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 "sysemu/device_tree.h"
  24 #include "sysemu/sysemu.h"
  25 #include "hw/loader.h"
  26 #include "hw/boards.h"
  27 #include "qemu/config-file.h"
  28
  29 #include <libfdt.h>
  30
  31 #define FDT_MAX_SIZE  0x10000
  32
  33 void *create_device_tree(int *sizep)
  34 {
  35     void *fdt;
  36     int ret;
  37
  38     *sizep = FDT_MAX_SIZE;
  39     fdt = g_malloc0(FDT_MAX_SIZE);
  40     ret = fdt_create(fdt, FDT_MAX_SIZE);
  41     if (ret < 0) {
  42         goto fail;
  43     }
  44     ret = fdt_finish_reservemap(fdt);
  45     if (ret < 0) {
  46         goto fail;
  47     }
  48     ret = fdt_begin_node(fdt, "");
  49     if (ret < 0) {
  50         goto fail;
  51     }
  52     ret = fdt_end_node(fdt);
  53     if (ret < 0) {
  54         goto fail;
  55     }
  56     ret = fdt_finish(fdt);
  57     if (ret < 0) {
  58         goto fail;
  59     }
  60     ret = fdt_open_into(fdt, fdt, *sizep);
  61     if (ret) {
  62         error_report("Unable to copy device tree in memory");
  63         exit(1);
  64     }
  65
  66     return fdt;
  67 fail:
  68     error_report("%s Couldn't create dt: %s", __func__, fdt_strerror(ret));
  69     exit(1);
  70 }
  71
  72 void *load_device_tree(const char *filename_path, int *sizep)
  73 {
  74     int dt_size;
  75     int dt_file_load_size;
  76     int ret;
  77     void *fdt = NULL;
  78
  79     *sizep = 0;
  80     dt_size = get_image_size(filename_path);
  81     if (dt_size < 0) {
  82         error_report("Unable to get size of device tree file '%s'",
  83                      filename_path);
  84         goto fail;
  85     }
  86
  87     /* Expand to 2x size to give enough room for manipulation.  */
  88     dt_size += 10000;
  89     dt_size *= 2;
  90     /* First allocate space in qemu for device tree */
  91     fdt = g_malloc0(dt_size);
  92
  93     dt_file_load_size = load_image(filename_path, fdt);
  94     if (dt_file_load_size < 0) {
  95         error_report("Unable to open device tree file '%s'",
  96                      filename_path);
  97         goto fail;
  98     }
  99
 100     ret = fdt_open_into(fdt, fdt, dt_size);
 101     if (ret) {
 102         error_report("Unable to copy device tree in memory");
 103         goto fail;
 104     }
 105
 106     /* Check sanity of device tree */
 107     if (fdt_check_header(fdt)) {
 108         error_report("Device tree file loaded into memory is invalid: %s",
 109                      filename_path);
 110         goto fail;
 111     }
 112     *sizep = dt_size;
 113     return fdt;
 114
 115 fail:
 116     g_free(fdt);
 117     return NULL;
 118 }
 119
 120 #ifdef CONFIG_LINUX
 121
 122 #define SYSFS_DT_BASEDIR "/proc/device-tree"
 123
 124 /**
 125  * read_fstree: this function is inspired from dtc read_fstree
 126  * @fdt: preallocated fdt blob buffer, to be populated
 127  * @dirname: directory to scan under SYSFS_DT_BASEDIR
 128  * the search is recursive and the tree is searched down to the
 129  * leaves (property files).
 130  *
 131  * the function asserts in case of error
 132  */
 133 static void read_fstree(void *fdt, const char *dirname)
 134 {
 135     DIR *d;
 136     struct dirent *de;
 137     struct stat st;
 138     const char *root_dir = SYSFS_DT_BASEDIR;
 139     const char *parent_node;
 140
 141     if (strstr(dirname, root_dir) != dirname) {
 142         error_setg(&error_fatal, "%s: %s must be searched within %s",
 143                    __func__, dirname, root_dir);
 144     }
 145     parent_node = &dirname[strlen(SYSFS_DT_BASEDIR)];
 146
 147     d = opendir(dirname);
 148     if (!d) {
 149         error_setg(&error_fatal, "%s cannot open %s", __func__, dirname);
 150     }
 151
 152     while ((de = readdir(d)) != NULL) {
 153         char *tmpnam;
 154
 155         if (!g_strcmp0(de->d_name, ".")
