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 "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  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("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_report("%s: %s must be searched within %s",
 144                      __func__, dirname, root_dir);
 145         exit(1);
 146     }
 147     parent_node = &dirname[strlen(SYSFS_DT_BASEDIR)];
 148
 149     d = opendir(dirname);
 150     if (!d) {
 151         error_report("%s cannot open %s", __func__, dirname);
 152         exit(1);
 153     }
 154
 155     while ((de = readdir(d)) != NULL) {
 156         char *tmpnam;
 157
 158         if (!g_strcmp0(de->d_name, ".")
 159             || !g_strcmp0(de->d_name, "..")) {
 160             continue;
 161         }
 162
 163         tmpnam = g_strdup_printf("%s/%s", dirname, de->d_name);
 164
 165         if (lstat(tmpnam, &st) < 0) {
 166             error_report("%s cannot lstat %s", __func__, tmpnam);
 167             exit(1);
 168         }
 169
 170         if (S_ISREG(st.st_mode)) {
 171             gchar *val;
 172             gsize len;
 173
 174             if (!g_file_get_contents(tmpnam, &val, &len, NULL)) {
 175                 error_report("%s not able to extract info from %s",
 176                              __func__, tmpnam);
 177                 exit(1);
 178             }
 179
 180             if (strlen(parent_node) > 0) {
 181                 qemu_fdt_setprop(fdt, parent_node,
 182                                  de->d_name, val, len);
 183             } else {
 184                 qemu_fdt_setprop(fdt, "/", de->d_name, val, len);
 185             }
 186             g_free(val);
 187         } else if (S_ISDIR(st.st_mode)) {
 188             char *node_name;
 189
 190             node_name = g_strdup_printf("%s/%s",
 191                                         parent_node, de->d_name);
 192             qemu_fdt_add_subnode(fdt, node_name);
 193             g_free(node_name);
 194             read_fstree(fdt, tmpnam);
 195         }
 196
 197         g_free(tmpnam);
 198     }
 199
 200     closedir(d);
 201 }
 202
 203 /* load_device_tree_from_sysfs: extract the dt blob from host sysfs */
 204 void *load_device_tree_from_sysfs(void)
 205 {
 206     void *host_fdt;
 207     int host_fdt_size;
 208
 209     host_fdt = create_device_tree(&host_fdt_size);
 210     read_fstree(host_fdt, SYSFS_DT_BASEDIR);
 211     if (fdt_check_header(host_fdt)) {
 212         error_report("%s host device tree extracted into memory is invalid",
 213                      __func__);
 214         exit(1);
 215     }
 216     return host_fdt;
 217 }
 218
 219 #endif /* CONFIG_LINUX */
 220
 221 static int findnode_nofail(void *fdt, const char *node_path)
 222 {
 223     int offset;
 224
 225     offset = fdt_path_offset(fdt, node_path);
 226     if (offset < 0) {
 227         error_report("%s Couldn't find node %s: %s", __func__, node_path,
 228                      fdt_strerror(offset));
 229         exit(1);
 230     }
 231
 232     return offset;
 233 }
 234
 235 char **qemu_fdt_node_path(void *fdt, const char *name, char *compat,
 236                           Error **errp)
 237 {
 238     int offset, len, ret;
 239     const char *iter_name;
 240     unsigned int path_len = 16, n = 0;
 241     GSList *path_list = NULL, *iter;
 242     char **path_array;
 243
 244     offset = fdt_node_offset_by_compatible(fdt, -1, compat);
 245
 246     while (offset >= 0) {
 247         iter_name = fdt_get_name(fdt, offset, &len);
 248         if (!iter_name) {
 249             offset = len;
 250             break;
 251         }
 252         if (!strcmp(iter_name, name)) {
 253             char *path;
 254
 255             path = g_malloc(path_len);
 256             while ((ret = fdt_get_path(fdt, offset, path, path_len))
 257                   == -FDT_ERR_NOSPACE) {
 258                 path_len += 16;
 259                 path = g_realloc(path, path_len);
 260             }
 261             path_list = g_slist_prepend(path_list, path);
 262             n++;
 263         }
 264         offset = fdt_node_offset_by_compatible(fdt, offset, compat);
 265     }
 266
 267     if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
 268         error_setg(errp, "%s: abort parsing dt for %s/%s: %s",
 269                    __func__, name, compat, fdt_strerror(offset));
