
+
+static union acpi_object simple_package_elements[] = {
+ {
+ .buffer = {
+ .type = ACPI_TYPE_BUFFER,
+ .length = sizeof(test_buffer),
+ .pointer = test_buffer,
+ },
+ },
+ {
+ .integer = {
+ .type = ACPI_TYPE_INTEGER,
+ .value = 0x01020304,
+ },
+ },
+};
+
+static u8 expected_simple_package[] = {
+ 0xab, 0xcd,
+ 0x00, 0x00,
+ 0x04, 0x03, 0x02, 0x01,
+};
+
+static u8 test_small_buffer[] = {
+ 0xde,
+};
+
+static union acpi_object complex_package_elements[] = {
+ {
+ .integer = {
+ .type = ACPI_TYPE_INTEGER,
+ .value = 0xdeadbeef,
+ },
+ },
+ {
+ .buffer = {
+ .type = ACPI_TYPE_BUFFER,
+ .length = sizeof(test_small_buffer),
+ .pointer = test_small_buffer,
+ },
+ },
+ {
+ .string = {
+ .type = ACPI_TYPE_STRING,
+ .length = sizeof("TEST") - 1,
+ .pointer = "TEST",
+ },
+ },
+ {
+ .buffer = {
+ .type = ACPI_TYPE_BUFFER,
+ .length = sizeof(test_small_buffer),
+ .pointer = test_small_buffer,
+ },
+ },
+ {
+ .integer = {
+ .type = ACPI_TYPE_INTEGER,
+ .value = 0x01020304,
+ },
+ }
+};
+
+static u8 expected_complex_package[] = {
+ 0xef, 0xbe, 0xad, 0xde,
+ 0xde,
+ 0x00,
+ 0x0a, 0x00, 0x54, 0x00, 0x45, 0x00, 0x53, 0x00, 0x54, 0x00, 0x00, 0x00,
+ 0xde,
+ 0x00,
+ 0x04, 0x03, 0x02, 0x01,
+};
+
+static const struct wmi_acpi_param wmi_acpi_params_array[] = {
+ {
+ .name = "single_integer",
+ .obj = {
+ .integer = {
+ .type = ACPI_TYPE_INTEGER,
+ .value = 0xdeadbeef,
+ },
+ },
+ .buffer = {
+ .data = expected_single_integer,
+ .length = sizeof(expected_single_integer),
+ },
+ },
+ {
+ .name = "single_string",
+ .obj = {
+ .string = {
+ .type = ACPI_TYPE_STRING,
+ .length = sizeof("TEST") - 1,
+ .pointer = "TEST",
+ },
+ },
+ .buffer = {
+ .data = expected_single_string,
+ .length = sizeof(expected_single_string),
+ },
+ },
+ {
+ .name = "single_buffer",
+ .obj = {
+ .buffer = {
+ .type = ACPI_TYPE_BUFFER,
+ .length = sizeof(test_buffer),
+ .pointer = test_buffer,
+ },
+ },
+ .buffer = {
+ .data = expected_single_buffer,
+ .length = sizeof(expected_single_buffer),
+ },
+ },
+ {
+ .name = "simple_package",
+ .obj = {
+ .package = {
+ .type = ACPI_TYPE_PACKAGE,
+ .count = ARRAY_SIZE(simple_package_elements),
+ .elements = simple_package_elements,
+ },
+ },
+ .buffer = {
+ .data = expected_simple_package,
+ .length = sizeof(expected_simple_package),
+ },
+ },
+ {
+ .name = "complex_package",
+ .obj = {
+ .package = {
+ .type = ACPI_TYPE_PACKAGE,
+ .count = ARRAY_SIZE(complex_package_elements),
+ .elements = complex_package_elements,
+ },
+ },
+ .buffer = {
