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