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 #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 }