+ .data = expected_complex_package,
+ .length = sizeof(expected_complex_package),
+ },
+ },
+};
+
+static void wmi_acpi_param_get_desc(const struct wmi_acpi_param *param, char *desc)
+{
+ strscpy(desc, param->name, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(wmi_unmarshal_acpi_object, wmi_acpi_params_array, wmi_acpi_param_get_desc);
+
+/* "WMI\0" */
+static u8 padded_wmi_string[] = {
+ 0x0a, 0x00,
+ 0x57, 0x00,
+ 0x4D, 0x00,
+ 0x49, 0x00,
+ 0x00, 0x00,
+ 0x00, 0x00,
+};
+
+static const struct wmi_string_param wmi_string_params_array[] = {
+ {
+ .name = "test",
+ .string = "TEST",
+ .buffer = {
+ .length = sizeof(expected_single_string),
+ .data = expected_single_string,
+ },
+ },
+ {
+ .name = "padded",
+ .string = "WMI",
+ .buffer = {
+ .length = sizeof(padded_wmi_string),
+ .data = padded_wmi_string,
+ },
+ },
+};
+
+static void wmi_string_param_get_desc(const struct wmi_string_param *param, char *desc)
+{
+ strscpy(desc, param->name, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(wmi_marshal_string, wmi_string_params_array, wmi_string_param_get_desc);
+
+static union acpi_object nested_package_elements[] = {
+ {
+ .package = {
+ .type = ACPI_TYPE_PACKAGE,
+ .count = ARRAY_SIZE(simple_package_elements),
+ .elements = simple_package_elements,
+ },
+ }
+};
+
+static const struct wmi_invalid_acpi_param wmi_invalid_acpi_params_array[] = {
+ {
+ .name = "nested_package",
+ .obj = {
+ .package = {
+ .type = ACPI_TYPE_PACKAGE,
+ .count = ARRAY_SIZE(nested_package_elements),
+ .elements = nested_package_elements,
+ },
+ },
+ },
+ {
+ .name = "reference",
+ .obj = {
+ .reference = {
+ .type = ACPI_TYPE_LOCAL_REFERENCE,
+ .actual_type = ACPI_TYPE_ANY,
+ .handle = NULL,
+ },
+ },
+ },
+ {
+ .name = "processor",
+ .obj = {
+ .processor = {
+ .type = ACPI_TYPE_PROCESSOR,
+ .proc_id = 0,
+ .pblk_address = 0,
+ .pblk_length = 0,
+ },
+ },
+ },
+ {
+ .name = "power_resource",
+ .obj = {
+ .power_resource = {
+ .type = ACPI_TYPE_POWER,
+ .system_level = 0,
+ .resource_order = 0,
+ },
+ },
+ },
+};
+
+static void wmi_invalid_acpi_param_get_desc(const struct wmi_invalid_acpi_param *param, char *desc)
+{
+ strscpy(desc, param->name, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(wmi_unmarshal_acpi_object_failure, wmi_invalid_acpi_params_array,
+ wmi_invalid_acpi_param_get_desc);
+
+static u8 oversized_wmi_string[] = {
+ 0x04, 0x00, 0x00, 0x00,
+};
+
+/*
+ * The error is that 3 bytes can not hold UTF-16 characters
+ * without cutting of the last one.
