drivers/base/swnode.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Software nodes for the firmware node framework.
   4  *
   5  * Copyright (C) 2018, Intel Corporation
   6  * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
   7  */
   8
   9 #include <linux/container_of.h>
  10 #include <linux/device.h>
  11 #include <linux/err.h>
  12 #include <linux/export.h>
  13 #include <linux/idr.h>
  14 #include <linux/init.h>
  15 #include <linux/kobject.h>
  16 #include <linux/kstrtox.h>
  17 #include <linux/list.h>
  18 #include <linux/property.h>
  19 #include <linux/slab.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/string.h>
  22 #include <linux/sysfs.h>
  23 #include <linux/types.h>
  24
  25 #include "base.h"
  26
  27 struct swnode {
  28         struct kobject kobj;
  29         struct fwnode_handle fwnode;
  30         const struct software_node *node;
  31         int id;
  32
  33         /* hierarchy */
  34         struct ida child_ids;
  35         struct list_head entry;
  36         struct list_head children;
  37         struct swnode *parent;
  38
  39         unsigned int allocated:1;
  40         unsigned int managed:1;
  41 };
  42
  43 static DEFINE_IDA(swnode_root_ids);
  44 static struct kset *swnode_kset;
  45
  46 #define kobj_to_swnode(_kobj_) container_of(_kobj_, struct swnode, kobj)
  47
  48 static const struct fwnode_operations software_node_ops;
  49
  50 bool is_software_node(const struct fwnode_handle *fwnode)
  51 {
  52         return !IS_ERR_OR_NULL(fwnode) && fwnode->ops == &software_node_ops;
  53 }
  54 EXPORT_SYMBOL_GPL(is_software_node);
  55
  56 #define to_swnode(__fwnode)                                             \
  57         ({                                                              \
  58                 typeof(__fwnode) __to_swnode_fwnode = __fwnode;         \
  59                                                                         \
  60                 is_software_node(__to_swnode_fwnode) ?                  \
  61                         container_of(__to_swnode_fwnode,                \
  62                                      struct swnode, fwnode) : NULL;     \
  63         })
  64
  65 static inline struct swnode *dev_to_swnode(struct device *dev)
  66 {
  67         struct fwnode_handle *fwnode = dev_fwnode(dev);
  68
  69         if (!fwnode)
  70                 return NULL;
  71
  72         if (!is_software_node(fwnode))
  73                 fwnode = fwnode->secondary;
  74
  75         return to_swnode(fwnode);
  76 }
  77
  78 static struct swnode *
  79 software_node_to_swnode(const struct software_node *node)
  80 {
  81         struct swnode *swnode = NULL;
  82         struct kobject *k;
  83
  84         if (!node)
  85                 return NULL;
  86
  87         spin_lock(&swnode_kset->list_lock);
  88
  89         list_for_each_entry(k, &swnode_kset->list, entry) {
  90                 swnode = kobj_to_swnode(k);
  91                 if (swnode->node == node)
  92                         break;
  93                 swnode = NULL;
  94         }
  95
  96         spin_unlock(&swnode_kset->list_lock);
  97
  98         return swnode;
  99 }
 100
 101 const struct software_node *to_software_node(const struct fwnode_handle *fwnode)
 102 {
 103         const struct swnode *swnode = to_swnode(fwnode);
 104
 105         return swnode ? swnode->node : NULL;
 106 }
 107 EXPORT_SYMBOL_GPL(to_software_node);
 108
 109 struct fwnode_handle *software_node_fwnode(const struct software_node *node)
 110 {
 111         struct swnode *swnode = software_node_to_swnode(node);
 112
 113         return swnode ? &swnode->fwnode : NULL;
 114 }
 115 EXPORT_SYMBOL_GPL(software_node_fwnode);
 116
 117 /* -------------------------------------------------------------------------- */
 118 /* property_entry processing */
 119
 120 static const struct property_entry *
 121 property_entry_get(const struct property_entry *prop, const char *name)
 122 {
 123         if (!prop)
 124                 return NULL;
 125
 126         for (; prop->name; prop++)
 127                 if (!strcmp(name, prop->name))
 128                         return prop;
 129
 130         return NULL;
 131 }
 132
 133 static const void *property_get_pointer(const struct property_entry *prop)
 134 {
 135         if (!prop->length)
 136                 return NULL;
 137
 138         return prop->is_inline ? &prop->value : prop->pointer;
 139 }
 140
 141 static const void *property_entry_find(const struct property_entry *props,
 142                                        const char *propname, size_t length)
 143 {
 144         const struct property_entry *prop;
