Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...
[linux-2.6.git] / drivers / acpi / debugfs.c
1 /*
2  * debugfs.c - ACPI debugfs interface to userspace.
3  */
4
5 #include <linux/init.h>
6 #include <linux/module.h>
7 #include <linux/kernel.h>
8 #include <linux/uaccess.h>
9 #include <linux/debugfs.h>
10 #include <acpi/acpi_drivers.h>
11
12 #define _COMPONENT              ACPI_SYSTEM_COMPONENT
13 ACPI_MODULE_NAME("debugfs");
14
15
16 /* /sys/modules/acpi/parameters/aml_debug_output */
17
18 module_param_named(aml_debug_output, acpi_gbl_enable_aml_debug_object,
19                    bool, 0644);
20 MODULE_PARM_DESC(aml_debug_output,
21                  "To enable/disable the ACPI Debug Object output.");
22
23 /* /sys/kernel/debug/acpi/custom_method */
24
25 static ssize_t cm_write(struct file *file, const char __user * user_buf,
26                         size_t count, loff_t *ppos)
27 {
28         static char *buf;
29         static int uncopied_bytes;
30         struct acpi_table_header table;
31         acpi_status status;
32
33         if (!(*ppos)) {
34                 /* parse the table header to get the table length */
35                 if (count <= sizeof(struct acpi_table_header))
36                         return -EINVAL;
37                 if (copy_from_user(&table, user_buf,
38                                    sizeof(struct acpi_table_header)))
39                         return -EFAULT;
40                 uncopied_bytes = table.length;
41                 buf = kzalloc(uncopied_bytes, GFP_KERNEL);
42                 if (!buf)
43                         return -ENOMEM;
44         }
45
46         if (uncopied_bytes < count) {
47                 kfree(buf);
48                 return -EINVAL;
49         }
50
51         if (copy_from_user(buf + (*ppos), user_buf, count)) {
52                 kfree(buf);
53                 return -EFAULT;
54         }
55
56         uncopied_bytes -= count;
57         *ppos += count;
58
59         if (!uncopied_bytes) {
60                 status = acpi_install_method(buf);
61                 kfree(buf);
62                 if (ACPI_FAILURE(status))
63                         return -EINVAL;
64                 add_taint(TAINT_OVERRIDDEN_ACPI_TABLE);
65         }
66
67         return count;
68 }
69
70 static const struct file_operations cm_fops = {
71         .write = cm_write,
72         .llseek = default_llseek,
73 };
74
75 int __init acpi_debugfs_init(void)
76 {
77         struct dentry *acpi_dir, *cm_dentry;
78
79         acpi_dir = debugfs_create_dir("acpi", NULL);
80         if (!acpi_dir)
81                 goto err;
82
83         cm_dentry = debugfs_create_file("custom_method", S_IWUSR,
84                                         acpi_dir, NULL, &cm_fops);
85         if (!cm_dentry)
86                 goto err;
87
88         return 0;
89
90 err:
91         if (acpi_dir)
92                 debugfs_remove(acpi_dir);
93         return -EINVAL;
94 }