Pileus Git - ~andy/linux/blob - drivers/of/fdt.c

   1 /*
   2  * Functions for working with the Flattened Device Tree data format
   3  *
   4  * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
   5  * benh@kernel.crashing.org
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * version 2 as published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/lmb.h>
  14 #include <linux/initrd.h>
  15 #include <linux/of.h>
  16 #include <linux/of_fdt.h>
  17
  18
  19 #ifdef CONFIG_PPC
  20 #include <asm/machdep.h>
  21 #endif /* CONFIG_PPC */
  22
  23 int __initdata dt_root_addr_cells;
  24 int __initdata dt_root_size_cells;
  25
  26 struct boot_param_header *initial_boot_params;
  27
  28 char *find_flat_dt_string(u32 offset)
  29 {
  30         return ((char *)initial_boot_params) +
  31                 be32_to_cpu(initial_boot_params->off_dt_strings) + offset;
  32 }
  33
  34 /**
  35  * of_scan_flat_dt - scan flattened tree blob and call callback on each.
  36  * @it: callback function
  37  * @data: context data pointer
  38  *
  39  * This function is used to scan the flattened device-tree, it is
  40  * used to extract the memory information at boot before we can
  41  * unflatten the tree
  42  */
  43 int __init of_scan_flat_dt(int (*it)(unsigned long node,
  44                                      const char *uname, int depth,
  45                                      void *data),
  46                            void *data)
  47 {
  48         unsigned long p = ((unsigned long)initial_boot_params) +
  49                 be32_to_cpu(initial_boot_params->off_dt_struct);
  50         int rc = 0;
  51         int depth = -1;
  52
  53         do {
  54                 u32 tag = be32_to_cpup((__be32 *)p);
  55                 char *pathp;
  56
  57                 p += 4;
  58                 if (tag == OF_DT_END_NODE) {
  59                         depth--;
  60                         continue;
  61                 }
  62                 if (tag == OF_DT_NOP)
  63                         continue;
  64                 if (tag == OF_DT_END)
  65                         break;
  66                 if (tag == OF_DT_PROP) {
  67                         u32 sz = be32_to_cpup((__be32 *)p);
  68                         p += 8;
  69                         if (be32_to_cpu(initial_boot_params->version) < 0x10)
  70                                 p = _ALIGN(p, sz >= 8 ? 8 : 4);
  71                         p += sz;
  72                         p = _ALIGN(p, 4);
  73                         continue;
  74                 }
  75                 if (tag != OF_DT_BEGIN_NODE) {
  76                         pr_err("Invalid tag %x in flat device tree!\n", tag);
  77                         return -EINVAL;
  78                 }
  79                 depth++;
  80                 pathp = (char *)p;
  81                 p = _ALIGN(p + strlen(pathp) + 1, 4);
  82                 if ((*pathp) == '/') {
  83                         char *lp, *np;
  84                         for (lp = NULL, np = pathp; *np; np++)
  85                                 if ((*np) == '/')
  86                                         lp = np+1;
  87                         if (lp != NULL)
  88                                 pathp = lp;
  89                 }
  90                 rc = it(p, pathp, depth, data);
  91                 if (rc != 0)
  92                         break;
  93         } while (1);
  94
  95         return rc;
  96 }
  97
  98 /**
  99  * of_get_flat_dt_root - find the root node in the flat blob
 100  */
 101 unsigned long __init of_get_flat_dt_root(void)
 102 {
 103         unsigned long p = ((unsigned long)initial_boot_params) +
 104                 be32_to_cpu(initial_boot_params->off_dt_struct);
 105
 106         while (be32_to_cpup((__be32 *)p) == OF_DT_NOP)
 107                 p += 4;
 108         BUG_ON(be32_to_cpup((__be32 *)p) != OF_DT_BEGIN_NODE);
 109         p += 4;
 110         return _ALIGN(p + strlen((char *)p) + 1, 4);
 111 }
 112
 113 /**
 114  * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
 115  *
 116  * This function can be used within scan_flattened_dt callback to get
 117  * access to properties
 118  */
 119 void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
 120                                  unsigned long *size)
 121 {
 122         unsigned long p = node;
 123
 124         do {
 125                 u32 tag = be32_to_cpup((__be32 *)p);
 126                 u32 sz, noff;
 127                 const char *nstr;
 128
 129                 p += 4;
 130                 if (tag == OF_DT_NOP)
 131                         continue;
 132                 if (tag != OF_DT_PROP)
 133                         return NULL;
 134
 135                 sz = be32_to_cpup((__be32 *)p);
 136                 noff = be32_to_cpup((__be32 *)(p + 4));
 137                 p += 8;
 138                 if (be32_to_cpu(initial_boot_params->version) < 0x10)
 139                         p = _ALIGN(p, sz >= 8 ? 8 : 4);
 140
 141                 nstr = find_flat_dt_string(noff);
 142                 if (nstr == NULL) {
 143                         pr_warning("Can't find property index name !\n");
 144                         return NULL;
 145                 }
 146                 if (strcmp(name, nstr) == 0) {
 147                         if (size)
 148                                 *size = sz;
 149                         return (void *)p;
 150                 }
 151                 p += sz;
 152                 p = _ALIGN(p, 4);
 153         } while (1);
 154 }
 155
 156 /**
 157  * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
 158  * @node: node to test
 159  * @compat: compatible string to compare with compatible list.
