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-common.h"
  22 #include "qemu/error-report.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  0x10000
  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
  88     /* Expand to 2x size to give enough room for manipulation.  */
  89     dt_size += 10000;
  90     dt_size *= 2;
  91     /* First allocate space in qemu for device tree */
  92     fdt = g_malloc0(dt_size);
  93
  94     dt_file_load_size = load_image(filename_path, fdt);
  95     if (dt_file_load_size < 0) {
  96         error_report("Unable to open device tree file '%s'",
  97                      filename_path);
  98         goto fail;
  99     }
 100
 101     ret = fdt_open_into(fdt, fdt, dt_size);
 102     if (ret) {
 103         error_report("Unable to copy device tree in memory");
 104         goto fail;
 105     }
 106
 107     /* Check sanity of device tree */
 108     if (fdt_check_header(fdt)) {
 109         error_report("Device tree file loaded into memory is invalid: %s",
 110                      filename_path);
 111         goto fail;
 112     }
 113     *sizep = dt_size;
 114     return fdt;
 115
 116 fail:
 117     g_free(fdt);
 118     return NULL;
 119 }
 120
 121 #ifdef CONFIG_LINUX
 122
 123 #define SYSFS_DT_BASEDIR "/proc/device-tree"
 124
 125 /**
 126  * read_fstree: this function is inspired from dtc read_fstree
 127  * @fdt: preallocated fdt blob buffer, to be populated
 128  * @dirname: directory to scan under SYSFS_DT_BASEDIR
 129  * the search is recursive and the tree is searched down to the
 130  * leaves (property files).
 131  *
 132  * the function asserts in case of error
 133  */
 134 static void read_fstree(void *fdt, const char *dirname)
 135 {
 136     DIR *d;
 137     struct dirent *de;
 138     struct stat st;
 139     const char *root_dir = SYSFS_DT_BASEDIR;
 140     const char *parent_node;
 141
 142     if (strstr(dirname, root_dir) != dirname) {
 143         error_setg(&error_fatal, "%s: %s must be searched within %s",
 144                    __func__, dirname, root_dir);
 145     }
 146     parent_node = &dirname[strlen(SYSFS_DT_BASEDIR)];
 147
 148     d = opendir(dirname);
 149     if (!d) {
 150         error_setg(&error_fatal, "%s cannot open %s", __func__, dirname);
 151     }
 152
 153     while ((de = readdir(d)) != NULL) {
 154         char *tmpnam;
 155
 156         if (!g_strcmp0(de->d_name, ".")
 157             || !g_strcmp0(de->d_name, "..")) {
 158             continue;
 159         }
 160
 161         tmpnam = g_strdup_printf("%s/%s", dirname, de->d_name);
 162
 163         if (lstat(tmpnam, &st) < 0) {
 164             error_setg(&error_fatal, "%s cannot lstat %s", __func__, tmpnam);
 165         }
 166
 167         if (S_ISREG(st.st_mode)) {
 168             gchar *val;
 169             gsize len;
 170
 171             if (!g_file_get_contents(tmpnam, &val, &len, NULL)) {
 172                 error_setg(&error_fatal, "%s not able to extract info from %s",
 173                            __func__, tmpnam);
 174             }
 175
 176             if (strlen(parent_node) > 0) {
 177                 qemu_fdt_setprop(fdt, parent_node,
 178                                  de->d_name, val, len);
 179             } else {
 180                 qemu_fdt_setprop(fdt, "/", de->d_name, val, len);
 181             }
 182             g_free(val);
 183         } else if (S_ISDIR(st.st_mode)) {
 184             char *node_name;
 185
 186             node_name = g_strdup_printf("%s/%s",
 187                                         parent_node, de->d_name);
 188             qemu_fdt_add_subnode(fdt, node_name);
 189             g_free(node_name);
 190             read_fstree(fdt, tmpnam);
 191         }
 192
 193         g_free(tmpnam);
 194     }
 195
 196     closedir(d);
 197 }
 198
 199 /* load_device_tree_from_sysfs: extract the dt blob from host sysfs */
 200 void *load_device_tree_from_sysfs(void)
 201 {
 202     void *host_fdt;
 203     int host_fdt_size;
 204
 205     host_fdt = create_device_tree(&host_fdt_size);
 206     read_fstree(host_fdt, SYSFS_DT_BASEDIR);
 207     if (fdt_check_header(host_fdt)) {
 208         error_setg(&error_fatal,
 209                    "%s host device tree extracted into memory is invalid",
 210                    __func__);
 211     }
 212     return host_fdt;
 213 }
 214
 215 #endif /* CONFIG_LINUX */
 216
 217 static int findnode_nofail(void *fdt, const char *node_path)
 218 {
 219     int offset;
 220
 221     offset = fdt_path_offset(fdt, node_path);
 222     if (offset < 0) {
 223         error_report("%s Couldn't find node %s: %s", __func__, node_path,
 224                      fdt_strerror(offset));
 225         exit(1);
 226     }
 227
 228     return offset;
 229 }
 230
 231 char **qemu_fdt_node_path(void *fdt, const char *name, char *compat,
 232                           Error **errp)
 233 {
 234     int offset, len, ret;
 235     const char *iter_name;
 236     unsigned int path_len = 16, n = 0;
 237     GSList *path_list = NULL, *iter;
 238     char **path_array;
 239
 240     offset = fdt_node_offset_by_compatible(fdt, -1, compat);
 241
 242     while (offset >= 0) {
 243         iter_name = fdt_get_name(fdt, offset, &len);