 156             || !g_strcmp0(de->d_name, "..")) {
 157             continue;
 158         }
 159
 160         tmpnam = g_strdup_printf("%s/%s", dirname, de->d_name);
 161
 162         if (lstat(tmpnam, &st) < 0) {
 163             error_setg(&error_fatal, "%s cannot lstat %s", __func__, tmpnam);
 164         }
 165
 166         if (S_ISREG(st.st_mode)) {
 167             gchar *val;
 168             gsize len;
 169
 170             if (!g_file_get_contents(tmpnam, &val, &len, NULL)) {
 171                 error_setg(&error_fatal, "%s not able to extract info from %s",
 172                            __func__, tmpnam);
 173             }
 174
 175             if (strlen(parent_node) > 0) {
 176                 qemu_fdt_setprop(fdt, parent_node,
 177                                  de->d_name, val, len);
 178             } else {
 179                 qemu_fdt_setprop(fdt, "/", de->d_name, val, len);
 180             }
 181             g_free(val);
 182         } else if (S_ISDIR(st.st_mode)) {
 183             char *node_name;
 184
 185             node_name = g_strdup_printf("%s/%s",
 186                                         parent_node, de->d_name);
 187             qemu_fdt_add_subnode(fdt, node_name);
 188             g_free(node_name);
 189             read_fstree(fdt, tmpnam);
 190         }
 191
 192         g_free(tmpnam);
 193     }
 194
 195     closedir(d);
 196 }
 197
 198 /* load_device_tree_from_sysfs: extract the dt blob from host sysfs */
 199 void *load_device_tree_from_sysfs(void)
 200 {
 201     void *host_fdt;
 202     int host_fdt_size;
 203
 204     host_fdt = create_device_tree(&host_fdt_size);
 205     read_fstree(host_fdt, SYSFS_DT_BASEDIR);
 206     if (fdt_check_header(host_fdt)) {
 207         error_setg(&error_fatal,
 208                    "%s host device tree extracted into memory is invalid",
 209                    __func__);
 210     }
 211     return host_fdt;
 212 }
 213
 214 #endif /* CONFIG_LINUX */
 215
 216 static int findnode_nofail(void *fdt, const char *node_path)
 217 {
 218     int offset;
 219
 220     offset = fdt_path_offset(fdt, node_path);
 221     if (offset < 0) {
 222         error_report("%s Couldn't find node %s: %s", __func__, node_path,
 223                      fdt_strerror(offset));
 224         exit(1);
 225     }
 226
 227     return offset;
 228 }
 229
 230 char **qemu_fdt_node_path(void *fdt, const char *name, char *compat,
 231                           Error **errp)
 232 {
 233     int offset, len, ret;
 234     const char *iter_name;
 235     unsigned int path_len = 16, n = 0;
 236     GSList *path_list = NULL, *iter;
 237     char **path_array;
 238
 239     offset = fdt_node_offset_by_compatible(fdt, -1, compat);
 240
 241     while (offset >= 0) {
 242         iter_name = fdt_get_name(fdt, offset, &len);
 243         if (!iter_name) {
 244             offset = len;
 245             break;
 246         }
 247         if (!strcmp(iter_name, name)) {
 248             char *path;
 249
 250             path = g_malloc(path_len);
 251             while ((ret = fdt_get_path(fdt, offset, path, path_len))
 252                   == -FDT_ERR_NOSPACE) {
 253                 path_len += 16;
 254                 path = g_realloc(path, path_len);
 255             }
 256             path_list = g_slist_prepend(path_list, path);
 257             n++;
 258         }
 259         offset = fdt_node_offset_by_compatible(fdt, offset, compat);
 260     }
 261
 262     if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
 263         error_setg(errp, "%s: abort parsing dt for %s/%s: %s",
 264                    __func__, name, compat, fdt_strerror(offset));
 265         for (iter = path_list; iter; iter = iter->next) {
 266             g_free(iter->data);
 267         }
 268         g_slist_free(path_list);
 269         return NULL;
 270     }
 271
 272     path_array = g_new(char *, n + 1);
 273     path_array[n--] = NULL;
 274
 275     for (iter = path_list; iter; iter = iter->next) {
