system/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 "qemu/cutils.h"
  25 #include "qemu/guest-random.h"
  26 #include "sysemu/device_tree.h"
  27 #include "hw/loader.h"
  28 #include "hw/boards.h"
  29 #include "qemu/config-file.h"
  30 #include "qapi/qapi-commands-machine.h"
  31 #include "qapi/qmp/qdict.h"
  32 #include "monitor/hmp.h"
  33
  34 #include <libfdt.h>
  35
  36 #define FDT_MAX_SIZE  0x100000
  37
  38 void *create_device_tree(int *sizep)
  39 {
  40     void *fdt;
  41     int ret;
  42
  43     *sizep = FDT_MAX_SIZE;
  44     fdt = g_malloc0(FDT_MAX_SIZE);
  45     ret = fdt_create(fdt, FDT_MAX_SIZE);
  46     if (ret < 0) {
  47         goto fail;
  48     }
  49     ret = fdt_finish_reservemap(fdt);
  50     if (ret < 0) {
  51         goto fail;
  52     }
  53     ret = fdt_begin_node(fdt, "");
  54     if (ret < 0) {
  55         goto fail;
  56     }
  57     ret = fdt_end_node(fdt);
  58     if (ret < 0) {
  59         goto fail;
  60     }
  61     ret = fdt_finish(fdt);
  62     if (ret < 0) {
  63         goto fail;
  64     }
  65     ret = fdt_open_into(fdt, fdt, *sizep);
  66     if (ret) {
  67         error_report("%s: Unable to copy device tree into memory: %s",
  68                      __func__, fdt_strerror(ret));
  69         exit(1);
  70     }
  71
  72     return fdt;
  73 fail:
  74     error_report("%s Couldn't create dt: %s", __func__, fdt_strerror(ret));
  75     exit(1);
  76 }
  77
  78 void *load_device_tree(const char *filename_path, int *sizep)
  79 {
  80     int dt_size;
  81     int dt_file_load_size;
  82     int ret;
  83     void *fdt = NULL;
  84
  85     *sizep = 0;
  86     dt_size = get_image_size(filename_path);
  87     if (dt_size < 0) {
  88         error_report("Unable to get size of device tree file '%s'",
  89                      filename_path);
  90         goto fail;
  91     }
  92     if (dt_size > INT_MAX / 2 - 10000) {
  93         error_report("Device tree file '%s' is too large", filename_path);
  94         goto fail;
  95     }
  96
  97     /* Expand to 2x size to give enough room for manipulation.  */
  98     dt_size += 10000;
  99     dt_size *= 2;
 100     /* First allocate space in qemu for device tree */
 101     fdt = g_malloc0(dt_size);
 102
 103     dt_file_load_size = load_image_size(filename_path, fdt, dt_size);
 104     if (dt_file_load_size < 0) {
 105         error_report("Unable to open device tree file '%s'",
 106                      filename_path);
 107         goto fail;
 108     }
 109
 110     ret = fdt_open_into(fdt, fdt, dt_size);
 111     if (ret) {
 112         error_report("%s: Unable to copy device tree into memory: %s",
 113                      __func__, fdt_strerror(ret));
 114         goto fail;
 115     }
 116
 117     /* Check sanity of device tree */
 118     if (fdt_check_header(fdt)) {
 119         error_report("Device tree file loaded into memory is invalid: %s",
 120                      filename_path);
 121         goto fail;
 122     }
 123     *sizep = dt_size;
 124     return fdt;
 125
 126 fail:
 127     g_free(fdt);
 128     return NULL;
 129 }
 130
 131 #ifdef CONFIG_LINUX
 132
 133 #define SYSFS_DT_BASEDIR "/proc/device-tree"
 134
 135 /**
 136  * read_fstree: this function is inspired from dtc read_fstree
 137  * @fdt: preallocated fdt blob buffer, to be populated
 138  * @dirname: directory to scan under SYSFS_DT_BASEDIR
 139  * the search is recursive and the tree is searched down to the
 140  * leaves (property files).
 141  *
 142  * the function asserts in case of error
 143  */
 144 static void read_fstree(void *fdt, const char *dirname)
 145 {
 146     DIR *d;
 147     struct dirent *de;
 148     struct stat st;
 149     const char *root_dir = SYSFS_DT_BASEDIR;
 150     const char *parent_node;
 151
 152     if (strstr(dirname, root_dir) != dirname) {
 153         error_report("%s: %s must be searched within %s",
 154                      __func__, dirname, root_dir);
 155         exit(1);
 156     }
 157     parent_node = &dirname[strlen(SYSFS_DT_BASEDIR)];
 158
 159     d = opendir(dirname);
 160     if (!d) {
 161         error_report("%s cannot open %s", __func__, dirname);
 162         exit(1);
 163     }
 164
 165     while ((de = readdir(d)) != NULL) {
 166         char *tmpnam;
 167
 168         if (!g_strcmp0(de->d_name, ".")
