WMI: fix potential NULL pointer dereference
[linux-2.6/x86.git] / arch / sparc / kernel / prom_common.c
blob1f830da2ddf2317df09c8b62340c41050ba55883
1 /* prom_common.c: OF device tree support common code.
3 * Paul Mackerras August 1996.
4 * Copyright (C) 1996-2005 Paul Mackerras.
6 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
7 * {engebret|bergner}@us.ibm.com
9 * Adapted for sparc by David S. Miller davem@davemloft.net
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/errno.h>
20 #include <linux/mutex.h>
21 #include <linux/slab.h>
22 #include <linux/of.h>
23 #include <asm/prom.h>
24 #include <asm/oplib.h>
25 #include <asm/leon.h>
27 #include "prom.h"
29 void (*prom_build_more)(struct device_node *dp, struct device_node ***nextp);
31 struct device_node *of_console_device;
32 EXPORT_SYMBOL(of_console_device);
34 char *of_console_path;
35 EXPORT_SYMBOL(of_console_path);
37 char *of_console_options;
38 EXPORT_SYMBOL(of_console_options);
40 int of_getintprop_default(struct device_node *np, const char *name, int def)
42 struct property *prop;
43 int len;
45 prop = of_find_property(np, name, &len);
46 if (!prop || len != 4)
47 return def;
49 return *(int *) prop->value;
51 EXPORT_SYMBOL(of_getintprop_default);
53 DEFINE_MUTEX(of_set_property_mutex);
54 EXPORT_SYMBOL(of_set_property_mutex);
56 int of_set_property(struct device_node *dp, const char *name, void *val, int len)
58 struct property **prevp;
59 void *new_val;
60 int err;
62 new_val = kmalloc(len, GFP_KERNEL);
63 if (!new_val)
64 return -ENOMEM;
66 memcpy(new_val, val, len);
68 err = -ENODEV;
70 mutex_lock(&of_set_property_mutex);
71 write_lock(&devtree_lock);
72 prevp = &dp->properties;
73 while (*prevp) {
74 struct property *prop = *prevp;
76 if (!strcasecmp(prop->name, name)) {
77 void *old_val = prop->value;
78 int ret;
80 ret = prom_setprop(dp->phandle, name, val, len);
82 err = -EINVAL;
83 if (ret >= 0) {
84 prop->value = new_val;
85 prop->length = len;
87 if (OF_IS_DYNAMIC(prop))
88 kfree(old_val);
90 OF_MARK_DYNAMIC(prop);
92 err = 0;
94 break;
96 prevp = &(*prevp)->next;
98 write_unlock(&devtree_lock);
99 mutex_unlock(&of_set_property_mutex);
101 /* XXX Upate procfs if necessary... */
103 return err;
105 EXPORT_SYMBOL(of_set_property);
107 int of_find_in_proplist(const char *list, const char *match, int len)
109 while (len > 0) {
110 int l;
112 if (!strcmp(list, match))
113 return 1;
114 l = strlen(list) + 1;
115 list += l;
116 len -= l;
118 return 0;
120 EXPORT_SYMBOL(of_find_in_proplist);
122 unsigned int prom_unique_id;
124 static struct property * __init build_one_prop(phandle node, char *prev,
125 char *special_name,
126 void *special_val,
127 int special_len)
129 static struct property *tmp = NULL;
130 struct property *p;
131 const char *name;
133 if (tmp) {
134 p = tmp;
135 memset(p, 0, sizeof(*p) + 32);
136 tmp = NULL;
137 } else {
138 p = prom_early_alloc(sizeof(struct property) + 32);
139 p->unique_id = prom_unique_id++;
142 p->name = (char *) (p + 1);
143 if (special_name) {
144 strcpy(p->name, special_name);
145 p->length = special_len;
146 p->value = prom_early_alloc(special_len);
147 memcpy(p->value, special_val, special_len);
148 } else {
149 if (prev == NULL) {
150 name = prom_firstprop(node, p->name);
151 } else {
152 name = prom_nextprop(node, prev, p->name);