 276         path_array[n--] = iter->data;
 277     }
 278
 279     g_slist_free(path_list);
 280
 281     return path_array;
 282 }
 283
 284 int qemu_fdt_setprop(void *fdt, const char *node_path,
 285                      const char *property, const void *val, int size)
 286 {
 287     int r;
 288
 289     r = fdt_setprop(fdt, findnode_nofail(fdt, node_path), property, val, size);
 290     if (r < 0) {
 291         error_report("%s: Couldn't set %s/%s: %s", __func__, node_path,
 292                      property, fdt_strerror(r));
 293         exit(1);
 294     }
 295
 296     return r;
 297 }
 298
 299 int qemu_fdt_setprop_cell(void *fdt, const char *node_path,
 300                           const char *property, uint32_t val)
 301 {
 302     int r;
 303
 304     r = fdt_setprop_cell(fdt, findnode_nofail(fdt, node_path), property, val);
 305     if (r < 0) {
 306         error_report("%s: Couldn't set %s/%s = %#08x: %s", __func__,
 307                      node_path, property, val, fdt_strerror(r));
 308         exit(1);
 309     }
 310
 311     return r;
 312 }
 313
 314 int qemu_fdt_setprop_u64(void *fdt, const char *node_path,
 315                          const char *property, uint64_t val)
 316 {
 317     val = cpu_to_be64(val);
 318     return qemu_fdt_setprop(fdt, node_path, property, &val, sizeof(val));
 319 }
 320
 321 int qemu_fdt_setprop_string(void *fdt, const char *node_path,
 322                             const char *property, const char *string)
 323 {
 324     int r;
 325
 326     r = fdt_setprop_string(fdt, findnode_nofail(fdt, node_path), property, string);
 327     if (r < 0) {
 328         error_report("%s: Couldn't set %s/%s = %s: %s", __func__,
 329                      node_path, property, string, fdt_strerror(r));
 330         exit(1);
 331     }
 332
 333     return r;
 334 }
 335
 336 const void *qemu_fdt_getprop(void *fdt, const char *node_path,
 337                              const char *property, int *lenp, Error **errp)
 338 {
 339     int len;
 340     const void *r;
 341
 342     if (!lenp) {
 343         lenp = &len;
 344     }
 345     r = fdt_getprop(fdt, findnode_nofail(fdt, node_path), property, lenp);
 346     if (!r) {
 347         error_setg(errp, "%s: Couldn't get %s/%s: %s", __func__,
 348                   node_path, property, fdt_strerror(*lenp));
 349     }
 350     return r;
 351 }
 352
 353 uint32_t qemu_fdt_getprop_cell(void *fdt, const char *node_path,
 354                                const char *property, int *lenp, Error **errp)
 355 {
 356     int len;
 357     const uint32_t *p;
 358
 359     if (!lenp) {
 360         lenp = &len;
 361     }
 362     p = qemu_fdt_getprop(fdt, node_path, property, lenp, errp);
 363     if (!p) {
 364         return 0;
 365     } else if (*lenp != 4) {
 366         error_setg(errp, "%s: %s/%s not 4 bytes long (not a cell?)",
 367                    __func__, node_path, property);
 368         *lenp = -EINVAL;
 369         return 0;
 370     }
 371     return be32_to_cpu(*p);
 372 }
 373
 374 uint32_t qemu_fdt_get_phandle(void *fdt, const char *path)
 375 {
 376     uint32_t r;
 377
 378     r = fdt_get_phandle(fdt, findnode_nofail(fdt, path));
 379     if (r == 0) {
 380         error_report("%s: Couldn't get phandle for %s: %s", __func__,
 381                      path, fdt_strerror(r));
 382         exit(1);
 383     }
 384
 385     return r;
 386 }
 387
 388 int qemu_fdt_setprop_phandle(void *fdt, const char *node_path,
 389                              const char *property,
 390                              const char *target_node_path)
 391 {
 392     uint32_t phandle = qemu_fdt_get_phandle(fdt, target_node_path);
 393     return qemu_fdt_setprop_cell(fdt, node_path, property, phandle);
 394 }
 395
 396 uint32_t qemu_fdt_alloc_phandle(void *fdt)
 397 {
 398     static int phandle = 0x0;
 399
 400     /*
 401      * We need to find out if the user gave us special instruction at
 402      * which phandle id to start allocating phandles.