 145         const void *pointer;
 146
 147         prop = property_entry_get(props, propname);
 148         if (!prop)
 149                 return ERR_PTR(-EINVAL);
 150         pointer = property_get_pointer(prop);
 151         if (!pointer)
 152                 return ERR_PTR(-ENODATA);
 153         if (length > prop->length)
 154                 return ERR_PTR(-EOVERFLOW);
 155         return pointer;
 156 }
 157
 158 static int
 159 property_entry_count_elems_of_size(const struct property_entry *props,
 160                                    const char *propname, size_t length)
 161 {
 162         const struct property_entry *prop;
 163
 164         prop = property_entry_get(props, propname);
 165         if (!prop)
 166                 return -EINVAL;
 167
 168         return prop->length / length;
 169 }
 170
 171 static int property_entry_read_int_array(const struct property_entry *props,
 172                                          const char *name,
 173                                          unsigned int elem_size, void *val,
 174                                          size_t nval)
 175 {
 176         const void *pointer;
 177         size_t length;
 178
 179         if (!val)
 180                 return property_entry_count_elems_of_size(props, name,
 181                                                           elem_size);
 182
 183         if (!is_power_of_2(elem_size) || elem_size > sizeof(u64))
 184                 return -ENXIO;
 185
 186         length = nval * elem_size;
 187
 188         pointer = property_entry_find(props, name, length);
 189         if (IS_ERR(pointer))
 190                 return PTR_ERR(pointer);
 191
 192         memcpy(val, pointer, length);
 193         return 0;
 194 }
 195
 196 static int property_entry_read_string_array(const struct property_entry *props,
 197                                             const char *propname,
 198                                             const char **strings, size_t nval)
 199 {
 200         const void *pointer;
 201         size_t length;
 202         int array_len;
 203
 204         /* Find out the array length. */
 205         array_len = property_entry_count_elems_of_size(props, propname,
 206                                                        sizeof(const char *));
 207         if (array_len < 0)
 208                 return array_len;
 209
 210         /* Return how many there are if strings is NULL. */
 211         if (!strings)
 212                 return array_len;
 213
 214         array_len = min_t(size_t, nval, array_len);
 215         length = array_len * sizeof(*strings);
 216
 217         pointer = property_entry_find(props, propname, length);
 218         if (IS_ERR(pointer))
 219                 return PTR_ERR(pointer);
 220
 221         memcpy(strings, pointer, length);
 222
 223         return array_len;
 224 }
 225
 226 static void property_entry_free_data(const struct property_entry *p)
 227 {
 228         const char * const *src_str;
 229         size_t i, nval;
 230
 231         if (p->type == DEV_PROP_STRING) {
 232                 src_str = property_get_pointer(p);
 233                 nval = p->length / sizeof(*src_str);
 234                 for (i = 0; i < nval; i++)
 235                         kfree(src_str[i]);
 236         }
 237
 238         if (!p->is_inline)
 239                 kfree(p->pointer);
 240
 241         kfree(p->name);
 242 }
 243
 244 static bool property_copy_string_array(const char **dst_ptr,
 245                                        const char * const *src_ptr,
 246                                        size_t nval)
 247 {
 248         int i;
 249
 250         for (i = 0; i < nval; i++) {
 251                 dst_ptr[i] = kstrdup(src_ptr[i], GFP_KERNEL);
 252                 if (!dst_ptr[i] && src_ptr[i]) {
 253                         while (--i >= 0)
 254                                 kfree(dst_ptr[i]);
 255                         return false;
 256                 }
 257         }
 258
 259         return true;
 260 }
 261
 262 static int property_entry_copy_data(struct property_entry *dst,
 263                                     const struct property_entry *src)
 264 {
 265         const void *pointer = property_get_pointer(src);
 266         void *dst_ptr;
 267         size_t nval;
 268
 269         /*
 270          * Properties with no data should not be marked as stored
 271          * out of line.
 272          */
 273         if (!src->is_inline && !src->length)
 274                 return -ENODATA;
 275
 276         /*
 277          * Reference properties are never stored inline as
 278          * they are too big.
