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/device.h>
  10 #include <linux/kernel.h>
  11 #include <linux/property.h>
  12 #include <linux/slab.h>
  13
  14 #include "base.h"
  15
  16 struct swnode {
  17         struct kobject kobj;
  18         struct fwnode_handle fwnode;
  19         const struct software_node *node;
  20         int id;
  21
  22         /* hierarchy */
  23         struct ida child_ids;
  24         struct list_head entry;
  25         struct list_head children;
  26         struct swnode *parent;
  27
  28         unsigned int allocated:1;
  29         unsigned int managed:1;
  30 };
  31
  32 static DEFINE_IDA(swnode_root_ids);
  33 static struct kset *swnode_kset;
  34
  35 #define kobj_to_swnode(_kobj_) container_of(_kobj_, struct swnode, kobj)
  36
  37 static const struct fwnode_operations software_node_ops;
  38
  39 bool is_software_node(const struct fwnode_handle *fwnode)
  40 {
  41         return !IS_ERR_OR_NULL(fwnode) && fwnode->ops == &software_node_ops;
  42 }
  43 EXPORT_SYMBOL_GPL(is_software_node);
  44
  45 #define to_swnode(__fwnode)                                             \
  46         ({                                                              \
  47                 typeof(__fwnode) __to_swnode_fwnode = __fwnode;         \
  48                                                                         \
  49                 is_software_node(__to_swnode_fwnode) ?                  \
  50                         container_of(__to_swnode_fwnode,                \
  51                                      struct swnode, fwnode) : NULL;     \
  52         })
  53
  54 static inline struct swnode *dev_to_swnode(struct device *dev)
  55 {
  56         struct fwnode_handle *fwnode = dev_fwnode(dev);
  57
  58         if (!fwnode)
  59                 return NULL;
  60
  61         if (!is_software_node(fwnode))
  62                 fwnode = fwnode->secondary;
  63
  64         return to_swnode(fwnode);
  65 }
  66
  67 static struct swnode *
  68 software_node_to_swnode(const struct software_node *node)
  69 {
  70         struct swnode *swnode = NULL;
  71         struct kobject *k;
  72
  73         if (!node)
  74                 return NULL;
  75
  76         spin_lock(&swnode_kset->list_lock);
  77
  78         list_for_each_entry(k, &swnode_kset->list, entry) {
  79                 swnode = kobj_to_swnode(k);
  80                 if (swnode->node == node)
  81                         break;
  82                 swnode = NULL;
  83         }
  84
  85         spin_unlock(&swnode_kset->list_lock);
  86
  87         return swnode;
  88 }
  89
  90 const struct software_node *to_software_node(const struct fwnode_handle *fwnode)
  91 {
  92         const struct swnode *swnode = to_swnode(fwnode);
  93
  94         return swnode ? swnode->node : NULL;
  95 }
  96 EXPORT_SYMBOL_GPL(to_software_node);
  97
  98 struct fwnode_handle *software_node_fwnode(const struct software_node *node)
  99 {
 100         struct swnode *swnode = software_node_to_swnode(node);
 101
 102         return swnode ? &swnode->fwnode : NULL;
 103 }
 104 EXPORT_SYMBOL_GPL(software_node_fwnode);
 105
 106 /* -------------------------------------------------------------------------- */
 107 /* property_entry processing */
 108
 109 static const struct property_entry *
 110 property_entry_get(const struct property_entry *prop, const char *name)
 111 {
 112         if (!prop)
 113                 return NULL;
 114
 115         for (; prop->name; prop++)
 116                 if (!strcmp(name, prop->name))
 117                         return prop;
 118
 119         return NULL;
 120 }
 121
 122 static const void *property_get_pointer(const struct property_entry *prop)
 123 {
 124         if (!prop->length)
 125                 return NULL;
 126
 127         return prop->is_inline ? &prop->value : prop->pointer;
 128 }
 129
 130 static const void *property_entry_find(const struct property_entry *props,
 131                                        const char *propname, size_t length)
 132 {
 133         const struct property_entry *prop;
 134         const void *pointer;
 135
 136         prop = property_entry_get(props, propname);
 137         if (!prop)
 138                 return ERR_PTR(-EINVAL);
 139         pointer = property_get_pointer(prop);
 140         if (!pointer)
 141                 return ERR_PTR(-ENODATA);
 142         if (length > prop->length)
 143                 return ERR_PTR(-EOVERFLOW);
 144         return pointer;
 145 }
 146
 147 static int
 148 property_entry_count_elems_of_size(const struct property_entry *props,
 149                                    const char *propname, size_t length)
 150 {
 151         const struct property_entry *prop;
 152
 153         prop = property_entry_get(props, propname);
 154         if (!prop)
 155                 return -EINVAL;
 156
 157         return prop->length / length;
 158 }
 159
 160 static int property_entry_read_int_array(const struct property_entry *props,
 161                                          const char *name,
 162                                          unsigned int elem_size, void *val,
