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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 <[email protected]>
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
27struct 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
43static DEFINE_IDA(swnode_root_ids);
44static struct kset *swnode_kset;
45
46#define kobj_to_swnode(_kobj_) container_of(_kobj_, struct swnode, kobj)
47
48static const struct fwnode_operations software_node_ops;
49
50bool is_software_node(const struct fwnode_handle *fwnode)
51{
52 return !IS_ERR_OR_NULL(fwnode) && fwnode->ops == &software_node_ops;
53}
54EXPORT_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
65static 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
78static struct swnode *
79software_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
101const 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}
107EXPORT_SYMBOL_GPL(to_software_node);
108
109struct 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}
115EXPORT_SYMBOL_GPL(software_node_fwnode);
116
117/* -------------------------------------------------------------------------- */
118/* property_entry processing */
119
120static const struct property_entry *
121property_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
133static 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
141static 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
158static int
159property_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
171static 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
196static 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
226static 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
244static 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
262static 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 */
322struct property_entry *
323property_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 = kzalloc_objs(*p, n + 1);
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}
351EXPORT_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 */
360void 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}
372EXPORT_SYMBOL_GPL(property_entries_free);
373
374/* -------------------------------------------------------------------------- */
375/* fwnode operations */
376
377static struct swnode *swnode_get(struct swnode *swnode)
378{
379 kobject_get(&swnode->kobj);
380
381 return swnode;
382}
383
384static void swnode_put(struct swnode *swnode)
385{
386 kobject_put(&swnode->kobj);
387}
388
389static struct fwnode_handle *software_node_get(struct fwnode_handle *fwnode)
390{
391 struct swnode *swnode = swnode_get(to_swnode(fwnode));
392
393 return &swnode->fwnode;
394}
395
396static void software_node_put(struct fwnode_handle *fwnode)
397{
398 swnode_put(to_swnode(fwnode));
399}
400
401static bool software_node_property_present(const struct fwnode_handle *fwnode,
402 const char *propname)
403{
404 struct swnode *swnode = to_swnode(fwnode);
405
406 return !!property_entry_get(swnode->node->properties, propname);
407}
408
409static int software_node_read_int_array(const struct fwnode_handle *fwnode,
410 const char *propname,
411 unsigned int elem_size, void *val,
412 size_t nval)
413{
414 struct swnode *swnode = to_swnode(fwnode);
415
416 return property_entry_read_int_array(swnode->node->properties, propname,
417 elem_size, val, nval);
418}
419
420static int software_node_read_string_array(const struct fwnode_handle *fwnode,
421 const char *propname,
422 const char **val, size_t nval)
423{
424 struct swnode *swnode = to_swnode(fwnode);
425
426 return property_entry_read_string_array(swnode->node->properties,
427 propname, val, nval);
428}
429
430static const char *
431software_node_get_name(const struct fwnode_handle *fwnode)
432{
433 const struct swnode *swnode = to_swnode(fwnode);
434
435 return kobject_name(&swnode->kobj);
436}
437
438static const char *
439software_node_get_name_prefix(const struct fwnode_handle *fwnode)
440{
441 struct fwnode_handle *parent;
442 const char *prefix;
443
444 parent = fwnode_get_parent(fwnode);
445 if (!parent)
446 return "";
447
448 /* Figure out the prefix from the parents. */
