aboutsummaryrefslogtreecommitdiffstats
path: root/fs/proc/proc_devtree.c
blob: 9bdd077d6f55a020f06e43d93a5f7540b214b523 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
/*
 * proc_devtree.c - handles /proc/device-tree
 *
 * Copyright 1997 Paul Mackerras
 */
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <asm/prom.h>
#include <asm/uaccess.h>

#ifndef HAVE_ARCH_DEVTREE_FIXUPS
static inline void set_node_proc_entry(struct device_node *np,
				       struct proc_dir_entry *de)
{
}
#endif

static struct proc_dir_entry *proc_device_tree;

/*
 * Supply data on a read from /proc/device-tree/node/property.
 */
static int property_read_proc(char *page, char **start, off_t off,
			      int count, int *eof, void *data)
{
	struct property *pp = data;
	int n;

	if (off >= pp->length) {
		*eof = 1;
		return 0;
	}
	n = pp->length - off;
	if (n > count)
		n = count;
	else
		*eof = 1;
	memcpy(page, pp->value + off, n);
	*start = page;
	return n;
}

/*
 * For a node with a name like "gc@10", we make symlinks called "gc"
 * and "@10" to it.
 */

/*
 * Add a property to a node
 */
static struct proc_dir_entry *
__proc_device_tree_add_prop(struct proc_dir_entry *de, struct property *pp)
{
	struct proc_dir_entry *ent;

	/*
	 * Unfortunately proc_register puts each new entry
	 * at the beginning of the list.  So we rearrange them.
	 */
	ent = create_proc_read_entry(pp->name,
				     strncmp(pp->name, "security-", 9)
				     ? S_IRUGO : S_IRUSR, de,
				     property_read_proc, pp);
	if (ent == NULL)
		return NULL;

	if (!strncmp(pp->name, "security-", 9))
		ent->size = 0; /* don't leak number of password chars */
	else
		ent->size = pp->length;

	return ent;
}


void proc_device_tree_add_prop(struct proc_dir_entry *pde, struct property *prop)
{
	__proc_device_tree_add_prop(pde, prop);
}

void proc_device_tree_remove_prop(struct proc_dir_entry *pde,
				  struct property *prop)
{
	remove_proc_entry(prop->name, pde);
}

void proc_device_tree_update_prop(struct proc_dir_entry *pde,
				  struct property *newprop,
				  struct property *oldprop)
{
	struct proc_dir_entry *ent;

	for (ent = pde->subdir; ent != NULL; ent = ent->next)
		if (ent->data == oldprop)
			break;
	if (ent == NULL) {
		printk(KERN_WARNING "device-tree: property \"%s\" "
		       " does not exist\n", oldprop->name);
	} else {
		ent->data = newprop;
		ent->size = newprop->length;
	}
}

/*
 * Process a node, adding entries for its children and its properties.
 */
void proc_device_tree_add_node(struct device_node *np,
			       struct proc_dir_entry *de)
{
	struct property *pp;
	struct proc_dir_entry *ent;
	struct device_node *child;
	const char *p;

	set_node_proc_entry(np, de);
	for (child = NULL; (child = of_get_next_child(np, child));) {
		p = strrchr(child->full_name, '/');
		if (!p)
			p = child->full_name;
		else
			++p;
		ent = proc_mkdir(p, de);
		if (ent == 0)
			break;
		proc_device_tree_add_node(child, ent);
	}
	of_node_put(child);
	for (pp = np->properties; pp != 0; pp = pp->next) {
		/*
		 * Yet another Apple device-tree bogosity: on some machines,
		 * they have properties & nodes with the same name. Those
		 * properties are quite unimportant for us though, thus we
		 * simply "skip" them here, but we do have to check.
		 */
		for (ent = de->subdir; ent != NULL; ent = ent->next)
			if (!strcmp(ent->name, pp->name))
				break;
		if (ent != NULL) {
			printk(KERN_WARNING "device-tree: property \"%s\" name"
			       " conflicts with node in %s\n", pp->name,
			       np->full_name);
			continue;
		}

		ent = __proc_device_tree_add_prop(de, pp);
		if (ent == 0)
			break;
	}
}

/*
 * Called on initialization to set up the /proc/device-tree subtree
 */
void proc_device_tree_init(void)
{
	struct device_node *root;
	if ( !have_of )
		return;
	proc_device_tree = proc_mkdir("device-tree", NULL);
	if (proc_device_tree == 0)
		return;
	root = of_find_node_by_path("/");
	if (root == 0) {
		printk(KERN_ERR "/proc/device-tree: can't find root\n");
		return;
	}
	proc_device_tree_add_node(root, proc_device_tree);
	of_node_put(root);
}