 163                                          size_t nval)
 164 {
 165         const void *pointer;
 166         size_t length;
 167
 168         if (!val)
 169                 return property_entry_count_elems_of_size(props, name,
 170                                                           elem_size);
 171
 172         if (!is_power_of_2(elem_size) || elem_size > sizeof(u64))
 173                 return -ENXIO;
 174
 175         length = nval * elem_size;
 176
 177         pointer = property_entry_find(props, name, length);
 178         if (IS_ERR(pointer))
 179                 return PTR_ERR(pointer);
 180
 181         memcpy(val, pointer, length);
 182         return 0;
 183 }
 184
 185 static int property_entry_read_string_array(const struct property_entry *props,
 186                                             const char *propname,
 187                                             const char **strings, size_t nval)
 188 {
 189         const void *pointer;
 190         size_t length;
 191         int array_len;
 192
 193         /* Find out the array length. */
 194         array_len = property_entry_count_elems_of_size(props, propname,
 195                                                        sizeof(const char *));
 196         if (array_len < 0)
 197                 return array_len;
 198
 199         /* Return how many there are if strings is NULL. */
 200         if (!strings)
 201                 return array_len;
 202
 203         array_len = min_t(size_t, nval, array_len);
 204         length = array_len * sizeof(*strings);
 205
 206         pointer = property_entry_find(props, propname, length);
 207         if (IS_ERR(pointer))
 208                 return PTR_ERR(pointer);
 209
 210         memcpy(strings, pointer, length);
 211
 212         return array_len;
 213 }
 214
 215 static void property_entry_free_data(const struct property_entry *p)
 216 {
 217         const char * const *src_str;
 218         size_t i, nval;
 219
 220         if (p->type == DEV_PROP_STRING) {
 221                 src_str = property_get_pointer(p);
 222                 nval = p->length / sizeof(*src_str);
 223                 for (i = 0; i < nval; i++)
 224                         kfree(src_str[i]);
 225         }
 226
 227         if (!p->is_inline)
 228                 kfree(p->pointer);
 229
 230         kfree(p->name);
 231 }
 232
 233 static bool property_copy_string_array(const char **dst_ptr,
 234                                        const char * const *src_ptr,
 235                                        size_t nval)
 236 {
 237         int i;
 238
 239         for (i = 0; i < nval; i++) {
 240                 dst_ptr[i] = kstrdup(src_ptr[i], GFP_KERNEL);
 241                 if (!dst_ptr[i] && src_ptr[i]) {
 242                         while (--i >= 0)
 243                                 kfree(dst_ptr[i]);
 244                         return false;
 245                 }
 246         }
 247
 248         return true;
 249 }
 250
 251 static int property_entry_copy_data(struct property_entry *dst,
 252                                     const struct property_entry *src)
 253 {
 254         const void *pointer = property_get_pointer(src);
 255         void *dst_ptr;
 256         size_t nval;
 257
 258         /*
 259          * Properties with no data should not be marked as stored
 260          * out of line.
 261          */
 262         if (!src->is_inline && !src->length)
 263                 return -ENODATA;
 264
 265         /*
 266          * Reference properties are never stored inline as
 267          * they are too big.
 268          */
 269         if (src->type == DEV_PROP_REF && src->is_inline)
 270                 return -EINVAL;
 271
 272         if (src->length <= sizeof(dst->value)) {
 273                 dst_ptr = &dst->value;
 274                 dst->is_inline = true;
 275         } else {
 276                 dst_ptr = kmalloc(src->length, GFP_KERNEL);
 277                 if (!dst_ptr)
 278                         return -ENOMEM;
 279                 dst->pointer = dst_ptr;
 280         }
 281
 282         if (src->type == DEV_PROP_STRING) {
 283                 nval = src->length / sizeof(const char *);
 284                 if (!property_copy_string_array(dst_ptr, pointer, nval)) {
 285                         if (!dst->is_inline)
 286                                 kfree(dst->pointer);
 287                         return -ENOMEM;
 288                 }
 289         } else {
 290                 memcpy(dst_ptr, pointer, src->length);
 291         }
 292
 293         dst->length = src->length;
 294         dst->type = src->type;
 295         dst->name = kstrdup(src->name, GFP_KERNEL);
 296         if (!dst->name) {
 297                 property_entry_free_data(dst);
 298                 return -ENOMEM;
 299         }
 300
 301         return 0;
 302 }
 303
 304 /**
 305  * property_entries_dup - duplicate array of properties
 306  * @properties: array of properties to copy
 307  *
 308  * This function creates a deep copy of the given NULL-terminated array
 309  * of property entries.
