device_tree.c

   1 /*
   2  * Functions to help device tree manipulation using libfdt.
   3  * It also provides functions to read entries from device tree proc
   4  * interface.
   5  *
   6  * Copyright 2008 IBM Corporation.
   7  * Authors: Jerone Young <jyoung5@us.ibm.com>
   8  *          Hollis Blanchard <hollisb@us.ibm.com>
   9  *
  10  * This work is licensed under the GNU GPL license version 2 or later.
  11  *
  12  */
  13
  14 #include "qemu/osdep.h"
  15
  16 #ifdef CONFIG_LINUX
  17 #include <dirent.h>
  18 #endif
  19
  20 #include "qapi/error.h"
  21 #include "qemu/error-report.h"
  22 #include "qemu/option.h"
  23 #include "qemu/bswap.h"
  24 #include "sysemu/device_tree.h"
  25 #include "sysemu/sysemu.h"
  26 #include "hw/loader.h"
  27 #include "hw/boards.h"
  28 #include "qemu/config-file.h"
  29
  30 #include <libfdt.h>
  31
  32 #define FDT_MAX_SIZE  0x100000
  33
  34 void *create_device_tree(int *sizep)
  35 {
  36     void *fdt;
  37     int ret;
  38
  39     *sizep = FDT_MAX_SIZE;
  40     fdt = g_malloc0(FDT_MAX_SIZE);
  41     ret = fdt_create(fdt, FDT_MAX_SIZE);
  42     if (ret < 0) {
  43         goto fail;
  44     }
  45     ret = fdt_finish_reservemap(fdt);
  46     if (ret < 0) {
  47         goto fail;
  48     }
  49     ret = fdt_begin_node(fdt, "");
  50     if (ret < 0) {
  51         goto fail;
  52     }
  53     ret = fdt_end_node(fdt);
  54     if (ret < 0) {
  55         goto fail;
  56     }
  57     ret = fdt_finish(fdt);
  58     if (ret < 0) {
  59         goto fail;
  60     }
  61     ret = fdt_open_into(fdt, fdt, *sizep);
  62     if (ret) {
  63         error_report("Unable to copy device tree in memory");
  64         exit(1);
  65     }
  66
  67     return fdt;
  68 fail:
  69     error_report("%s Couldn't create dt: %s", __func__, fdt_strerror(ret));
  70     exit(1);
  71 }
  72
  73 void *load_device_tree(const char *filename_path, int *sizep)
  74 {
  75     int dt_size;
  76     int dt_file_load_size;
  77     int ret;
  78     void *fdt = NULL;
  79
  80     *sizep = 0;
  81     dt_size = get_image_size(filename_path);
  82     if (dt_size < 0) {
  83         error_report("Unable to get size of device tree file '%s'",
  84                      filename_path);
  85         goto fail;
  86     }
  87     if (dt_size > INT_MAX / 2 - 10000) {
  88         error_report("Device tree file '%s' is too large", filename_path);
  89         goto fail;
  90     }
  91
  92     /* Expand to 2x size to give enough room for manipulation.  */
  93     dt_size += 10000;
  94     dt_size *= 2;
  95     /* First allocate space in qemu for device tree */
  96     fdt = g_malloc0(dt_size);
  97
  98     dt_file_load_size = load_image_size(filename_path, fdt, dt_size);
  99     if (dt_file_load_size < 0) {
 100         error_report("Unable to open device tree file '%s'",
 101                      filename_path);
 102         goto fail;
 103     }
 104
 105     ret = fdt_open_into(fdt, fdt, dt_size);
 106     if (ret) {
 107         error_report("Unable to copy device tree in memory");
 108         goto fail;
 109     }
 110
 111     /* Check sanity of device tree */
 112     if (fdt_check_header(fdt)) {
 113         error_report("Device tree file loaded into memory is invalid: %s",
 114                      filename_path);
 115         goto fail;
 116     }
 117     *sizep = dt_size;
 118     return fdt;
 119
 120 fail:
 121     g_free(fdt);
 122     return NULL;
 123 }
 124
 125 #ifdef CONFIG_LINUX
 126
 127 #define SYSFS_DT_BASEDIR "/proc/device-tree"
 128
 129 /**
 130  * read_fstree: this function is inspired from dtc read_fstree
 131  * @fdt: preallocated fdt blob buffer, to be populated
 132  * @dirname: directory to scan under SYSFS_DT_BASEDIR
 133  * the search is recursive and the tree is searched down to the
 134  * leaves (property files).
