1 // SPDX-License-Identifier: GPL-2.0
5  * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com>
27  * struct target - info about current target node as recursing through overlay
29  * @in_livetree:	@np is a node in the live devicetree
33  * in the live devicetree where the overlay subtree is targeted to be grafted
35  * also recurses to the next level of the live devicetree, as long as overlay
36  * subtree node also exists in the live devicetree.  When a node in the overlay
37  * subtree does not exist at the same level in the live devicetree, target->np
47  * struct fragment - info about fragment nodes in overlay expanded device tree
67  * @cset:		changeset to apply fragments to live device tree
82 /* flags are sticky - once set, do not reset */
102  * of_resolve_phandles() finds the largest phandle in the live tree.
103  * of_overlay_apply() may add a larger phandle to the live tree.
128  * of_overlay_notifier_register() - Register notifier for overlay operations
146  * of_overlay_notifier_unregister() - Unregister notifier for overlay operations
161 	ovcs->notify_state = action;  in overlay_notify()
163 	for (i = 0; i < ovcs->count; i++) {  in overlay_notify()
164 		struct fragment *fragment = &ovcs->fragments[i];  in overlay_notify()
166 		nd.target = fragment->target;  in overlay_notify()
167 		nd.overlay = fragment->overlay;  in overlay_notify()
184  * the ovcs->overlay_root.  When duplicating the properties, the paths
185  * need to be adjusted to be the correct path for the live device tree.
189  * where symbol_path_tail can be a single node or it may be a multi-node path.
211 	if (!prop->value)  in dup_and_fixup_symbol_prop()
213 	if (strnlen(prop->value, prop->length) >= prop->length)  in dup_and_fixup_symbol_prop()
215 	path = prop->value;  in dup_and_fixup_symbol_prop()
220 	fragment_node = __of_find_node_by_path(ovcs->overlay_root, path + 1);  in dup_and_fixup_symbol_prop()
225 	for (k = 0; k < ovcs->count; k++) {  in dup_and_fixup_symbol_prop()
226 		fragment = &ovcs->fragments[k];  in dup_and_fixup_symbol_prop()
227 		if (fragment->overlay == overlay_node)  in dup_and_fixup_symbol_prop()
230 	if (k >= ovcs->count)  in dup_and_fixup_symbol_prop()
233 	overlay_name_len = snprintf(NULL, 0, "%pOF", fragment->overlay);  in dup_and_fixup_symbol_prop()
240 	target_path = kasprintf(GFP_KERNEL, "%pOF", fragment->target);  in dup_and_fixup_symbol_prop()
249 	new_prop->name = kstrdup(prop->name, GFP_KERNEL);  in dup_and_fixup_symbol_prop()
250 	new_prop->length = target_path_len + path_tail_len + 1;  in dup_and_fixup_symbol_prop()
251 	new_prop->value = kzalloc(new_prop->length, GFP_KERNEL);  in dup_and_fixup_symbol_prop()
252 	if (!new_prop->name || !new_prop->value)  in dup_and_fixup_symbol_prop()
255 	strcpy(new_prop->value, target_path);  in dup_and_fixup_symbol_prop()
256 	strcpy(new_prop->value + target_path_len, path_tail);  in dup_and_fixup_symbol_prop()
265 	kfree(new_prop->name);  in dup_and_fixup_symbol_prop()
266 	kfree(new_prop->value);  in dup_and_fixup_symbol_prop()
275  * add_changeset_property() - add @overlay_prop to overlay changeset
281  * If @overlay_prop does not already exist in live devicetree, add changeset
285  * @target may be either in the live devicetree or in a new subtree that
291  * Properties "#address-cells" and "#size-cells" are not updated if they
292  * are already in the live tree, but if present in the live tree, the values
293  * in the overlay must match the values in the live tree.
