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 | |
19 | static 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 | |
24 | static 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 | |
31 | static 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 | |
42 | static 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 | |
49 | static 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 | */ |
69 | static 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(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 | } |
93 | core_initcall(proc_ppc64_create); |
94 | |