linux-next/drivers/platform/x86/wmi-bmof.c
Armin Wolf a66ccfc253
platform/x86: wmi: Do not instantiate older WMI drivers multiple times
Many older WMI drivers cannot be instantiated multiple times for
two reasons:

- they are using the legacy GUID-based WMI API
- they are singletons (with global state)

Prevent such WMI drivers from binding to WMI devices with a duplicated
GUID, as this would mean that the WMI driver will be instantiated at
least two times (one for the original GUID and one for the duplicated
GUID).
WMI drivers which can be instantiated multiple times can signal this
by setting a flag inside struct wmi_driver.

Tested on a ASUS Prime B650-Plus.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20240226193557.2888-2-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
2024-03-12 12:47:35 +02:00

106 lines
2.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* WMI embedded Binary MOF driver
*
* 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/device.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/sysfs.h>
#include <linux/types.h>
#include <linux/wmi.h>
#define WMI_BMOF_GUID "05901221-D566-11D1-B2F0-00A0C9062910"
struct bmof_priv {
union acpi_object *bmofdata;
struct bin_attribute bmof_bin_attr;
};
static ssize_t read_bmof(struct file *filp, struct kobject *kobj, struct bin_attribute *attr,
char *buf, loff_t off, size_t count)
{
struct bmof_priv *priv = container_of(attr, struct bmof_priv, bmof_bin_attr);
return memory_read_from_buffer(buf, count, &off, priv->bmofdata->buffer.pointer,
priv->bmofdata->buffer.length);
}
static int wmi_bmof_probe(struct wmi_device *wdev, const void *context)
{
struct bmof_priv *priv;
int ret;
priv = devm_kzalloc(&wdev->dev, sizeof(struct bmof_priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
dev_set_drvdata(&wdev->dev, priv);
priv->bmofdata = wmidev_block_query(wdev, 0);
if (!priv->bmofdata) {
dev_err(&wdev->dev, "failed to read Binary MOF\n");
return -EIO;
}
if (priv->bmofdata->type != ACPI_TYPE_BUFFER) {
dev_err(&wdev->dev, "Binary MOF is not a buffer\n");
ret = -EIO;
goto err_free;
}
sysfs_bin_attr_init(&priv->bmof_bin_attr);
priv->bmof_bin_attr.attr.name = "bmof";
priv->bmof_bin_attr.attr.mode = 0400;
priv->bmof_bin_attr.read = read_bmof;
priv->bmof_bin_attr.size = priv->bmofdata->buffer.length;
ret = device_create_bin_file(&wdev->dev, &priv->bmof_bin_attr);
if (ret)
goto err_free;
return 0;
err_free:
kfree(priv->bmofdata);
return ret;
}
static void wmi_bmof_remove(struct wmi_device *wdev)
{
struct bmof_priv *priv = dev_get_drvdata(&wdev->dev);
device_remove_bin_file(&wdev->dev, &priv->bmof_bin_attr);
kfree(priv->bmofdata);
}
static const struct wmi_device_id wmi_bmof_id_table[] = {
{ .guid_string = WMI_BMOF_GUID },
{ },
};
static struct wmi_driver wmi_bmof_driver = {
.driver = {
.name = "wmi-bmof",
},
.probe = wmi_bmof_probe,
.remove = wmi_bmof_remove,
.id_table = wmi_bmof_id_table,
.no_singleton = true,
};
module_wmi_driver(wmi_bmof_driver);
MODULE_DEVICE_TABLE(wmi, wmi_bmof_id_table);
MODULE_AUTHOR("Andrew Lutomirski <luto@kernel.org>");
MODULE_DESCRIPTION("WMI embedded Binary MOF driver");
MODULE_LICENSE("GPL");