 160  */
 161 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
 162 {
 163         const char *cp;
 164         unsigned long cplen, l;
 165
 166         cp = of_get_flat_dt_prop(node, "compatible", &cplen);
 167         if (cp == NULL)
 168                 return 0;
 169         while (cplen > 0) {
 170                 if (strncasecmp(cp, compat, strlen(compat)) == 0)
 171                         return 1;
 172                 l = strlen(cp) + 1;
 173                 cp += l;
 174                 cplen -= l;
 175         }
 176
 177         return 0;
 178 }
 179
 180 static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size,
 181                                        unsigned long align)
 182 {
 183         void *res;
 184
 185         *mem = _ALIGN(*mem, align);
 186         res = (void *)*mem;
 187         *mem += size;
 188
 189         return res;
 190 }
 191
 192 /**
 193  * unflatten_dt_node - Alloc and populate a device_node from the flat tree
 194  * @p: pointer to node in flat tree
 195  * @dad: Parent struct device_node
 196  * @allnextpp: pointer to ->allnext from last allocated device_node
 197  * @fpsize: Size of the node path up at the current depth.
 198  */
 199 unsigned long __init unflatten_dt_node(unsigned long mem,
 200                                         unsigned long *p,
 201                                         struct device_node *dad,
 202                                         struct device_node ***allnextpp,
 203                                         unsigned long fpsize)
 204 {
 205         struct device_node *np;
 206         struct property *pp, **prev_pp = NULL;
 207         char *pathp;
 208         u32 tag;
 209         unsigned int l, allocl;
 210         int has_name = 0;
 211         int new_format = 0;
 212
 213         tag = be32_to_cpup((__be32 *)(*p));
 214         if (tag != OF_DT_BEGIN_NODE) {
 215                 pr_err("Weird tag at start of node: %x\n", tag);
 216                 return mem;
 217         }
 218         *p += 4;
 219         pathp = (char *)*p;
 220         l = allocl = strlen(pathp) + 1;
 221         *p = _ALIGN(*p + l, 4);
 222
 223         /* version 0x10 has a more compact unit name here instead of the full
 224          * path. we accumulate the full path size using "fpsize", we'll rebuild
 225          * it later. We detect this because the first character of the name is
 226          * not '/'.