+ */
+static u8 undersized_wmi_string[] = {
+ 0x03, 0x00, 0x00, 0x00, 0x00,
+};
+
+static u8 non_ascii_wmi_string[] = {
+ 0x04, 0x00, 0xC4, 0x00, 0x00, 0x00,
+};
+
+static const struct wmi_invalid_string_param wmi_invalid_string_params_array[] = {
+ {
+ .name = "empty_buffer",
+ .buffer = {
+ .length = 0,
+ .data = ZERO_SIZE_PTR,
+ },
+
+ },
+ {
+ .name = "oversized",
+ .buffer = {
+ .length = sizeof(oversized_wmi_string),
+ .data = oversized_wmi_string,
+ },
+ },
+ {
+ .name = "undersized",
+ .buffer = {
+ .length = sizeof(undersized_wmi_string),
+ .data = undersized_wmi_string,
+ },
+ },
+ {
+ .name = "non_ascii",
+ .buffer = {
+ .length = sizeof(non_ascii_wmi_string),
+ .data = non_ascii_wmi_string,
+ },
+ },
+};
+
+static void wmi_invalid_string_param_get_desc(const struct wmi_invalid_string_param *param,
+ char *desc)
+{
+ strscpy(desc, param->name, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(wmi_marshal_string_failure, wmi_invalid_string_params_array,
+ wmi_invalid_string_param_get_desc);
+
+KUNIT_DEFINE_ACTION_WRAPPER(kfree_wrapper, kfree, const void *);
+
+static void wmi_unmarshal_acpi_object_test(struct kunit *test)
+{
+ const struct wmi_acpi_param *param = test->param_value;
+ struct wmi_buffer result;
+ int ret;
+
+ ret = wmi_unmarshal_acpi_object(&param->obj, &result, param->buffer.length);
+ if (ret < 0)
+ KUNIT_FAIL_AND_ABORT(test, "Unmarshalling of ACPI object failed\n");
+
+ kunit_add_action(test, kfree_wrapper, result.data);
+
+ KUNIT_EXPECT_TRUE(test, IS_ALIGNED((uintptr_t)result.data, 8));
+ KUNIT_EXPECT_EQ(test, result.length, param->buffer.length);
+ KUNIT_EXPECT_MEMEQ(test, result.data, param->buffer.data, result.length);
+}
+
+static void wmi_unmarshal_acpi_object_failure_test(struct kunit *test)
+{
+ const struct wmi_invalid_acpi_param *param = test->param_value;
+ struct wmi_buffer result;
+ int ret;
+
+ ret = wmi_unmarshal_acpi_object(&param->obj, &result, 0);
+ if (ret < 0)
+ return;
+
+ kfree(result.data);
+ KUNIT_FAIL(test, "Invalid ACPI object was not rejected\n");
+}
+
+static void wmi_marshal_string_test(struct kunit *test)
+{
+ const struct wmi_string_param *param = test->param_value;
+ struct acpi_buffer result;
+ int ret;
+
+ ret = wmi_marshal_string(&param->buffer, &result);
+ if (ret < 0)
+ KUNIT_FAIL_AND_ABORT(test, "Marshalling of WMI string failed\n");
+
+ kunit_add_action(test, kfree_wrapper, result.pointer);
+
+ KUNIT_EXPECT_EQ(test, result.length, strlen(param->string));
+ KUNIT_EXPECT_STREQ(test, result.pointer, param->string);
+}
+
+static void wmi_marshal_string_failure_test(struct kunit *test)
+{
+ const struct wmi_invalid_string_param *param = test->param_value;
+ struct acpi_buffer result;
+ int ret;
+
+ ret = wmi_marshal_string(&param->buffer, &result);
+ if (ret < 0)
+ return;
+
+ kfree(result.pointer);
+ KUNIT_FAIL(test, "Invalid string was not rejected\n");
+}
+
+static void wmi_unmarshal_acpi_object_undersized_test(struct kunit *test)
+{
+ const union acpi_object obj = {
+ .integer = {
+ .type = ACPI_TYPE_INTEGER,
+ .value = 0xdeadbeef,
+ },
+ };
+ struct wmi_buffer result;
+ int ret;
+
+ ret = wmi_unmarshal_acpi_object(&obj, &result, sizeof(expected_single_integer) + 1);
+ if (ret < 0)
+ return;
+
+ kfree(result.data);
+ KUNIT_FAIL(test, "Undersized unmarshalling result was not rejected\n");
+}
+
+static struct kunit_case wmi_marshalling_test_cases[] = {
+ KUNIT_CASE_PARAM(wmi_unmarshal_acpi_object_test,
+ wmi_unmarshal_acpi_object_gen_params),
+ KUNIT_CASE_PARAM(wmi_marshal_string_test,
+ wmi_marshal_string_gen_params),
+ KUNIT_CASE_PARAM(wmi_unmarshal_acpi_object_failure_test,
+ wmi_unmarshal_acpi_object_failure_gen_params),
+ KUNIT_CASE_PARAM(wmi_marshal_string_failure_test,
+ wmi_marshal_string_failure_gen_params),
+ KUNIT_CASE(wmi_unmarshal_acpi_object_undersized_test),
+ {}
+};
+
+static struct kunit_suite wmi_marshalling_test_suite = {
+ .name = "wmi_marshalling",
+ .test_cases = wmi_marshalling_test_cases,
+};
+
+kunit_test_suite(wmi_marshalling_test_suite);
+
+MODULE_AUTHOR("Armin Wolf <W_Armin@gmx.de>");
+MODULE_DESCRIPTION("KUnit test for the ACPI-WMI marshalling code");
+MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");
+MODULE_LICENSE("GPL");
diff --git a/drivers/platform/wmi/tests/string_kunit.c b/drivers/platform/wmi/tests/string_kunit.c
new file mode 100644
index 000000000..117f32ee2
--- /dev/null
+++ b/drivers/platform/wmi/tests/string_kunit.c
@@ -0,0 +1,296 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * KUnit test for the ACPI-WMI string conversion code.