 135  *
 136  * the function asserts in case of error
 137  */
 138 static void read_fstree(void *fdt, const char *dirname)
 139 {
 140     DIR *d;
 141     struct dirent *de;
 142     struct stat st;
 143     const char *root_dir = SYSFS_DT_BASEDIR;
 144     const char *parent_node;
 145
 146     if (strstr(dirname, root_dir) != dirname) {
 147         error_report("%s: %s must be searched within %s",
 148                      __func__, dirname, root_dir);
 149         exit(1);
 150     }
 151     parent_node = &dirname[strlen(SYSFS_DT_BASEDIR)];
 152
 153     d = opendir(dirname);
 154     if (!d) {
 155         error_report("%s cannot open %s", __func__, dirname);
 156         exit(1);
 157     }
 158
 159     while ((de = readdir(d)) != NULL) {
 160         char *tmpnam;
 161
 162         if (!g_strcmp0(de->d_name, ".")
 163             || !g_strcmp0(de->d_name, "..")) {
 164             continue;
 165         }
 166
 167         tmpnam = g_strdup_printf("%s/%s", dirname, de->d_name);
 168
 169         if (lstat(tmpnam, &st) < 0) {
 170             error_report("%s cannot lstat %s", __func__, tmpnam);
 171             exit(1);
 172         }
 173
 174         if (S_ISREG(st.st_mode)) {
 175             gchar *val;
 176             gsize len;
 177
 178             if (!g_file_get_contents(tmpnam, &val, &len, NULL)) {
 179                 error_report("%s not able to extract info from %s",
 180                              __func__, tmpnam);
 181                 exit(1);
 182             }
 183
 184             if (strlen(parent_node) > 0) {
 185                 qemu_fdt_setprop(fdt, parent_node,
 186                                  de->d_name, val, len);
 187             } else {
 188                 qemu_fdt_setprop(fdt, "/", de->d_name, val, len);
 189             }
 190             g_free(val);
 191         } else if (S_ISDIR(st.st_mode)) {
 192             char *node_name;
 193
 194             node_name = g_strdup_printf("%s/%s",
 195                                         parent_node, de->d_name);
 196             qemu_fdt_add_subnode(fdt, node_name);
 197             g_free(node_name);
 198             read_fstree(fdt, tmpnam);
 199         }
 200
 201         g_free(tmpnam);
 202     }
 203
 204     closedir(d);
 205 }
 206
 207 /* load_device_tree_from_sysfs: extract the dt blob from host sysfs */
 208 void *load_device_tree_from_sysfs(void)
 209 {
 210     void *host_fdt;
 211     int host_fdt_size;
 212
 213     host_fdt = create_device_tree(&host_fdt_size);
 214     read_fstree(host_fdt, SYSFS_DT_BASEDIR);
 215     if (fdt_check_header(host_fdt)) {
 216         error_report("%s host device tree extracted into memory is invalid",
 217                      __func__);
 218         exit(1);
 219     }
 220     return host_fdt;
 221 }
 222
 223 #endif /* CONFIG_LINUX */
 224
 225 static int findnode_nofail(void *fdt, const char *node_path)
 226 {
 227     int offset;
 228
 229     offset = fdt_path_offset(fdt, node_path);
 230     if (offset < 0) {
 231         error_report("%s Couldn't find node %s: %s", __func__, node_path,
 232                      fdt_strerror(offset));
 233         exit(1);
 234     }
 235
 236     return offset;
 237 }
 238
 239 char **qemu_fdt_node_unit_path(void *fdt, const char *name, Error **errp)
 240 {
 241     char *prefix =  g_strdup_printf("%s@", name);
 242     unsigned int path_len = 16, n = 0;
 243     GSList *path_list = NULL, *iter;
 244     const char *iter_name;
 245     int offset, len, ret;
 246     char **path_array;
 247
 248     offset = fdt_next_node(fdt, -1, NULL);
