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);
94