 169             || !g_strcmp0(de->d_name, "..")) {
 170             continue;
 171         }
 172
 173         tmpnam = g_strdup_printf("%s/%s", dirname, de->d_name);
 174
 175         if (lstat(tmpnam, &st) < 0) {
 176             error_report("%s cannot lstat %s", __func__, tmpnam);
 177             exit(1);
 178         }
 179
 180         if (S_ISREG(st.st_mode)) {
 181             gchar *val;
 182             gsize len;
 183
 184             if (!g_file_get_contents(tmpnam, &val, &len, NULL)) {
 185                 error_report("%s not able to extract info from %s",
 186                              __func__, tmpnam);
 187                 exit(1);
 188             }
 189
 190             if (strlen(parent_node) > 0) {
 191                 qemu_fdt_setprop(fdt, parent_node,
 192                                  de->d_name, val, len);
 193             } else {
 194                 qemu_fdt_setprop(fdt, "/", de->d_name, val, len);
 195             }
 196             g_free(val);
 197         } else if (S_ISDIR(st.st_mode)) {
 198             char *node_name;
 199
 200             node_name = g_strdup_printf("%s/%s",
 201                                         parent_node, de->d_name);
 202             qemu_fdt_add_subnode(fdt, node_name);
 203             g_free(node_name);
 204             read_fstree(fdt, tmpnam);
 205         }
 206
 207         g_free(tmpnam);
 208     }
 209
 210     closedir(d);
 211 }
 212
 213 /* load_device_tree_from_sysfs: extract the dt blob from host sysfs */
 214 void *load_device_tree_from_sysfs(void)
 215 {
 216     void *host_fdt;
 217     int host_fdt_size;
 218
 219     host_fdt = create_device_tree(&host_fdt_size);
 220     read_fstree(host_fdt, SYSFS_DT_BASEDIR);
 221     if (fdt_check_header(host_fdt)) {
 222         error_report("%s host device tree extracted into memory is invalid",
 223                      __func__);
 224         exit(1);
 225     }
 226     return host_fdt;
 227 }
 228
 229 #endif /* CONFIG_LINUX */
 230
 231 static int findnode_nofail(void *fdt, const char *node_path)
 232 {
 233     int offset;
 234
 235     offset = fdt_path_offset(fdt, node_path);
 236     if (offset < 0) {
 237         error_report("%s Couldn't find node %s: %s", __func__, node_path,
 238                      fdt_strerror(offset));
 239         exit(1);
 240     }
 241
 242     return offset;
 243 }
 244
 245 char **qemu_fdt_node_unit_path(void *fdt, const char *name, Error **errp)
 246 {
 247     char *prefix =  g_strdup_printf("%s@", name);
 248     unsigned int path_len = 16, n = 0;
 249     GSList *path_list = NULL, *iter;
 250     const char *iter_name;
 251     int offset, len, ret;
 252     char **path_array;
 253
 254     offset = fdt_next_node(fdt, -1, NULL);
 255
 256     while (offset >= 0) {
 257         iter_name = fdt_get_name(fdt, offset, &len);
 258         if (!iter_name) {
 259             offset = len;
 260             break;
 261         }
 262         if (!strcmp(iter_name, name) || g_str_has_prefix(iter_name, prefix)) {
 263             char *path;
 264
 265             path = g_malloc(path_len);
 266             while ((ret = fdt_get_path(fdt, offset, path, path_len))
 267                   == -FDT_ERR_NOSPACE) {
 268                 path_len += 16;
 269                 path = g_realloc(path, path_len);
 270             }
 271             path_list = g_slist_prepend(path_list, path);
 272             n++;
 273         }
 274         offset = fdt_next_node(fdt, offset, NULL);
 275     }
 276     g_free(prefix);
 277
 278     if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
 279         error_setg(errp, "%s: abort parsing dt for %s node units: %s",
 280                    __func__, name, fdt_strerror(offset));
 281         for (iter = path_list; iter; iter = iter->next) {
 282             g_free(iter->data);
 283         }
 284         g_slist_free(path_list);
 285         return NULL;
 286     }
 287
 288     path_array = g_new(char *, n + 1);
