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 void __initdata (*of_pdt_build_more)(struct device_node *dp);
25 
26 #if defined(CONFIG_SPARC)
27 unsigned int of_pdt_unique_id __initdata;
28 
29 #define of_pdt_incr_unique_id(p) do { \
30 	(p)->unique_id = of_pdt_unique_id++; \
31 } while (0)
32 
of_pdt_build_full_name(struct device_node * dp)33 static char * __init of_pdt_build_full_name(struct device_node *dp)
34 {
35 	int len, ourlen, plen;
36 	char *n;
37 
38 	dp->path_component_name = build_path_component(dp);
39 
40 	plen = strlen(dp->parent->full_name);
41 	ourlen = strlen(dp->path_component_name);
42 	len = ourlen + plen + 2;
43 
44 	n = prom_early_alloc(len);
45 	strcpy(n, dp->parent->full_name);
46 	if (!of_node_is_root(dp->parent)) {
47 		strcpy(n + plen, "/");
48 		plen++;
49 	}
50 	strcpy(n + plen, dp->path_component_name);
51 
52 	return n;
53 }
54 
55 #else /* CONFIG_SPARC */
56 
of_pdt_incr_unique_id(void * p)57 static inline void of_pdt_incr_unique_id(void *p) { }
irq_trans_init(struct device_node * dp)58 static inline void irq_trans_init(struct device_node *dp) { }
59 
of_pdt_build_full_name(struct device_node * dp)60 static char * __init of_pdt_build_full_name(struct device_node *dp)
61 {
62 	static int failsafe_id = 0; /* for generating unique names on failure */
63 	char *buf;
64 	int len;
65 
66 	if (of_pdt_prom_ops->pkg2path(dp->phandle, NULL, 0, &len))
67 		goto failsafe;
68 
69 	buf = prom_early_alloc(len + 1);
70 	if (of_pdt_prom_ops->pkg2path(dp->phandle, buf, len, &len))
71 		goto failsafe;
72 	return buf;
73 
74  failsafe:
75 	buf = prom_early_alloc(strlen(dp->parent->full_name) +
76 			       strlen(dp->name) + 16);
77 	sprintf(buf, "%s/%s@unknown%i",
78 		of_node_is_root(dp->parent) ? "" : dp->parent->full_name,
79 		dp->name, failsafe_id++);
80 	pr_err("%s: pkg2path failed; assigning %s\n", __func__, buf);
81 	return buf;
82 }
83 
84 #endif /* !CONFIG_SPARC */
85 
of_pdt_build_one_prop(phandle node,char * prev,char * special_name,void * special_val,int special_len)86 static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
87 					       char *special_name,
88 					       void *special_val,
89 					       int special_len)
90 {
91 	static struct property *tmp = NULL;
92 	struct property *p;
93 	int err;
94 
95 	if (tmp) {
96 		p = tmp;
97 		memset(p, 0, sizeof(*p) + 32);
98 		tmp = NULL;
99 	} else {
100 		p = prom_early_alloc(sizeof(struct property) + 32);
101 		of_pdt_incr_unique_id(p);
102 	}
103 
104 	p->name = (char *) (p + 1);
105 	if (special_name) {
106 		strcpy(p->name, special_name);
107 		p->length = special_len;
108 		p->value = prom_early_alloc(special_len);
109 		memcpy(p->value, special_val, special_len);
110 	} else {
111 		err = of_pdt_prom_ops->nextprop(node, prev, p->name);
112 		if (err) {
113 			tmp = p;
114 			return NULL;
115 		}
116 		p->length = of_pdt_prom_ops->getproplen(node, p->name);
117 		if (p->length <= 0) {
118 			p->length = 0;
119 		} else {
120 			int len;
121 
122 			p->value = prom_early_alloc(p->length + 1);
123 			len = of_pdt_prom_ops->getproperty(node, p->name,
124 					p->value, p->length);
125 			if (len <= 0)
126 				p->length = 0;
127 			((unsigned char *)p->value)[p->length] = '\0';
128 		}
129 	}
130 	return p;
131 }
132 
of_pdt_build_prop_list(phandle node)133 static struct property * __init of_pdt_build_prop_list(phandle node)
134 {
135 	struct property *head, *tail;
136 
137 	head = tail = of_pdt_build_one_prop(node, NULL,
138 				     ".node", &node, sizeof(node));
139 
140 	tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
141 	tail = tail->next;
142 	while(tail) {
143 		tail->next = of_pdt_build_one_prop(node, tail->name,
144 					    NULL, NULL, 0);
145 		tail = tail->next;
146 	}
147 
148 	return head;
149 }
150 
of_pdt_get_one_property(phandle node,const char * name)151 static char * __init of_pdt_get_one_property(phandle node, const char *name)
152 {
153 	char *buf = "<NULL>";
154 	int len;
155 
156 	len = of_pdt_prom_ops->getproplen(node, name);
157 	if (len > 0) {
158 		buf = prom_early_alloc(len);
159 		len = of_pdt_prom_ops->getproperty(node, name, buf, len);
160 	}
161 
162 	return buf;
163 }
164 
of_pdt_create_node(phandle node,struct device_node * parent)165 static struct device_node * __init of_pdt_create_node(phandle node,
166 						    struct device_node *parent)
167 {
168 	struct device_node *dp;
169 
170 	if (!node)
171 		return NULL;
172 
173 	dp = prom_early_alloc(sizeof(*dp));
174 	of_node_init(dp);
175 	of_pdt_incr_unique_id(dp);
176 	dp->parent = parent;
177 
178 	dp->name = of_pdt_get_one_property(node, "name");
179 	dp->type = of_pdt_get_one_property(node, "device_type");
180 	dp->phandle = node;
181 
182 	dp->properties = of_pdt_build_prop_list(node);
183 
184 	irq_trans_init(dp);
185 
186 	return dp;
187 }
188 
of_pdt_build_tree(struct device_node * parent,phandle node)189 static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
190 						   phandle node)
191 {
192 	struct device_node *ret = NULL, *prev_sibling = NULL;
193 	struct device_node *dp;
194 
195 	while (1) {
196 		dp = of_pdt_create_node(node, parent);
197 		if (!dp)
198 			break;
199 
200 		if (prev_sibling)
201 			prev_sibling->sibling = dp;
202 
203 		if (!ret)
204 			ret = dp;
205 		prev_sibling = dp;
206 
207 		dp->full_name = of_pdt_build_full_name(dp);
208 
209 		dp->child = of_pdt_build_tree(dp, of_pdt_prom_ops->getchild(node));
210 
211 		if (of_pdt_build_more)
212 			of_pdt_build_more(dp);
213 
214 		node = of_pdt_prom_ops->getsibling(node);
215 	}
216 
217 	return ret;
218 }
219 
kernel_tree_alloc(u64 size,u64 align)220 static void * __init kernel_tree_alloc(u64 size, u64 align)
221 {
222 	return prom_early_alloc(size);
223 }
224 
of_pdt_build_devicetree(phandle root_node,struct of_pdt_ops * ops)225 void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
226 {
227 	BUG_ON(!ops);
228 	of_pdt_prom_ops = ops;
229 
230 	of_root = of_pdt_create_node(root_node, NULL);
231 #if defined(CONFIG_SPARC)
232 	of_root->path_component_name = "";
233 #endif
234 	of_root->full_name = "/";
235 
236 	of_root->child = of_pdt_build_tree(of_root,
237 				of_pdt_prom_ops->getchild(of_root->phandle));
238 
239 	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
240 	of_alias_scan(kernel_tree_alloc);
241 }
242