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/slab.h>
23 #include <linux/kernel.h>
24
25 #include <asm/machdep.h>
26 #include <asm/vdso_datapage.h>
27 #include <asm/rtas.h>
28 #include <asm/uaccess.h>
29 #include <asm/prom.h>
30
31 static loff_t page_map_seek( struct file *file, loff_t off, int whence);
32 static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
33 loff_t *ppos);
34 static int page_map_mmap( struct file *file, struct vm_area_struct *vma );
35
36 static const struct file_operations page_map_fops = {
37 .llseek = page_map_seek,
38 .read = page_map_read,
39 .mmap = page_map_mmap
40 };
41
42 /*
43 * Create the ppc64 and ppc64/rtas directories early. This allows us to
44 * assume that they have been previously created in drivers.
45 */
proc_ppc64_create(void)46 static int __init proc_ppc64_create(void)
47 {
48 struct proc_dir_entry *root;
49
50 root = proc_mkdir("ppc64", NULL);
51 if (!root)
52 return 1;
53
54 if (!of_find_node_by_path("/rtas"))
55 return 0;
56
57 if (!proc_mkdir("rtas", root))
58 return 1;
59
60 if (!proc_symlink("rtas", NULL, "ppc64/rtas"))
61 return 1;
62
63 return 0;
64 }
65 core_initcall(proc_ppc64_create);
66
proc_ppc64_init(void)67 static int __init proc_ppc64_init(void)
68 {
69 struct proc_dir_entry *pde;
70
71 pde = proc_create_data("ppc64/systemcfg", S_IFREG|S_IRUGO, NULL,
72 &page_map_fops, vdso_data);
73 if (!pde)
74 return 1;
75 pde->size = PAGE_SIZE;
76
77 return 0;
78 }
79 __initcall(proc_ppc64_init);
80
page_map_seek(struct file * file,loff_t off,int whence)81 static loff_t page_map_seek( struct file *file, loff_t off, int whence)
82 {
83 loff_t new;
84 struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
85
86 switch(whence) {
87 case 0:
88 new = off;
89 break;
90 case 1:
91 new = file->f_pos + off;
92 break;
93 case 2:
94 new = dp->size + off;
95 break;
96 default:
97 return -EINVAL;
98 }
99 if ( new < 0 || new > dp->size )
100 return -EINVAL;
101 return (file->f_pos = new);
102 }
103
page_map_read(struct file * file,char __user * buf,size_t nbytes,loff_t * ppos)104 static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
105 loff_t *ppos)
106 {
107 struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
108 return simple_read_from_buffer(buf, nbytes, ppos, dp->data, dp->size);
109 }
110
page_map_mmap(struct file * file,struct vm_area_struct * vma)111 static int page_map_mmap( struct file *file, struct vm_area_struct *vma )
112 {
113 struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
114
115 if ((vma->vm_end - vma->vm_start) > dp->size)
116 return -EINVAL;
117
118 remap_pfn_range(vma, vma->vm_start, __pa(dp->data) >> PAGE_SHIFT,
119 dp->size, vma->vm_page_prot);
120 return 0;
121 }
122
123