449 while (is_software_node(parent))
450 parent = fwnode_get_next_parent(parent);
451
452 prefix = fwnode_get_name_prefix(parent);
453 fwnode_handle_put(parent);
454
455 /* Guess something if prefix was NULL. */
456 return prefix ?: "/";
457}
458
459static struct fwnode_handle *
460software_node_get_parent(const struct fwnode_handle *fwnode)
461{
462 struct swnode *swnode = to_swnode(fwnode);
463
464 if (!swnode || !swnode->parent)
465 return NULL;
466
467 return fwnode_handle_get(&swnode->parent->fwnode);
468}
469
470static struct fwnode_handle *
471software_node_get_next_child(const struct fwnode_handle *fwnode,
472 struct fwnode_handle *child)
473{
474 struct swnode *p = to_swnode(fwnode);
475 struct swnode *c = to_swnode(child);
476
477 if (!p || list_empty(&p->children) ||
478 (c && list_is_last(&c->entry, &p->children))) {
479 fwnode_handle_put(child);
480 return NULL;
481 }
482
483 if (c)
484 c = list_next_entry(c, entry);
485 else
486 c = list_first_entry(&p->children, struct swnode, entry);
487
488 fwnode_handle_put(child);
489 return fwnode_handle_get(&c->fwnode);
490}
491
492static struct fwnode_handle *
493software_node_get_named_child_node(const struct fwnode_handle *fwnode,
494 const char *childname)
495{
496 struct swnode *swnode = to_swnode(fwnode);
497 struct swnode *child;
498
499 if (!swnode || list_empty(&swnode->children))
500 return NULL;
501
502 list_for_each_entry(child, &swnode->children, entry) {
503 if (!strcmp(childname, kobject_name(&child->kobj))) {
504 swnode_get(child);
505 return &child->fwnode;
506 }
507 }
508 return NULL;
509}
510
511static int
512software_node_get_reference_args(const struct fwnode_handle *fwnode,
513 const char *propname, const char *nargs_prop,
514 unsigned int nargs, unsigned int index,
515 struct fwnode_reference_args *args)
516{
517 struct swnode *swnode = to_swnode(fwnode);
518 const struct software_node_ref_args *ref_array;
519 const struct software_node_ref_args *ref;
520 const struct property_entry *prop;
521 struct fwnode_handle *refnode;
522 u32 nargs_prop_val;
523 int error;
524 int i;
525
526 prop = property_entry_get(swnode->node->properties, propname);
527 if (!prop)
528 return -ENOENT;
529
530 if (prop->type != DEV_PROP_REF)
531 return -EINVAL;
532
533 /*
534 * We expect that references are never stored inline, even
535 * single ones, as they are too big.
536 */
537 if (prop->is_inline)
538 return -EINVAL;
539
540 if (index >= prop->length / sizeof(*ref))
541 return -ENOENT;
542
543 ref_array = prop->pointer;
544 ref = &ref_array[index];
545
546 /*
547 * A software node can reference other software nodes or firmware
548 * nodes (which are the abstraction layer sitting on top of them).
549 * This is done to ensure we can create references to static software
550 * nodes before they're registered with the firmware node framework.
551 * At the time the reference is being resolved, we expect the swnodes
552 * in question to already have been registered and to be backed by
553 * a firmware node. This is why we use the fwnode API below to read the
554 * relevant properties and bump the reference count.
555 */
556
557 if (ref->swnode)
558 refnode = software_node_fwnode(ref->swnode);
559 else if (ref->fwnode)
560 refnode = ref->fwnode;
561 else
562 return -EINVAL;
563
564 if (!refnode)
565 return -ENOTCONN;
566
567 if (nargs_prop) {
568 error = fwnode_property_read_u32(refnode, nargs_prop, &nargs_prop_val);
569 if (error)
570 return error;
571
572 nargs = nargs_prop_val;
573 }
574
575 if (nargs > NR_FWNODE_REFERENCE_ARGS)
576 return -EINVAL;
577
578 if (!args)
579 return 0;
580
581 args->fwnode = fwnode_handle_get(refnode);
582 args->nargs = nargs;
583
584 for (i = 0; i < nargs; i++)
585 args->args[i] = ref->args[i];
586
587 return 0;
588}
589
590static struct fwnode_handle *
591swnode_graph_find_next_port(const struct fwnode_handle *parent,
592 struct fwnode_handle *port)
593{
594 struct fwnode_handle *old = port;
595
596 while ((port = software_node_get_next_child(parent, old))) {
597 /*
598 * fwnode ports have naming style "port@", so we search for any
599 * children that follow that convention.