 289     path_array[n--] = NULL;
 290
 291     for (iter = path_list; iter; iter = iter->next) {
 292         path_array[n--] = iter->data;
 293     }
 294
 295     g_slist_free(path_list);
 296
 297     return path_array;
 298 }
 299
 300 char **qemu_fdt_node_path(void *fdt, const char *name, const char *compat,
 301                           Error **errp)
 302 {
 303     int offset, len, ret;
 304     const char *iter_name;
 305     unsigned int path_len = 16, n = 0;
 306     GSList *path_list = NULL, *iter;
 307     char **path_array;
 308
 309     offset = fdt_node_offset_by_compatible(fdt, -1, compat);
 310
 311     while (offset >= 0) {
 312         iter_name = fdt_get_name(fdt, offset, &len);
 313         if (!iter_name) {
 314             offset = len;
 315             break;
 316         }
 317         if (!name || !strcmp(iter_name, name)) {
 318             char *path;
 319
 320             path = g_malloc(path_len);
 321             while ((ret = fdt_get_path(fdt, offset, path, path_len))
 322                   == -FDT_ERR_NOSPACE) {
 323                 path_len += 16;
 324                 path = g_realloc(path, path_len);
 325             }
 326             path_list = g_slist_prepend(path_list, path);
 327             n++;
 328         }
 329         offset = fdt_node_offset_by_compatible(fdt, offset, compat);
 330     }
 331
 332     if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
 333         error_setg(errp, "%s: abort parsing dt for %s/%s: %s",
 334                    __func__, name, compat, fdt_strerror(offset));
 335         for (iter = path_list; iter; iter = iter->next) {
 336             g_free(iter->data);
 337         }
 338         g_slist_free(path_list);
 339         return NULL;
 340     }
 341
 342     path_array = g_new(char *, n + 1);
 343     path_array[n--] = NULL;
 344
 345     for (iter = path_list; iter; iter = iter->next) {
 346         path_array[n--] = iter->data;
 347     }
 348
 349     g_slist_free(path_list);
 350
 351     return path_array;
 352 }
 353
 354 int qemu_fdt_setprop(void *fdt, const char *node_path,
 355                      const char *property, const void *val, int size)
 356 {
 357     int r;
 358
 359     r = fdt_setprop(fdt, findnode_nofail(fdt, node_path), property, val, size);
 360     if (r < 0) {
 361         error_report("%s: Couldn't set %s/%s: %s", __func__, node_path,
 362                      property, fdt_strerror(r));
 363         exit(1);
 364     }
 365
 366     return r;
 367 }
 368
 369 int qemu_fdt_setprop_cell(void *fdt, const char *node_path,
 370                           const char *property, uint32_t val)
 371 {
 372     int r;
 373
 374     r = fdt_setprop_cell(fdt, findnode_nofail(fdt, node_path), property, val);
 375     if (r < 0) {
 376         error_report("%s: Couldn't set %s/%s = %#08x: %s", __func__,
 377                      node_path, property, val, fdt_strerror(r));
 378         exit(1);
 379     }
 380
 381     return r;
 382 }
 383
 384 int qemu_fdt_setprop_u64(void *fdt, const char *node_path,
 385                          const char *property, uint64_t val)
 386 {
 387     val = cpu_to_be64(val);
 388     return qemu_fdt_setprop(fdt, node_path, property, &val, sizeof(val));
 389 }
 390
 391 int qemu_fdt_setprop_string(void *fdt, const char *node_path,
 392                             const char *property, const char *string)
 393 {
 394     int r;
 395
 396     r = fdt_setprop_string(fdt, findnode_nofail(fdt, node_path), property, string);
 397     if (r < 0) {
 398         error_report("%s: Couldn't set %s/%s = %s: %s", __func__,
 399                      node_path, property, string, fdt_strerror(r));
 400         exit(1);
 401     }
 402
 403     return r;
 404 }
 405
 406 /*
 407  * libfdt doesn't allow us to add string arrays directly but they are
 408  * test a series of null terminated strings with a length. We build
 409  * the string up here so we can calculate the final length.
