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 "qemu-common.h"
  21 #include "qemu/error-report.h"
  22 #include "sysemu/device_tree.h"
  23 #include "sysemu/sysemu.h"
  24 #include "hw/loader.h"
  25 #include "hw/boards.h"
  26 #include "qemu/config-file.h"
  27
  28 #include <libfdt.h>
  29
  30 #define FDT_MAX_SIZE  0x10000
  31
  32 void *create_device_tree(int *sizep)
  33 {
  34     void *fdt;
  35     int ret;
  36
  37     *sizep = FDT_MAX_SIZE;
  38     fdt = g_malloc0(FDT_MAX_SIZE);
  39     ret = fdt_create(fdt, FDT_MAX_SIZE);
  40     if (ret < 0) {
  41         goto fail;
  42     }
  43     ret = fdt_finish_reservemap(fdt);
  44     if (ret < 0) {
  45         goto fail;
  46     }
  47     ret = fdt_begin_node(fdt, "");
  48     if (ret < 0) {
  49         goto fail;
  50     }
  51     ret = fdt_end_node(fdt);
  52     if (ret < 0) {
  53         goto fail;
  54     }
  55     ret = fdt_finish(fdt);
  56     if (ret < 0) {
  57         goto fail;
  58     }
  59     ret = fdt_open_into(fdt, fdt, *sizep);
  60     if (ret) {
  61         error_report("Unable to copy device tree in memory");
  62         exit(1);
  63     }
  64
  65     return fdt;
  66 fail:
  67     error_report("%s Couldn't create dt: %s", __func__, fdt_strerror(ret));
  68     exit(1);
  69 }
  70
  71 void *load_device_tree(const char *filename_path, int *sizep)
  72 {
  73     int dt_size;
  74     int dt_file_load_size;
  75     int ret;
  76     void *fdt = NULL;
  77
  78     *sizep = 0;
  79     dt_size = get_image_size(filename_path);
  80     if (dt_size < 0) {
  81         error_report("Unable to get size of device tree file '%s'",
  82                      filename_path);
  83         goto fail;
  84     }
  85
  86     /* Expand to 2x size to give enough room for manipulation.  */
  87     dt_size += 10000;
  88     dt_size *= 2;
  89     /* First allocate space in qemu for device tree */
  90     fdt = g_malloc0(dt_size);
  91
  92     dt_file_load_size = load_image(filename_path, fdt);
  93     if (dt_file_load_size < 0) {
  94         error_report("Unable to open device tree file '%s'",
  95                      filename_path);
  96         goto fail;
  97     }
  98
  99     ret = fdt_open_into(fdt, fdt, dt_size);
 100     if (ret) {
 101         error_report("Unable to copy device tree in memory");
 102         goto fail;
 103     }
 104
 105     /* Check sanity of device tree */
 106     if (fdt_check_header(fdt)) {
 107         error_report("Device tree file loaded into memory is invalid: %s",
 108                      filename_path);
 109         goto fail;
 110     }
 111     *sizep = dt_size;
 112     return fdt;
 113
 114 fail:
 115     g_free(fdt);
 116     return NULL;
 117 }
 118
 119 #ifdef CONFIG_LINUX
 120
 121 #define SYSFS_DT_BASEDIR "/proc/device-tree"
 122
 123 /**
 124  * read_fstree: this function is inspired from dtc read_fstree
 125  * @fdt: preallocated fdt blob buffer, to be populated
 126  * @dirname: directory to scan under SYSFS_DT_BASEDIR
 127  * the search is recursive and the tree is searched down to the
 128  * leaves (property files).
 129  *
 130  * the function asserts in case of error
 131  */
 132 static void read_fstree(void *fdt, const char *dirname)
 133 {
 134     DIR *d;
 135     struct dirent *de;
 136     struct stat st;
 137     const char *root_dir = SYSFS_DT_BASEDIR;
 138     const char *parent_node;
 139
 140     if (strstr(dirname, root_dir) != dirname) {
 141         error_setg(&error_fatal, "%s: %s must be searched within %s",
 142                    __func__, dirname, root_dir);
 143     }
 144     parent_node = &dirname[strlen(SYSFS_DT_BASEDIR)];
 145
 146     d = opendir(dirname);
 147     if (!d) {
 148         error_setg(&error_fatal, "%s cannot open %s", __func__, dirname);
 149     }
 150
 151     while ((de = readdir(d)) != NULL) {
 152         char *tmpnam;
 153
 154         if (!g_strcmp0(de->d_name, ".")