600 */
601 if (!strncmp(to_swnode(port)->node->name, "port@",
602 strlen("port@")))
603 return port;
604 old = port;
605 }
606
607 return NULL;
608}
609
610static struct fwnode_handle *
611software_node_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
612 struct fwnode_handle *endpoint)
613{
614 struct swnode *swnode = to_swnode(fwnode);
615 struct fwnode_handle *parent;
616 struct fwnode_handle *port;
617
618 if (!swnode)
619 return NULL;
620
621 if (endpoint) {
622 port = software_node_get_parent(endpoint);
623 parent = software_node_get_parent(port);
624 } else {
625 parent = software_node_get_named_child_node(fwnode, "ports");
626 if (!parent)
627 parent = software_node_get(&swnode->fwnode);
628
629 port = swnode_graph_find_next_port(parent, NULL);
630 }
631
632 for (; port; port = swnode_graph_find_next_port(parent, port)) {
633 endpoint = software_node_get_next_child(port, endpoint);
634 if (endpoint) {
635 fwnode_handle_put(port);
636 break;
637 }
638 }
639
640 fwnode_handle_put(parent);
641
642 return endpoint;
643}
644
645static struct fwnode_handle *
646software_node_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
647{
648 struct swnode *swnode = to_swnode(fwnode);
649 const struct software_node_ref_args *ref;
650 const struct property_entry *prop;
651
652 if (!swnode)
653 return NULL;
654
655 prop = property_entry_get(swnode->node->properties, "remote-endpoint");
656 if (!prop || prop->type != DEV_PROP_REF || prop->is_inline)
657 return NULL;
658
659 ref = prop->pointer;
660
661 if (!ref->swnode)
662 return NULL;
663
664 return software_node_get(software_node_fwnode(ref->swnode));
665}
666
667static struct fwnode_handle *
668software_node_graph_get_port_parent(struct fwnode_handle *fwnode)
669{
670 struct swnode *swnode = to_swnode(fwnode);
671
672 swnode = swnode->parent;
673 if (swnode && !strcmp(swnode->node->name, "ports"))
674 swnode = swnode->parent;
675
676 return swnode ? software_node_get(&swnode->fwnode) : NULL;
677}
678
679static int
680software_node_graph_parse_endpoint(const struct fwnode_handle *fwnode,
681 struct fwnode_endpoint *endpoint)
682{
683 struct swnode *swnode = to_swnode(fwnode);
684 const char *parent_name = swnode->parent->node->name;
685 int ret;
686
687 if (strlen("port@") >= strlen(parent_name) ||
688 strncmp(parent_name, "port@", strlen("port@")))
689 return -EINVAL;
690
691 /* Ports have naming style "port@n", we need to select the n */
692 ret = kstrtou32(parent_name + strlen("port@"), 10, &endpoint->port);
693 if (ret)
694 return ret;
695
696 endpoint->id = swnode->id;
697 endpoint->local_fwnode = fwnode;
698
699 return 0;
700}
701
702static int software_node_add_links(struct fwnode_handle *fwnode)
703{
704 const struct software_node_ref_args *ref, *ref_array;
705 struct swnode *swnode = to_swnode(fwnode);
706 const struct property_entry *prop;
707 struct fwnode_handle *refnode;
708 unsigned int count;
709
710 if (!swnode || !swnode->node->properties)
711 return 0;
712
713 /*
714 * Unlike Device Tree, where phandles appear in many non-supplier
715 * contexts and a curated allowlist is required, a software node only
716 * carries a DEV_PROP_REF property when the author explicitly describes
717 * a reference to another node. Every such reference is therefore an
718 * intentional supplier dependency, so we create fwnode links for all
719 * of them.
720 */
721 for (prop = swnode->node->properties; prop->name; prop++) {
722 if (prop->type != DEV_PROP_REF || prop->is_inline)
723 continue;
724
725 /*
726 * TODO: Graph "remote-endpoint" references go both ways
727 * between endpoint child nodes and would create endpoint
728 * cycles. Let's leave it out for now until we have potential
729 * users.