 270         for (iter = path_list; iter; iter = iter->next) {
 271             g_free(iter->data);
 272         }
 273         g_slist_free(path_list);
 274         return NULL;
 275     }
 276
 277     path_array = g_new(char *, n + 1);
 278     path_array[n--] = NULL;
 279
 280     for (iter = path_list; iter; iter = iter->next) {
 281         path_array[n--] = iter->data;
 282     }
 283
 284     g_slist_free(path_list);
 285
 286     return path_array;
 287 }
 288
 289 int qemu_fdt_setprop(void *fdt, const char *node_path,
 290                      const char *property, const void *val, int size)
 291 {
 292     int r;
 293
 294     r = fdt_setprop(fdt, findnode_nofail(fdt, node_path), property, val, size);
 295     if (r < 0) {
 296         error_report("%s: Couldn't set %s/%s: %s", __func__, node_path,
 297                      property, fdt_strerror(r));
 298         exit(1);
 299     }
 300
 301     return r;
 302 }
 303
 304 int qemu_fdt_setprop_cell(void *fdt, const char *node_path,
 305                           const char *property, uint32_t val)
 306 {
 307     int r;
 308
 309     r = fdt_setprop_cell(fdt, findnode_nofail(fdt, node_path), property, val);
 310     if (r < 0) {
 311         error_report("%s: Couldn't set %s/%s = %#08x: %s", __func__,
 312                      node_path, property, val, fdt_strerror(r));
 313         exit(1);
 314     }
 315
 316     return r;
 317 }
 318
 319 int qemu_fdt_setprop_u64(void *fdt, const char *node_path,
 320                          const char *property, uint64_t val)
 321 {
 322     val = cpu_to_be64(val);
 323     return qemu_fdt_setprop(fdt, node_path, property, &val, sizeof(val));
 324 }
 325
 326 int qemu_fdt_setprop_string(void *fdt, const char *node_path,
 327                             const char *property, const char *string)
 328 {
 329     int r;
 330
 331     r = fdt_setprop_string(fdt, findnode_nofail(fdt, node_path), property, string);
 332     if (r < 0) {
 333         error_report("%s: Couldn't set %s/%s = %s: %s", __func__,
 334                      node_path, property, string, fdt_strerror(r));
 335         exit(1);
 336     }
 337
 338     return r;
 339 }
 340
 341 const void *qemu_fdt_getprop(void *fdt, const char *node_path,
 342                              const char *property, int *lenp, Error **errp)
 343 {
 344     int len;
 345     const void *r;
 346
 347     if (!lenp) {
 348         lenp = &len;
 349     }
 350     r = fdt_getprop(fdt, findnode_nofail(fdt, node_path), property, lenp);
 351     if (!r) {
 352         error_setg(errp, "%s: Couldn't get %s/%s: %s", __func__,
 353                   node_path, property, fdt_strerror(*lenp));
 354     }
 355     return r;
 356 }
 357
 358 uint32_t qemu_fdt_getprop_cell(void *fdt, const char *node_path,
 359                                const char *property, int *lenp, Error **errp)
 360 {
 361     int len;
 362     const uint32_t *p;
 363
 364     if (!lenp) {
 365         lenp = &len;
 366     }
 367     p = qemu_fdt_getprop(fdt, node_path, property, lenp, errp);
 368     if (!p) {
 369         return 0;
 370     } else if (*lenp != 4) {
 371         error_setg(errp, "%s: %s/%s not 4 bytes long (not a cell?)",
 372                    __func__, node_path, property);
 373         *lenp = -EINVAL;
 374         return 0;
 375     }
 376     return be32_to_cpu(*p);
 377 }
 378
 379 uint32_t qemu_fdt_get_phandle(void *fdt, const char *path)
 380 {
 381     uint32_t r;
 382
 383     r = fdt_get_phandle(fdt, findnode_nofail(fdt, path));
 384     if (r == 0) {
 385         error_report("%s: Couldn't get phandle for %s: %s", __func__,
 386                      path, fdt_strerror(r));
 387         exit(1);
 388     }
 389
 390     return r;
 391 }
 392
 393 int qemu_fdt_setprop_phandle(void *fdt, const char *node_path,
 394                              const char *property,
 395                              const char *target_node_path)
 396 {
 397     uint32_t phandle = qemu_fdt_get_phandle(fdt, target_node_path);
 398     return qemu_fdt_setprop_cell(fdt, node_path, property, phandle);
 399 }
 400
 401 uint32_t qemu_fdt_alloc_phandle(void *fdt)
 402 {
 403     static int phandle = 0x0;
 404
 405     /*
 406      * We need to find out if the user gave us special instruction at
 407      * which phandle id to start allocating phandles.