 279          */
 280         if (src->type == DEV_PROP_REF && src->is_inline)
 281                 return -EINVAL;
 282
 283         if (src->length <= sizeof(dst->value)) {
 284                 dst_ptr = &dst->value;
 285                 dst->is_inline = true;
 286         } else {
 287                 dst_ptr = kmalloc(src->length, GFP_KERNEL);
 288                 if (!dst_ptr)
 289                         return -ENOMEM;
 290                 dst->pointer = dst_ptr;
 291         }
 292
 293         if (src->type == DEV_PROP_STRING) {
 294                 nval = src->length / sizeof(const char *);
 295                 if (!property_copy_string_array(dst_ptr, pointer, nval)) {
 296                         if (!dst->is_inline)
 297                                 kfree(dst->pointer);
 298                         return -ENOMEM;
 299                 }
 300         } else {
 301                 memcpy(dst_ptr, pointer, src->length);
 302         }
 303
 304         dst->length = src->length;
 305         dst->type = src->type;
 306         dst->name = kstrdup(src->name, GFP_KERNEL);
 307         if (!dst->name) {
 308                 property_entry_free_data(dst);
 309                 return -ENOMEM;
 310         }
 311
 312         return 0;
 313 }
 314
 315 /**
 316  * property_entries_dup - duplicate array of properties
 317  * @properties: array of properties to copy
 318  *
 319  * This function creates a deep copy of the given NULL-terminated array
 320  * of property entries.
 321  */
 322 struct property_entry *
 323 property_entries_dup(const struct property_entry *properties)
 324 {
 325         struct property_entry *p;
 326         int i, n = 0;
 327         int ret;
 328
 329         if (!properties)
 330                 return NULL;
 331
 332         while (properties[n].name)
 333                 n++;
 334
 335         p = kcalloc(n + 1, sizeof(*p), GFP_KERNEL);
 336         if (!p)
 337                 return ERR_PTR(-ENOMEM);
 338
 339         for (i = 0; i < n; i++) {
 340                 ret = property_entry_copy_data(&p[i], &properties[i]);
 341                 if (ret) {
 342                         while (--i >= 0)
 343                                 property_entry_free_data(&p[i]);
 344                         kfree(p);
 345                         return ERR_PTR(ret);
 346                 }
 347         }
 348
 349         return p;
 350 }
 351 EXPORT_SYMBOL_GPL(property_entries_dup);
 352
 353 /**
 354  * property_entries_free - free previously allocated array of properties
 355  * @properties: array of properties to destroy
 356  *
 357  * This function frees given NULL-terminated array of property entries,
 358  * along with their data.
 359  */
 360 void property_entries_free(const struct property_entry *properties)
 361 {
 362         const struct property_entry *p;
 363
 364         if (!properties)
 365                 return;
 366
 367         for (p = properties; p->name; p++)
 368                 property_entry_free_data(p);
 369
 370         kfree(properties);
 371 }
 372 EXPORT_SYMBOL_GPL(property_entries_free);
 373
 374 /* -------------------------------------------------------------------------- */
 375 /* fwnode operations */
 376
 377 static struct fwnode_handle *software_node_get(struct fwnode_handle *fwnode)
 378 {
 379         struct swnode *swnode = to_swnode(fwnode);
 380
 381         kobject_get(&swnode->kobj);
 382
 383         return &swnode->fwnode;
 384 }
 385
 386 static void software_node_put(struct fwnode_handle *fwnode)
 387 {
 388         struct swnode *swnode = to_swnode(fwnode);
 389
 390         kobject_put(&swnode->kobj);
 391 }
 392
 393 static bool software_node_property_present(const struct fwnode_handle *fwnode,
 394                                            const char *propname)
 395 {
 396         struct swnode *swnode = to_swnode(fwnode);
 397
 398         return !!property_entry_get(swnode->node->properties, propname);
 399 }
 400
 401 static int software_node_read_int_array(const struct fwnode_handle *fwnode,
 402                                         const char *propname,
 403                                         unsigned int elem_size, void *val,
 404                                         size_t nval)
 405 {
 406         struct swnode *swnode = to_swnode(fwnode);
 407
 408         return property_entry_read_int_array(swnode->node->properties, propname,
 409                                              elem_size, val, nval);
 410 }
 411
 412 static int software_node_read_string_array(const struct fwnode_handle *fwnode,
 413                                            const char *propname,
 414                                            const char **val, size_t nval)
 415 {
 416         struct swnode *swnode = to_swnode(fwnode);
 417
 418         return property_entry_read_string_array(swnode->node->properties,
 419                                                 propname, val, nval);
 420 }
 421
 422 static const char *
 423 software_node_get_name(const struct fwnode_handle *fwnode)
 424 {
 425         const struct swnode *swnode = to_swnode(fwnode);
 426
 427         return kobject_name(&swnode->kobj);
 428 }
 429