 310  */
 311 struct property_entry *
 312 property_entries_dup(const struct property_entry *properties)
 313 {
 314         struct property_entry *p;
 315         int i, n = 0;
 316         int ret;
 317
 318         if (!properties)
 319                 return NULL;
 320
 321         while (properties[n].name)
 322                 n++;
 323
 324         p = kcalloc(n + 1, sizeof(*p), GFP_KERNEL);
 325         if (!p)
 326                 return ERR_PTR(-ENOMEM);
 327
 328         for (i = 0; i < n; i++) {
 329                 ret = property_entry_copy_data(&p[i], &properties[i]);
 330                 if (ret) {
 331                         while (--i >= 0)
 332                                 property_entry_free_data(&p[i]);
 333                         kfree(p);
 334                         return ERR_PTR(ret);
 335                 }
 336         }
 337
 338         return p;
 339 }
 340 EXPORT_SYMBOL_GPL(property_entries_dup);
 341
 342 /**
 343  * property_entries_free - free previously allocated array of properties
 344  * @properties: array of properties to destroy
 345  *
 346  * This function frees given NULL-terminated array of property entries,
 347  * along with their data.
 348  */
 349 void property_entries_free(const struct property_entry *properties)
 350 {
 351         const struct property_entry *p;
 352
 353         if (!properties)
 354                 return;
 355
 356         for (p = properties; p->name; p++)
 357                 property_entry_free_data(p);
 358
 359         kfree(properties);
 360 }
 361 EXPORT_SYMBOL_GPL(property_entries_free);
 362
 363 /* -------------------------------------------------------------------------- */
 364 /* fwnode operations */
 365
 366 static struct fwnode_handle *software_node_get(struct fwnode_handle *fwnode)
 367 {
 368         struct swnode *swnode = to_swnode(fwnode);
 369
 370         kobject_get(&swnode->kobj);
 371
 372         return &swnode->fwnode;
 373 }
 374
 375 static void software_node_put(struct fwnode_handle *fwnode)
 376 {
 377         struct swnode *swnode = to_swnode(fwnode);
 378
 379         kobject_put(&swnode->kobj);
 380 }
 381
 382 static bool software_node_property_present(const struct fwnode_handle *fwnode,
 383                                            const char *propname)
 384 {
 385         struct swnode *swnode = to_swnode(fwnode);
 386
 387         return !!property_entry_get(swnode->node->properties, propname);
 388 }
 389
 390 static int software_node_read_int_array(const struct fwnode_handle *fwnode,
 391                                         const char *propname,
 392                                         unsigned int elem_size, void *val,
 393                                         size_t nval)
 394 {
 395         struct swnode *swnode = to_swnode(fwnode);
 396
 397         return property_entry_read_int_array(swnode->node->properties, propname,
 398                                              elem_size, val, nval);
 399 }
 400
 401 static int software_node_read_string_array(const struct fwnode_handle *fwnode,
 402                                            const char *propname,
 403                                            const char **val, size_t nval)
 404 {
 405         struct swnode *swnode = to_swnode(fwnode);
 406
 407         return property_entry_read_string_array(swnode->node->properties,
 408                                                 propname, val, nval);
 409 }
 410
 411 static const char *
 412 software_node_get_name(const struct fwnode_handle *fwnode)
 413 {
 414         const struct swnode *swnode = to_swnode(fwnode);
 415
 416         if (!swnode)
 417                 return "(null)";
 418
 419         return kobject_name(&swnode->kobj);
 420 }
 421
 422 static const char *
 423 software_node_get_name_prefix(const struct fwnode_handle *fwnode)
 424 {
 425         struct fwnode_handle *parent;
 426         const char *prefix;
 427
 428         parent = fwnode_get_parent(fwnode);
 429         if (!parent)
 430                 return "";
 431
 432         /* Figure out the prefix from the parents. */
 433         while (is_software_node(parent))
 434                 parent = fwnode_get_next_parent(parent);
 435
 436         prefix = fwnode_get_name_prefix(parent);
 437         fwnode_handle_put(parent);
 438
 439         /* Guess something if prefix was NULL. */
 440         return prefix ?: "/";
 441 }
 442
 443 static struct fwnode_handle *
 444 software_node_get_parent(const struct fwnode_handle *fwnode)
 445 {
 446         struct swnode *swnode = to_swnode(fwnode);
 447
 448         if (!swnode || !swnode->parent)
 449                 return NULL;
 450
 451         return fwnode_handle_get(&swnode->parent->fwnode);
 452 }
 453
 454 static struct fwnode_handle *
 455 software_node_get_next_child(const struct fwnode_handle *fwnode,
 456                              struct fwnode_handle *child)
 457 {
 458         struct swnode *p = to_swnode(fwnode);
 459         struct swnode *c = to_swnode(child);
 460
 461         if (!p || list_empty(&p->children) ||
 462             (c && list_is_last(&c->entry, &p->children))) {
 463                 fwnode_handle_put(child);
 464                 return NULL;
 465         }
 466
 467         if (c)
 468                 c = list_next_entry(c, entry);
