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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.com9 *10 * Adapted for sparc by David S. Miller davem@davemloft.net11 * 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