 430 static const char *
 431 software_node_get_name_prefix(const struct fwnode_handle *fwnode)
 432 {
 433         struct fwnode_handle *parent;
 434         const char *prefix;
 435
 436         parent = fwnode_get_parent(fwnode);
 437         if (!parent)
 438                 return "";
 439
 440         /* Figure out the prefix from the parents. */
 441         while (is_software_node(parent))
 442                 parent = fwnode_get_next_parent(parent);
 443
 444         prefix = fwnode_get_name_prefix(parent);
 445         fwnode_handle_put(parent);
 446
 447         /* Guess something if prefix was NULL. */
 448         return prefix ?: "/";
 449 }
 450
 451 static struct fwnode_handle *
 452 software_node_get_parent(const struct fwnode_handle *fwnode)
 453 {
 454         struct swnode *swnode = to_swnode(fwnode);
 455
 456         if (!swnode || !swnode->parent)
 457                 return NULL;
 458
 459         return fwnode_handle_get(&swnode->parent->fwnode);
 460 }
 461
 462 static struct fwnode_handle *
 463 software_node_get_next_child(const struct fwnode_handle *fwnode,
 464                              struct fwnode_handle *child)
 465 {
 466         struct swnode *p = to_swnode(fwnode);
 467         struct swnode *c = to_swnode(child);
 468
 469         if (!p || list_empty(&p->children) ||
 470             (c && list_is_last(&c->entry, &p->children))) {
 471                 fwnode_handle_put(child);
 472                 return NULL;
 473         }
 474
 475         if (c)
 476                 c = list_next_entry(c, entry);
 477         else
 478                 c = list_first_entry(&p->children, struct swnode, entry);
 479
 480         fwnode_handle_put(child);
 481         return fwnode_handle_get(&c->fwnode);
 482 }
 483
 484 static struct fwnode_handle *
 485 software_node_get_named_child_node(const struct fwnode_handle *fwnode,
 486                                    const char *childname)
 487 {
 488         struct swnode *swnode = to_swnode(fwnode);
 489         struct swnode *child;
 490
 491         if (!swnode || list_empty(&swnode->children))
 492                 return NULL;
 493
 494         list_for_each_entry(child, &swnode->children, entry) {
 495                 if (!strcmp(childname, kobject_name(&child->kobj))) {
 496                         kobject_get(&child->kobj);
 497                         return &child->fwnode;
 498                 }
 499         }
 500         return NULL;
 501 }
 502
 503 static int
 504 software_node_get_reference_args(const struct fwnode_handle *fwnode,
 505                                  const char *propname, const char *nargs_prop,
 506                                  unsigned int nargs, unsigned int index,
 507                                  struct fwnode_reference_args *args)
 508 {
 509         struct swnode *swnode = to_swnode(fwnode);
 510         const struct software_node_ref_args *ref_array;
 511         const struct software_node_ref_args *ref;
 512         const struct property_entry *prop;
 513         struct fwnode_handle *refnode;
 514         u32 nargs_prop_val;
 515         int error;
 516         int i;
 517
 518         prop = property_entry_get(swnode->node->properties, propname);
 519         if (!prop)
 520                 return -ENOENT;
 521
 522         if (prop->type != DEV_PROP_REF)
 523                 return -EINVAL;
 524
 525         /*
 526          * We expect that references are never stored inline, even
 527          * single ones, as they are too big.
 528          */
 529         if (prop->is_inline)
 530                 return -EINVAL;
 531
 532         if (index * sizeof(*ref) >= prop->length)
 533                 return -ENOENT;
 534
 535         ref_array = prop->pointer;
 536         ref = &ref_array[index];
 537
 538         refnode = software_node_fwnode(ref->node);
 539         if (!refnode)
 540                 return -ENOENT;
 541
 542         if (nargs_prop) {
 543                 error = property_entry_read_int_array(ref->node->properties,
 544                                                       nargs_prop, sizeof(u32),
 545                                                       &nargs_prop_val, 1);
 546                 if (error)
 547                         return error;
 548
 549                 nargs = nargs_prop_val;
 550         }
 551
 552         if (nargs > NR_FWNODE_REFERENCE_ARGS)
 553                 return -EINVAL;
 554
 555         if (!args)
 556                 return 0;
 557
 558         args->fwnode = software_node_get(refnode);
 559         args->nargs = nargs;
 560
 561         for (i = 0; i < nargs; i++)
 562                 args->args[i] = ref->args[i];
 563
 564         return 0;
 565 }
 566
 567 static struct fwnode_handle *
 568 swnode_graph_find_next_port(const struct fwnode_handle *parent,
 569                             struct fwnode_handle *port)
 570 {
 571         struct fwnode_handle *old = port;
 572
 573         while ((port = software_node_get_next_child(parent, old))) {
 574                 /*
 575                  * fwnode ports have naming style "port@", so we search for any
 576                  * children that follow that convention.