 469         else
 470                 c = list_first_entry(&p->children, struct swnode, entry);
 471
 472         fwnode_handle_put(child);
 473         return fwnode_handle_get(&c->fwnode);
 474 }
 475
 476 static struct fwnode_handle *
 477 software_node_get_named_child_node(const struct fwnode_handle *fwnode,
 478                                    const char *childname)
 479 {
 480         struct swnode *swnode = to_swnode(fwnode);
 481         struct swnode *child;
 482
 483         if (!swnode || list_empty(&swnode->children))
 484                 return NULL;
 485
 486         list_for_each_entry(child, &swnode->children, entry) {
 487                 if (!strcmp(childname, kobject_name(&child->kobj))) {
 488                         kobject_get(&child->kobj);
 489                         return &child->fwnode;
 490                 }
 491         }
 492         return NULL;
 493 }
 494
 495 static int
 496 software_node_get_reference_args(const struct fwnode_handle *fwnode,
 497                                  const char *propname, const char *nargs_prop,
 498                                  unsigned int nargs, unsigned int index,
 499                                  struct fwnode_reference_args *args)
 500 {
 501         struct swnode *swnode = to_swnode(fwnode);
 502         const struct software_node_ref_args *ref_array;
 503         const struct software_node_ref_args *ref;
 504         const struct property_entry *prop;
 505         struct fwnode_handle *refnode;
 506         u32 nargs_prop_val;
 507         int error;
 508         int i;
 509
 510         if (!swnode)
 511                 return -ENOENT;
 512
 513         prop = property_entry_get(swnode->node->properties, propname);
 514         if (!prop)
 515                 return -ENOENT;
 516
 517         if (prop->type != DEV_PROP_REF)
 518                 return -EINVAL;
 519
 520         /*
 521          * We expect that references are never stored inline, even
 522          * single ones, as they are too big.
 523          */
 524         if (prop->is_inline)
 525                 return -EINVAL;
 526
 527         if (index * sizeof(*ref) >= prop->length)
 528                 return -ENOENT;
 529
 530         ref_array = prop->pointer;
 531         ref = &ref_array[index];
 532
 533         refnode = software_node_fwnode(ref->node);
 534         if (!refnode)
 535                 return -ENOENT;
 536
 537         if (nargs_prop) {
 538                 error = property_entry_read_int_array(ref->node->properties,
 539                                                       nargs_prop, sizeof(u32),
 540                                                       &nargs_prop_val, 1);
 541                 if (error)
 542                         return error;
 543
 544                 nargs = nargs_prop_val;
 545         }
 546
 547         if (nargs > NR_FWNODE_REFERENCE_ARGS)
 548                 return -EINVAL;
 549
 550         args->fwnode = software_node_get(refnode);
 551         args->nargs = nargs;
 552
 553         for (i = 0; i < nargs; i++)
 554                 args->args[i] = ref->args[i];
 555
 556         return 0;
 557 }
 558
 559 static struct fwnode_handle *
 560 swnode_graph_find_next_port(const struct fwnode_handle *parent,
 561                             struct fwnode_handle *port)
 562 {
 563         struct fwnode_handle *old = port;
 564
 565         while ((port = software_node_get_next_child(parent, old))) {
 566                 /*
 567                  * fwnode ports have naming style "port@", so we search for any
 568                  * children that follow that convention.
 569                  */
 570                 if (!strncmp(to_swnode(port)->node->name, "port@",
 571                              strlen("port@")))
 572                         return port;
 573                 old = port;
 574         }
 575
 576         return NULL;
 577 }
 578
 579 static struct fwnode_handle *
 580 software_node_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
 581                                       struct fwnode_handle *endpoint)
 582 {
 583         struct swnode *swnode = to_swnode(fwnode);
 584         struct fwnode_handle *parent;
 585         struct fwnode_handle *port;
 586
 587         if (!swnode)
 588                 return NULL;
 589
 590         if (endpoint) {
 591                 port = software_node_get_parent(endpoint);
 592                 parent = software_node_get_parent(port);
 593         } else {
 594                 parent = software_node_get_named_child_node(fwnode, "ports");
 595                 if (!parent)
 596                         parent = software_node_get(&swnode->fwnode);
 597
 598                 port = swnode_graph_find_next_port(parent, NULL);
 599         }
 600
 601         for (; port; port = swnode_graph_find_next_port(parent, port)) {
 602                 endpoint = software_node_get_next_child(port, endpoint);
 603                 if (endpoint) {
 604                         fwnode_handle_put(port);
 605                         break;
 606                 }
 607         }
 608
 609         fwnode_handle_put(parent);
 610
 611         return endpoint;
 612 }
 613
 614 static struct fwnode_handle *
 615 software_node_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
 616 {