 227          */
 228         if ((*pathp) != '/') {
 229                 new_format = 1;
 230                 if (fpsize == 0) {
 231                         /* root node: special case. fpsize accounts for path
 232                          * plus terminating zero. root node only has '/', so
 233                          * fpsize should be 2, but we want to avoid the first
 234                          * level nodes to have two '/' so we use fpsize 1 here
 235                          */
 236                         fpsize = 1;
 237                         allocl = 2;
 238                 } else {
 239                         /* account for '/' and path size minus terminal 0
 240                          * already in 'l'
 241                          */
 242                         fpsize += l;
 243                         allocl = fpsize;
 244                 }
 245         }
 246
 247         np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
 248                                 __alignof__(struct device_node));
 249         if (allnextpp) {
 250                 memset(np, 0, sizeof(*np));
 251                 np->full_name = ((char *)np) + sizeof(struct device_node);
 252                 if (new_format) {
 253                         char *fn = np->full_name;
 254                         /* rebuild full path for new format */
 255                         if (dad && dad->parent) {
 256                                 strcpy(fn, dad->full_name);
 257 #ifdef DEBUG
 258                                 if ((strlen(fn) + l + 1) != allocl) {
 259                                         pr_debug("%s: p: %d, l: %d, a: %d\n",
 260                                                 pathp, (int)strlen(fn),
 261                                                 l, allocl);
 262                                 }
 263 #endif
 264                                 fn += strlen(fn);
 265                         }
 266                         *(fn++) = '/';
 267                         memcpy(fn, pathp, l);
 268                 } else
 269                         memcpy(np->full_name, pathp, l);
 270                 prev_pp = &np->properties;
 271                 **allnextpp = np;
 272                 *allnextpp = &np->allnext;
 273                 if (dad != NULL) {
 274                         np->parent = dad;
 275                         /* we temporarily use the next field as `last_child'*/
 276                         if (dad->next == NULL)
 277                                 dad->child = np;
 278                         else
 279                                 dad->next->sibling = np;
 280                         dad->next = np;
 281                 }
 282                 kref_init(&np->kref);
 283         }
 284         while (1) {
 285                 u32 sz, noff;
 286                 char *pname;
 287
 288                 tag = be32_to_cpup((__be32 *)(*p));
 289                 if (tag == OF_DT_NOP) {
 290                         *p += 4;
 291                         continue;
 292                 }
 293                 if (tag != OF_DT_PROP)
 294                         break;
 295                 *p += 4;
 296                 sz = be32_to_cpup((__be32 *)(*p));
 297                 noff = be32_to_cpup((__be32 *)((*p) + 4));
 298                 *p += 8;
 299                 if (be32_to_cpu(initial_boot_params->version) < 0x10)
 300                         *p = _ALIGN(*p, sz >= 8 ? 8 : 4);
 301
 302                 pname = find_flat_dt_string(noff);
 303                 if (pname == NULL) {
 304                         pr_info("Can't find property name in list !\n");
 305                         break;
 306                 }
 307                 if (strcmp(pname, "name") == 0)
 308                         has_name = 1;
 309                 l = strlen(pname) + 1;
 310                 pp = unflatten_dt_alloc(&mem, sizeof(struct property),
 311                                         __alignof__(struct property));
 312                 if (allnextpp) {
 313                         /* We accept flattened tree phandles either in
 314                          * ePAPR-style "phandle" properties, or the
 315                          * legacy "linux,phandle" properties.  If both
 316                          * appear and have different values, things
 317                          * will get weird.  Don't do that. */
 318                         if ((strcmp(pname, "phandle") == 0) ||
 319                             (strcmp(pname, "linux,phandle") == 0)) {
 320                                 if (np->phandle == 0)
 321                                         np->phandle = *((u32 *)*p);
 322                         }
 323                         /* And we process the "ibm,phandle" property
 324                          * used in pSeries dynamic device tree
 325                          * stuff */
 326                         if (strcmp(pname, "ibm,phandle") == 0)
 327                                 np->phandle = *((u32 *)*p);
 328                         pp->name = pname;
 329                         pp->length = sz;
 330                         pp->value = (void *)*p;
 331                         *prev_pp = pp;