730 */
731 if (!strcmp(prop->name, "remote-endpoint"))
732 continue;
733
734 ref_array = prop->pointer;
735 count = prop->length / sizeof(*ref_array);
736
737 for (unsigned int i = 0; i < count; i++) {
738 ref = &ref_array[i];
739
740 if (ref->swnode)
741 refnode = software_node_fwnode(ref->swnode);
742 else if (ref->fwnode)
743 refnode = ref->fwnode;
744 else
745 continue;
746
747 /* Supplier not registered yet, or self-reference. */
748 if (!refnode || refnode == &swnode->fwnode)
749 continue;
750
751 fwnode_link_add(&swnode->fwnode, refnode, 0);
752 }
753 }
754
755 return 0;
756}
757
758static const struct fwnode_operations software_node_ops = {
759 .get = software_node_get,
760 .put = software_node_put,
761 .property_present = software_node_property_present,
762 .property_read_bool = software_node_property_present,
763 .property_read_int_array = software_node_read_int_array,
764 .property_read_string_array = software_node_read_string_array,
765 .get_name = software_node_get_name,
766 .get_name_prefix = software_node_get_name_prefix,
767 .get_parent = software_node_get_parent,
768 .get_next_child_node = software_node_get_next_child,
769 .get_named_child_node = software_node_get_named_child_node,
770 .get_reference_args = software_node_get_reference_args,
771 .graph_get_next_endpoint = software_node_graph_get_next_endpoint,
772 .graph_get_remote_endpoint = software_node_graph_get_remote_endpoint,
773 .graph_get_port_parent = software_node_graph_get_port_parent,
774 .graph_parse_endpoint = software_node_graph_parse_endpoint,
775 .add_links = software_node_add_links,
776};
777
778/* -------------------------------------------------------------------------- */
779
780/**
781 * software_node_find_by_name - Find software node by name
782 * @parent: Parent of the software node
783 * @name: Name of the software node
784 *
785 * The function will find a node that is child of @parent and that is named
786 * @name. If no node is found, the function returns NULL.
787 *
788 * NOTE: you will need to drop the reference with fwnode_handle_put() after use.
789 */
790const struct software_node *
791software_node_find_by_name(const struct software_node *parent, const char *name)
792{
793 struct swnode *swnode = NULL;
794 struct kobject *k;
795
796 if (!name)
797 return NULL;
798
799 spin_lock(&swnode_kset->list_lock);
800
801 list_for_each_entry(k, &swnode_kset->list, entry) {
802 swnode = kobj_to_swnode(k);
803 if (parent == swnode->node->parent && swnode->node->name &&
804 !strcmp(name, swnode->node->name)) {
805 swnode_get(swnode);
806 break;
807 }
808 swnode = NULL;
809 }
810
811 spin_unlock(&swnode_kset->list_lock);
812
813 return swnode ? swnode->node : NULL;
814}
815EXPORT_SYMBOL_GPL(software_node_find_by_name);
816
817static struct software_node *software_node_alloc(const struct property_entry *properties)
818{
819 struct property_entry *props;
820 struct software_node *node;
821
822 props = property_entries_dup(properties);
823 if (IS_ERR(props))
824 return ERR_CAST(props);
825
826 node = kzalloc_obj(*node);
827 if (!node) {
828 property_entries_free(props);
829 return ERR_PTR(-ENOMEM);
830 }
831
832 node->properties = props;
833
834 return node;
835}
836
837static void software_node_free(const struct software_node *node)
838{
839 property_entries_free(node->properties);
840 kfree(node);
841}
842
843static void software_node_release(struct kobject *kobj)
844{
845 struct swnode *swnode = kobj_to_swnode(kobj);
