Linux Kernel  3.7.1
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proc_powerpc.c
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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);