 155             || !g_strcmp0(de->d_name, "..")) {
 156             continue;
 157         }
 158
 159         tmpnam = g_strdup_printf("%s/%s", dirname, de->d_name);
 160
 161         if (lstat(tmpnam, &st) < 0) {
 162             error_setg(&error_fatal, "%s cannot lstat %s", __func__, tmpnam);
 163         }
 164
 165         if (S_ISREG(st.st_mode)) {
 166             gchar *val;
 167             gsize len;
 168
 169             if (!g_file_get_contents(tmpnam, &val, &len, NULL)) {
 170                 error_setg(&error_fatal, "%s not able to extract info from %s",
 171                            __func__, tmpnam);
 172             }
 173
 174             if (strlen(parent_node) > 0) {
 175                 qemu_fdt_setprop(fdt, parent_node,
 176                                  de->d_name, val, len);
 177             } else {
 178                 qemu_fdt_setprop(fdt, "/", de->d_name, val, len);
 179             }
 180             g_free(val);
 181         } else if (S_ISDIR(st.st_mode)) {
 182             char *node_name;
 183
 184             node_name = g_strdup_printf("%s/%s",
 185                                         parent_node, de->d_name);
 186             qemu_fdt_add_subnode(fdt, node_name);
 187             g_free(node_name);
 188             read_fstree(fdt, tmpnam);
 189         }
 190
 191         g_free(tmpnam);
 192     }
 193
 194     closedir(d);
 195 }
 196
 197 /* load_device_tree_from_sysfs: extract the dt blob from host sysfs */
 198 void *load_device_tree_from_sysfs(void)
 199 {
 200     void *host_fdt;
 201     int host_fdt_size;
 202
 203     host_fdt = create_device_tree(&host_fdt_size);
 204     read_fstree(host_fdt, SYSFS_DT_BASEDIR);
 205     if (fdt_check_header(host_fdt)) {
 206         error_setg(&error_fatal,
 207                    "%s host device tree extracted into memory is invalid",
 208                    __func__);
 209     }
 210     return host_fdt;
 211 }
 212
 213 #endif /* CONFIG_LINUX */
 214
 215 static int findnode_nofail(void *fdt, const char *node_path)
 216 {
 217     int offset;
 218
 219     offset = fdt_path_offset(fdt, node_path);
 220     if (offset < 0) {
 221         error_report("%s Couldn't find node %s: %s", __func__, node_path,
 222                      fdt_strerror(offset));
 223         exit(1);
 224     }
 225
 226     return offset;
 227 }
 228
 229 char **qemu_fdt_node_path(void *fdt, const char *name, char *compat,
 230                           Error **errp)
 231 {
 232     int offset, len, ret;
 233     const char *iter_name;
 234     unsigned int path_len = 16, n = 0;
 235     GSList *path_list = NULL, *iter;
 236     char **path_array;
 237
 238     offset = fdt_node_offset_by_compatible(fdt, -1, compat);
 239
 240     while (offset >= 0) {
 241         iter_name = fdt_get_name(fdt, offset, &len);
 242         if (!iter_name) {
 243             offset = len;
 244             break;
 245         }
 246         if (!strcmp(iter_name, name)) {
 247             char *path;
 248
 249             path = g_malloc(path_len);
 250             while ((ret = fdt_get_path(fdt, offset, path, path_len))
 251                   == -FDT_ERR_NOSPACE) {
 252                 path_len += 16;
 253                 path = g_realloc(path, path_len);
 254             }
 255             path_list = g_slist_prepend(path_list, path);
 256             n++;
 257         }
 258         offset = fdt_node_offset_by_compatible(fdt, offset, compat);
 259     }
 260
 261     if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
 262         error_setg(errp, "%s: abort parsing dt for %s/%s: %s",
 263                    __func__, name, compat, fdt_strerror(offset));
 264         for (iter = path_list; iter; iter = iter->next) {
 265             g_free(iter->data);
 266         }
 267         g_slist_free(path_list);
 268         return NULL;
 269     }
 270
 271     path_array = g_new(char *, n + 1);
 272     path_array[n--] = NULL;
 273
 274     for (iter = path_list; iter; iter = iter->next) {