+ *
+ * Copyright (C) 2025 Armin Wolf <W_Armin@gmx.de>
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/wmi.h>
+
+#include <kunit/resource.h>
+#include <kunit/test.h>
+
+#include <asm/byteorder.h>
+
+struct wmi_string_param {
+ const char *name;
+ const struct wmi_string *wmi_string;
+ /*
+ * Remember that using sizeof() on a struct wmi_string will
+ * always return a size of two bytes due to the flexible
+ * array member!
+ */
+ size_t wmi_string_length;
+ const u8 *utf8_string;
+ size_t utf8_string_length;
+};
+
+#define TEST_WMI_STRING_LENGTH 12
+
+static const struct wmi_string test_wmi_string = {
+ .length = cpu_to_le16(10),
+ .chars = {
+ cpu_to_le16(u'T'),
+ cpu_to_le16(u'E'),
+ cpu_to_le16(u'S'),
+ cpu_to_le16(u'T'),
+ cpu_to_le16(u'\0'),
+ },
+};
+
+static const u8 test_utf8_string[] = "TEST";
+
+#define SPECIAL_WMI_STRING_LENGTH 14
+
+static const struct wmi_string special_wmi_string = {
+ .length = cpu_to_le16(12),
+ .chars = {
+ cpu_to_le16(u'Ä'),
+ cpu_to_le16(u'Ö'),
+ cpu_to_le16(u'Ü'),
+ cpu_to_le16(u'ß'),
+ cpu_to_le16(u'€'),
+ cpu_to_le16(u'\0'),
+ },
+};
+
+static const u8 special_utf8_string[] = "ÄÖÜ߀";
+
+#define MULTI_POINT_WMI_STRING_LENGTH 12
+
+static const struct wmi_string multi_point_wmi_string = {
+ .length = cpu_to_le16(10),
+ .chars = {
+ cpu_to_le16(u'K'),
+ /* 🐧 */
+ cpu_to_le16(0xD83D),
+ cpu_to_le16(0xDC27),
+ cpu_to_le16(u'!'),
+ cpu_to_le16(u'\0'),
+ },
+};
+
+static const u8 multi_point_utf8_string[] = "K🐧!";
+
+#define PADDED_TEST_WMI_STRING_LENGTH 14
+
+static const struct wmi_string padded_test_wmi_string = {
+ .length = cpu_to_le16(12),
+ .chars = {
+ cpu_to_le16(u'T'),
+ cpu_to_le16(u'E'),
+ cpu_to_le16(u'S'),
+ cpu_to_le16(u'T'),
+ cpu_to_le16(u'\0'),
+ cpu_to_le16(u'\0'),
+ },
+};
+
+static const u8 padded_test_utf8_string[] = "TEST\0";
+
+#define OVERSIZED_TEST_WMI_STRING_LENGTH 14
+
+static const struct wmi_string oversized_test_wmi_string = {
+ .length = cpu_to_le16(8),
+ .chars = {
+ cpu_to_le16(u'T'),
+ cpu_to_le16(u'E'),
+ cpu_to_le16(u'S'),
+ cpu_to_le16(u'T'),
+ cpu_to_le16(u'!'),
+ cpu_to_le16(u'\0'),
+ },
+};
+
+static const u8 oversized_test_utf8_string[] = "TEST!";
+
+#define INVALID_TEST_WMI_STRING_LENGTH 14
+
+static const struct wmi_string invalid_test_wmi_string = {
+ .length = cpu_to_le16(12),
+ .chars = {
+ cpu_to_le16(u'T'),
+ /* 🐧, with low surrogate missing */
+ cpu_to_le16(0xD83D),
+ cpu_to_le16(u'E'),
+ cpu_to_le16(u'S'),
+ cpu_to_le16(u'T'),
+ cpu_to_le16(u'\0'),
+ },
+};
+
+/* We have to split the string here to end the hex escape sequence */
+static const u8 invalid_test_utf8_string[] = "T" "\xF0\x9F" "EST";
+
+static const struct wmi_string_param wmi_string_params_array[] = {
+ {
+ .name = "ascii_string",
+ .wmi_string = &test_wmi_string,