 617         struct swnode *swnode = to_swnode(fwnode);
 618         const struct software_node_ref_args *ref;
 619         const struct property_entry *prop;
 620
 621         if (!swnode)
 622                 return NULL;
 623
 624         prop = property_entry_get(swnode->node->properties, "remote-endpoint");
 625         if (!prop || prop->type != DEV_PROP_REF || prop->is_inline)
 626                 return NULL;
 627
 628         ref = prop->pointer;
 629
 630         return software_node_get(software_node_fwnode(ref[0].node));
 631 }
 632
 633 static struct fwnode_handle *
 634 software_node_graph_get_port_parent(struct fwnode_handle *fwnode)
 635 {
 636         struct swnode *swnode = to_swnode(fwnode);
 637
 638         swnode = swnode->parent;
 639         if (swnode && !strcmp(swnode->node->name, "ports"))
 640                 swnode = swnode->parent;
 641
 642         return swnode ? software_node_get(&swnode->fwnode) : NULL;
 643 }
 644
 645 static int
 646 software_node_graph_parse_endpoint(const struct fwnode_handle *fwnode,
 647                                    struct fwnode_endpoint *endpoint)
 648 {
 649         struct swnode *swnode = to_swnode(fwnode);
 650         const char *parent_name = swnode->parent->node->name;
 651         int ret;
 652
 653         if (strlen("port@") >= strlen(parent_name) ||
 654             strncmp(parent_name, "port@", strlen("port@")))
 655                 return -EINVAL;
 656
 657         /* Ports have naming style "port@n", we need to select the n */
 658         ret = kstrtou32(parent_name + strlen("port@"), 10, &endpoint->port);
 659         if (ret)
 660                 return ret;
 661
 662         endpoint->id = swnode->id;
 663         endpoint->local_fwnode = fwnode;
 664
 665         return 0;
 666 }
 667
 668 static const struct fwnode_operations software_node_ops = {
 669         .get = software_node_get,
 670         .put = software_node_put,
 671         .property_present = software_node_property_present,
 672         .property_read_int_array = software_node_read_int_array,
 673         .property_read_string_array = software_node_read_string_array,
 674         .get_name = software_node_get_name,
 675         .get_name_prefix = software_node_get_name_prefix,
 676         .get_parent = software_node_get_parent,
 677         .get_next_child_node = software_node_get_next_child,
 678         .get_named_child_node = software_node_get_named_child_node,
 679         .get_reference_args = software_node_get_reference_args,
 680         .graph_get_next_endpoint = software_node_graph_get_next_endpoint,
 681         .graph_get_remote_endpoint = software_node_graph_get_remote_endpoint,
 682         .graph_get_port_parent = software_node_graph_get_port_parent,
 683         .graph_parse_endpoint = software_node_graph_parse_endpoint,
 684 };
 685
 686 /* -------------------------------------------------------------------------- */
 687
 688 /**
 689  * software_node_find_by_name - Find software node by name
 690  * @parent: Parent of the software node
 691  * @name: Name of the software node
 692  *
 693  * The function will find a node that is child of @parent and that is named
 694  * @name. If no node is found, the function returns NULL.
 695  *
 696  * NOTE: you will need to drop the reference with fwnode_handle_put() after use.
 697  */
 698 const struct software_node *
 699 software_node_find_by_name(const struct software_node *parent, const char *name)
 700 {
 701         struct swnode *swnode = NULL;
 702         struct kobject *k;
 703
 704         if (!name)
 705                 return NULL;
 706
 707         spin_lock(&swnode_kset->list_lock);
 708
 709         list_for_each_entry(k, &swnode_kset->list, entry) {
 710                 swnode = kobj_to_swnode(k);
 711                 if (parent == swnode->node->parent && swnode->node->name &&
 712                     !strcmp(name, swnode->node->name)) {
 713                         kobject_get(&swnode->kobj);
 714                         break;
 715                 }
 716                 swnode = NULL;
 717         }
 718
 719         spin_unlock(&swnode_kset->list_lock);
 720
 721         return swnode ? swnode->node : NULL;
 722 }
 723 EXPORT_SYMBOL_GPL(software_node_find_by_name);
 724
 725 static struct software_node *software_node_alloc(const struct property_entry *properties)
 726 {
 727         struct property_entry *props;
 728         struct software_node *node;
 729
 730         props = property_entries_dup(properties);
 731         if (IS_ERR(props))
 732                 return ERR_CAST(props);
 733
 734         node = kzalloc(sizeof(*node), GFP_KERNEL);
 735         if (!node) {
 736                 property_entries_free(props);
 737                 return ERR_PTR(-ENOMEM);
 738         }
 739
 740         node->properties = props;
 741
 742         return node;
 743 }
 744
 745 static void software_node_free(const struct software_node *node)
 746 {
 747         property_entries_free(node->properties);
 748         kfree(node);
 749 }
 750
 751 static void software_node_release(struct kobject *kobj)
 752 {
 753         struct swnode *swnode = kobj_to_swnode(kobj);
 754
 755         if (swnode->parent) {
 756                 ida_simple_remove(&swnode->parent->child_ids, swnode->id);
 757                 list_del(&swnode->entry);
