drivers/of/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 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         int len, ourlen, plen;
  36         char *n;
  37
  38         dp->path_component_name = build_path_component(dp);
  39
  40         plen = strlen(dp->parent->full_name);
  41         ourlen = strlen(dp->path_component_name);
  42         len = ourlen + plen + 2;
  43
  44         n = prom_early_alloc(len);
  45         strcpy(n, dp->parent->full_name);
  46         if (!of_node_is_root(dp->parent)) {
  47                 strcpy(n + plen, "/");
  48                 plen++;
  49         }
  50         strcpy(n + plen, dp->path_component_name);
  51
  52         return n;
  53 }
  54
  55 #else /* CONFIG_SPARC */
  56
  57 static inline void of_pdt_incr_unique_id(void *p) { }
  58 static inline void irq_trans_init(struct device_node *dp) { }
  59
  60 static char * __init of_pdt_build_full_name(struct device_node *dp)
  61 {
  62         static int failsafe_id = 0; /* for generating unique names on failure */
  63         char *buf;
  64         int len;
  65
  66         if (of_pdt_prom_ops->pkg2path(dp->phandle, NULL, 0, &len))
  67                 goto failsafe;
  68
  69         buf = prom_early_alloc(len + 1);
  70         if (of_pdt_prom_ops->pkg2path(dp->phandle, buf, len, &len))
  71                 goto failsafe;
  72         return buf;
  73
  74  failsafe:
  75         buf = prom_early_alloc(strlen(dp->parent->full_name) +
  76                                strlen(dp->name) + 16);
  77         sprintf(buf, "%s/%s@unknown%i",
  78                 of_node_is_root(dp->parent) ? "" : dp->parent->full_name,
  79                 dp->name, failsafe_id++);
  80         pr_err("%s: pkg2path failed; assigning %s\n", __func__, buf);
  81         return buf;
  82 }
  83
  84 #endif /* !CONFIG_SPARC */
  85
  86 static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
  87                                                char *special_name,
  88                                                void *special_val,
  89                                                int special_len)
  90 {
  91         static struct property *tmp = NULL;
  92         struct property *p;
  93         int err;
  94
  95         if (tmp) {
  96                 p = tmp;
  97                 memset(p, 0, sizeof(*p) + 32);
  98                 tmp = NULL;
  99         } else {
 100                 p = prom_early_alloc(sizeof(struct property) + 32);
 101                 of_pdt_incr_unique_id(p);
 102         }
 103
 104         p->name = (char *) (p + 1);
 105         if (special_name) {
 106                 strcpy(p->name, special_name);
 107                 p->length = special_len;
 108                 p->value = prom_early_alloc(special_len);
 109                 memcpy(p->value, special_val, special_len);
 110         } else {
 111                 err = of_pdt_prom_ops->nextprop(node, prev, p->name);
 112                 if (err) {
 113                         tmp = p;
 114                         return NULL;
 115                 }
 116                 p->length = of_pdt_prom_ops->getproplen(node, p->name);
 117                 if (p->length <= 0) {
 118                         p->length = 0;
 119                 } else {
 120                         int len;
 121
 122                         p->value = prom_early_alloc(p->length + 1);
 123                         len = of_pdt_prom_ops->getproperty(node, p->name,
 124                                         p->value, p->length);
 125                         if (len <= 0)
 126                                 p->length = 0;
 127                         ((unsigned char *)p->value)[p->length] = '\0';
 128                 }
 129         }
 130         return p;
 131 }
 132
 133 static struct property * __init of_pdt_build_prop_list(phandle node)
 134 {
 135         struct property *head, *tail;
 136
 137         head = tail = of_pdt_build_one_prop(node, NULL,
 138                                      ".node", &node, sizeof(node));
 139
 140         tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
 141         tail = tail->next;
 142         while(tail) {
 143                 tail->next = of_pdt_build_one_prop(node, tail->name,
 144                                             NULL, NULL, 0);
 145                 tail = tail->next;
 146         }
 147
 148         return head;
 149 }
 150
 151 static char * __init of_pdt_get_one_property(phandle node, const char *name)
 152 {
 153         char *buf = "<NULL>";
 154         int len;
 155
 156         len = of_pdt_prom_ops->getproplen(node, name);
 157         if (len > 0) {
 158                 buf = prom_early_alloc(len);
 159                 len = of_pdt_prom_ops->getproperty(node, name, buf, len);
 160         }
 161
 162         return buf;
 163 }
 164
 165 static struct device_node * __init of_pdt_create_node(phandle node,
 166                                                     struct device_node *parent)
 167 {
 168         struct device_node *dp;
 169
 170         if (!node)
 171                 return NULL;
 172
 173         dp = prom_early_alloc(sizeof(*dp));
 174         of_node_init(dp);
 175         of_pdt_incr_unique_id(dp);
 176         dp->parent = parent;
 177
 178         dp->name = of_pdt_get_one_property(node, "name");
 179         dp->type = of_pdt_get_one_property(node, "device_type");
 180         dp->phandle = node;
 181
 182         dp->properties = of_pdt_build_prop_list(node);
 183
 184         irq_trans_init(dp);
 185
 186         return dp;
 187 }
 188
 189 static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
 190                                                    phandle node)
 191 {
 192         struct device_node *ret = NULL, *prev_sibling = NULL;
 193         struct device_node *dp;
 194
 195         while (1) {
 196                 dp = of_pdt_create_node(node, parent);
 197                 if (!dp)
 198                         break;
 199
 200                 if (prev_sibling)
 201                         prev_sibling->sibling = dp;
 202
 203                 if (!ret)
 204                         ret = dp;
 205                 prev_sibling = dp;
 206
 207                 dp->full_name = of_pdt_build_full_name(dp);
 208
 209                 dp->child = of_pdt_build_tree(dp, of_pdt_prom_ops->getchild(node));
 210
 211                 if (of_pdt_build_more)
 212                         of_pdt_build_more(dp);
 213
 214                 node = of_pdt_prom_ops->getsibling(node);
 215         }
 216
 217         return ret;
 218 }
 219
 220 static void * __init kernel_tree_alloc(u64 size, u64 align)
 221 {
 222         return prom_early_alloc(size);
 223 }
 224
 225 void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
 226 {
 227         BUG_ON(!ops);
 228         of_pdt_prom_ops = ops;
 229
 230         of_root = of_pdt_create_node(root_node, NULL);
 231 #if defined(CONFIG_SPARC)
 232         of_root->path_component_name = "";
 233 #endif
 234         of_root->full_name = "/";
 235
 236         of_root->child = of_pdt_build_tree(of_root,
 237                                 of_pdt_prom_ops->getchild(of_root->phandle));
 238
 239         /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
 240         of_alias_scan(kernel_tree_alloc);
 241 }