846
847 fwnode_links_purge(&swnode->fwnode);
848
849 if (swnode->parent) {
850 ida_free(&swnode->parent->child_ids, swnode->id);
851 list_del(&swnode->entry);
852 } else {
853 ida_free(&swnode_root_ids, swnode->id);
854 }
855
856 if (swnode->allocated)
857 software_node_free(swnode->node);
858
859 ida_destroy(&swnode->child_ids);
860 kfree(swnode);
861}
862
863static const struct kobj_type software_node_type = {
864 .release = software_node_release,
865 .sysfs_ops = &kobj_sysfs_ops,
866};
867
868static struct fwnode_handle *
869swnode_register(const struct software_node *node, struct swnode *parent,
870 unsigned int allocated)
871{
872 struct swnode *swnode;
873 int ret;
874
875 swnode = kzalloc_obj(*swnode);
876 if (!swnode)
877 return ERR_PTR(-ENOMEM);
878
879 ret = ida_alloc(parent ? &parent->child_ids : &swnode_root_ids,
880 GFP_KERNEL);
881 if (ret < 0) {
882 kfree(swnode);
883 return ERR_PTR(ret);
884 }
885
886 swnode->id = ret;
887 swnode->node = node;
888 swnode->parent = parent;
889 swnode->kobj.kset = swnode_kset;
890 fwnode_init(&swnode->fwnode, &software_node_ops);
891
892 ida_init(&swnode->child_ids);
893 INIT_LIST_HEAD(&swnode->entry);
894 INIT_LIST_HEAD(&swnode->children);
895
896 if (node->name)
897 ret = kobject_init_and_add(&swnode->kobj, &software_node_type,
898 parent ? &parent->kobj : NULL,
899 "%s", node->name);
900 else
901 ret = kobject_init_and_add(&swnode->kobj, &software_node_type,
902 parent ? &parent->kobj : NULL,
903 "node%d", swnode->id);
904 if (ret) {
905 swnode_put(swnode);
906 return ERR_PTR(ret);
907 }
908
909 /*
910 * Assign the flag only in the successful case, so
911 * the above swnode_put() won't mess up with properties.
912 */
913 swnode->allocated = allocated;
914
915 if (parent)
916 list_add_tail(&swnode->entry, &parent->children);
917
918 kobject_uevent(&swnode->kobj, KOBJ_ADD);
919 return &swnode->fwnode;
920}
921
922/**
923 * software_node_register_node_group - Register a group of software nodes
924 * @node_group: NULL terminated array of software node pointers to be registered
925 *
926 * Register multiple software nodes at once. If any node in the array
927 * has its .parent pointer set (which can only be to another software_node),
928 * then its parent **must** have been registered before it is; either outside
929 * of this function or by ordering the array such that parent comes before
930 * child.
931 */
932int software_node_register_node_group(const struct software_node * const *node_group)
933{
934 unsigned int i;
935 int ret;
936
937 if (!node_group)
938 return 0;
939
940 for (i = 0; node_group[i]; i++) {
941 ret = software_node_register(node_group[i]);
942 if (ret) {
943 software_node_unregister_node_group(node_group);
944 return ret;
945 }
946 }
947
948 return 0;
949}
950EXPORT_SYMBOL_GPL(software_node_register_node_group);
951
952/**
953 * software_node_unregister_node_group - Unregister a group of software nodes
954 * @node_group: NULL terminated array of software node pointers to be unregistered
955 *
956 * Unregister multiple software nodes at once. If parent pointers are set up
957 * in any of the software nodes then the array **must** be ordered such that
958 * parents come before their children.
959 *
960 * NOTE: If you are uncertain whether the array is ordered such that
961 * parents will be unregistered before their children, it is wiser to
962 * remove the nodes individually, in the correct order (child before
963 * parent).