 758         } else {
 759                 ida_simple_remove(&swnode_root_ids, swnode->id);
 760         }
 761
 762         if (swnode->allocated)
 763                 software_node_free(swnode->node);
 764
 765         ida_destroy(&swnode->child_ids);
 766         kfree(swnode);
 767 }
 768
 769 static struct kobj_type software_node_type = {
 770         .release = software_node_release,
 771         .sysfs_ops = &kobj_sysfs_ops,
 772 };
 773
 774 static struct fwnode_handle *
 775 swnode_register(const struct software_node *node, struct swnode *parent,
 776                 unsigned int allocated)
 777 {
 778         struct swnode *swnode;
 779         int ret;
 780
 781         swnode = kzalloc(sizeof(*swnode), GFP_KERNEL);
 782         if (!swnode)
 783                 return ERR_PTR(-ENOMEM);
 784
 785         ret = ida_simple_get(parent ? &parent->child_ids : &swnode_root_ids,
 786                              0, 0, GFP_KERNEL);
 787         if (ret < 0) {
 788                 kfree(swnode);
 789                 return ERR_PTR(ret);
 790         }
 791
 792         swnode->id = ret;
 793         swnode->node = node;
 794         swnode->parent = parent;
 795         swnode->kobj.kset = swnode_kset;
 796         fwnode_init(&swnode->fwnode, &software_node_ops);
 797
 798         ida_init(&swnode->child_ids);
 799         INIT_LIST_HEAD(&swnode->entry);
 800         INIT_LIST_HEAD(&swnode->children);
 801
 802         if (node->name)
 803                 ret = kobject_init_and_add(&swnode->kobj, &software_node_type,
 804                                            parent ? &parent->kobj : NULL,
 805                                            "%s", node->name);
 806         else
 807                 ret = kobject_init_and_add(&swnode->kobj, &software_node_type,
 808                                            parent ? &parent->kobj : NULL,
 809                                            "node%d", swnode->id);
 810         if (ret) {
 811                 kobject_put(&swnode->kobj);
 812                 return ERR_PTR(ret);
 813         }
 814
 815         /*
 816          * Assign the flag only in the successful case, so
 817          * the above kobject_put() won't mess up with properties.
 818          */
 819         swnode->allocated = allocated;
 820
 821         if (parent)
 822                 list_add_tail(&swnode->entry, &parent->children);
 823
 824         kobject_uevent(&swnode->kobj, KOBJ_ADD);
 825         return &swnode->fwnode;
 826 }
 827
 828 /**
 829  * software_node_register_nodes - Register an array of software nodes
 830  * @nodes: Zero terminated array of software nodes to be registered
 831  *
 832  * Register multiple software nodes at once. If any node in the array
 833  * has its .parent pointer set (which can only be to another software_node),
 834  * then its parent **must** have been registered before it is; either outside
 835  * of this function or by ordering the array such that parent comes before
 836  * child.
 837  */
 838 int software_node_register_nodes(const struct software_node *nodes)
 839 {
 840         int ret;
 841         int i;
 842
 843         for (i = 0; nodes[i].name; i++) {
 844                 const struct software_node *parent = nodes[i].parent;
 845
 846                 if (parent && !software_node_to_swnode(parent)) {
 847                         ret = -EINVAL;
 848                         goto err_unregister_nodes;
 849                 }
 850
 851                 ret = software_node_register(&nodes[i]);
 852                 if (ret)
 853                         goto err_unregister_nodes;
 854         }
 855
 856         return 0;
 857
 858 err_unregister_nodes:
 859         software_node_unregister_nodes(nodes);
 860         return ret;
 861 }
 862 EXPORT_SYMBOL_GPL(software_node_register_nodes);
 863
 864 /**
 865  * software_node_unregister_nodes - Unregister an array of software nodes
 866  * @nodes: Zero terminated array of software nodes to be unregistered
 867  *
 868  * Unregister multiple software nodes at once. If parent pointers are set up
 869  * in any of the software nodes then the array **must** be ordered such that
 870  * parents come before their children.
 871  *
 872  * NOTE: If you are uncertain whether the array is ordered such that
 873  * parents will be unregistered before their children, it is wiser to
 874  * remove the nodes individually, in the correct order (child before
 875  * parent).
 876  */
 877 void software_node_unregister_nodes(const struct software_node *nodes)
 878 {
 879         unsigned int i = 0;
 880
 881         while (nodes[i].name)
 882                 i++;
 883
 884         while (i--)
 885                 software_node_unregister(&nodes[i]);
 886 }
 887 EXPORT_SYMBOL_GPL(software_node_unregister_nodes);
 888
 889 /**
 890  * software_node_register_node_group - Register a group of software nodes
 891  * @node_group: NULL terminated array of software node pointers to be registered
 892  *
 893  * Register multiple software nodes at once. If any node in the array
 894  * has its .parent pointer set (which can only be to another software_node),
 895  * then its parent **must** have been registered before it is; either outside
 896  * of this function or by ordering the array such that parent comes before
 897  * child.