 577                  */
 578                 if (!strncmp(to_swnode(port)->node->name, "port@",
 579                              strlen("port@")))
 580                         return port;
 581                 old = port;
 582         }
 583
 584         return NULL;
 585 }
 586
 587 static struct fwnode_handle *
 588 software_node_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
 589                                       struct fwnode_handle *endpoint)
 590 {
 591         struct swnode *swnode = to_swnode(fwnode);
 592         struct fwnode_handle *parent;
 593         struct fwnode_handle *port;
 594
 595         if (!swnode)
 596                 return NULL;
 597
 598         if (endpoint) {
 599                 port = software_node_get_parent(endpoint);
 600                 parent = software_node_get_parent(port);
 601         } else {
 602                 parent = software_node_get_named_child_node(fwnode, "ports");
 603                 if (!parent)
 604                         parent = software_node_get(&swnode->fwnode);
 605
 606                 port = swnode_graph_find_next_port(parent, NULL);
 607         }
 608
 609         for (; port; port = swnode_graph_find_next_port(parent, port)) {
 610                 endpoint = software_node_get_next_child(port, endpoint);
 611                 if (endpoint) {
 612                         fwnode_handle_put(port);
 613                         break;
 614                 }
 615         }
 616
 617         fwnode_handle_put(parent);
 618
 619         return endpoint;
 620 }
 621
 622 static struct fwnode_handle *
 623 software_node_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
 624 {
 625         struct swnode *swnode = to_swnode(fwnode);
 626         const struct software_node_ref_args *ref;
 627         const struct property_entry *prop;
 628
 629         if (!swnode)
 630                 return NULL;
 631
 632         prop = property_entry_get(swnode->node->properties, "remote-endpoint");
 633         if (!prop || prop->type != DEV_PROP_REF || prop->is_inline)
 634                 return NULL;
 635
 636         ref = prop->pointer;
 637
 638         return software_node_get(software_node_fwnode(ref[0].node));
 639 }
 640
 641 static struct fwnode_handle *
 642 software_node_graph_get_port_parent(struct fwnode_handle *fwnode)
 643 {
 644         struct swnode *swnode = to_swnode(fwnode);
 645
 646         swnode = swnode->parent;
 647         if (swnode && !strcmp(swnode->node->name, "ports"))
 648                 swnode = swnode->parent;
 649
 650         return swnode ? software_node_get(&swnode->fwnode) : NULL;
 651 }
 652
 653 static int
 654 software_node_graph_parse_endpoint(const struct fwnode_handle *fwnode,
 655                                    struct fwnode_endpoint *endpoint)
 656 {
 657         struct swnode *swnode = to_swnode(fwnode);
 658         const char *parent_name = swnode->parent->node->name;
 659         int ret;
 660
 661         if (strlen("port@") >= strlen(parent_name) ||
 662             strncmp(parent_name, "port@", strlen("port@")))
 663                 return -EINVAL;
 664
 665         /* Ports have naming style "port@n", we need to select the n */
 666         ret = kstrtou32(parent_name + strlen("port@"), 10, &endpoint->port);
 667         if (ret)
 668                 return ret;
 669
 670         endpoint->id = swnode->id;
 671         endpoint->local_fwnode = fwnode;
 672
 673         return 0;
 674 }
 675
 676 static const struct fwnode_operations software_node_ops = {
 677         .get = software_node_get,
 678         .put = software_node_put,
 679         .property_present = software_node_property_present,
 680         .property_read_int_array = software_node_read_int_array,
 681         .property_read_string_array = software_node_read_string_array,
 682         .get_name = software_node_get_name,
 683         .get_name_prefix = software_node_get_name_prefix,
 684         .get_parent = software_node_get_parent,
 685         .get_next_child_node = software_node_get_next_child,
 686         .get_named_child_node = software_node_get_named_child_node,
 687         .get_reference_args = software_node_get_reference_args,
 688         .graph_get_next_endpoint = software_node_graph_get_next_endpoint,
 689         .graph_get_remote_endpoint = software_node_graph_get_remote_endpoint,
 690         .graph_get_port_parent = software_node_graph_get_port_parent,
 691         .graph_parse_endpoint = software_node_graph_parse_endpoint,
 692 };
 693
 694 /* -------------------------------------------------------------------------- */
 695
 696 /**
 697  * software_node_find_by_name - Find software node by name
 698  * @parent: Parent of the software node
 699  * @name: Name of the software node
 700  *
 701  * The function will find a node that is child of @parent and that is named
 702  * @name. If no node is found, the function returns NULL.
 703  *
 704  * NOTE: you will need to drop the reference with fwnode_handle_put() after use.