 408      */
 409     if (!phandle) {
 410         phandle = machine_phandle_start(current_machine);
 411     }
 412
 413     if (!phandle) {
 414         /*
 415          * None or invalid phandle given on the command line, so fall back to
 416          * default starting point.
 417          */
 418         phandle = 0x8000;
 419     }
 420
 421     return phandle++;
 422 }
 423
 424 int qemu_fdt_nop_node(void *fdt, const char *node_path)
 425 {
 426     int r;
 427
 428     r = fdt_nop_node(fdt, findnode_nofail(fdt, node_path));
 429     if (r < 0) {
 430         error_report("%s: Couldn't nop node %s: %s", __func__, node_path,
 431                      fdt_strerror(r));
 432         exit(1);
 433     }
 434
 435     return r;
 436 }
 437
 438 int qemu_fdt_add_subnode(void *fdt, const char *name)
 439 {
 440     char *dupname = g_strdup(name);
 441     char *basename = strrchr(dupname, '/');
 442     int retval;
 443     int parent = 0;
 444
 445     if (!basename) {
 446         g_free(dupname);
 447         return -1;
 448     }
 449
 450     basename[0] = '\0';
 451     basename++;
 452
 453     if (dupname[0]) {
 454         parent = findnode_nofail(fdt, dupname);
 455     }
 456
 457     retval = fdt_add_subnode(fdt, parent, basename);
 458     if (retval < 0) {
 459         error_report("FDT: Failed to create subnode %s: %s", name,
 460                      fdt_strerror(retval));
 461         exit(1);
 462     }
 463
 464     g_free(dupname);
 465     return retval;
 466 }
 467
 468 void qemu_fdt_dumpdtb(void *fdt, int size)
 469 {
 470     const char *dumpdtb = qemu_opt_get(qemu_get_machine_opts(), "dumpdtb");
 471
 472     if (dumpdtb) {
 473         /* Dump the dtb to a file and quit */
 474         exit(g_file_set_contents(dumpdtb, fdt, size, NULL) ? 0 : 1);
 475     }
 476 }
 477
 478 int qemu_fdt_setprop_sized_cells_from_array(void *fdt,
 479                                             const char *node_path,
 480                                             const char *property,
 481                                             int numvalues,
 482                                             uint64_t *values)
 483 {
 484     uint32_t *propcells;
 485     uint64_t value;
 486     int cellnum, vnum, ncells;
 487     uint32_t hival;
 488     int ret;
 489
 490     propcells = g_new0(uint32_t, numvalues * 2);
 491
 492     cellnum = 0;
 493     for (vnum = 0; vnum < numvalues; vnum++) {
 494         ncells = values[vnum * 2];
 495         if (ncells != 1 && ncells != 2) {
 496             ret = -1;
 497             goto out;
 498         }
 499         value = values[vnum * 2 + 1];
 500         hival = cpu_to_be32(value >> 32);
 501         if (ncells > 1) {
 502             propcells[cellnum++] = hival;
 503         } else if (hival != 0) {
 504             ret = -1;
 505             goto out;
 506         }
 507         propcells[cellnum++] = cpu_to_be32(value);
 508     }
 509
 510     ret = qemu_fdt_setprop(fdt, node_path, property, propcells,
 511                            cellnum * sizeof(uint32_t));
 512 out:
 513     g_free(propcells);
 514     return ret;
 515 }