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 #if defined(CONFIG_SPARC) 25 unsigned 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 31 static 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 38 static inline void of_pdt_incr_unique_id(void *p) { } 39 static inline void irq_trans_init(struct device_node *dp) { } 40 41 static 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 65 static 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 } 111 112 static 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 } 129 130 static 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 } 143 144 static 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 } 168 169 static 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 } 194 195 static void * __init kernel_tree_alloc(u64 size, u64 align) 196 { 197 return prom_early_alloc(size); 198 } 199 200 void __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