xref: /linux/arch/powerpc/kernel/proc_powerpc.c (revision 4413e16d9d21673bb5048a2e542f1aaa00015c2e)
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 <asm/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 	loff_t new;
35 	struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
36 
37 	switch(whence) {
38 	case 0:
39 		new = off;
40 		break;
41 	case 1:
42 		new = file->f_pos + off;
43 		break;
44 	case 2:
45 		new = dp->size + off;
46 		break;
47 	default:
48 		return -EINVAL;
49 	}
50 	if ( new < 0 || new > dp->size )
51 		return -EINVAL;
52 	return (file->f_pos = new);
53 }
54 
55 static ssize_t page_map_read( struct file *file, char __user *buf, size_t nbytes,
56 			      loff_t *ppos)
57 {
58 	struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
59 	return simple_read_from_buffer(buf, nbytes, ppos, dp->data, dp->size);
60 }
61 
62 static int page_map_mmap( struct file *file, struct vm_area_struct *vma )
63 {
64 	struct proc_dir_entry *dp = PDE(file->f_path.dentry->d_inode);
65 
66 	if ((vma->vm_end - vma->vm_start) > dp->size)
67 		return -EINVAL;
68 
69 	remap_pfn_range(vma, vma->vm_start, __pa(dp->data) >> PAGE_SHIFT,
70 						dp->size, vma->vm_page_prot);
71 	return 0;
72 }
73 
74 static const struct file_operations page_map_fops = {
75 	.llseek	= page_map_seek,
76 	.read	= page_map_read,
77 	.mmap	= page_map_mmap
78 };
79 
80 
81 static int __init proc_ppc64_init(void)
82 {
83 	struct proc_dir_entry *pde;
84 
85 	pde = proc_create_data("powerpc/systemcfg", S_IFREG|S_IRUGO, NULL,
86 			       &page_map_fops, vdso_data);
87 	if (!pde)
88 		return 1;
89 	pde->size = PAGE_SIZE;
90 
91 	return 0;
92 }
93 __initcall(proc_ppc64_init);
94 
95 #endif /* CONFIG_PPC64 */
96 
97 /*
98  * Create the ppc64 and ppc64/rtas directories early. This allows us to
99  * assume that they have been previously created in drivers.
100  */
101 static int __init proc_ppc64_create(void)
102 {
103 	struct proc_dir_entry *root;
104 
105 	root = proc_mkdir("powerpc", NULL);
106 	if (!root)
107 		return 1;
108 
109 #ifdef CONFIG_PPC64
110 	if (!proc_symlink("ppc64", NULL, "powerpc"))
111 		pr_err("Failed to create link /proc/ppc64 -> /proc/powerpc\n");
112 #endif
113 
114 	if (!of_find_node_by_path("/rtas"))
115 		return 0;
116 
117 	if (!proc_mkdir("rtas", root))
118 		return 1;
119 
120 	if (!proc_symlink("rtas", NULL, "powerpc/rtas"))
121 		return 1;
122 
123 	return 0;
124 }
125 core_initcall(proc_ppc64_create);
126