1 /*
2  * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen IBM Corporation
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
17  */
18 
19 #include <linux/init.h>
20 #include <linux/mm.h>
21 #include <linux/proc_fs.h>
22 #include <linux/kernel.h>
23 
24 #include <asm/machdep.h>
25 #include <asm/vdso_datapage.h>
26 #include <asm/rtas.h>
27 #include <linux/uaccess.h>
28 #include <asm/prom.h>
29 
30 #ifdef CONFIG_PPC64
31 
32 static loff_t page_map_seek(struct file *file, loff_t off, int whence)
33 {
34 	return fixed_size_llseek(file, off, whence, PAGE_SIZE);
35 }
36 
37 static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
38 			      loff_t *ppos)
39 {
40 	return simple_read_from_buffer(buf, nbytes, ppos,
41 			PDE_DATA(file_inode(file)), PAGE_SIZE);
42 }
43 
44 static int page_map_mmap( struct file *file, struct vm_area_struct *vma )
45 {
46 	if ((vma->vm_end - vma->vm_start) > PAGE_SIZE)
47 		return -EINVAL;
48 
49 	remap_pfn_range(vma, vma->vm_start,
50 			__pa(PDE_DATA(file_inode(file))) >> PAGE_SHIFT,
51 			PAGE_SIZE, vma->vm_page_prot);
52 	return 0;
53 }
54 
55 static const struct file_operations page_map_fops = {
56 	.llseek	= page_map_seek,
57 	.read	= page_map_read,
58 	.mmap	= page_map_mmap
59 };
60 
61 
62 static int __init proc_ppc64_init(void)
63 {
64 	struct proc_dir_entry *pde;
65 
66 	pde = proc_create_data("powerpc/systemcfg", S_IFREG|S_IRUGO, NULL,
67 			       &page_map_fops, vdso_data);
68 	if (!pde)
69 		return 1;
70 	proc_set_size(pde, PAGE_SIZE);
71 
72 	return 0;
73 }
74 __initcall(proc_ppc64_init);
75 
76 #endif /* CONFIG_PPC64 */
77 
78 /*
79  * Create the ppc64 and ppc64/rtas directories early. This allows us to
80  * assume that they have been previously created in drivers.
81  */
82 static int __init proc_ppc64_create(void)
83 {
84 	struct proc_dir_entry *root;
85 
86 	root = proc_mkdir("powerpc", NULL);
87 	if (!root)
88 		return 1;
89 
90 #ifdef CONFIG_PPC64
91 	if (!proc_symlink("ppc64", NULL, "powerpc"))
92 		pr_err("Failed to create link /proc/ppc64 -> /proc/powerpc\n");
93 #endif
94 
95 	if (!of_find_node_by_path("/rtas"))
96 		return 0;
97 
98 	if (!proc_mkdir("rtas", root))
99 		return 1;
100 
101 	if (!proc_symlink("rtas", NULL, "powerpc/rtas"))
102 		return 1;
103 
104 	return 0;
105 }
106 core_initcall(proc_ppc64_create);
107