 332                         prev_pp = &pp->next;
 333                 }
 334                 *p = _ALIGN((*p) + sz, 4);
 335         }
 336         /* with version 0x10 we may not have the name property, recreate
 337          * it here from the unit name if absent
 338          */
 339         if (!has_name) {
 340                 char *p1 = pathp, *ps = pathp, *pa = NULL;
 341                 int sz;
 342
 343                 while (*p1) {
 344                         if ((*p1) == '@')
 345                                 pa = p1;
 346                         if ((*p1) == '/')
 347                                 ps = p1 + 1;
 348                         p1++;
 349                 }
 350                 if (pa < ps)
 351                         pa = p1;
 352                 sz = (pa - ps) + 1;
 353                 pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
 354                                         __alignof__(struct property));
 355                 if (allnextpp) {
 356                         pp->name = "name";
 357                         pp->length = sz;
 358                         pp->value = pp + 1;
 359                         *prev_pp = pp;
 360                         prev_pp = &pp->next;
 361                         memcpy(pp->value, ps, sz - 1);
 362                         ((char *)pp->value)[sz - 1] = 0;
 363                         pr_debug("fixed up name for %s -> %s\n", pathp,
 364                                 (char *)pp->value);
 365                 }
 366         }
 367         if (allnextpp) {
 368                 *prev_pp = NULL;
 369                 np->name = of_get_property(np, "name", NULL);
 370                 np->type = of_get_property(np, "device_type", NULL);
 371
 372                 if (!np->name)
 373                         np->name = "<NULL>";
 374                 if (!np->type)
 375                         np->type = "<NULL>";
 376         }
 377         while (tag == OF_DT_BEGIN_NODE) {
 378                 mem = unflatten_dt_node(mem, p, np, allnextpp, fpsize);
 379                 tag = be32_to_cpup((__be32 *)(*p));
 380         }
 381         if (tag != OF_DT_END_NODE) {
 382                 pr_err("Weird tag at end of node: %x\n", tag);
 383                 return mem;
 384         }
 385         *p += 4;
 386         return mem;
 387 }
 388
 389 #ifdef CONFIG_BLK_DEV_INITRD
 390 /**
 391  * early_init_dt_check_for_initrd - Decode initrd location from flat tree
 392  * @node: reference to node containing initrd location ('chosen')
 393  */
 394 void __init early_init_dt_check_for_initrd(unsigned long node)
 395 {
 396         unsigned long start, end, len;
 397         __be32 *prop;
 398
 399         pr_debug("Looking for initrd properties... ");
 400
 401         prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
 402         if (!prop)
 403                 return;
 404         start = of_read_ulong(prop, len/4);
 405
 406         prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
 407         if (!prop)
 408                 return;
 409         end = of_read_ulong(prop, len/4);
 410
 411         early_init_dt_setup_initrd_arch(start, end);
 412         pr_debug("initrd_start=0x%lx  initrd_end=0x%lx\n", start, end);
 413 }
 414 #else
 415 inline void early_init_dt_check_for_initrd(unsigned long node)
 416 {
 417 }
 418 #endif /* CONFIG_BLK_DEV_INITRD */
 419
 420 /**
 421  * early_init_dt_scan_root - fetch the top level address and size cells
 422  */
 423 int __init early_init_dt_scan_root(unsigned long node, const char *uname,
 424                                    int depth, void *data)
 425 {
 426         __be32 *prop;
 427
 428         if (depth != 0)
 429                 return 0;
 430
 431         dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
 432         dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
 433
 434         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
 435         if (prop)
 436                 dt_root_size_cells = be32_to_cpup(prop);
 437         pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
 438
 439         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
 440         if (prop)
 441                 dt_root_addr_cells = be32_to_cpup(prop);
 442         pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
 443
 444         /* break now */
 445         return 1;
 446 }
 447
 448 u64 __init dt_mem_next_cell(int s, __be32 **cellp)
 449 {
 450         __be32 *p = *cellp;
 451
 452         *cellp = p + s;
 453         return of_read_number(p, s);
 454 }
 455
 456 /**
 457  * early_init_dt_scan_memory - Look for an parse memory nodes
 458  */
 459 int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
 460                                      int depth, void *data)
 461 {
 462         char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 463         __be32 *reg, *endp;
 464         unsigned long l;
 465
 466         /* We are scanning "memory" nodes only */
 467         if (type == NULL) {
 468                 /*
 469                  * The longtrail doesn't have a device_type on the
 470                  * /memory node, so look for the node called /memory@0.