 705  */
 706 const struct software_node *
 707 software_node_find_by_name(const struct software_node *parent, const char *name)
 708 {
 709         struct swnode *swnode = NULL;
 710         struct kobject *k;
 711
 712         if (!name)
 713                 return NULL;
 714
 715         spin_lock(&swnode_kset->list_lock);
 716
 717         list_for_each_entry(k, &swnode_kset->list, entry) {
 718                 swnode = kobj_to_swnode(k);
 719                 if (parent == swnode->node->parent && swnode->node->name &&
 720                     !strcmp(name, swnode->node->name)) {
 721                         kobject_get(&swnode->kobj);
 722                         break;
 723                 }
 724                 swnode = NULL;
 725         }
 726
 727         spin_unlock(&swnode_kset->list_lock);
 728
 729         return swnode ? swnode->node : NULL;
 730 }
 731 EXPORT_SYMBOL_GPL(software_node_find_by_name);
 732
 733 static struct software_node *software_node_alloc(const struct property_entry *properties)
 734 {
 735         struct property_entry *props;
 736         struct software_node *node;
 737
 738         props = property_entries_dup(properties);
 739         if (IS_ERR(props))
 740                 return ERR_CAST(props);
 741
 742         node = kzalloc(sizeof(*node), GFP_KERNEL);
 743         if (!node) {
 744                 property_entries_free(props);
 745                 return ERR_PTR(-ENOMEM);
 746         }
 747
 748         node->properties = props;
 749
 750         return node;
 751 }
 752
 753 static void software_node_free(const struct software_node *node)
 754 {
 755         property_entries_free(node->properties);
 756         kfree(node);
 757 }
 758
 759 static void software_node_release(struct kobject *kobj)
 760 {
 761         struct swnode *swnode = kobj_to_swnode(kobj);
 762
 763         if (swnode->parent) {
 764                 ida_free(&swnode->parent->child_ids, swnode->id);
 765                 list_del(&swnode->entry);
 766         } else {
 767                 ida_free(&swnode_root_ids, swnode->id);
 768         }
 769
 770         if (swnode->allocated)
 771                 software_node_free(swnode->node);
 772
 773         ida_destroy(&swnode->child_ids);
 774         kfree(swnode);
 775 }
 776
 777 static const struct kobj_type software_node_type = {
 778         .release = software_node_release,
 779         .sysfs_ops = &kobj_sysfs_ops,
 780 };
 781
 782 static struct fwnode_handle *
 783 swnode_register(const struct software_node *node, struct swnode *parent,
 784                 unsigned int allocated)
 785 {
 786         struct swnode *swnode;
 787         int ret;
 788
 789         swnode = kzalloc(sizeof(*swnode), GFP_KERNEL);
 790         if (!swnode)
 791                 return ERR_PTR(-ENOMEM);
 792
 793         ret = ida_alloc(parent ? &parent->child_ids : &swnode_root_ids,
 794                         GFP_KERNEL);
 795         if (ret < 0) {
 796                 kfree(swnode);
 797                 return ERR_PTR(ret);
 798         }
 799
 800         swnode->id = ret;
 801         swnode->node = node;
 802         swnode->parent = parent;
 803         swnode->kobj.kset = swnode_kset;
 804         fwnode_init(&swnode->fwnode, &software_node_ops);
 805
 806         ida_init(&swnode->child_ids);
 807         INIT_LIST_HEAD(&swnode->entry);
 808         INIT_LIST_HEAD(&swnode->children);
 809
 810         if (node->name)
 811                 ret = kobject_init_and_add(&swnode->kobj, &software_node_type,
 812                                            parent ? &parent->kobj : NULL,
 813                                            "%s", node->name);
 814         else
 815                 ret = kobject_init_and_add(&swnode->kobj, &software_node_type,
 816                                            parent ? &parent->kobj : NULL,
 817                                            "node%d", swnode->id);
 818         if (ret) {
 819                 kobject_put(&swnode->kobj);
 820                 return ERR_PTR(ret);
 821         }
 822
 823         /*
 824          * Assign the flag only in the successful case, so
 825          * the above kobject_put() won't mess up with properties.
 826          */
 827         swnode->allocated = allocated;
 828
 829         if (parent)
 830                 list_add_tail(&swnode->entry, &parent->children);
 831
 832         kobject_uevent(&swnode->kobj, KOBJ_ADD);
 833         return &swnode->fwnode;
 834 }
 835
 836 /**
 837  * software_node_register_node_group - Register a group of software nodes
 838  * @node_group: NULL terminated array of software node pointers to be registered
 839  *
 840  * Register multiple software nodes at once. If any node in the array
 841  * has its .parent pointer set (which can only be to another software_node),
 842  * then its parent **must** have been registered before it is; either outside
 843  * of this function or by ordering the array such that parent comes before
 844  * child.
