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
22static struct of_pdt_ops *of_pdt_prom_ops __initdata;
23
24#if defined(CONFIG_SPARC)
25unsigned 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
31static 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
38static inline void of_pdt_incr_unique_id(void *p) { }
39static inline void irq_trans_init(struct device_node *dp) { }
40
41static 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
65static 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
112static 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
130static 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
144static 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
169static 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
195static void * __init kernel_tree_alloc(u64 size, u64 align)
196{
197	return prom_early_alloc(size);
198}
199
200void __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