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 #ifdef CONFIG_PPC64
32 
33 static loff_t page_map_seek( struct file *file, loff_t off, int whence)
34 {
35 	loff_t new;
36 	struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
37 
38 	switch(whence) {
39 	case 0:
40 		new = off;
41 		break;
42 	case 1:
43 		new = file->f_pos + off;
44 		break;
45 	case 2:
46 		new = dp->size + off;
47 		break;
48 	default:
49 		return -EINVAL;
50 	}
51 	if ( new < 0 || new > dp->size )
52 		return -EINVAL;
53 	return (file->f_pos = new);
54 }
55 
56 static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
57 			      loff_t *ppos)
58 {
59 	struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
60 	return simple_read_from_buffer(buf, nbytes, ppos, dp->data, dp->size);
61 }
62 
63 static int page_map_mmap( struct file *file, struct vm_area_struct *vma )
64 {
65 	struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
66 
67 	if ((vma->vm_end - vma->vm_start) > dp->size)
68 		return -EINVAL;
69 
70 	remap_pfn_range(vma, vma->vm_start, __pa(dp->data) >> PAGE_SHIFT,
71 						dp->size, vma->vm_page_prot);
72 	return 0;
73 }
74 
75 static const struct file_operations page_map_fops = {
76 	.llseek	= page_map_seek,
77 	.read	= page_map_read,
78 	.mmap	= page_map_mmap
79 };
80 
81 
82 static int __init proc_ppc64_init(void)
83 {
84 	struct proc_dir_entry *pde;
85 
86 	pde = proc_create_data("powerpc/systemcfg", S_IFREG|S_IRUGO, NULL,
87 			       &page_map_fops, vdso_data);
88 	if (!pde)
89 		return 1;
90 	pde->size = PAGE_SIZE;
91 
92 	return 0;
93 }
94 __initcall(proc_ppc64_init);
95 
96 #endif /* CONFIG_PPC64 */
97 
98 /*
99  * Create the ppc64 and ppc64/rtas directories early. This allows us to
100  * assume that they have been previously created in drivers.
101  */
102 static int __init proc_ppc64_create(void)
103 {
104 	struct proc_dir_entry *root;
105 
106 	root = proc_mkdir("powerpc", NULL);
107 	if (!root)
108 		return 1;
109 
110 #ifdef CONFIG_PPC64
111 	if (!proc_symlink("ppc64", NULL, "powerpc"))
112 		pr_err("Failed to create link /proc/ppc64 -> /proc/powerpc\n");
113 #endif
114 
115 	if (!of_find_node_by_path("/rtas"))
116 		return 0;
117 
118 	if (!proc_mkdir("rtas", root))
119 		return 1;
120 
121 	if (!proc_symlink("rtas", NULL, "powerpc/rtas"))
122 		return 1;
123 
124 	return 0;
125 }
126 core_initcall(proc_ppc64_create);
127