 403      */
 404     if (!phandle) {
 405         phandle = machine_phandle_start(current_machine);
 406     }
 407
 408     if (!phandle) {
 409         /*
 410          * None or invalid phandle given on the command line, so fall back to
 411          * default starting point.
 412          */
 413         phandle = 0x8000;
 414     }
 415
 416     return phandle++;
 417 }
 418
 419 int qemu_fdt_nop_node(void *fdt, const char *node_path)
 420 {
 421     int r;
 422
 423     r = fdt_nop_node(fdt, findnode_nofail(fdt, node_path));
 424     if (r < 0) {
 425         error_report("%s: Couldn't nop node %s: %s", __func__, node_path,
 426                      fdt_strerror(r));
 427         exit(1);
 428     }
 429
 430     return r;
 431 }
 432
 433 int qemu_fdt_add_subnode(void *fdt, const char *name)
 434 {
 435     char *dupname = g_strdup(name);
 436     char *basename = strrchr(dupname, '/');
 437     int retval;
 438     int parent = 0;
 439
 440     if (!basename) {
 441         g_free(dupname);
 442         return -1;
 443     }
 444
 445     basename[0] = '\0';
 446     basename++;
 447
 448     if (dupname[0]) {
 449         parent = findnode_nofail(fdt, dupname);
 450     }
 451
 452     retval = fdt_add_subnode(fdt, parent, basename);
 453     if (retval < 0) {
 454         error_report("FDT: Failed to create subnode %s: %s", name,
 455                      fdt_strerror(retval));
 456         exit(1);
 457     }
 458
 459     g_free(dupname);
 460     return retval;
 461 }
 462
 463 void qemu_fdt_dumpdtb(void *fdt, int size)
 464 {
 465     const char *dumpdtb = qemu_opt_get(qemu_get_machine_opts(), "dumpdtb");
 466
 467     if (dumpdtb) {
 468         /* Dump the dtb to a file and quit */
 469         exit(g_file_set_contents(dumpdtb, fdt, size, NULL) ? 0 : 1);
 470     }
 471 }
 472
 473 int qemu_fdt_setprop_sized_cells_from_array(void *fdt,
 474                                             const char *node_path,
 475                                             const char *property,
 476                                             int numvalues,
 477                                             uint64_t *values)
 478 {
 479     uint32_t *propcells;
 480     uint64_t value;
 481     int cellnum, vnum, ncells;
 482     uint32_t hival;
 483     int ret;
 484
 485     propcells = g_new0(uint32_t, numvalues * 2);
 486
 487     cellnum = 0;
 488     for (vnum = 0; vnum < numvalues; vnum++) {
 489         ncells = values[vnum * 2];
 490         if (ncells != 1 && ncells != 2) {
 491             ret = -1;
 492             goto out;
 493         }
 494         value = values[vnum * 2 + 1];
 495         hival = cpu_to_be32(value >> 32);
 496         if (ncells > 1) {
 497             propcells[cellnum++] = hival;
 498         } else if (hival != 0) {
 499             ret = -1;
 500             goto out;
 501         }
 502         propcells[cellnum++] = cpu_to_be32(value);
 503     }
 504
 505     ret = qemu_fdt_setprop(fdt, node_path, property, propcells,
 506                            cellnum * sizeof(uint32_t));
 507 out:
 508     g_free(propcells);
 509     return ret;
 510 }