 410  */
 411 int qemu_fdt_setprop_string_array(void *fdt, const char *node_path,
 412                                   const char *prop, char **array, int len)
 413 {
 414     int ret, i, total_len = 0;
 415     char *str, *p;
 416     for (i = 0; i < len; i++) {
 417         total_len += strlen(array[i]) + 1;
 418     }
 419     p = str = g_malloc0(total_len);
 420     for (i = 0; i < len; i++) {
 421         int offset = strlen(array[i]) + 1;
 422         pstrcpy(p, offset, array[i]);
 423         p += offset;
 424     }
 425
 426     ret = qemu_fdt_setprop(fdt, node_path, prop, str, total_len);
 427     g_free(str);
 428     return ret;
 429 }
 430
 431 const void *qemu_fdt_getprop(void *fdt, const char *node_path,
 432                              const char *property, int *lenp, Error **errp)
 433 {
 434     int len;
 435     const void *r;
 436
 437     if (!lenp) {
 438         lenp = &len;
 439     }
 440     r = fdt_getprop(fdt, findnode_nofail(fdt, node_path), property, lenp);
 441     if (!r) {
 442         error_setg(errp, "%s: Couldn't get %s/%s: %s", __func__,
 443                   node_path, property, fdt_strerror(*lenp));
 444     }
 445     return r;
 446 }
 447
 448 uint32_t qemu_fdt_getprop_cell(void *fdt, const char *node_path,
 449                                const char *property, int *lenp, Error **errp)
 450 {
 451     int len;
 452     const uint32_t *p;
 453
 454     if (!lenp) {
 455         lenp = &len;
 456     }
 457     p = qemu_fdt_getprop(fdt, node_path, property, lenp, errp);
 458     if (!p) {
 459         return 0;
 460     } else if (*lenp != 4) {
 461         error_setg(errp, "%s: %s/%s not 4 bytes long (not a cell?)",
 462                    __func__, node_path, property);
 463         *lenp = -EINVAL;
 464         return 0;
 465     }
 466     return be32_to_cpu(*p);
 467 }
 468
 469 uint32_t qemu_fdt_get_phandle(void *fdt, const char *path)
 470 {
 471     uint32_t r;
 472
 473     r = fdt_get_phandle(fdt, findnode_nofail(fdt, path));
 474     if (r == 0) {
 475         error_report("%s: Couldn't get phandle for %s: %s", __func__,
 476                      path, fdt_strerror(r));
 477         exit(1);
 478     }
 479
 480     return r;
 481 }
 482
 483 int qemu_fdt_setprop_phandle(void *fdt, const char *node_path,
 484                              const char *property,
 485                              const char *target_node_path)
 486 {
 487     uint32_t phandle = qemu_fdt_get_phandle(fdt, target_node_path);
 488     return qemu_fdt_setprop_cell(fdt, node_path, property, phandle);
 489 }
 490
 491 uint32_t qemu_fdt_alloc_phandle(void *fdt)
 492 {
 493     static int phandle = 0x0;
 494
 495     /*
 496      * We need to find out if the user gave us special instruction at
 497      * which phandle id to start allocating phandles.
 498      */
 499     if (!phandle) {
 500         phandle = machine_phandle_start(current_machine);
 501     }
 502
 503     if (!phandle) {
 504         /*
 505          * None or invalid phandle given on the command line, so fall back to
 506          * default starting point.
 507          */
 508         phandle = 0x8000;
 509     }
 510
 511     return phandle++;
 512 }
 513
 514 int qemu_fdt_nop_node(void *fdt, const char *node_path)
 515 {
 516     int r;
 517
 518     r = fdt_nop_node(fdt, findnode_nofail(fdt, node_path));
 519     if (r < 0) {
 520         error_report("%s: Couldn't nop node %s: %s", __func__, node_path,
 521                      fdt_strerror(r));
 522         exit(1);
 523     }
 524
 525     return r;
 526 }
 527
 528 int qemu_fdt_add_subnode(void *fdt, const char *name)
 529 {
 530     char *dupname = g_strdup(name);
 531     char *basename = strrchr(dupname, '/');
 532     int retval;
 533     int parent = 0;
 534
 535     if (!basename) {
 536         g_free(dupname);
 537         return -1;
 538     }
 539
 540     basename[0] = '\0';
 541     basename++;
 542
 543     if (dupname[0]) {
 544         parent = findnode_nofail(fdt, dupname);
 545     }
 546
 547     retval = fdt_add_subnode(fdt, parent, basename);
 548     if (retval < 0) {
 549         error_report("%s: Failed to create subnode %s: %s",
 550                      __func__, name, fdt_strerror(retval));
 551         exit(1);
 552     }
 553
 554     g_free(dupname);
 555     return retval;
 556 }
 557
 558 /*
 559  * qemu_fdt_add_path: Like qemu_fdt_add_subnode(), but will add
 560  * all missing subnodes from the given path.
