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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proc_powerpc.c (2062B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen IBM Corporation
      4 */
      5
      6#include <linux/init.h>
      7#include <linux/mm.h>
      8#include <linux/proc_fs.h>
      9#include <linux/kernel.h>
     10#include <linux/of.h>
     11
     12#include <asm/machdep.h>
     13#include <asm/vdso_datapage.h>
     14#include <asm/rtas.h>
     15#include <linux/uaccess.h>
     16
     17#ifdef CONFIG_PPC64
     18
     19static loff_t page_map_seek(struct file *file, loff_t off, int whence)
     20{
     21	return fixed_size_llseek(file, off, whence, PAGE_SIZE);
     22}
     23
     24static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
     25			      loff_t *ppos)
     26{
     27	return simple_read_from_buffer(buf, nbytes, ppos,
     28			pde_data(file_inode(file)), PAGE_SIZE);
     29}
     30
     31static int page_map_mmap( struct file *file, struct vm_area_struct *vma )
     32{
     33	if ((vma->vm_end - vma->vm_start) > PAGE_SIZE)
     34		return -EINVAL;
     35
     36	remap_pfn_range(vma, vma->vm_start,
     37			__pa(pde_data(file_inode(file))) >> PAGE_SHIFT,
     38			PAGE_SIZE, vma->vm_page_prot);
     39	return 0;
     40}
     41
     42static const struct proc_ops page_map_proc_ops = {
     43	.proc_lseek	= page_map_seek,
     44	.proc_read	= page_map_read,
     45	.proc_mmap	= page_map_mmap,
     46};
     47
     48
     49static int __init proc_ppc64_init(void)
     50{
     51	struct proc_dir_entry *pde;
     52
     53	pde = proc_create_data("powerpc/systemcfg", S_IFREG | 0444, NULL,
     54			       &page_map_proc_ops, vdso_data);
     55	if (!pde)
     56		return 1;
     57	proc_set_size(pde, PAGE_SIZE);
     58
     59	return 0;
     60}
     61__initcall(proc_ppc64_init);
     62
     63#endif /* CONFIG_PPC64 */
     64
     65/*
     66 * Create the ppc64 and ppc64/rtas directories early. This allows us to
     67 * assume that they have been previously created in drivers.
     68 */
     69static int __init proc_ppc64_create(void)
     70{
     71	struct proc_dir_entry *root;
     72
     73	root = proc_mkdir("powerpc", NULL);
     74	if (!root)
     75		return 1;
     76
     77#ifdef CONFIG_PPC64
     78	if (!proc_symlink("ppc64", NULL, "powerpc"))
     79		pr_err("Failed to create link /proc/ppc64 -> /proc/powerpc\n");
     80#endif
     81
     82	if (!of_find_node_by_path("/rtas"))
     83		return 0;
     84
     85	if (!proc_mkdir("rtas", root))
     86		return 1;
     87
     88	if (!proc_symlink("rtas", NULL, "powerpc/rtas"))
     89		return 1;
     90
     91	return 0;
     92}
     93core_initcall(proc_ppc64_create);