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 = -ENOMEM;
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			goto err_dir;
126
127		pg = pfn_to_page((pa_data+sizeof(*data)-1) >> PAGE_SHIFT);
128		if (PageHighMem(pg)) {
129			data = ioremap_cache(pa_data, sizeof(*data));
130			if (!data) {
131				kfree(node);
132				error = -ENXIO;
133				goto err_dir;
134			}
135		} else
136			data = __va(pa_data);
137
138		node->paddr = pa_data;
139		node->type = data->type;
140		node->len = data->len;
141		error = create_setup_data_node(d, no, node);
142		pa_data = data->next;
143
144		if (PageHighMem(pg))
145			iounmap(data);
146		if (error)
147			goto err_dir;
148		no++;
149	}
150
151	return 0;
152
153err_dir:
154	debugfs_remove(d);
155	return error;
156}
157
158static struct debugfs_blob_wrapper boot_params_blob = {
159	.data		= &boot_params,
160	.size		= sizeof(boot_params),
161};
162
163static int __init boot_params_kdebugfs_init(void)
164{
165	struct dentry *dbp, *version, *data;
166	int error = -ENOMEM;
167
168	dbp = debugfs_create_dir("boot_params", NULL);
169	if (!dbp)
170		return -ENOMEM;
171
172	version = debugfs_create_x16("version", S_IRUGO, dbp,
173				     &boot_params.hdr.version);
174	if (!version)
175		goto err_dir;
176
177	data = debugfs_create_blob("data", S_IRUGO, dbp,
178				   &boot_params_blob);
179	if (!data)
180		goto err_version;
181
182	error = create_setup_data_nodes(dbp);
183	if (error)
184		goto err_data;
185
186	return 0;
187
188err_data:
189	debugfs_remove(data);
190err_version:
191	debugfs_remove(version);
192err_dir:
193	debugfs_remove(dbp);
194	return error;
195}
196#endif /* CONFIG_DEBUG_BOOT_PARAMS */
197
198static int __init arch_kdebugfs_init(void)
199{
200	int error = 0;
201
202	arch_debugfs_dir = debugfs_create_dir("x86", NULL);
203	if (!arch_debugfs_dir)
204		return -ENOMEM;
205
206#ifdef CONFIG_DEBUG_BOOT_PARAMS
207	error = boot_params_kdebugfs_init();
208#endif
209
210	return error;
211}
212arch_initcall(arch_kdebugfs_init);