 249
 250     while (offset >= 0) {
 251         iter_name = fdt_get_name(fdt, offset, &len);
 252         if (!iter_name) {
 253             offset = len;
 254             break;
 255         }
 256         if (!strcmp(iter_name, name) || g_str_has_prefix(iter_name, prefix)) {
 257             char *path;
 258
 259             path = g_malloc(path_len);
 260             while ((ret = fdt_get_path(fdt, offset, path, path_len))
 261                   == -FDT_ERR_NOSPACE) {
 262                 path_len += 16;
 263                 path = g_realloc(path, path_len);
 264             }
 265             path_list = g_slist_prepend(path_list, path);
 266             n++;
 267         }
 268         offset = fdt_next_node(fdt, offset, NULL);
 269     }
 270     g_free(prefix);
 271
 272     if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
 273         error_setg(errp, "%s: abort parsing dt for %s node units: %s",
 274                    __func__, name, fdt_strerror(offset));
 275         for (iter = path_list; iter; iter = iter->next) {
 276             g_free(iter->data);
 277         }
 278         g_slist_free(path_list);
 279         return NULL;
 280     }
 281
 282     path_array = g_new(char *, n + 1);
 283     path_array[n--] = NULL;
 284
 285     for (iter = path_list; iter; iter = iter->next) {
 286         path_array[n--] = iter->data;
 287     }
 288
 289     g_slist_free(path_list);
 290
 291     return path_array;
 292 }
 293
 294 char **qemu_fdt_node_path(void *fdt, const char *name, const char *compat,
 295                           Error **errp)
 296 {
 297     int offset, len, ret;
 298     const char *iter_name;
 299     unsigned int path_len = 16, n = 0;
 300     GSList *path_list = NULL, *iter;
 301     char **path_array;
 302
 303     offset = fdt_node_offset_by_compatible(fdt, -1, compat);
 304
 305     while (offset >= 0) {
 306         iter_name = fdt_get_name(fdt, offset, &len);
 307         if (!iter_name) {
 308             offset = len;
 309             break;
 310         }
 311         if (!name || !strcmp(iter_name, name)) {
 312             char *path;
 313
 314             path = g_malloc(path_len);
 315             while ((ret = fdt_get_path(fdt, offset, path, path_len))
 316                   == -FDT_ERR_NOSPACE) {
 317                 path_len += 16;
 318                 path = g_realloc(path, path_len);
 319             }
 320             path_list = g_slist_prepend(path_list, path);
 321             n++;
 322         }
 323         offset = fdt_node_offset_by_compatible(fdt, offset, compat);
 324     }
 325
 326     if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
 327         error_setg(errp, "%s: abort parsing dt for %s/%s: %s",
 328                    __func__, name, compat, fdt_strerror(offset));
 329         for (iter = path_list; iter; iter = iter->next) {
 330             g_free(iter->data);
 331         }
 332         g_slist_free(path_list);
 333         return NULL;
 334     }
 335
 336     path_array = g_new(char *, n + 1);
 337     path_array[n--] = NULL;
 338
 339     for (iter = path_list; iter; iter = iter->next) {
 340         path_array[n--] = iter->data;
 341     }
 342
 343     g_slist_free(path_list);
 344
 345     return path_array;
 346 }
 347
 348 int qemu_fdt_setprop(void *fdt, const char *node_path,
 349                      const char *property, const void *val, int size)
 350 {
 351     int r;
 352
 353     r = fdt_setprop(fdt, findnode_nofail(fdt, node_path), property, val, size);
 354     if (r < 0) {