+ .wmi_string_length = TEST_WMI_STRING_LENGTH,
+ .utf8_string = test_utf8_string,
+ .utf8_string_length = sizeof(test_utf8_string),
+ },
+ {
+ .name = "special_string",
+ .wmi_string = &special_wmi_string,
+ .wmi_string_length = SPECIAL_WMI_STRING_LENGTH,
+ .utf8_string = special_utf8_string,
+ .utf8_string_length = sizeof(special_utf8_string),
+ },
+ {
+ .name = "multi_point_string",
+ .wmi_string = &multi_point_wmi_string,
+ .wmi_string_length = MULTI_POINT_WMI_STRING_LENGTH,
+ .utf8_string = multi_point_utf8_string,
+ .utf8_string_length = sizeof(multi_point_utf8_string),
+ },
+};
+
+static void wmi_string_param_get_desc(const struct wmi_string_param *param, char *desc)
+{
+ strscpy(desc, param->name, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(wmi_string, wmi_string_params_array, wmi_string_param_get_desc);
+
+static void wmi_string_to_utf8s_test(struct kunit *test)
+{
+ const struct wmi_string_param *param = test->param_value;
+ ssize_t ret;
+ u8 *result;
+
+ result = kunit_kzalloc(test, param->utf8_string_length, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, result);
+
+ ret = wmi_string_to_utf8s(param->wmi_string, result, param->utf8_string_length);
+
+ KUNIT_EXPECT_EQ(test, ret, param->utf8_string_length - 1);
+ KUNIT_EXPECT_MEMEQ(test, result, param->utf8_string, param->utf8_string_length);
+}
+
+static void wmi_string_from_utf8s_test(struct kunit *test)
+{
+ const struct wmi_string_param *param = test->param_value;
+ struct wmi_string *result;
+ size_t max_chars;
+ ssize_t ret;
+
+ max_chars = (param->wmi_string_length - sizeof(*result)) / 2;
+ result = kunit_kzalloc(test, param->wmi_string_length, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, result);
+
+ ret = wmi_string_from_utf8s(result, max_chars, param->utf8_string,
+ param->utf8_string_length);
+
+ KUNIT_EXPECT_EQ(test, ret, max_chars - 1);
+ KUNIT_EXPECT_MEMEQ(test, result, param->wmi_string, param->wmi_string_length);
+}
+
+static void wmi_string_to_utf8s_padded_test(struct kunit *test)
+{
+ u8 result[sizeof(padded_test_utf8_string)];
+ ssize_t ret;
+
+ ret = wmi_string_to_utf8s(&padded_test_wmi_string, result, sizeof(result));
+
+ KUNIT_EXPECT_EQ(test, ret, sizeof(test_utf8_string) - 1);
+ KUNIT_EXPECT_MEMEQ(test, result, test_utf8_string, sizeof(test_utf8_string));
+}
+
+static void wmi_string_from_utf8s_padded_test(struct kunit *test)
+{
+ struct wmi_string *result;
+ size_t max_chars;
+ ssize_t ret;
+
+ max_chars = (PADDED_TEST_WMI_STRING_LENGTH - sizeof(*result)) / 2;
+ result = kunit_kzalloc(test, PADDED_TEST_WMI_STRING_LENGTH, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, result);
+
+ ret = wmi_string_from_utf8s(result, max_chars, padded_test_utf8_string,
+ sizeof(padded_test_utf8_string));
+
+ KUNIT_EXPECT_EQ(test, ret, sizeof(test_utf8_string) - 1);