155 if (!name || strlen(name) == 0) {
156 tmp = p;
157 return NULL;
159 #ifdef CONFIG_SPARC32
160 strcpy(p->name, name);
161 #endif
162 p->length = prom_getproplen(node, p->name);
163 if (p->length <= 0) {
164 p->length = 0;
165 } else {
166 int len;
168 p->value = prom_early_alloc(p->length + 1);
169 len = prom_getproperty(node, p->name, p->value,
170 p->length);
171 if (len <= 0)
172 p->length = 0;
173 ((unsigned char *)p->value)[p->length] = '\0';
176 return p;
179 static struct property * __init build_prop_list(phandle node)
181 struct property *head, *tail;
183 head = tail = build_one_prop(node, NULL,
184 ".node", &node, sizeof(node));
186 tail->next = build_one_prop(node, NULL, NULL, NULL, 0);
187 tail = tail->next;
188 while(tail) {
189 tail->next = build_one_prop(node, tail->name,
190 NULL, NULL, 0);
191 tail = tail->next;
194 return head;
197 static char * __init get_one_property(phandle node, const char *name)
199 char *buf = "<NULL>";
200 int len;
202 len = prom_getproplen(node, name);
203 if (len > 0) {
204 buf = prom_early_alloc(len);
205 len = prom_getproperty(node, name, buf, len);
208 return buf;
211 static struct device_node * __init prom_create_node(phandle node,
212 struct device_node *parent)
214 struct device_node *dp;
216 if (!node)
217 return NULL;
219 dp = prom_early_alloc(sizeof(*dp));
220 dp->unique_id = prom_unique_id++;
221 dp->parent = parent;
223 kref_init(&dp->kref);
225 dp->name = get_one_property(node, "name");
226 dp->type = get_one_property(node, "device_type");
227 dp->phandle = node;
229 dp->properties = build_prop_list(node);
231 irq_trans_init(dp);
233 return dp;
236 char * __init build_full_name(struct device_node *dp)
238 int len, ourlen, plen;
239 char *n;
241 plen = strlen(dp->parent->full_name);
242 ourlen = strlen(dp->path_component_name);
243 len = ourlen + plen + 2;
245 n = prom_early_alloc(len);
246 strcpy(n, dp->parent->full_name);
247 if (!of_node_is_root(dp->parent)) {
248 strcpy(n + plen, "/");
249 plen++;
251 strcpy(n + plen, dp->path_component_name);
253 return n;
256 static struct device_node * __init prom_build_tree(struct device_node *parent,
257 phandle node,
258 struct device_node ***nextp)
260 struct device_node *ret = NULL, *prev_sibling = NULL;
261 struct device_node *dp;
263 while (1) {
264 dp = prom_create_node(node, parent);
265 if (!dp)
266 break;
268 if (prev_sibling)
269 prev_sibling->sibling = dp;
271 if (!ret)
272 ret = dp;
273 prev_sibling = dp;
275 *(*nextp) = dp;
276 *nextp = &dp->allnext;
278 dp->path_component_name = build_path_component(dp);
279 dp->full_name = build_full_name(dp);
281 dp->child = prom_build_tree(dp, prom_getchild(node), nextp);
283 if (prom_build_more)
284 prom_build_more(dp, nextp);
286 node = prom_getsibling(node);
289 return ret;
292 unsigned int prom_early_allocated __initdata;
294 void __init prom_build_devicetree(void)
296 struct device_node **nextp;
298 allnodes = prom_create_node(prom_root_node, NULL);
299 allnodes->path_component_name = "";
300 allnodes->full_name = "/";
302 nextp = &allnodes->allnext;
303 allnodes->child = prom_build_tree(allnodes,
304 prom_getchild(allnodes->phandle),
305 &nextp);
306 of_console_init();
308 printk("PROM: Built device tree with %u bytes of memory.\n",
309 prom_early_allocated);