 355         error_report("%s: Couldn't set %s/%s: %s", __func__, node_path,
 356                      property, fdt_strerror(r));
 357         exit(1);
 358     }
 359
 360     return r;
 361 }
 362
 363 int qemu_fdt_setprop_cell(void *fdt, const char *node_path,
 364                           const char *property, uint32_t val)
 365 {
 366     int r;
 367
 368     r = fdt_setprop_cell(fdt, findnode_nofail(fdt, node_path), property, val);
 369     if (r < 0) {
 370         error_report("%s: Couldn't set %s/%s = %#08x: %s", __func__,
 371                      node_path, property, val, fdt_strerror(r));
 372         exit(1);
 373     }
 374
 375     return r;
 376 }
 377
 378 int qemu_fdt_setprop_u64(void *fdt, const char *node_path,
 379                          const char *property, uint64_t val)
 380 {
 381     val = cpu_to_be64(val);
 382     return qemu_fdt_setprop(fdt, node_path, property, &val, sizeof(val));
 383 }
 384
 385 int qemu_fdt_setprop_string(void *fdt, const char *node_path,
 386                             const char *property, const char *string)
 387 {
 388     int r;
 389
 390     r = fdt_setprop_string(fdt, findnode_nofail(fdt, node_path), property, string);
 391     if (r < 0) {
 392         error_report("%s: Couldn't set %s/%s = %s: %s", __func__,
 393                      node_path, property, string, fdt_strerror(r));
 394         exit(1);
 395     }
 396
 397     return r;
 398 }
 399
 400 const void *qemu_fdt_getprop(void *fdt, const char *node_path,
 401                              const char *property, int *lenp, Error **errp)
 402 {
 403     int len;
 404     const void *r;
 405
 406     if (!lenp) {
 407         lenp = &len;
 408     }
 409     r = fdt_getprop(fdt, findnode_nofail(fdt, node_path), property, lenp);
 410     if (!r) {
 411         error_setg(errp, "%s: Couldn't get %s/%s: %s", __func__,
 412                   node_path, property, fdt_strerror(*lenp));
 413     }
 414     return r;
 415 }
 416
 417 uint32_t qemu_fdt_getprop_cell(void *fdt, const char *node_path,
 418                                const char *property, int *lenp, Error **errp)
 419 {
 420     int len;
 421     const uint32_t *p;
 422
 423     if (!lenp) {
 424         lenp = &len;
 425     }
 426     p = qemu_fdt_getprop(fdt, node_path, property, lenp, errp);
 427     if (!p) {
 428         return 0;
 429     } else if (*lenp != 4) {
 430         error_setg(errp, "%s: %s/%s not 4 bytes long (not a cell?)",
 431                    __func__, node_path, property);
 432         *lenp = -EINVAL;
 433         return 0;
 434     }
 435     return be32_to_cpu(*p);
 436 }
 437
 438 uint32_t qemu_fdt_get_phandle(void *fdt, const char *path)
 439 {
 440     uint32_t r;
 441
 442     r = fdt_get_phandle(fdt, findnode_nofail(fdt, path));
 443     if (r == 0) {
 444         error_report("%s: Couldn't get phandle for %s: %s", __func__,
 445                      path, fdt_strerror(r));
 446         exit(1);
 447     }
 448
 449     return r;
 450 }
 451
 452 int qemu_fdt_setprop_phandle(void *fdt, const char *node_path,
 453                              const char *property,
 454                              const char *target_node_path)
 455 {
 456     uint32_t phandle = qemu_fdt_get_phandle(fdt, target_node_path);
 457     return qemu_fdt_setprop_cell(fdt, node_path, property, phandle);
 458 }
 459
 460 uint32_t qemu_fdt_alloc_phandle(void *fdt)
 461 {
 462     static int phandle = 0x0;
 463
 464     /*
 465      * We need to find out if the user gave us special instruction at
 466      * which phandle id to start allocating phandles.