 275         path_array[n--] = iter->data;
 276     }
 277
 278     g_slist_free(path_list);
 279
 280     return path_array;
 281 }
 282
 283 int qemu_fdt_setprop(void *fdt, const char *node_path,
 284                      const char *property, const void *val, int size)
 285 {
 286     int r;
 287
 288     r = fdt_setprop(fdt, findnode_nofail(fdt, node_path), property, val, size);
 289     if (r < 0) {
 290         error_report("%s: Couldn't set %s/%s: %s", __func__, node_path,
 291                      property, fdt_strerror(r));
 292         exit(1);
 293     }
 294
 295     return r;
 296 }
 297
 298 int qemu_fdt_setprop_cell(void *fdt, const char *node_path,
 299                           const char *property, uint32_t val)
 300 {
 301     int r;
 302
 303     r = fdt_setprop_cell(fdt, findnode_nofail(fdt, node_path), property, val);
 304     if (r < 0) {
 305         error_report("%s: Couldn't set %s/%s = %#08x: %s", __func__,
 306                      node_path, property, val, fdt_strerror(r));
 307         exit(1);
 308     }
 309
 310     return r;
 311 }
 312
 313 int qemu_fdt_setprop_u64(void *fdt, const char *node_path,
 314                          const char *property, uint64_t val)
 315 {
 316     val = cpu_to_be64(val);
 317     return qemu_fdt_setprop(fdt, node_path, property, &val, sizeof(val));
 318 }
 319
 320 int qemu_fdt_setprop_string(void *fdt, const char *node_path,
 321                             const char *property, const char *string)
 322 {
 323     int r;
 324
 325     r = fdt_setprop_string(fdt, findnode_nofail(fdt, node_path), property, string);
 326     if (r < 0) {
 327         error_report("%s: Couldn't set %s/%s = %s: %s", __func__,
 328                      node_path, property, string, fdt_strerror(r));
 329         exit(1);
 330     }
 331
 332     return r;
 333 }
 334
 335 const void *qemu_fdt_getprop(void *fdt, const char *node_path,
 336                              const char *property, int *lenp, Error **errp)
 337 {
 338     int len;
 339     const void *r;
 340
 341     if (!lenp) {
 342         lenp = &len;
 343     }
 344     r = fdt_getprop(fdt, findnode_nofail(fdt, node_path), property, lenp);
 345     if (!r) {
 346         error_setg(errp, "%s: Couldn't get %s/%s: %s", __func__,
 347                   node_path, property, fdt_strerror(*lenp));
 348     }
 349     return r;
 350 }
 351
 352 uint32_t qemu_fdt_getprop_cell(void *fdt, const char *node_path,
 353                                const char *property, int *lenp, Error **errp)
 354 {
 355     int len;
 356     const uint32_t *p;
 357
 358     if (!lenp) {
 359         lenp = &len;
 360     }
 361     p = qemu_fdt_getprop(fdt, node_path, property, lenp, errp);
 362     if (!p) {
 363         return 0;
 364     } else if (*lenp != 4) {
 365         error_setg(errp, "%s: %s/%s not 4 bytes long (not a cell?)",
 366                    __func__, node_path, property);
 367         *lenp = -EINVAL;
 368         return 0;
 369     }
 370     return be32_to_cpu(*p);
 371 }
 372
 373 uint32_t qemu_fdt_get_phandle(void *fdt, const char *path)
 374 {
 375     uint32_t r;
 376
 377     r = fdt_get_phandle(fdt, findnode_nofail(fdt, path));
 378     if (r == 0) {
 379         error_report("%s: Couldn't get phandle for %s: %s", __func__,
 380                      path, fdt_strerror(r));
 381         exit(1);
 382     }
 383
 384     return r;
 385 }
 386
 387 int qemu_fdt_setprop_phandle(void *fdt, const char *node_path,
 388                              const char *property,
 389                              const char *target_node_path)
 390 {
 391     uint32_t phandle = qemu_fdt_get_phandle(fdt, target_node_path);
 392     return qemu_fdt_setprop_cell(fdt, node_path, property, phandle);
 393 }
 394
 395 uint32_t qemu_fdt_alloc_phandle(void *fdt)
 396 {
 397     static int phandle = 0x0;
 398
 399     /*
 400      * We need to find out if the user gave us special instruction at
 401      * which phandle id to start allocating phandles.
