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
20struct dentry *arch_debugfs_dir;
21EXPORT_SYMBOL(arch_debugfs_dir);
22
23#ifdef CONFIG_DEBUG_BOOT_PARAMS
24struct setup_data_node {
25	u64 paddr;
26	u32 type;
27	u32 len;
28};
29
30static 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
71static const struct file_operations fops_setup_data = {
72	.read		= setup_data_read,
73	.open		= simple_open,
74	.llseek		= default_llseek,
75};
76
77static int __init
78create_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
99err_type:
100	debugfs_remove(type);
101err_dir:
102	debugfs_remove(d);
103	return -ENOMEM;
104}
105
106static 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
155err_dir:
156	debugfs_remove(d);
157	return error;
158}
159
160static struct debugfs_blob_wrapper boot_params_blob = {
161	.data		= &boot_params,
162	.size		= sizeof(boot_params),
163};
164
165static 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
190err_data:
191	debugfs_remove(data);
192err_version:
193	debugfs_remove(version);
194err_dir:
195	debugfs_remove(dbp);
196	return error;
197}
198#endif /* CONFIG_DEBUG_BOOT_PARAMS */
199
200static 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}
214arch_initcall(arch_kdebugfs_init);
215