297  * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
307 	if (target->in_livetree)  in add_changeset_property()
308 		if (!of_prop_cmp(overlay_prop->name, "name") ||  in add_changeset_property()
309 		    !of_prop_cmp(overlay_prop->name, "phandle") ||  in add_changeset_property()
310 		    !of_prop_cmp(overlay_prop->name, "linux,phandle"))  in add_changeset_property()
313 	if (target->in_livetree)  in add_changeset_property()
314 		prop = of_find_property(target->np, overlay_prop->name, NULL);  in add_changeset_property()
319 		if (!of_prop_cmp(prop->name, "#address-cells")) {  in add_changeset_property()
321 				pr_err("ERROR: changing value of #address-cells is not allowed in %pOF\n",  in add_changeset_property()
322 				       target->np);  in add_changeset_property()
323 				ret = -EINVAL;  in add_changeset_property()
327 		} else if (!of_prop_cmp(prop->name, "#size-cells")) {  in add_changeset_property()
329 				pr_err("ERROR: changing value of #size-cells is not allowed in %pOF\n",  in add_changeset_property()
330 				       target->np);  in add_changeset_property()
331 				ret = -EINVAL;  in add_changeset_property()
339 			return -EINVAL;  in add_changeset_property()
346 		return -ENOMEM;  in add_changeset_property()
349 		if (!target->in_livetree) {  in add_changeset_property()
350 			new_prop->next = target->np->deadprops;  in add_changeset_property()
351 			target->np->deadprops = new_prop;  in add_changeset_property()
353 		ret = of_changeset_add_property(&ovcs->cset, target->np,  in add_changeset_property()
356 		ret = of_changeset_update_property(&ovcs->cset, target->np,  in add_changeset_property()
360 	if (!of_node_check_flag(target->np, OF_OVERLAY))  in add_changeset_property()
362 		       target->np, new_prop->name);  in add_changeset_property()
365 		kfree(new_prop->name);  in add_changeset_property()
366 		kfree(new_prop->value);  in add_changeset_property()
373  * add_changeset_node() - add @node (and children) to overlay changeset
375  * @target:	where @node will be placed in live tree or changeset
387  * NOTE_1: A live devicetree created from a flattened device tree (FDT) will
388  *       not contain the full path in node->full_name.  Thus an overlay
390  *       node->full_name.  However, a live devicetree created from Open
391  *       Firmware may have the full path in node->full_name.
394  *       the full path in node->full_name.  Even though it expects the overlay
397  *       to nodes in the live devicetree so that it can apply an overlay to
398  *       a live devicetree created from Open Firmware.
402  * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
414 	node_kbasename = kbasename(node->full_name);  in add_changeset_node()
416 	for_each_child_of_node(target->np, tchild)  in add_changeset_node()
417 		if (!of_node_cmp(node_kbasename, kbasename(tchild->full_name)))  in add_changeset_node()
423 			return -ENOMEM;  in add_changeset_node()
425 		tchild->parent = target->np;  in add_changeset_node()
426 		tchild->name = __of_get_property(node, "name", NULL);  in add_changeset_node()
428 		if (!tchild->name)  in add_changeset_node()
429 			tchild->name = "<NULL>";  in add_changeset_node()
434 			tchild->phandle = be32_to_cpup(phandle);  in add_changeset_node()
438 		ret = of_changeset_attach_node(&ovcs->cset, tchild);  in add_changeset_node()
450 	if (node->phandle && tchild->phandle) {  in add_changeset_node()
451 		ret = -EINVAL;  in add_changeset_node()
454 		target_child.in_livetree = target->in_livetree;  in add_changeset_node()
463  * build_changeset_next_level() - add level of overlay changeset
465  * @target:		where to place @overlay_node in live tree
469  * @ovcs->cset changeset.  If an added node has child nodes, they will
474  * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
488 				 target->np, prop->name, ret);  in build_changeset_next_level()
497 				 target->np, child, ret);  in build_changeset_next_level()
507  * Add the properties from __overlay__ node to the @ovcs->cset changeset.
