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 int qemu_fdt_setprop(void *fdt, const char *node_path,
 230                      const char *property, const void *val, int size)
 231 {
 232     int r;
 233
 234     r = fdt_setprop(fdt, findnode_nofail(fdt, node_path), property, val, size);
 235     if (r < 0) {
 236         error_report("%s: Couldn't set %s/%s: %s", __func__, node_path,
 237                      property, fdt_strerror(r));
 238         exit(1);
 239     }
 240
 241     return r;
 242 }
 243
 244 int qemu_fdt_setprop_cell(void *fdt, const char *node_path,
 245                           const char *property, uint32_t val)
 246 {
 247     int r;
 248
 249     r = fdt_setprop_cell(fdt, findnode_nofail(fdt, node_path), property, val);
 250     if (r < 0) {
 251         error_report("%s: Couldn't set %s/%s = %#08x: %s", __func__,
 252                      node_path, property, val, fdt_strerror(r));
 253         exit(1);
 254     }
 255
 256     return r;
 257 }
 258
 259 int qemu_fdt_setprop_u64(void *fdt, const char *node_path,
 260                          const char *property, uint64_t val)
 261 {
 262     val = cpu_to_be64(val);
 263     return qemu_fdt_setprop(fdt, node_path, property, &val, sizeof(val));
 264 }
 265
 266 int qemu_fdt_setprop_string(void *fdt, const char *node_path,
 267                             const char *property, const char *string)
 268 {
 269     int r;
 270
 271     r = fdt_setprop_string(fdt, findnode_nofail(fdt, node_path), property, string);
 272     if (r < 0) {
 273         error_report("%s: Couldn't set %s/%s = %s: %s", __func__,
 274                      node_path, property, string, fdt_strerror(r));
 275         exit(1);
 276     }
 277
 278     return r;
 279 }
 280
 281 const void *qemu_fdt_getprop(void *fdt, const char *node_path,
 282                              const char *property, int *lenp)
 283 {
 284     int len;
 285     const void *r;
 286     if (!lenp) {
 287         lenp = &len;
 288     }
 289     r = fdt_getprop(fdt, findnode_nofail(fdt, node_path), property, lenp);
 290     if (!r) {
 291         error_report("%s: Couldn't get %s/%s: %s", __func__,
 292                      node_path, property, fdt_strerror(*lenp));
 293         exit(1);
 294     }
 295     return r;
 296 }
 297
 298 uint32_t qemu_fdt_getprop_cell(void *fdt, const char *node_path,
 299                                const char *property)
 300 {
 301     int len;
 302     const uint32_t *p = qemu_fdt_getprop(fdt, node_path, property, &len);
 303     if (len != 4) {
 304         error_report("%s: %s/%s not 4 bytes long (not a cell?)",
 305                      __func__, node_path, property);
 306         exit(1);
 307     }
 308     return be32_to_cpu(*p);
 309 }
 310
 311 uint32_t qemu_fdt_get_phandle(void *fdt, const char *path)
 312 {
 313     uint32_t r;
 314
 315     r = fdt_get_phandle(fdt, findnode_nofail(fdt, path));
 316     if (r == 0) {
 317         error_report("%s: Couldn't get phandle for %s: %s", __func__,
 318                      path, fdt_strerror(r));
 319         exit(1);
 320     }
 321
 322     return r;
 323 }
 324
 325 int qemu_fdt_setprop_phandle(void *fdt, const char *node_path,
 326                              const char *property,
 327                              const char *target_node_path)
 328 {
 329     uint32_t phandle = qemu_fdt_get_phandle(fdt, target_node_path);
 330     return qemu_fdt_setprop_cell(fdt, node_path, property, phandle);
 331 }
 332
 333 uint32_t qemu_fdt_alloc_phandle(void *fdt)
 334 {
 335     static int phandle = 0x0;
 336
 337     /*
 338      * We need to find out if the user gave us special instruction at
 339      * which phandle id to start allocating phandles.
 340      */
 341     if (!phandle) {
 342         phandle = machine_phandle_start(current_machine);
 343     }
 344
 345     if (!phandle) {
 346         /*
 347          * None or invalid phandle given on the command line, so fall back to
 348          * default starting point.
 349          */
 350         phandle = 0x8000;
 351     }
 352
 353     return phandle++;
 354 }
 355
 356 int qemu_fdt_nop_node(void *fdt, const char *node_path)
 357 {
 358     int r;
 359
 360     r = fdt_nop_node(fdt, findnode_nofail(fdt, node_path));
 361     if (r < 0) {
 362         error_report("%s: Couldn't nop node %s: %s", __func__, node_path,
 363                      fdt_strerror(r));
 364         exit(1);
 365     }
 366
 367     return r;
 368 }
 369
 370 int qemu_fdt_add_subnode(void *fdt, const char *name)
 371 {
 372     char *dupname = g_strdup(name);
 373     char *basename = strrchr(dupname, '/');
 374     int retval;
 375     int parent = 0;
 376
 377     if (!basename) {
 378         g_free(dupname);
 379         return -1;
 380     }
 381
 382     basename[0] = '\0';
 383     basename++;
 384
 385     if (dupname[0]) {
 386         parent = findnode_nofail(fdt, dupname);
 387     }
 388
 389     retval = fdt_add_subnode(fdt, parent, basename);
 390     if (retval < 0) {
 391         error_report("FDT: Failed to create subnode %s: %s", name,
 392                      fdt_strerror(retval));
 393         exit(1);
 394     }
 395
 396     g_free(dupname);
 397     return retval;
 398 }
 399
 400 void qemu_fdt_dumpdtb(void *fdt, int size)
 401 {
 402     const char *dumpdtb = qemu_opt_get(qemu_get_machine_opts(), "dumpdtb");
 403
 404     if (dumpdtb) {
 405         /* Dump the dtb to a file and quit */
 406         exit(g_file_set_contents(dumpdtb, fdt, size, NULL) ? 0 : 1);
 407     }
 408 }
 409
 410 int qemu_fdt_setprop_sized_cells_from_array(void *fdt,
 411                                             const char *node_path,
 412                                             const char *property,
 413                                             int numvalues,
 414                                             uint64_t *values)
 415 {
 416     uint32_t *propcells;
 417     uint64_t value;
 418     int cellnum, vnum, ncells;
 419     uint32_t hival;
 420     int ret;
 421
 422     propcells = g_new0(uint32_t, numvalues * 2);
 423
 424     cellnum = 0;
 425     for (vnum = 0; vnum < numvalues; vnum++) {
 426         ncells = values[vnum * 2];
 427         if (ncells != 1 && ncells != 2) {
 428             ret = -1;
 429             goto out;
 430         }
 431         value = values[vnum * 2 + 1];
 432         hival = cpu_to_be32(value >> 32);
 433         if (ncells > 1) {
 434             propcells[cellnum++] = hival;
 435         } else if (hival != 0) {
 436             ret = -1;
 437             goto out;
 438         }
 439         propcells[cellnum++] = cpu_to_be32(value);
 440     }
 441
 442     ret = qemu_fdt_setprop(fdt, node_path, property, propcells,
 443                            cellnum * sizeof(uint32_t));
 444 out:
 445     g_free(propcells);
 446     return ret;
 447 }