1 // SPDX-License-Identifier: GPL-2.0+
2 /* pdt.c: OF PROM device tree support code.
3 *
4 * Paul Mackerras August 1996.
5 * Copyright (C) 1996-2005 Paul Mackerras.
6 *
7 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8 * {engebret|bergner}@us.ibm.com
9 *
10 * Adapted for sparc by David S. Miller davem@davemloft.net
11 * Adapted for multiple architectures by Andres Salomon <dilinger@queued.net>
12 */
13
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/errno.h>
17 #include <linux/mutex.h>
18 #include <linux/slab.h>
19 #include <linux/of.h>
20 #include <linux/of_pdt.h>
21
22 static struct of_pdt_ops *of_pdt_prom_ops __initdata;
23
24 #if defined(CONFIG_SPARC)
25 unsigned int of_pdt_unique_id __initdata;
26
27 #define of_pdt_incr_unique_id(p) do { \
28 (p)->unique_id = of_pdt_unique_id++; \
29 } while (0)
30
of_pdt_build_full_name(struct device_node * dp)31 static char * __init of_pdt_build_full_name(struct device_node *dp)
32 {
33 return build_path_component(dp);
34 }
35
36 #else /* CONFIG_SPARC */
37
of_pdt_incr_unique_id(void * p)38 static inline void of_pdt_incr_unique_id(void *p) { }
irq_trans_init(struct device_node * dp)39 static inline void irq_trans_init(struct device_node *dp) { }
40
of_pdt_build_full_name(struct device_node * dp)41 static char * __init of_pdt_build_full_name(struct device_node *dp)
42 {
43 static int failsafe_id = 0; /* for generating unique names on failure */
44 const char *name;
45 char path[256];
46 char *buf;
47 int len;
48
49 if (!of_pdt_prom_ops->pkg2path(dp->phandle, path, sizeof(path), &len)) {
50 name = kbasename(path);
51 buf = prom_early_alloc(strlen(name) + 1);
52 strcpy(buf, name);
53 return buf;
54 }
55
56 name = of_get_property(dp, "name", &len);
57 buf = prom_early_alloc(len + 16);
58 sprintf(buf, "%s@unknown%i", name, failsafe_id++);
59 pr_err("%s: pkg2path failed; assigning %s\n", __func__, buf);
60 return buf;
61 }
62
63 #endif /* !CONFIG_SPARC */
64
of_pdt_build_one_prop(phandle node,char * prev,char * special_name,void * special_val,int special_len)65 static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
66 char *special_name,
67 void *special_val,
68 int special_len)
69 {
70 static struct property *tmp = NULL;
71 struct property *p;
72 int err;
73
74 if (tmp) {
75 p = tmp;
76 memset(p, 0, sizeof(*p) + 32);
77 tmp = NULL;
78 } else {
79 p = prom_early_alloc(sizeof(struct property) + 32);
80 of_pdt_incr_unique_id(p);
81 }
82
83 p->name = (char *) (p + 1);
84 if (special_name) {
85 strcpy(p->name, special_name);
86 p->length = special_len;
87 p->value = prom_early_alloc(special_len);
88 memcpy(p->value, special_val, special_len);
89 } else {
90 err = of_pdt_prom_ops->nextprop(node, prev, p->name);
91 if (err) {
92 tmp = p;
93 return NULL;
94 }
95 p->length = of_pdt_prom_ops->getproplen(node, p->name);
96 if (p->length <= 0) {
97 p->length = 0;
98 } else {
99 int len;
100
101 p->value = prom_early_alloc(p->length + 1);
102 len = of_pdt_prom_ops->getproperty(node, p->name,
103 p->value, p->length);
104 if (len <= 0)
105 p->length = 0;
106 ((unsigned char *)p->value)[p->length] = '\0';
107 }
108 }
109 return p;
110 }
111
of_pdt_build_prop_list(phandle node)112 static struct property * __init of_pdt_build_prop_list(phandle node)
113 {
114 struct property *head, *tail;
115
116 head = tail = of_pdt_build_one_prop(node, NULL,
117 ".node", &node, sizeof(node));
118
119 tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
120 tail = tail->next;
121 while(tail) {
122 tail->next = of_pdt_build_one_prop(node, tail->name,
123 NULL, NULL, 0);
124 tail = tail->next;
125 }
126
127 return head;
128 }
129
of_pdt_get_one_property(phandle node,const char * name)130 static char * __init of_pdt_get_one_property(phandle node, const char *name)
131 {
132 char *buf = "<NULL>";
133 int len;
134
135 len = of_pdt_prom_ops->getproplen(node, name);
136 if (len > 0) {
137 buf = prom_early_alloc(len);
138 len = of_pdt_prom_ops->getproperty(node, name, buf, len);
139 }
140
141 return buf;
142 }
143
of_pdt_create_node(phandle node,struct device_node * parent)144 static struct device_node * __init of_pdt_create_node(phandle node,
145 struct device_node *parent)
146 {
147 struct device_node *dp;
148
149 if (!node)
150 return NULL;
151
152 dp = prom_early_alloc(sizeof(*dp));
153 of_node_init(dp);
154 of_pdt_incr_unique_id(dp);
155 dp->parent = parent;
156
157 dp->name = of_pdt_get_one_property(node, "name");
158 dp->phandle = node;
159
160 dp->properties = of_pdt_build_prop_list(node);
161
162 dp->full_name = of_pdt_build_full_name(dp);
163
164 irq_trans_init(dp);
165
166 return dp;
167 }
168
of_pdt_build_tree(struct device_node * parent,phandle node)169 static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
170 phandle node)
171 {
172 struct device_node *ret = NULL, *prev_sibling = NULL;
173 struct device_node *dp;
174
175 while (1) {
176 dp = of_pdt_create_node(node, parent);
177 if (!dp)
178 break;
179
180 if (prev_sibling)
181 prev_sibling->sibling = dp;
182
183 if (!ret)
184 ret = dp;
185 prev_sibling = dp;
186
187 dp->child = of_pdt_build_tree(dp, of_pdt_prom_ops->getchild(node));
188
189 node = of_pdt_prom_ops->getsibling(node);
190 }
191
192 return ret;
193 }
194
kernel_tree_alloc(u64 size,u64 align)195 static void * __init kernel_tree_alloc(u64 size, u64 align)
196 {
197 return prom_early_alloc(size);
198 }
199
of_pdt_build_devicetree(phandle root_node,struct of_pdt_ops * ops)200 void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
201 {
202 BUG_ON(!ops);
203 of_pdt_prom_ops = ops;
204
205 of_root = of_pdt_create_node(root_node, NULL);
206 of_root->full_name = "/";
207
208 of_root->child = of_pdt_build_tree(of_root,
209 of_pdt_prom_ops->getchild(of_root->phandle));
210
211 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
212 of_alias_scan(kernel_tree_alloc);
213 }
214