 244         if (!iter_name) {
 245             offset = len;
 246             break;
 247         }
 248         if (!strcmp(iter_name, name)) {
 249             char *path;
 250
 251             path = g_malloc(path_len);
 252             while ((ret = fdt_get_path(fdt, offset, path, path_len))
 253                   == -FDT_ERR_NOSPACE) {
 254                 path_len += 16;
 255                 path = g_realloc(path, path_len);
 256             }
 257             path_list = g_slist_prepend(path_list, path);
 258             n++;
 259         }
 260         offset = fdt_node_offset_by_compatible(fdt, offset, compat);
 261     }
 262
 263     if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
 264         error_setg(errp, "%s: abort parsing dt for %s/%s: %s",
 265                    __func__, name, compat, fdt_strerror(offset));
 266         for (iter = path_list; iter; iter = iter->next) {
 267             g_free(iter->data);
 268         }
 269         g_slist_free(path_list);
 270         return NULL;
 271     }
 272
 273     path_array = g_new(char *, n + 1);
 274     path_array[n--] = NULL;
 275
 276     for (iter = path_list; iter; iter = iter->next) {
 277         path_array[n--] = iter->data;
 278     }
 279
 280     g_slist_free(path_list);
 281
 282     return path_array;
 283 }
 284
 285 int qemu_fdt_setprop(void *fdt, const char *node_path,
 286                      const char *property, const void *val, int size)
 287 {
 288     int r;
 289
 290     r = fdt_setprop(fdt, findnode_nofail(fdt, node_path), property, val, size);
 291     if (r < 0) {
 292         error_report("%s: Couldn't set %s/%s: %s", __func__, node_path,
 293                      property, fdt_strerror(r));
 294         exit(1);
 295     }
 296
 297     return r;
 298 }
 299
 300 int qemu_fdt_setprop_cell(void *fdt, const char *node_path,
 301                           const char *property, uint32_t val)
 302 {
 303     int r;
 304
 305     r = fdt_setprop_cell(fdt, findnode_nofail(fdt, node_path), property, val);
 306     if (r < 0) {
 307         error_report("%s: Couldn't set %s/%s = %#08x: %s", __func__,
 308                      node_path, property, val, fdt_strerror(r));
 309         exit(1);
 310     }
 311
 312     return r;
 313 }
 314
 315 int qemu_fdt_setprop_u64(void *fdt, const char *node_path,
 316                          const char *property, uint64_t val)
 317 {
 318     val = cpu_to_be64(val);
 319     return qemu_fdt_setprop(fdt, node_path, property, &val, sizeof(val));
 320 }
 321
 322 int qemu_fdt_setprop_string(void *fdt, const char *node_path,
 323                             const char *property, const char *string)
 324 {
 325     int r;
 326
 327     r = fdt_setprop_string(fdt, findnode_nofail(fdt, node_path), property, string);
 328     if (r < 0) {
 329         error_report("%s: Couldn't set %s/%s = %s: %s", __func__,
 330                      node_path, property, string, fdt_strerror(r));
 331         exit(1);
 332     }
 333
 334     return r;
 335 }
 336
 337 const void *qemu_fdt_getprop(void *fdt, const char *node_path,
 338                              const char *property, int *lenp, Error **errp)
 339 {
 340     int len;
 341     const void *r;
 342
 343     if (!lenp) {
 344         lenp = &len;
 345     }
 346     r = fdt_getprop(fdt, findnode_nofail(fdt, node_path), property, lenp);
 347     if (!r) {
 348         error_setg(errp, "%s: Couldn't get %s/%s: %s", __func__,
 349                   node_path, property, fdt_strerror(*lenp));
 350     }
 351     return r;
 352 }
 353
 354 uint32_t qemu_fdt_getprop_cell(void *fdt, const char *node_path,
 355                                const char *property, int *lenp, Error **errp)
 356 {
 357     int len;
 358     const uint32_t *p;
 359
 360     if (!lenp) {
 361         lenp = &len;
 362     }
 363     p = qemu_fdt_getprop(fdt, node_path, property, lenp, errp);
 364     if (!p) {
 365         return 0;
 366     } else if (*lenp != 4) {
 367         error_setg(errp, "%s: %s/%s not 4 bytes long (not a cell?)",
 368                    __func__, node_path, property);
 369         *lenp = -EINVAL;
 370         return 0;
 371     }
 372     return be32_to_cpu(*p);
 373 }
 374
 375 uint32_t qemu_fdt_get_phandle(void *fdt, const char *path)
 376 {
 377     uint32_t r;
 378
 379     r = fdt_get_phandle(fdt, findnode_nofail(fdt, path));
 380     if (r == 0) {
 381         error_report("%s: Couldn't get phandle for %s: %s", __func__,
 382                      path, fdt_strerror(r));
 383         exit(1);
 384     }
 385
 386     return r;
 387 }
 388
 389 int qemu_fdt_setprop_phandle(void *fdt, const char *node_path,
 390                              const char *property,
 391                              const char *target_node_path)
 392 {
 393     uint32_t phandle = qemu_fdt_get_phandle(fdt, target_node_path);
 394     return qemu_fdt_setprop_cell(fdt, node_path, property, phandle);
 395 }
 396
 397 uint32_t qemu_fdt_alloc_phandle(void *fdt)
 398 {
 399     static int phandle = 0x0;
 400
 401     /*
 402      * We need to find out if the user gave us special instruction at
 403      * which phandle id to start allocating phandles.