 471                  */
 472                 if (depth != 1 || strcmp(uname, "memory@0") != 0)
 473                         return 0;
 474         } else if (strcmp(type, "memory") != 0)
 475                 return 0;
 476
 477         reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
 478         if (reg == NULL)
 479                 reg = of_get_flat_dt_prop(node, "reg", &l);
 480         if (reg == NULL)
 481                 return 0;
 482
 483         endp = reg + (l / sizeof(__be32));
 484
 485         pr_debug("memory scan node %s, reg size %ld, data: %x %x %x %x,\n",
 486             uname, l, reg[0], reg[1], reg[2], reg[3]);
 487
 488         while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
 489                 u64 base, size;
 490
 491                 base = dt_mem_next_cell(dt_root_addr_cells, &reg);
 492                 size = dt_mem_next_cell(dt_root_size_cells, &reg);
 493
 494                 if (size == 0)
 495                         continue;
 496                 pr_debug(" - %llx ,  %llx\n", (unsigned long long)base,
 497                     (unsigned long long)size);
 498
 499                 early_init_dt_add_memory_arch(base, size);
 500         }
 501
 502         return 0;
 503 }
 504
 505 int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
 506                                      int depth, void *data)
 507 {
 508         unsigned long l;
 509         char *p;
 510
 511         pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
 512
 513         if (depth != 1 ||
 514             (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
 515                 return 0;
 516
 517         early_init_dt_check_for_initrd(node);
 518
 519         /* Retreive command line */
 520         p = of_get_flat_dt_prop(node, "bootargs", &l);
 521         if (p != NULL && l > 0)
 522                 strlcpy(cmd_line, p, min((int)l, COMMAND_LINE_SIZE));
 523
 524 #ifdef CONFIG_CMDLINE
 525 #ifndef CONFIG_CMDLINE_FORCE
 526         if (p == NULL || l == 0 || (l == 1 && (*p) == 0))
 527 #endif
 528                 strlcpy(cmd_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
 529 #endif /* CONFIG_CMDLINE */
 530
 531         early_init_dt_scan_chosen_arch(node);
 532
 533         pr_debug("Command line is: %s\n", cmd_line);
 534
 535         /* break now */
 536         return 1;
 537 }
 538
 539 /**
 540  * unflatten_device_tree - create tree of device_nodes from flat blob
 541  *
 542  * unflattens the device-tree passed by the firmware, creating the
 543  * tree of struct device_node. It also fills the "name" and "type"
 544  * pointers of the nodes so the normal device-tree walking functions
 545  * can be used.
 546  */
 547 void __init unflatten_device_tree(void)
 548 {
 549         unsigned long start, mem, size;
 550         struct device_node **allnextp = &allnodes;
 551
 552         pr_debug(" -> unflatten_device_tree()\n");
 553
 554         /* First pass, scan for size */
 555         start = ((unsigned long)initial_boot_params) +
 556                 be32_to_cpu(initial_boot_params->off_dt_struct);
 557         size = unflatten_dt_node(0, &start, NULL, NULL, 0);
 558         size = (size | 3) + 1;
 559
 560         pr_debug("  size is %lx, allocating...\n", size);
 561
 562         /* Allocate memory for the expanded device tree */
 563         mem = lmb_alloc(size + 4, __alignof__(struct device_node));
 564         mem = (unsigned long) __va(mem);
 565
 566         ((__be32 *)mem)[size / 4] = cpu_to_be32(0xdeadbeef);
 567
 568         pr_debug("  unflattening %lx...\n", mem);
 569
 570         /* Second pass, do actual unflattening */
 571         start = ((unsigned long)initial_boot_params) +
 572                 be32_to_cpu(initial_boot_params->off_dt_struct);
 573         unflatten_dt_node(mem, &start, NULL, &allnextp, 0);
 574         if (be32_to_cpup((__be32 *)start) != OF_DT_END)
 575                 pr_warning("Weird tag at end of tree: %08x\n", *((u32 *)start));
 576         if (be32_to_cpu(((__be32 *)mem)[size / 4]) != 0xdeadbeef)
 577                 pr_warning("End of tree marker overwritten: %08x\n",
 578                            be32_to_cpu(((__be32 *)mem)[size / 4]));
 579         *allnextp = NULL;
 580
 581         /* Get pointer to OF "/chosen" node for use everywhere */
 582         of_chosen = of_find_node_by_path("/chosen");
 583         if (of_chosen == NULL)
 584                 of_chosen = of_find_node_by_path("/chosen@0");
 585
 586         pr_debug(" <- unflatten_device_tree()\n");
 587 }