520 				 target->np, prop->name, ret);  in build_changeset_symbols_node()
535 	if (ce_1->action != OF_RECONFIG_ATTACH_NODE &&  in find_dup_cset_node_entry()
536 	    ce_1->action != OF_RECONFIG_DETACH_NODE)  in find_dup_cset_node_entry()
540 	list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) {  in find_dup_cset_node_entry()
541 		if ((ce_2->action != OF_RECONFIG_ATTACH_NODE &&  in find_dup_cset_node_entry()
542 		     ce_2->action != OF_RECONFIG_DETACH_NODE) ||  in find_dup_cset_node_entry()
543 		    of_node_cmp(ce_1->np->full_name, ce_2->np->full_name))  in find_dup_cset_node_entry()
546 		fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);  in find_dup_cset_node_entry()
547 		fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);  in find_dup_cset_node_entry()
553 			       ce_1->np);  in find_dup_cset_node_entry()
554 			return -EINVAL;  in find_dup_cset_node_entry()
568 	if (ce_1->action != OF_RECONFIG_ADD_PROPERTY &&  in find_dup_cset_prop()
569 	    ce_1->action != OF_RECONFIG_REMOVE_PROPERTY &&  in find_dup_cset_prop()
570 	    ce_1->action != OF_RECONFIG_UPDATE_PROPERTY)  in find_dup_cset_prop()
574 	list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) {  in find_dup_cset_prop()
575 		if ((ce_2->action != OF_RECONFIG_ADD_PROPERTY &&  in find_dup_cset_prop()
576 		     ce_2->action != OF_RECONFIG_REMOVE_PROPERTY &&  in find_dup_cset_prop()
577 		     ce_2->action != OF_RECONFIG_UPDATE_PROPERTY) ||  in find_dup_cset_prop()
578 		    of_node_cmp(ce_1->np->full_name, ce_2->np->full_name))  in find_dup_cset_prop()
581 		fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);  in find_dup_cset_prop()
582 		fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);  in find_dup_cset_prop()
587 		    !of_prop_cmp(ce_1->prop->name, ce_2->prop->name)) {  in find_dup_cset_prop()
589 			       ce_1->np, ce_1->prop->name);  in find_dup_cset_prop()
590 			return -EINVAL;  in find_dup_cset_prop()
598  * changeset_dup_entry_check() - check for duplicate entries
601  * Check changeset @ovcs->cset for multiple {add or delete} node entries for
605  * Return: 0 on success, or -EINVAL if duplicate changeset entry found.
612 	list_for_each_entry(ce_1, &ovcs->cset.entries, node) {  in changeset_dup_entry_check()
617 	return dup_entry ? -EINVAL : 0;  in changeset_dup_entry_check()
621  * build_changeset() - populate overlay changeset in @ovcs from @ovcs->fragments
624  * Create changeset @ovcs->cset to contain the nodes and properties of the
625  * overlay device tree fragments in @ovcs->fragments[].  If an error occurs,
627  * in @ovcs->cset.
629  * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
630  * invalid overlay in @ovcs->fragments[].
639 	 * if there is a symbols fragment in ovcs->fragments[i] it is  in build_changeset()
642 	if (ovcs->symbols_fragment)  in build_changeset()
643 		fragments_count = ovcs->count - 1;  in build_changeset()
645 		fragments_count = ovcs->count;  in build_changeset()
648 		fragment = &ovcs->fragments[i];  in build_changeset()
650 		target.np = fragment->target;  in build_changeset()
653 						 fragment->overlay);  in build_changeset()
656 				 fragment->target);  in build_changeset()
661 	if (ovcs->symbols_fragment) {  in build_changeset()
662 		fragment = &ovcs->fragments[ovcs->count - 1];  in build_changeset()
664 		target.np = fragment->target;  in build_changeset()
667 						   fragment->overlay);  in build_changeset()
670 				 fragment->target);  in build_changeset()
683  * 2) "target-path" property containing the path of the target
701 	ret = of_property_read_string(info_node, "target-path", &path);  in find_target()
716  * init_overlay_changeset() - initialize overlay changeset from overlay tree