 404      */
 405     if (!phandle) {
 406         phandle = machine_phandle_start(current_machine);
 407     }
 408
 409     if (!phandle) {
 410         /*
 411          * None or invalid phandle given on the command line, so fall back to
 412          * default starting point.
 413          */
 414         phandle = 0x8000;
 415     }
 416
 417     return phandle++;
 418 }
 419
 420 int qemu_fdt_nop_node(void *fdt, const char *node_path)
 421 {
 422     int r;
 423
 424     r = fdt_nop_node(fdt, findnode_nofail(fdt, node_path));
 425     if (r < 0) {
 426         error_report("%s: Couldn't nop node %s: %s", __func__, node_path,
 427                      fdt_strerror(r));
 428         exit(1);
 429     }
 430
 431     return r;
 432 }
 433
 434 int qemu_fdt_add_subnode(void *fdt, const char *name)
 435 {
 436     char *dupname = g_strdup(name);
 437     char *basename = strrchr(dupname, '/');
 438     int retval;
 439     int parent = 0;
 440
 441     if (!basename) {
 442         g_free(dupname);
 443         return -1;
 444     }
 445
 446     basename[0] = '\0';
 447     basename++;
 448
 449     if (dupname[0]) {
 450         parent = findnode_nofail(fdt, dupname);
 451     }
 452
 453     retval = fdt_add_subnode(fdt, parent, basename);
 454     if (retval < 0) {
 455         error_report("FDT: Failed to create subnode %s: %s", name,
 456                      fdt_strerror(retval));
 457         exit(1);
 458     }
 459
 460     g_free(dupname);
 461     return retval;
 462 }
 463
 464 void qemu_fdt_dumpdtb(void *fdt, int size)
 465 {
 466     const char *dumpdtb = qemu_opt_get(qemu_get_machine_opts(), "dumpdtb");
 467
 468     if (dumpdtb) {
 469         /* Dump the dtb to a file and quit */
 470         exit(g_file_set_contents(dumpdtb, fdt, size, NULL) ? 0 : 1);
 471     }
 472 }
 473
 474 int qemu_fdt_setprop_sized_cells_from_array(void *fdt,
 475                                             const char *node_path,
 476                                             const char *property,
 477                                             int numvalues,
 478                                             uint64_t *values)
 479 {
 480     uint32_t *propcells;
 481     uint64_t value;
 482     int cellnum, vnum, ncells;
 483     uint32_t hival;
 484     int ret;
 485
 486     propcells = g_new0(uint32_t, numvalues * 2);
 487
 488     cellnum = 0;
 489     for (vnum = 0; vnum < numvalues; vnum++) {
 490         ncells = values[vnum * 2];
 491         if (ncells != 1 && ncells != 2) {
 492             ret = -1;
 493             goto out;
 494         }
 495         value = values[vnum * 2 + 1];
 496         hival = cpu_to_be32(value >> 32);
 497         if (ncells > 1) {
 498             propcells[cellnum++] = hival;
 499         } else if (hival != 0) {
 500             ret = -1;
 501             goto out;
 502         }
 503         propcells[cellnum++] = cpu_to_be32(value);
 504     }
 505
 506     ret = qemu_fdt_setprop(fdt, node_path, property, propcells,
 507                            cellnum * sizeof(uint32_t));
 508 out:
 509     g_free(propcells);
 510     return ret;
 511 }