 561  */
 562 int qemu_fdt_add_path(void *fdt, const char *path)
 563 {
 564     const char *name;
 565     int namelen, retval;
 566     int parent = 0;
 567
 568     if (path[0] != '/') {
 569         return -1;
 570     }
 571
 572     do {
 573         name = path + 1;
 574         path = strchr(name, '/');
 575         namelen = path != NULL ? path - name : strlen(name);
 576
 577         retval = fdt_subnode_offset_namelen(fdt, parent, name, namelen);
 578         if (retval < 0 && retval != -FDT_ERR_NOTFOUND) {
 579             error_report("%s: Unexpected error in finding subnode %.*s: %s",
 580                          __func__, namelen, name, fdt_strerror(retval));
 581             exit(1);
 582         } else if (retval == -FDT_ERR_NOTFOUND) {
 583             retval = fdt_add_subnode_namelen(fdt, parent, name, namelen);
 584             if (retval < 0) {
 585                 error_report("%s: Failed to create subnode %.*s: %s",
 586                              __func__, namelen, name, fdt_strerror(retval));
 587                 exit(1);
 588             }
 589         }
 590
 591         parent = retval;
 592     } while (path);
 593
 594     return retval;
 595 }
 596
 597 void qemu_fdt_dumpdtb(void *fdt, int size)
 598 {
 599     const char *dumpdtb = current_machine->dumpdtb;
 600
 601     if (dumpdtb) {
 602         /* Dump the dtb to a file and quit */
 603         if (g_file_set_contents(dumpdtb, fdt, size, NULL)) {
 604             info_report("dtb dumped to %s. Exiting.", dumpdtb);
 605             exit(0);
 606         }
 607         error_report("%s: Failed dumping dtb to %s", __func__, dumpdtb);
 608         exit(1);
 609     }
 610 }
 611
 612 int qemu_fdt_setprop_sized_cells_from_array(void *fdt,
 613                                             const char *node_path,
 614                                             const char *property,
 615                                             int numvalues,
 616                                             uint64_t *values)
 617 {
 618     uint32_t *propcells;
 619     uint64_t value;
 620     int cellnum, vnum, ncells;
 621     uint32_t hival;
 622     int ret;
 623
 624     propcells = g_new0(uint32_t, numvalues * 2);
 625
 626     cellnum = 0;
 627     for (vnum = 0; vnum < numvalues; vnum++) {
 628         ncells = values[vnum * 2];
 629         if (ncells != 1 && ncells != 2) {
 630             ret = -1;
 631             goto out;
 632         }
 633         value = values[vnum * 2 + 1];
 634         hival = cpu_to_be32(value >> 32);
 635         if (ncells > 1) {
 636             propcells[cellnum++] = hival;
 637         } else if (hival != 0) {
 638             ret = -1;
 639             goto out;
 640         }
 641         propcells[cellnum++] = cpu_to_be32(value);
 642     }
 643
 644     ret = qemu_fdt_setprop(fdt, node_path, property, propcells,
 645                            cellnum * sizeof(uint32_t));
 646 out:
 647     g_free(propcells);
 648     return ret;
 649 }
 650
 651 void qmp_dumpdtb(const char *filename, Error **errp)
 652 {
 653     g_autoptr(GError) err = NULL;
 654     uint32_t size;
 655
 656     if (!current_machine->fdt) {
 657         error_setg(errp, "This machine doesn't have a FDT");
 658         return;
 659     }
 660
 661     size = fdt_totalsize(current_machine->fdt);
 662
 663     g_assert(size > 0);
 664
 665     if (!g_file_set_contents(filename, current_machine->fdt, size, &err)) {
 666         error_setg(errp, "Error saving FDT to file %s: %s",
 667                    filename, err->message);
 668     }
 669 }
 670
 671 void qemu_fdt_randomize_seeds(void *fdt)
 672 {
 673     int noffset, poffset, len;
 674     const char *name;
 675     uint8_t *data;
 676
 677     for (noffset = fdt_next_node(fdt, 0, NULL);
 678          noffset >= 0;
 679          noffset = fdt_next_node(fdt, noffset, NULL)) {
 680         for (poffset = fdt_first_property_offset(fdt, noffset);
 681              poffset >= 0;
 682              poffset = fdt_next_property_offset(fdt, poffset)) {
 683             data = (uint8_t *)fdt_getprop_by_offset(fdt, poffset, &name, &len);
 684             if (!data || strcmp(name, "rng-seed"))
 685                 continue;
 686             qemu_guest_getrandom_nofail(data, len);
 687         }
 688     }
 689 }