1bad614b2SGary R Hook // SPDX-License-Identifier: GPL-2.0 2bad614b2SGary R Hook /* 3bad614b2SGary R Hook * IOMMU debugfs core infrastructure 4bad614b2SGary R Hook * 5bad614b2SGary R Hook * Copyright (C) 2018 Advanced Micro Devices, Inc. 6bad614b2SGary R Hook * 7bad614b2SGary R Hook * Author: Gary R Hook <gary.hook@amd.com> 8bad614b2SGary R Hook */ 9bad614b2SGary R Hook 10bad614b2SGary R Hook #include <linux/pci.h> 11bad614b2SGary R Hook #include <linux/iommu.h> 12bad614b2SGary R Hook #include <linux/debugfs.h> 13bad614b2SGary R Hook 14bad614b2SGary R Hook struct dentry *iommu_debugfs_dir; 15bad614b2SGary R Hook 16bad614b2SGary R Hook /** 17bad614b2SGary R Hook * iommu_debugfs_setup - create the top-level iommu directory in debugfs 18bad614b2SGary R Hook * 19bad614b2SGary R Hook * Provide base enablement for using debugfs to expose internal data of an 20bad614b2SGary R Hook * IOMMU driver. When called, this function creates the 21bad614b2SGary R Hook * /sys/kernel/debug/iommu directory. 22bad614b2SGary R Hook * 23bad614b2SGary R Hook * Emit a strong warning at boot time to indicate that this feature is 24bad614b2SGary R Hook * enabled. 25bad614b2SGary R Hook * 26bad614b2SGary R Hook * This function is called from iommu_init; drivers may then call 27bad614b2SGary R Hook * iommu_debugfs_new_driver_dir() to instantiate a vendor-specific 28bad614b2SGary R Hook * directory to be used to expose internal data. 29bad614b2SGary R Hook */ 30bad614b2SGary R Hook void iommu_debugfs_setup(void) 31bad614b2SGary R Hook { 32bad614b2SGary R Hook if (!iommu_debugfs_dir) { 33bad614b2SGary R Hook iommu_debugfs_dir = debugfs_create_dir("iommu", NULL); 34bad614b2SGary R Hook pr_warn("\n"); 35bad614b2SGary R Hook pr_warn("*************************************************************\n"); 36bad614b2SGary R Hook pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); 37bad614b2SGary R Hook pr_warn("** **\n"); 38bad614b2SGary R Hook pr_warn("** IOMMU DebugFS SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n"); 39bad614b2SGary R Hook pr_warn("** **\n"); 40bad614b2SGary R Hook pr_warn("** This means that this kernel is built to expose internal **\n"); 41bad614b2SGary R Hook pr_warn("** IOMMU data structures, which may compromise security on **\n"); 42bad614b2SGary R Hook pr_warn("** your system. **\n"); 43bad614b2SGary R Hook pr_warn("** **\n"); 44bad614b2SGary R Hook pr_warn("** If you see this message and you are not debugging the **\n"); 45bad614b2SGary R Hook pr_warn("** kernel, report this immediately to your vendor! **\n"); 46bad614b2SGary R Hook pr_warn("** **\n"); 47bad614b2SGary R Hook pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); 48bad614b2SGary R Hook pr_warn("*************************************************************\n"); 49bad614b2SGary R Hook } 50bad614b2SGary R Hook } 51bad614b2SGary R Hook 52bad614b2SGary R Hook /** 53bad614b2SGary R Hook * iommu_debugfs_new_driver_dir - create a vendor directory under debugfs/iommu 54bad614b2SGary R Hook * @vendor: name of the vendor-specific subdirectory to create 55bad614b2SGary R Hook * 56bad614b2SGary R Hook * This function is called by an IOMMU driver to create the top-level debugfs 57bad614b2SGary R Hook * directory for that driver. 58bad614b2SGary R Hook * 59bad614b2SGary R Hook * Return: upon success, a pointer to the dentry for the new directory. 60bad614b2SGary R Hook * NULL in case of failure. 61bad614b2SGary R Hook */ 62bad614b2SGary R Hook struct dentry *iommu_debugfs_new_driver_dir(const char *vendor) 63bad614b2SGary R Hook { 64bad614b2SGary R Hook return debugfs_create_dir(vendor, iommu_debugfs_dir); 65bad614b2SGary R Hook } 66bad614b2SGary R Hook EXPORT_SYMBOL_GPL(iommu_debugfs_new_driver_dir); 67