blob: 5df67f1d6c612537f10ac2fd84b6720911d16723 [file] [log] [blame]
Zhang Ruia25ee922010-07-15 10:46:15 +08001/*
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
13ACPI_MODULE_NAME("debugfs");
14
Zhang Ruic637e482010-07-15 10:46:17 +080015
16/* /sys/modules/acpi/parameters/aml_debug_output */
17
18module_param_named(aml_debug_output, acpi_gbl_enable_aml_debug_object,
19 bool, 0644);
20MODULE_PARM_DESC(aml_debug_output,
21 "To enable/disable the ACPI Debug Object output.");
22
Zhang Ruia25ee922010-07-15 10:46:15 +080023/* /sys/kernel/debug/acpi/custom_method */
24
25static 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
70static const struct file_operations cm_fops = {
71 .write = cm_write,
Arnd Bergmann6038f372010-08-15 18:52:59 +020072 .llseek = default_llseek,
Zhang Ruia25ee922010-07-15 10:46:15 +080073};
74
75int __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
Dave Jonesed3aada2010-11-13 00:58:54 -050083 cm_dentry = debugfs_create_file("custom_method", S_IWUSR,
Zhang Ruia25ee922010-07-15 10:46:15 +080084 acpi_dir, NULL, &cm_fops);
85 if (!cm_dentry)
86 goto err;
87
88 return 0;
89
90err:
91 if (acpi_dir)
92 debugfs_remove(acpi_dir);
93 return -EINVAL;
94}