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