 467      */
 468     if (!phandle) {
 469         phandle = machine_phandle_start(current_machine);
 470     }
 471
 472     if (!phandle) {
 473         /*
 474          * None or invalid phandle given on the command line, so fall back to
 475          * default starting point.
 476          */
 477         phandle = 0x8000;
 478     }
 479
 480     return phandle++;
 481 }
 482
 483 int qemu_fdt_nop_node(void *fdt, const char *node_path)
 484 {
 485     int r;
 486
 487     r = fdt_nop_node(fdt, findnode_nofail(fdt, node_path));
 488     if (r < 0) {
 489         error_report("%s: Couldn't nop node %s: %s", __func__, node_path,
 490                      fdt_strerror(r));
 491         exit(1);
 492     }
 493
 494     return r;
 495 }
 496
 497 int qemu_fdt_add_subnode(void *fdt, const char *name)
 498 {
 499     char *dupname = g_strdup(name);
 500     char *basename = strrchr(dupname, '/');
 501     int retval;
 502     int parent = 0;
 503
 504     if (!basename) {
 505         g_free(dupname);
 506         return -1;
 507     }
 508
 509     basename[0] = '\0';
 510     basename++;
 511
 512     if (dupname[0]) {
 513         parent = findnode_nofail(fdt, dupname);
 514     }
 515
 516     retval = fdt_add_subnode(fdt, parent, basename);
 517     if (retval < 0) {
 518         error_report("FDT: Failed to create subnode %s: %s", name,
 519                      fdt_strerror(retval));
 520         exit(1);
 521     }
 522
 523     g_free(dupname);
 524     return retval;
 525 }
 526
 527 void qemu_fdt_dumpdtb(void *fdt, int size)
 528 {
 529     const char *dumpdtb = qemu_opt_get(qemu_get_machine_opts(), "dumpdtb");
 530
 531     if (dumpdtb) {
 532         /* Dump the dtb to a file and quit */
 533         if (g_file_set_contents(dumpdtb, fdt, size, NULL)) {
 534             info_report("dtb dumped to %s. Exiting.", dumpdtb);
 535             exit(0);
 536         }
 537         error_report("%s: Failed dumping dtb to %s", __func__, dumpdtb);
 538         exit(1);
 539     }
 540 }
 541
 542 int qemu_fdt_setprop_sized_cells_from_array(void *fdt,
 543                                             const char *node_path,
 544                                             const char *property,
 545                                             int numvalues,
 546                                             uint64_t *values)
 547 {
 548     uint32_t *propcells;
 549     uint64_t value;
 550     int cellnum, vnum, ncells;
 551     uint32_t hival;
 552     int ret;
 553
 554     propcells = g_new0(uint32_t, numvalues * 2);
 555
 556     cellnum = 0;
 557     for (vnum = 0; vnum < numvalues; vnum++) {
 558         ncells = values[vnum * 2];
 559         if (ncells != 1 && ncells != 2) {
 560             ret = -1;
 561             goto out;
 562         }
 563         value = values[vnum * 2 + 1];
 564         hival = cpu_to_be32(value >> 32);
 565         if (ncells > 1) {
 566             propcells[cellnum++] = hival;
 567         } else if (hival != 0) {
 568             ret = -1;
 569             goto out;
 570         }
 571         propcells[cellnum++] = cpu_to_be32(value);
 572     }
 573
 574     ret = qemu_fdt_setprop(fdt, node_path, property, propcells,
 575                            cellnum * sizeof(uint32_t));
 576 out:
 577     g_free(propcells);
 578     return ret;
 579 }