x86: Constify a few items
[linux-3.10.git] / arch / x86 / kernel / kdebugfs.c
1 /*
2  * Architecture specific debugfs files
3  *
4  * Copyright (C) 2007, Intel Corp.
5  *      Huang Ying <ying.huang@intel.com>
6  *
7  * This file is released under the GPLv2.
8  */
9 #include <linux/debugfs.h>
10 #include <linux/uaccess.h>
11 #include <linux/module.h>
12 #include <linux/slab.h>
13 #include <linux/init.h>
14 #include <linux/stat.h>
15 #include <linux/io.h>
16 #include <linux/mm.h>
17
18 #include <asm/setup.h>
19
20 struct dentry *arch_debugfs_dir;
21 EXPORT_SYMBOL(arch_debugfs_dir);
22
23 #ifdef CONFIG_DEBUG_BOOT_PARAMS
24 struct setup_data_node {
25         u64 paddr;
26         u32 type;
27         u32 len;
28 };
29
30 static ssize_t setup_data_read(struct file *file, char __user *user_buf,
31                                size_t count, loff_t *ppos)
32 {
33         struct setup_data_node *node = file->private_data;
34         unsigned long remain;
35         loff_t pos = *ppos;
36         struct page *pg;
37         void *p;
38         u64 pa;
39
40         if (pos < 0)
41                 return -EINVAL;
42
43         if (pos >= node->len)
44                 return 0;
45
46         if (count > node->len - pos)
47                 count = node->len - pos;
48
49         pa = node->paddr + sizeof(struct setup_data) + pos;
50         pg = pfn_to_page((pa + count - 1) >> PAGE_SHIFT);
51         if (PageHighMem(pg)) {
52                 p = ioremap_cache(pa, count);
53                 if (!p)
54                         return -ENXIO;
55         } else
56                 p = __va(pa);
57
58         remain = copy_to_user(user_buf, p, count);
59
60         if (PageHighMem(pg))
61                 iounmap(p);
62
63         if (remain)
64                 return -EFAULT;
65
66         *ppos = pos + count;
67
68         return count;
69 }
70
71 static const struct file_operations fops_setup_data = {
72         .read           = setup_data_read,
73         .open           = simple_open,
74         .llseek         = default_llseek,
75 };
76
77 static int __init
78 create_setup_data_node(struct dentry *parent, int no,
79                        struct setup_data_node *node)
80 {
81         struct dentry *d, *type, *data;
82         char buf[16];
83
84         sprintf(buf, "%d", no);
85         d = debugfs_create_dir(buf, parent);
86         if (!d)
87                 return -ENOMEM;
88
89         type = debugfs_create_x32("type", S_IRUGO, d, &node->type);
90         if (!type)
91                 goto err_dir;
92
93         data = debugfs_create_file("data", S_IRUGO, d, node, &fops_setup_data);
94         if (!data)
95                 goto err_type;
96
97         return 0;
98
99 err_type:
100         debugfs_remove(type);
101 err_dir:
102         debugfs_remove(d);
103         return -ENOMEM;
104 }
105
106 static int __init create_setup_data_nodes(struct dentry *parent)
107 {
108         struct setup_data_node *node;
109         struct setup_data *data;
110         int error;
111         struct dentry *d;
112         struct page *pg;
113         u64 pa_data;
114         int no = 0;
115
116         d = debugfs_create_dir("setup_data", parent);
117         if (!d)
118                 return -ENOMEM;
119
120         pa_data = boot_params.hdr.setup_data;
121
122         while (pa_data) {
123                 node = kmalloc(sizeof(*node), GFP_KERNEL);
124                 if (!node) {
125                         error = -ENOMEM;
126                         goto err_dir;
127                 }
128
129                 pg = pfn_to_page((pa_data+sizeof(*data)-1) >> PAGE_SHIFT);
130                 if (PageHighMem(pg)) {
131                         data = ioremap_cache(pa_data, sizeof(*data));
132                         if (!data) {
133                                 kfree(node);
134                                 error = -ENXIO;
135                                 goto err_dir;
136                         }
137                 } else
138                         data = __va(pa_data);
139
140                 node->paddr = pa_data;
141                 node->type = data->type;
142                 node->len = data->len;
143                 error = create_setup_data_node(d, no, node);
144                 pa_data = data->next;
145
146                 if (PageHighMem(pg))
147                         iounmap(data);
148                 if (error)
149                         goto err_dir;
150                 no++;
151         }
152
153         return 0;
154
155 err_dir:
156         debugfs_remove(d);
157         return error;
158 }
159
160 static struct debugfs_blob_wrapper boot_params_blob = {
161         .data           = &boot_params,
162         .size           = sizeof(boot_params),
163 };
164
165 static int __init boot_params_kdebugfs_init(void)
166 {
167         struct dentry *dbp, *version, *data;
168         int error = -ENOMEM;
169
170         dbp = debugfs_create_dir("boot_params", NULL);
171         if (!dbp)
172                 return -ENOMEM;
173
174         version = debugfs_create_x16("version", S_IRUGO, dbp,
175                                      &boot_params.hdr.version);
176         if (!version)
177                 goto err_dir;
178
179         data = debugfs_create_blob("data", S_IRUGO, dbp,
180                                    &boot_params_blob);
181         if (!data)
182                 goto err_version;
183
184         error = create_setup_data_nodes(dbp);
185         if (error)
186                 goto err_data;
187
188         return 0;
189
190 err_data:
191         debugfs_remove(data);
192 err_version:
193         debugfs_remove(version);
194 err_dir:
195         debugfs_remove(dbp);
196         return error;
197 }
198 #endif /* CONFIG_DEBUG_BOOT_PARAMS */
199
200 static int __init arch_kdebugfs_init(void)
201 {
202         int error = 0;
203
204         arch_debugfs_dir = debugfs_create_dir("x86", NULL);
205         if (!arch_debugfs_dir)
206                 return -ENOMEM;
207
208 #ifdef CONFIG_DEBUG_BOOT_PARAMS
209         error = boot_params_kdebugfs_init();
210 #endif
211
212         return error;
213 }
214 arch_initcall(arch_kdebugfs_init);