964 */
965void software_node_unregister_node_group(const struct software_node * const *node_group)
966{
967 unsigned int i = 0;
968
969 if (!node_group)
970 return;
971
972 while (node_group[i])
973 i++;
974
975 while (i--)
976 software_node_unregister(node_group[i]);
977}
978EXPORT_SYMBOL_GPL(software_node_unregister_node_group);
979
980/**
981 * software_node_register - Register static software node
982 * @node: The software node to be registered
983 */
984int software_node_register(const struct software_node *node)
985{
986 struct swnode *parent = software_node_to_swnode(node->parent);
987
988 if (software_node_to_swnode(node))
989 return -EEXIST;
990
991 if (node->parent && !parent)
992 return -EINVAL;
993
994 return PTR_ERR_OR_ZERO(swnode_register(node, parent, 0));
995}
996EXPORT_SYMBOL_GPL(software_node_register);
997
998/**
999 * software_node_unregister - Unregister static software node
1000 * @node: The software node to be unregistered
1001 */
1002void software_node_unregister(const struct software_node *node)
1003{
1004 struct swnode *swnode;
1005
1006 swnode = software_node_to_swnode(node);
1007 if (swnode)
1008 fwnode_remove_software_node(&swnode->fwnode);
1009}
1010EXPORT_SYMBOL_GPL(software_node_unregister);
1011
1012struct fwnode_handle *
1013fwnode_create_software_node(const struct property_entry *properties,
1014 const struct fwnode_handle *parent)
1015{
1016 struct fwnode_handle *fwnode;
1017 struct software_node *node;
1018 struct swnode *p;
1019
1020 if (IS_ERR(parent))
1021 return ERR_CAST(parent);
1022
1023 p = to_swnode(parent);
1024 if (parent && !p)
1025 return ERR_PTR(-EINVAL);
1026
1027 node = software_node_alloc(properties);
1028 if (IS_ERR(node))
1029 return ERR_CAST(node);
1030
1031 node->parent = p ? p->node : NULL;
1032
1033 fwnode = swnode_register(node, p, 1);
1034 if (IS_ERR(fwnode))
1035 software_node_free(node);
1036
1037 return fwnode;
1038}
1039EXPORT_SYMBOL_GPL(fwnode_create_software_node);
1040
1041void fwnode_remove_software_node(struct fwnode_handle *fwnode)
1042{
1043 struct swnode *swnode = to_swnode(fwnode);
1044
1045 if (!swnode)
1046 return;
1047
1048 swnode_put(swnode);
1049}
1050EXPORT_SYMBOL_GPL(fwnode_remove_software_node);
1051
1052/**
1053 * device_add_software_node - Assign software node to a device
1054 * @dev: The device the software node is meant for.
1055 * @node: The software node.
1056 *
1057 * This function will make @node the secondary firmware node pointer of @dev. If
1058 * @dev has no primary node, then @node will become the primary node. The
1059 * function will register @node automatically if it wasn't already registered.
1060 */
1061int device_add_software_node(struct device *dev, const struct software_node *node)
1062{
1063 struct swnode *swnode;
1064 int ret;
1065
1066 /* Only one software node per device. */
1067 if (dev_to_swnode(dev))
1068 return -EBUSY;
1069
1070 swnode = software_node_to_swnode(node);
1071 if (swnode) {
1072 swnode_get(swnode);
1073 } else {
1074 ret = software_node_register(node);
1075 if (ret)
1076 return ret;
1077
1078 swnode = software_node_to_swnode(node);
1079 }
1080
1081 set_secondary_fwnode(dev, &swnode->fwnode);
1082
1083 /*
1084 * If the device has been fully registered by the time this function is
1085 * called, software_node_notify() must be called separately so that the
1086 * symlinks get created and the reference count of the node is kept in
1087 * balance.
1088 */
1089 if (device_is_registered(dev))
1090 software_node_notify(dev);
1091
1092 return 0;
1093}
1094EXPORT_SYMBOL_GPL(device_add_software_node);
1095
1096/**
1097 * device_remove_software_node - Remove device's software node
1098 * @dev: The device with the software node.
1099 *
1100 * This function will unregister the software node of @dev.
1101 */
1102void device_remove_software_node(struct device *dev)
1103{
1104 struct swnode *swnode;
1105
1106 swnode = dev_to_swnode(dev);
1107 if (!swnode)
1108 return;
1109
1110 if (device_is_registered(dev))
1111 software_node_notify_remove(dev);
1112
1113 set_secondary_fwnode(dev, NULL);
1114 swnode_put(swnode);
1115}
1116EXPORT_SYMBOL_GPL(device_remove_software_node);
1117
1118/**
1119 * device_create_managed_software_node - Create a software node for a device
1120 * @dev: The device the software node is assigned to.
