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 33 static 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 40 static inline void of_pdt_incr_unique_id(void *p) { } 41 static inline void irq_trans_init(struct device_node *dp) { } 42 43 static 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 67 static 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 } 113 114 static 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 } 131 132 static 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 } 145 146 static 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->type = of_pdt_get_one_property(node, "device_type"); 161 dp->phandle = node; 162 163 dp->properties = of_pdt_build_prop_list(node); 164 165 dp->full_name = of_pdt_build_full_name(dp); 166 167 irq_trans_init(dp); 168 169 return dp; 170 } 171 172 static struct device_node * __init of_pdt_build_tree(struct device_node *parent, 173 phandle node) 174 { 175 struct device_node *ret = NULL, *prev_sibling = NULL; 176 struct device_node *dp; 177 178 while (1) { 179 dp = of_pdt_create_node(node, parent); 180 if (!dp) 181 break; 182 183 if (prev_sibling) 184 prev_sibling->sibling = dp; 185 186 if (!ret) 187 ret = dp; 188 prev_sibling = dp; 189 190 dp->child = of_pdt_build_tree(dp, of_pdt_prom_ops->getchild(node)); 191 192 if (of_pdt_build_more) 193 of_pdt_build_more(dp); 194 195 node = of_pdt_prom_ops->getsibling(node); 196 } 197 198 return ret; 199 } 200 201 static void * __init kernel_tree_alloc(u64 size, u64 align) 202 { 203 return prom_early_alloc(size); 204 } 205 206 void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops) 207 { 208 BUG_ON(!ops); 209 of_pdt_prom_ops = ops; 210 211 of_root = of_pdt_create_node(root_node, NULL); 212 of_root->full_name = "/"; 213 214 of_root->child = of_pdt_build_tree(of_root, 215 of_pdt_prom_ops->getchild(of_root->phandle)); 216 217 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */ 218 of_alias_scan(kernel_tree_alloc); 219 } 220