cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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thunderbolt.c (2376B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * WMI Thunderbolt driver
      4 *
      5 * Copyright (C) 2017 Dell Inc. All Rights Reserved.
      6 */
      7
      8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
      9
     10#include <linux/acpi.h>
     11#include <linux/device.h>
     12#include <linux/fs.h>
     13#include <linux/kernel.h>
     14#include <linux/module.h>
     15#include <linux/string.h>
     16#include <linux/sysfs.h>
     17#include <linux/types.h>
     18#include <linux/wmi.h>
     19
     20#define INTEL_WMI_THUNDERBOLT_GUID "86CCFD48-205E-4A77-9C48-2021CBEDE341"
     21
     22static ssize_t force_power_store(struct device *dev,
     23				 struct device_attribute *attr,
     24				 const char *buf, size_t count)
     25{
     26	struct acpi_buffer input;
     27	acpi_status status;
     28	u8 mode;
     29
     30	input.length = sizeof(u8);
     31	input.pointer = &mode;
     32	mode = hex_to_bin(buf[0]);
     33	dev_dbg(dev, "force_power: storing %#x\n", mode);
     34	if (mode == 0 || mode == 1) {
     35		status = wmi_evaluate_method(INTEL_WMI_THUNDERBOLT_GUID, 0, 1,
     36					     &input, NULL);
     37		if (ACPI_FAILURE(status)) {
     38			dev_dbg(dev, "force_power: failed to evaluate ACPI method\n");
     39			return -ENODEV;
     40		}
     41	} else {
     42		dev_dbg(dev, "force_power: unsupported mode\n");
     43		return -EINVAL;
     44	}
     45	return count;
     46}
     47
     48static DEVICE_ATTR_WO(force_power);
     49
     50static struct attribute *tbt_attrs[] = {
     51	&dev_attr_force_power.attr,
     52	NULL
     53};
     54
     55static const struct attribute_group tbt_attribute_group = {
     56	.attrs = tbt_attrs,
     57};
     58
     59static int intel_wmi_thunderbolt_probe(struct wmi_device *wdev,
     60				       const void *context)
     61{
     62	int ret;
     63
     64	ret = sysfs_create_group(&wdev->dev.kobj, &tbt_attribute_group);
     65	kobject_uevent(&wdev->dev.kobj, KOBJ_CHANGE);
     66	return ret;
     67}
     68
     69static void intel_wmi_thunderbolt_remove(struct wmi_device *wdev)
     70{
     71	sysfs_remove_group(&wdev->dev.kobj, &tbt_attribute_group);
     72	kobject_uevent(&wdev->dev.kobj, KOBJ_CHANGE);
     73}
     74
     75static const struct wmi_device_id intel_wmi_thunderbolt_id_table[] = {
     76	{ .guid_string = INTEL_WMI_THUNDERBOLT_GUID },
     77	{ },
     78};
     79
     80static struct wmi_driver intel_wmi_thunderbolt_driver = {
     81	.driver = {
     82		.name = "intel-wmi-thunderbolt",
     83	},
     84	.probe = intel_wmi_thunderbolt_probe,
     85	.remove = intel_wmi_thunderbolt_remove,
     86	.id_table = intel_wmi_thunderbolt_id_table,
     87};
     88
     89module_wmi_driver(intel_wmi_thunderbolt_driver);
     90
     91MODULE_DEVICE_TABLE(wmi, intel_wmi_thunderbolt_id_table);
     92MODULE_AUTHOR("Mario Limonciello <mario.limonciello@dell.com>");
     93MODULE_DESCRIPTION("Intel WMI Thunderbolt force power driver");
     94MODULE_LICENSE("GPL v2");