linux/drivers/iommu/iommu-debugfs.c

67 lines
2.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* IOMMU debugfs core infrastructure
*
* Copyright (C) 2018 Advanced Micro Devices, Inc.
*
* Author: Gary R Hook <gary.hook@amd.com>
*/
#include <linux/pci.h>
#include <linux/iommu.h>
#include <linux/debugfs.h>
struct dentry *iommu_debugfs_dir;
/**
* iommu_debugfs_setup - create the top-level iommu directory in debugfs
*
* Provide base enablement for using debugfs to expose internal data of an
* IOMMU driver. When called, this function creates the
* /sys/kernel/debug/iommu directory.
*
* Emit a strong warning at boot time to indicate that this feature is
* enabled.
*
* This function is called from iommu_init; drivers may then call
* iommu_debugfs_new_driver_dir() to instantiate a vendor-specific
* directory to be used to expose internal data.
*/
void iommu_debugfs_setup(void)
{
if (!iommu_debugfs_dir) {
iommu_debugfs_dir = debugfs_create_dir("iommu", NULL);
pr_warn("\n");
pr_warn("*************************************************************\n");
pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
pr_warn("** **\n");
pr_warn("** IOMMU DebugFS SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n");
pr_warn("** **\n");
pr_warn("** This means that this kernel is built to expose internal **\n");
pr_warn("** IOMMU data structures, which may compromise security on **\n");
pr_warn("** your system. **\n");
pr_warn("** **\n");
pr_warn("** If you see this message and you are not debugging the **\n");
pr_warn("** kernel, report this immediately to your vendor! **\n");
pr_warn("** **\n");
pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
pr_warn("*************************************************************\n");
}
}
/**
* iommu_debugfs_new_driver_dir - create a vendor directory under debugfs/iommu
* @vendor: name of the vendor-specific subdirectory to create
*
* This function is called by an IOMMU driver to create the top-level debugfs
* directory for that driver.
*
* Return: upon success, a pointer to the dentry for the new directory.
* NULL in case of failure.
*/
struct dentry *iommu_debugfs_new_driver_dir(const char *vendor)
{
return debugfs_create_dir(vendor, iommu_debugfs_dir);
}
EXPORT_SYMBOL_GPL(iommu_debugfs_new_driver_dir);