+ KUNIT_EXPECT_MEMEQ(test, result, &test_wmi_string, sizeof(test_wmi_string));
+}
+
+static void wmi_string_to_utf8s_oversized_test(struct kunit *test)
+{
+ u8 result[sizeof(oversized_test_utf8_string)];
+ ssize_t ret;
+
+ ret = wmi_string_to_utf8s(&oversized_test_wmi_string, result, sizeof(result));
+
+ KUNIT_EXPECT_EQ(test, ret, sizeof(test_utf8_string) - 1);
+ KUNIT_EXPECT_MEMEQ(test, result, test_utf8_string, sizeof(test_utf8_string));
+}
+
+static void wmi_string_from_utf8s_oversized_test(struct kunit *test)
+{
+ struct wmi_string *result;
+ size_t max_chars;
+ ssize_t ret;
+
+ max_chars = (TEST_WMI_STRING_LENGTH - sizeof(*result)) / 2;
+ result = kunit_kzalloc(test, TEST_WMI_STRING_LENGTH, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, result);
+
+ ret = wmi_string_from_utf8s(result, max_chars, oversized_test_utf8_string,
+ sizeof(oversized_test_utf8_string));
+
+ KUNIT_EXPECT_EQ(test, ret, sizeof(test_utf8_string) - 1);
+ KUNIT_EXPECT_MEMEQ(test, result, &test_wmi_string, sizeof(test_wmi_string));
+}
+
+static void wmi_string_to_utf8s_invalid_test(struct kunit *test)
+{
+ u8 result[sizeof(invalid_test_utf8_string)];
+ ssize_t ret;
+
+ ret = wmi_string_to_utf8s(&invalid_test_wmi_string, result, sizeof(result));
+
+ KUNIT_EXPECT_EQ(test, ret, sizeof(test_utf8_string) - 1);
+ KUNIT_EXPECT_MEMEQ(test, result, test_utf8_string, sizeof(test_utf8_string));
+}
+
+static void wmi_string_from_utf8s_invalid_test(struct kunit *test)
+{
+ struct wmi_string *result;
+ size_t max_chars;
+ ssize_t ret;
+
+ max_chars = (INVALID_TEST_WMI_STRING_LENGTH - sizeof(*result)) / 2;
+ result = kunit_kzalloc(test, INVALID_TEST_WMI_STRING_LENGTH, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, result);
+
+ ret = wmi_string_from_utf8s(result, max_chars, invalid_test_utf8_string,
+ sizeof(invalid_test_utf8_string));
+
+ KUNIT_EXPECT_EQ(test, ret, -EINVAL);
+}
+
+static struct kunit_case wmi_string_test_cases[] = {
+ KUNIT_CASE_PARAM(wmi_string_to_utf8s_test, wmi_string_gen_params),
+ KUNIT_CASE_PARAM(wmi_string_from_utf8s_test, wmi_string_gen_params),
+ KUNIT_CASE(wmi_string_to_utf8s_padded_test),
+ KUNIT_CASE(wmi_string_from_utf8s_padded_test),
+ KUNIT_CASE(wmi_string_to_utf8s_oversized_test),
+ KUNIT_CASE(wmi_string_from_utf8s_oversized_test),
+ KUNIT_CASE(wmi_string_to_utf8s_invalid_test),
+ KUNIT_CASE(wmi_string_from_utf8s_invalid_test),
+ {}
+};
+
+static struct kunit_suite wmi_string_test_suite = {
+ .name = "wmi_string",
+ .test_cases = wmi_string_test_cases,
+};
+
+kunit_test_suite(wmi_string_test_suite);
+
+MODULE_AUTHOR("Armin Wolf <W_Armin@gmx.de>");
+MODULE_DESCRIPTION("KUnit test for the ACPI-WMI string conversion code");
+MODULE_LICENSE("GPL");
generated by cgit v1.3.1 (git 2.54.0) at 2026-10-28 06:49:29 +0000