 898  */
 899 int software_node_register_node_group(const struct software_node **node_group)
 900 {
 901         unsigned int i;
 902         int ret;
 903
 904         if (!node_group)
 905                 return 0;
 906
 907         for (i = 0; node_group[i]; i++) {
 908                 ret = software_node_register(node_group[i]);
 909                 if (ret) {
 910                         software_node_unregister_node_group(node_group);
 911                         return ret;
 912                 }
 913         }
 914
 915         return 0;
 916 }
 917 EXPORT_SYMBOL_GPL(software_node_register_node_group);
 918
 919 /**
 920  * software_node_unregister_node_group - Unregister a group of software nodes
 921  * @node_group: NULL terminated array of software node pointers to be unregistered
 922  *
 923  * Unregister multiple software nodes at once. If parent pointers are set up
 924  * in any of the software nodes then the array **must** be ordered such that
 925  * parents come before their children.
 926  *
 927  * NOTE: If you are uncertain whether the array is ordered such that
 928  * parents will be unregistered before their children, it is wiser to
 929  * remove the nodes individually, in the correct order (child before
 930  * parent).
 931  */
 932 void software_node_unregister_node_group(
 933                 const struct software_node **node_group)
 934 {
 935         unsigned int i = 0;
 936
 937         if (!node_group)
 938                 return;
 939
 940         while (node_group[i])
 941                 i++;
 942
 943         while (i--)
 944                 software_node_unregister(node_group[i]);
 945 }
 946 EXPORT_SYMBOL_GPL(software_node_unregister_node_group);
 947
 948 /**
 949  * software_node_register - Register static software node
 950  * @node: The software node to be registered
 951  */
 952 int software_node_register(const struct software_node *node)
 953 {
 954         struct swnode *parent = software_node_to_swnode(node->parent);
 955
 956         if (software_node_to_swnode(node))
 957                 return -EEXIST;
 958
 959         if (node->parent && !parent)
 960                 return -EINVAL;
 961
 962         return PTR_ERR_OR_ZERO(swnode_register(node, parent, 0));
 963 }
 964 EXPORT_SYMBOL_GPL(software_node_register);
 965
 966 /**
 967  * software_node_unregister - Unregister static software node
 968  * @node: The software node to be unregistered
 969  */
 970 void software_node_unregister(const struct software_node *node)
 971 {
 972         struct swnode *swnode;
 973
 974         swnode = software_node_to_swnode(node);
 975         if (swnode)
 976                 fwnode_remove_software_node(&swnode->fwnode);
 977 }
 978 EXPORT_SYMBOL_GPL(software_node_unregister);
 979
 980 struct fwnode_handle *
 981 fwnode_create_software_node(const struct property_entry *properties,
 982                             const struct fwnode_handle *parent)
 983 {
 984         struct fwnode_handle *fwnode;
 985         struct software_node *node;
 986         struct swnode *p;
 987
 988         if (IS_ERR(parent))
 989                 return ERR_CAST(parent);
 990
 991         p = to_swnode(parent);
 992         if (parent && !p)
 993                 return ERR_PTR(-EINVAL);
 994
 995         node = software_node_alloc(properties);
 996         if (IS_ERR(node))
 997                 return ERR_CAST(node);
 998
 999         node->parent = p ? p->node : NULL;
1000
1001         fwnode = swnode_register(node, p, 1);
1002         if (IS_ERR(fwnode))
1003                 software_node_free(node);
1004
1005         return fwnode;
1006 }
1007 EXPORT_SYMBOL_GPL(fwnode_create_software_node);
1008
1009 void fwnode_remove_software_node(struct fwnode_handle *fwnode)
1010 {
1011         struct swnode *swnode = to_swnode(fwnode);
1012
1013         if (!swnode)
1014                 return;
1015
1016         kobject_put(&swnode->kobj);
1017 }
1018 EXPORT_SYMBOL_GPL(fwnode_remove_software_node);
1019
1020 /**
1021  * device_add_software_node - Assign software node to a device
1022  * @dev: The device the software node is meant for.
1023  * @node: The software node.
1024  *
1025  * This function will make @node the secondary firmware node pointer of @dev. If
1026  * @dev has no primary node, then @node will become the primary node. The
1027  * function will register @node automatically if it wasn't already registered.