 402      */
 403     if (!phandle) {
 404         phandle = machine_phandle_start(current_machine);
 405     }
 406
 407     if (!phandle) {
 408         /*
 409          * None or invalid phandle given on the command line, so fall back to
 410          * default starting point.
 411          */
 412         phandle = 0x8000;
 413     }
 414
 415     return phandle++;
 416 }
 417
 418 int qemu_fdt_nop_node(void *fdt, const char *node_path)
 419 {
 420     int r;
 421
 422     r = fdt_nop_node(fdt, findnode_nofail(fdt, node_path));
 423     if (r < 0) {
 424         error_report("%s: Couldn't nop node %s: %s", __func__, node_path,
 425                      fdt_strerror(r));
 426         exit(1);
 427     }
 428
 429     return r;
 430 }
 431
 432 int qemu_fdt_add_subnode(void *fdt, const char *name)
 433 {
 434     char *dupname = g_strdup(name);
 435     char *basename = strrchr(dupname, '/');
 436     int retval;
 437     int parent = 0;
 438
 439     if (!basename) {
 440         g_free(dupname);
 441         return -1;
 442     }
 443
 444     basename[0] = '\0';
 445     basename++;
 446
 447     if (dupname[0]) {
 448         parent = findnode_nofail(fdt, dupname);
 449     }
 450
 451     retval = fdt_add_subnode(fdt, parent, basename);
 452     if (retval < 0) {
 453         error_report("FDT: Failed to create subnode %s: %s", name,
 454                      fdt_strerror(retval));
 455         exit(1);
 456     }
 457
 458     g_free(dupname);
 459     return retval;
 460 }
 461
 462 void qemu_fdt_dumpdtb(void *fdt, int size)
 463 {
 464     const char *dumpdtb = qemu_opt_get(qemu_get_machine_opts(), "dumpdtb");
 465
 466     if (dumpdtb) {
 467         /* Dump the dtb to a file and quit */
 468         exit(g_file_set_contents(dumpdtb, fdt, size, NULL) ? 0 : 1);
 469     }
 470 }
 471
 472 int qemu_fdt_setprop_sized_cells_from_array(void *fdt,
 473                                             const char *node_path,
 474                                             const char *property,
 475                                             int numvalues,
 476                                             uint64_t *values)
 477 {
 478     uint32_t *propcells;
 479     uint64_t value;
 480     int cellnum, vnum, ncells;
 481     uint32_t hival;
 482     int ret;
 483
 484     propcells = g_new0(uint32_t, numvalues * 2);
 485
 486     cellnum = 0;
 487     for (vnum = 0; vnum < numvalues; vnum++) {
 488         ncells = values[vnum * 2];
 489         if (ncells != 1 && ncells != 2) {
 490             ret = -1;
 491             goto out;
 492         }
 493         value = values[vnum * 2 + 1];
 494         hival = cpu_to_be32(value >> 32);
 495         if (ncells > 1) {
 496             propcells[cellnum++] = hival;
 497         } else if (hival != 0) {
 498             ret = -1;
 499             goto out;
 500         }
 501         propcells[cellnum++] = cpu_to_be32(value);
 502     }
 503
 504     ret = qemu_fdt_setprop(fdt, node_path, property, propcells,
 505                            cellnum * sizeof(uint32_t));
 506 out:
 507     g_free(propcells);
 508     return ret;
 509 }