719  * Initialize @ovcs.  Populate @ovcs->fragments with node information from
724  * Return: 0 on success, -ENOMEM if memory allocation failure, -EINVAL if error
743 	 * Warn for some issues.  Can not return -EINVAL for these until  in init_overlay_changeset()
746 	if (!of_node_check_flag(ovcs->overlay_root, OF_DYNAMIC))  in init_overlay_changeset()
747 		pr_debug("%s() ovcs->overlay_root is not dynamic\n", __func__);  in init_overlay_changeset()
749 	if (!of_node_check_flag(ovcs->overlay_root, OF_DETACHED))  in init_overlay_changeset()
750 		pr_debug("%s() ovcs->overlay_root is not detached\n", __func__);  in init_overlay_changeset()
752 	if (!of_node_is_root(ovcs->overlay_root))  in init_overlay_changeset()
753 		pr_debug("%s() ovcs->overlay_root is not root\n", __func__);  in init_overlay_changeset()
755 	of_changeset_init(&ovcs->cset);  in init_overlay_changeset()
760 	for_each_child_of_node(ovcs->overlay_root, node) {  in init_overlay_changeset()
768 	node = of_get_child_by_name(ovcs->overlay_root, "__symbols__");  in init_overlay_changeset()
776 		ret = -ENOMEM;  in init_overlay_changeset()
779 	ovcs->fragments = fragments;  in init_overlay_changeset()
782 	for_each_child_of_node(ovcs->overlay_root, node) {  in init_overlay_changeset()
788 		fragment->overlay = overlay_node;  in init_overlay_changeset()
789 		fragment->target = find_target(node);  in init_overlay_changeset()
790 		if (!fragment->target) {  in init_overlay_changeset()
791 			of_node_put(fragment->overlay);  in init_overlay_changeset()
792 			ret = -EINVAL;  in init_overlay_changeset()
801 	 * if there is a symbols fragment in ovcs->fragments[i] it is  in init_overlay_changeset()
804 	node = of_get_child_by_name(ovcs->overlay_root, "__symbols__");  in init_overlay_changeset()
806 		ovcs->symbols_fragment = 1;  in init_overlay_changeset()
808 		fragment->overlay = node;  in init_overlay_changeset()
809 		fragment->target = of_find_node_by_path("/__symbols__");  in init_overlay_changeset()
811 		if (!fragment->target) {  in init_overlay_changeset()
812 			pr_err("symbols in overlay, but not in live tree\n");  in init_overlay_changeset()
813 			ret = -EINVAL;  in init_overlay_changeset()
822 		ret = -EINVAL;  in init_overlay_changeset()
826 	ovcs->count = cnt;  in init_overlay_changeset()
840 	if (ovcs->cset.entries.next)  in free_overlay_changeset()
841 		of_changeset_destroy(&ovcs->cset);  in free_overlay_changeset()
843 	if (ovcs->id) {  in free_overlay_changeset()
844 		idr_remove(&ovcs_idr, ovcs->id);  in free_overlay_changeset()
845 		list_del(&ovcs->ovcs_list);  in free_overlay_changeset()
846 		ovcs->id = 0;  in free_overlay_changeset()
850 	for (i = 0; i < ovcs->count; i++) {  in free_overlay_changeset()
851 		of_node_put(ovcs->fragments[i].target);  in free_overlay_changeset()
852 		of_node_put(ovcs->fragments[i].overlay);  in free_overlay_changeset()
854 	kfree(ovcs->fragments);  in free_overlay_changeset()
857 	 * There should be no live pointers into ovcs->overlay_mem and  in free_overlay_changeset()
858 	 * ovcs->new_fdt due to the policy that overlay notifiers are not  in free_overlay_changeset()
866 	if (ovcs->notify_state == OF_OVERLAY_INIT ||  in free_overlay_changeset()
867 	    ovcs->notify_state == OF_OVERLAY_POST_REMOVE) {  in free_overlay_changeset()
868 		kfree(ovcs->overlay_mem);  in free_overlay_changeset()
869 		kfree(ovcs->new_fdt);  in free_overlay_changeset()
877  * of_overlay_apply() - Create and apply an overlay changeset
882  * If an error is returned by an overlay changeset pre-apply notifier
883  * then no further overlay changeset pre-apply notifier will be called.
885  * If an error is returned by an overlay changeset post-apply notifier
886  * then no further overlay changeset post-apply notifier will be called.