 845  */
 846 int software_node_register_node_group(const struct software_node **node_group)
 847 {
 848         unsigned int i;
 849         int ret;
 850
 851         if (!node_group)
 852                 return 0;
 853
 854         for (i = 0; node_group[i]; i++) {
 855                 ret = software_node_register(node_group[i]);
 856                 if (ret) {
 857                         software_node_unregister_node_group(node_group);
 858                         return ret;
 859                 }
 860         }
 861
 862         return 0;
 863 }
 864 EXPORT_SYMBOL_GPL(software_node_register_node_group);
 865
 866 /**
 867  * software_node_unregister_node_group - Unregister a group of software nodes
 868  * @node_group: NULL terminated array of software node pointers to be unregistered
 869  *
 870  * Unregister multiple software nodes at once. If parent pointers are set up
 871  * in any of the software nodes then the array **must** be ordered such that
 872  * parents come before their children.
 873  *
 874  * NOTE: If you are uncertain whether the array is ordered such that
 875  * parents will be unregistered before their children, it is wiser to
 876  * remove the nodes individually, in the correct order (child before
 877  * parent).
 878  */
 879 void software_node_unregister_node_group(
 880                 const struct software_node **node_group)
 881 {
 882         unsigned int i = 0;
 883
 884         if (!node_group)
 885                 return;
 886
 887         while (node_group[i])
 888                 i++;
 889
 890         while (i--)
 891                 software_node_unregister(node_group[i]);
 892 }
 893 EXPORT_SYMBOL_GPL(software_node_unregister_node_group);
 894
 895 /**
 896  * software_node_register - Register static software node
 897  * @node: The software node to be registered
 898  */
 899 int software_node_register(const struct software_node *node)
 900 {
 901         struct swnode *parent = software_node_to_swnode(node->parent);
 902
 903         if (software_node_to_swnode(node))
 904                 return -EEXIST;
 905
 906         if (node->parent && !parent)
 907                 return -EINVAL;
 908
 909         return PTR_ERR_OR_ZERO(swnode_register(node, parent, 0));
 910 }
 911 EXPORT_SYMBOL_GPL(software_node_register);
 912
 913 /**
 914  * software_node_unregister - Unregister static software node
 915  * @node: The software node to be unregistered
 916  */
 917 void software_node_unregister(const struct software_node *node)
 918 {
 919         struct swnode *swnode;
 920
 921         swnode = software_node_to_swnode(node);
 922         if (swnode)
 923                 fwnode_remove_software_node(&swnode->fwnode);
 924 }
 925 EXPORT_SYMBOL_GPL(software_node_unregister);
 926
 927 struct fwnode_handle *
 928 fwnode_create_software_node(const struct property_entry *properties,
 929                             const struct fwnode_handle *parent)
 930 {
 931         struct fwnode_handle *fwnode;
 932         struct software_node *node;
 933         struct swnode *p;
 934
 935         if (IS_ERR(parent))
 936                 return ERR_CAST(parent);
 937
 938         p = to_swnode(parent);
 939         if (parent && !p)
 940                 return ERR_PTR(-EINVAL);
 941
 942         node = software_node_alloc(properties);
 943         if (IS_ERR(node))
 944                 return ERR_CAST(node);
 945
 946         node->parent = p ? p->node : NULL;
 947
 948         fwnode = swnode_register(node, p, 1);
 949         if (IS_ERR(fwnode))
 950                 software_node_free(node);
 951
 952         return fwnode;
 953 }
 954 EXPORT_SYMBOL_GPL(fwnode_create_software_node);
 955
 956 void fwnode_remove_software_node(struct fwnode_handle *fwnode)
 957 {
 958         struct swnode *swnode = to_swnode(fwnode);
 959
 960         if (!swnode)
 961                 return;
 962
 963         kobject_put(&swnode->kobj);
 964 }
 965 EXPORT_SYMBOL_GPL(fwnode_remove_software_node);
 966
 967 /**
 968  * device_add_software_node - Assign software node to a device
 969  * @dev: The device the software node is meant for.
 970  * @node: The software node.
 971  *
 972  * This function will make @node the secondary firmware node pointer of @dev. If
 973  * @dev has no primary node, then @node will become the primary node. The
 974  * function will register @node automatically if it wasn't already registered.