1028  */
1029 int device_add_software_node(struct device *dev, const struct software_node *node)
1030 {
1031         struct swnode *swnode;
1032         int ret;
1033
1034         /* Only one software node per device. */
1035         if (dev_to_swnode(dev))
1036                 return -EBUSY;
1037
1038         swnode = software_node_to_swnode(node);
1039         if (swnode) {
1040                 kobject_get(&swnode->kobj);
1041         } else {
1042                 ret = software_node_register(node);
1043                 if (ret)
1044                         return ret;
1045
1046                 swnode = software_node_to_swnode(node);
1047         }
1048
1049         set_secondary_fwnode(dev, &swnode->fwnode);
1050
1051         /*
1052          * If the device has been fully registered by the time this function is
1053          * called, software_node_notify() must be called separately so that the
1054          * symlinks get created and the reference count of the node is kept in
1055          * balance.
1056          */
1057         if (device_is_registered(dev))
1058                 software_node_notify(dev);
1059
1060         return 0;
1061 }
1062 EXPORT_SYMBOL_GPL(device_add_software_node);
1063
1064 /**
1065  * device_remove_software_node - Remove device's software node
1066  * @dev: The device with the software node.
1067  *
1068  * This function will unregister the software node of @dev.
1069  */
1070 void device_remove_software_node(struct device *dev)
1071 {
1072         struct swnode *swnode;
1073
1074         swnode = dev_to_swnode(dev);
1075         if (!swnode)
1076                 return;
1077
1078         if (device_is_registered(dev))
1079                 software_node_notify_remove(dev);
1080
1081         set_secondary_fwnode(dev, NULL);
1082         kobject_put(&swnode->kobj);
1083 }
1084 EXPORT_SYMBOL_GPL(device_remove_software_node);
1085
1086 /**
1087  * device_create_managed_software_node - Create a software node for a device
1088  * @dev: The device the software node is assigned to.
1089  * @properties: Device properties for the software node.
1090  * @parent: Parent of the software node.
1091  *
1092  * Creates a software node as a managed resource for @dev, which means the
1093  * lifetime of the newly created software node is tied to the lifetime of @dev.
1094  * Software nodes created with this function should not be reused or shared
1095  * because of that. The function takes a deep copy of @properties for the
1096  * software node.
1097  *
1098  * Since the new software node is assigned directly to @dev, and since it should
1099  * not be shared, it is not returned to the caller. The function returns 0 on
1100  * success, and errno in case of an error.
1101  */
1102 int device_create_managed_software_node(struct device *dev,
1103                                         const struct property_entry *properties,
1104                                         const struct software_node *parent)
1105 {
1106         struct fwnode_handle *p = software_node_fwnode(parent);
1107         struct fwnode_handle *fwnode;
1108
1109         if (parent && !p)
1110                 return -EINVAL;
1111
1112         fwnode = fwnode_create_software_node(properties, p);
1113         if (IS_ERR(fwnode))
1114                 return PTR_ERR(fwnode);
1115
1116         to_swnode(fwnode)->managed = true;
1117         set_secondary_fwnode(dev, fwnode);
1118
1119         if (device_is_registered(dev))
1120                 software_node_notify(dev);
1121
1122         return 0;
1123 }
1124 EXPORT_SYMBOL_GPL(device_create_managed_software_node);
1125
1126 void software_node_notify(struct device *dev)
1127 {
1128         struct swnode *swnode;
1129         int ret;
1130
1131         swnode = dev_to_swnode(dev);
1132         if (!swnode)
1133                 return;
1134
1135         ret = sysfs_create_link(&dev->kobj, &swnode->kobj, "software_node");
1136         if (ret)
1137                 return;
1138
1139         ret = sysfs_create_link(&swnode->kobj, &dev->kobj, dev_name(dev));
1140         if (ret) {
1141                 sysfs_remove_link(&dev->kobj, "software_node");
1142                 return;
1143         }
1144
1145         kobject_get(&swnode->kobj);
1146 }
1147
1148 void software_node_notify_remove(struct device *dev)
1149 {
1150         struct swnode *swnode;
1151
1152         swnode = dev_to_swnode(dev);
1153         if (!swnode)
1154                 return;
1155
1156         sysfs_remove_link(&swnode->kobj, dev_name(dev));
1157         sysfs_remove_link(&dev->kobj, "software_node");
1158         kobject_put(&swnode->kobj);
1159
1160         if (swnode->managed) {
1161                 set_secondary_fwnode(dev, NULL);
1162                 kobject_put(&swnode->kobj);
1163         }
1164 }
1165
1166 static int __init software_node_init(void)
1167 {
1168         swnode_kset = kset_create_and_add("software_nodes", NULL, kernel_kobj);
1169         if (!swnode_kset)
1170                 return -ENOMEM;
1171         return 0;
1172 }
1173 postcore_initcall(software_node_init);
1174
1175 static void __exit software_node_exit(void)
1176 {
1177         ida_destroy(&swnode_root_ids);
1178         kset_unregister(swnode_kset);
1179 }
1180 __exitcall(software_node_exit);