1121 * @properties: Device properties for the software node.
1122 * @parent: Parent of the software node.
1123 *
1124 * Creates a software node as a managed resource for @dev, which means the
1125 * lifetime of the newly created software node is tied to the lifetime of @dev.
1126 * Software nodes created with this function should not be reused or shared
1127 * because of that. The function takes a deep copy of @properties for the
1128 * software node.
1129 *
1130 * Since the new software node is assigned directly to @dev, and since it should
1131 * not be shared, it is not returned to the caller. The function returns 0 on
1132 * success, and errno in case of an error.
1133 */
1134int device_create_managed_software_node(struct device *dev,
1135 const struct property_entry *properties,
1136 const struct software_node *parent)
1137{
1138 struct fwnode_handle *p = software_node_fwnode(parent);
1139 struct fwnode_handle *fwnode;
1140
1141 if (parent && !p)
1142 return -EINVAL;
1143
1144 fwnode = fwnode_create_software_node(properties, p);
1145 if (IS_ERR(fwnode))
1146 return PTR_ERR(fwnode);
1147
1148 to_swnode(fwnode)->managed = true;
1149 set_secondary_fwnode(dev, fwnode);
1150
1151 if (device_is_registered(dev))
1152 software_node_notify(dev);
1153
1154 return 0;
1155}
1156EXPORT_SYMBOL_GPL(device_create_managed_software_node);
1157
1158void software_node_notify(struct device *dev)
1159{
1160 struct swnode *swnode;
1161 int ret;
1162
1163 swnode = dev_to_swnode(dev);
1164 if (!swnode)
1165 return;
1166
1167 /*
1168 * When the software node is the device's secondary firmware node,
1169 * the core only records the owning device on the primary fwnode
1170 * (see device_add()). fw_devlink resolves a supplier device through
1171 * fwnode->dev, so without this a consumer referencing the software
1172 * node could never find the supplier device and would defer forever.
1173 * Make fwnode.dev point to its owner in that case.
1174 */
1175 if (!device_match_fwnode(dev, &swnode->fwnode) && !swnode->fwnode.dev)
1176 swnode->fwnode.dev = dev;
1177
1178 swnode_get(swnode);
1179 ret = sysfs_create_link(&dev->kobj, &swnode->kobj, "software_node");
1180 if (ret)
1181 return;
1182
1183 ret = sysfs_create_link(&swnode->kobj, &dev->kobj, dev_name(dev));
1184 if (ret) {
1185 sysfs_remove_link(&dev->kobj, "software_node");
1186 return;
1187 }
1188}
1189
1190void software_node_notify_remove(struct device *dev)
1191{
1192 struct swnode *swnode;
1193
1194 swnode = dev_to_swnode(dev);
1195 if (!swnode)
1196 return;
1197
1198 sysfs_remove_link(&swnode->kobj, dev_name(dev));
1199 sysfs_remove_link(&dev->kobj, "software_node");
1200
1201 /*
1202 * Drop the device pointer mirrored onto a secondary software node in
1203 * software_node_notify(). For a primary software node the core owns
1204 * fwnode->dev and clears it in device_del().
1205 */
1206 if (!device_match_fwnode(dev, &swnode->fwnode) && swnode->fwnode.dev == dev)
1207 swnode->fwnode.dev = NULL;
1208
1209 swnode_put(swnode);
1210
1211 if (swnode->managed) {
1212 set_secondary_fwnode(dev, NULL);
1213 swnode_put(swnode);
1214 }
1215}
1216
1217void __init software_node_init(void)
1218{
1219 swnode_kset = kset_create_and_add("software_nodes", NULL, kernel_kobj);
1220 if (!swnode_kset)
1221 pr_err("failed to register software nodes\n");
1222}