 975  */
 976 int device_add_software_node(struct device *dev, const struct software_node *node)
 977 {
 978         struct swnode *swnode;
 979         int ret;
 980
 981         /* Only one software node per device. */
 982         if (dev_to_swnode(dev))
 983                 return -EBUSY;
 984
 985         swnode = software_node_to_swnode(node);
 986         if (swnode) {
 987                 kobject_get(&swnode->kobj);
 988         } else {
 989                 ret = software_node_register(node);
 990                 if (ret)
 991                         return ret;
 992
 993                 swnode = software_node_to_swnode(node);
 994         }
 995
 996         set_secondary_fwnode(dev, &swnode->fwnode);
 997
 998         /*
 999          * If the device has been fully registered by the time this function is
1000          * called, software_node_notify() must be called separately so that the
1001          * symlinks get created and the reference count of the node is kept in
1002          * balance.
1003          */
1004         if (device_is_registered(dev))
1005                 software_node_notify(dev);
1006
1007         return 0;
1008 }
1009 EXPORT_SYMBOL_GPL(device_add_software_node);
1010
1011 /**
1012  * device_remove_software_node - Remove device's software node
1013  * @dev: The device with the software node.
1014  *
1015  * This function will unregister the software node of @dev.
1016  */
1017 void device_remove_software_node(struct device *dev)
1018 {
1019         struct swnode *swnode;
1020
1021         swnode = dev_to_swnode(dev);
1022         if (!swnode)
1023                 return;
1024
1025         if (device_is_registered(dev))
1026                 software_node_notify_remove(dev);
1027
1028         set_secondary_fwnode(dev, NULL);
1029         kobject_put(&swnode->kobj);
1030 }
1031 EXPORT_SYMBOL_GPL(device_remove_software_node);
1032
1033 /**
1034  * device_create_managed_software_node - Create a software node for a device
1035  * @dev: The device the software node is assigned to.
1036  * @properties: Device properties for the software node.
1037  * @parent: Parent of the software node.
1038  *
1039  * Creates a software node as a managed resource for @dev, which means the
1040  * lifetime of the newly created software node is tied to the lifetime of @dev.
1041  * Software nodes created with this function should not be reused or shared
1042  * because of that. The function takes a deep copy of @properties for the
1043  * software node.
1044  *
1045  * Since the new software node is assigned directly to @dev, and since it should
1046  * not be shared, it is not returned to the caller. The function returns 0 on
1047  * success, and errno in case of an error.
1048  */
1049 int device_create_managed_software_node(struct device *dev,
1050                                         const struct property_entry *properties,
1051                                         const struct software_node *parent)
1052 {
1053         struct fwnode_handle *p = software_node_fwnode(parent);
1054         struct fwnode_handle *fwnode;
1055
1056         if (parent && !p)
1057                 return -EINVAL;
1058
1059         fwnode = fwnode_create_software_node(properties, p);
1060         if (IS_ERR(fwnode))
1061                 return PTR_ERR(fwnode);
1062
1063         to_swnode(fwnode)->managed = true;
1064         set_secondary_fwnode(dev, fwnode);
1065
1066         if (device_is_registered(dev))
1067                 software_node_notify(dev);
1068
1069         return 0;
1070 }
1071 EXPORT_SYMBOL_GPL(device_create_managed_software_node);
1072
1073 void software_node_notify(struct device *dev)
1074 {
1075         struct swnode *swnode;
1076         int ret;
1077
1078         swnode = dev_to_swnode(dev);
1079         if (!swnode)
1080                 return;
1081
1082         ret = sysfs_create_link(&dev->kobj, &swnode->kobj, "software_node");
1083         if (ret)
1084                 return;
1085
1086         ret = sysfs_create_link(&swnode->kobj, &dev->kobj, dev_name(dev));
1087         if (ret) {
1088                 sysfs_remove_link(&dev->kobj, "software_node");
1089                 return;
1090         }
1091
1092         kobject_get(&swnode->kobj);
1093 }
1094
1095 void software_node_notify_remove(struct device *dev)
1096 {
1097         struct swnode *swnode;
1098
1099         swnode = dev_to_swnode(dev);
1100         if (!swnode)
1101                 return;
1102
1103         sysfs_remove_link(&swnode->kobj, dev_name(dev));
1104         sysfs_remove_link(&dev->kobj, "software_node");
1105         kobject_put(&swnode->kobj);
1106
1107         if (swnode->managed) {
1108                 set_secondary_fwnode(dev, NULL);
1109                 kobject_put(&swnode->kobj);
1110         }
1111 }
1112
1113 static int __init software_node_init(void)
1114 {
1115         swnode_kset = kset_create_and_add("software_nodes", NULL, kernel_kobj);
1116         if (!swnode_kset)
1117                 return -ENOMEM;
1118         return 0;
1119 }
1120 postcore_initcall(software_node_init);
1121
1122 static void __exit software_node_exit(void)
1123 {
1124         ida_destroy(&swnode_root_ids);
1125         kset_unregister(swnode_kset);
1126 }
1127 __exitcall(software_node_exit);