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("/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
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