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