906 	ret = of_resolve_phandles(ovcs->overlay_root);  in of_overlay_apply()
923 	ret = __of_changeset_apply_entries(&ovcs->cset, &ret_revert);  in of_overlay_apply()
933 	ret = __of_changeset_apply_notify(&ovcs->cset);  in of_overlay_apply()
950  * of_overlay_fdt_apply() - Create and apply an overlay changeset
982 		return -EBUSY;  in of_overlay_fdt_apply()
988 		return -EINVAL;  in of_overlay_fdt_apply()
993 		return -EINVAL;  in of_overlay_fdt_apply()
997 		return -ENOMEM;  in of_overlay_fdt_apply()
1003 	 * ovcs->notify_state must be set to OF_OVERLAY_INIT before allocating  in of_overlay_fdt_apply()
1007 	ovcs->id = idr_alloc(&ovcs_idr, ovcs, 1, 0, GFP_KERNEL);  in of_overlay_fdt_apply()
1008 	if (ovcs->id <= 0) {  in of_overlay_fdt_apply()
1009 		ret = ovcs->id;  in of_overlay_fdt_apply()
1013 	INIT_LIST_HEAD(&ovcs->ovcs_list);  in of_overlay_fdt_apply()
1014 	list_add_tail(&ovcs->ovcs_list, &ovcs_list);  in of_overlay_fdt_apply()
1022 		ret = -ENOMEM;  in of_overlay_fdt_apply()
1025 	ovcs->new_fdt = new_fdt;  in of_overlay_fdt_apply()
1031 					    &ovcs->overlay_root);  in of_overlay_fdt_apply()
1034 		ret = -EINVAL;  in of_overlay_fdt_apply()
1037 	ovcs->overlay_mem = overlay_mem;  in of_overlay_fdt_apply()
1046 	*ret_ovcs_id = ovcs->id;  in of_overlay_fdt_apply()
1097 		list_for_each_entry(ce, &ovcs->cset.entries, node) {  in node_overlaps_later_cs()
1098 			if (find_node(ce->np, remove_ce_node)) {  in node_overlaps_later_cs()
1100 					__func__, remove_ovcs->id, ovcs->id,  in node_overlaps_later_cs()
1104 			if (find_node(remove_ce_node, ce->np)) {  in node_overlaps_later_cs()
1106 					__func__, remove_ovcs->id, ovcs->id,  in node_overlaps_later_cs()
1117  * We can safely remove the overlay only if it's the top-most one.
1130 	list_for_each_entry(remove_ce, &remove_ovcs->cset.entries, node) {  in overlay_removal_is_ok()
1131 		if (node_overlaps_later_cs(remove_ovcs, remove_ce->np)) {  in overlay_removal_is_ok()
1132 			pr_err("overlay #%d is not topmost\n", remove_ovcs->id);  in overlay_removal_is_ok()
1141  * of_overlay_remove() - Revert and free an overlay changeset
1148  * then an attempt is made to re-apply any changeset entry that was
1149  * reverted.  If an error occurs on re-apply then the state of the device
1153  * A non-zero return value will not revert the changeset if error is from:
1154  *   - parameter checks
1155  *   - overlay changeset pre-remove notifier
1156  *   - overlay changeset entry revert
1158  * If an error is returned by an overlay changeset pre-remove notifier
1159  * then no further overlay changeset pre-remove notifier will be called.
1164  * A non-zero return value will revert the changeset if error is from:
1165  *   - overlay changeset entry notifier
1166  *   - overlay changeset post-remove notifier
1168  * If an error is returned by an overlay changeset post-remove notifier
1169  * then no further overlay changeset post-remove notifier will be called.
1181 		ret = -EBUSY;  in of_overlay_remove()
1189 		ret = -ENODEV;  in of_overlay_remove()
1195 		ret = -EBUSY;  in of_overlay_remove()
1204 	ret = __of_changeset_revert_entries(&ovcs->cset, &ret_apply);  in of_overlay_remove()
1211 	ret = __of_changeset_revert_notify(&ovcs->cset);  in of_overlay_remove()
1246  * of_overlay_remove_all() - Reverts and frees all overlay changesets
1259 		ret = of_overlay_remove(&ovcs->id);  in of_overlay_remove_all()