pdt.c

  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#include "of_private.h"
 23
 24static struct of_pdt_ops *of_pdt_prom_ops __initdata;
 25
 26#if defined(CONFIG_SPARC)
 27unsigned 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
 33static char * __init of_pdt_build_full_name(struct device_node *dp)
 34{
 35	return build_path_component(dp);
 36}
 37
 38#else /* CONFIG_SPARC */
 39
 40static inline void of_pdt_incr_unique_id(void *p) { }
 41static inline void irq_trans_init(struct device_node *dp) { }
 42
 43static char * __init of_pdt_build_full_name(struct device_node *dp)
 44{
 45	static int failsafe_id = 0; /* for generating unique names on failure */
 46	const char *name;
 47	char path[256];
 48	char *buf;
 49	int len;
 50
 51	if (!of_pdt_prom_ops->pkg2path(dp->phandle, path, sizeof(path), &len)) {
 52		name = kbasename(path);
 53		buf = prom_early_alloc(strlen(name) + 1);
 54		strcpy(buf, name);
 55		return buf;
 56	}
 57
 58	name = of_get_property(dp, "name", &len);
 59	buf = prom_early_alloc(len + 16);
 60	sprintf(buf, "%s@unknown%i", name, failsafe_id++);
 61	pr_err("%s: pkg2path failed; assigning %s\n", __func__, buf);
 62	return buf;
 63}
 64
 65#endif /* !CONFIG_SPARC */
 66
 67static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
 68					       char *special_name,
 69					       void *special_val,
 70					       int special_len)
 71{
 72	static struct property *tmp = NULL;
 73	struct property *p;
 74	int err;
 75
 76	if (tmp) {
 77		p = tmp;
 78		memset(p, 0, sizeof(*p) + 32);
 79		tmp = NULL;
 80	} else {
 81		p = prom_early_alloc(sizeof(struct property) + 32);
 82		of_pdt_incr_unique_id(p);
 83	}
 84
 85	p->name = (char *) (p + 1);
 86	if (special_name) {
 87		strcpy(p->name, special_name);
 88		p->length = special_len;
 89		p->value = prom_early_alloc(special_len);
 90		memcpy(p->value, special_val, special_len);
 91	} else {
 92		err = of_pdt_prom_ops->nextprop(node, prev, p->name);
 93		if (err) {
 94			tmp = p;
 95			return NULL;
 96		}
 97		p->length = of_pdt_prom_ops->getproplen(node, p->name);
 98		if (p->length <= 0) {
 99			p->length = 0;
100		} else {
101			int len;
102
103			p->value = prom_early_alloc(p->length + 1);
104			len = of_pdt_prom_ops->getproperty(node, p->name,
105					p->value, p->length);
106			if (len <= 0)
107				p->length = 0;
108			((unsigned char *)p->value)[p->length] = '\0';
109		}
110	}
111	return p;
112}
113
114static struct property * __init of_pdt_build_prop_list(phandle node)
115{
116	struct property *head, *tail;
117
118	head = tail = of_pdt_build_one_prop(node, NULL,
119				     ".node", &node, sizeof(node));
120
121	tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
122	tail = tail->next;
123	while(tail) {
124		tail->next = of_pdt_build_one_prop(node, tail->name,
125					    NULL, NULL, 0);
126		tail = tail->next;
127	}
128
129	return head;
130}
131
132static char * __init of_pdt_get_one_property(phandle node, const char *name)
133{
134	char *buf = "<NULL>";
135	int len;
136
137	len = of_pdt_prom_ops->getproplen(node, name);
138	if (len > 0) {
139		buf = prom_early_alloc(len);
140		len = of_pdt_prom_ops->getproperty(node, name, buf, len);
141	}
142
143	return buf;
144}
145
146static struct device_node * __init of_pdt_create_node(phandle node,
147						    struct device_node *parent)
148{
149	struct device_node *dp;
150
151	if (!node)
152		return NULL;
153
154	dp = prom_early_alloc(sizeof(*dp));
155	of_node_init(dp);
156	of_pdt_incr_unique_id(dp);
157	dp->parent = parent;
158
159	dp->name = of_pdt_get_one_property(node, "name");
160	dp->phandle = node;
161
162	dp->properties = of_pdt_build_prop_list(node);
163
164	dp->full_name = of_pdt_build_full_name(dp);
165
166	irq_trans_init(dp);
167
168	return dp;
169}
170
171static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
172						   phandle node)
173{
174	struct device_node *ret = NULL, *prev_sibling = NULL;
175	struct device_node *dp;
176
177	while (1) {
178		dp = of_pdt_create_node(node, parent);
179		if (!dp)
180			break;
181
182		if (prev_sibling)
183			prev_sibling->sibling = dp;
184
185		if (!ret)
186			ret = dp;
187		prev_sibling = dp;
188
189		dp->child = of_pdt_build_tree(dp, of_pdt_prom_ops->getchild(node));
190
191		node = of_pdt_prom_ops->getsibling(node);
192	}
193
194	return ret;
195}
196
197static void * __init kernel_tree_alloc(u64 size, u64 align)
198{
199	return prom_early_alloc(size);
200}
201
202void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
203{
204	BUG_ON(!ops);
205	of_pdt_prom_ops = ops;
206
207	of_root = of_pdt_create_node(root_node, NULL);
208	of_root->full_name = "/";
209
210	of_root->child = of_pdt_build_tree(of_root,
211				of_pdt_prom_ops->getchild(of_root->phandle));
212
213	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
214	of_alias_scan(kernel_tree_alloc);
215}