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()
273  * add_changeset_property() - add @overlay_prop to overlay changeset
279  * If @overlay_prop does not already exist in live devicetree, add changeset
283  * @target may be either in the live devicetree or in a new subtree that
289  * Properties "#address-cells" and "#size-cells" are not updated if they
290  * are already in the live tree, but if present in the live tree, the values
291  * in the overlay must match the values in the live tree.
295  * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
306 	if (target->in_livetree)  in add_changeset_property()
307 		if (!of_prop_cmp(overlay_prop->name, "name") ||  in add_changeset_property()
308 		    !of_prop_cmp(overlay_prop->name, "phandle") ||  in add_changeset_property()
309 		    !of_prop_cmp(overlay_prop->name, "linux,phandle"))  in add_changeset_property()
312 	if (target->in_livetree)  in add_changeset_property()
313 		prop = of_find_property(target->np, overlay_prop->name, NULL);  in add_changeset_property()
318 		if (!of_prop_cmp(prop->name, "#address-cells")) {  in add_changeset_property()
320 				pr_err("ERROR: changing value of #address-cells is not allowed in %pOF\n",  in add_changeset_property()
321 				       target->np);  in add_changeset_property()
322 				ret = -EINVAL;  in add_changeset_property()
326 		} else if (!of_prop_cmp(prop->name, "#size-cells")) {  in add_changeset_property()
328 				pr_err("ERROR: changing value of #size-cells is not allowed in %pOF\n",  in add_changeset_property()
329 				       target->np);  in add_changeset_property()
330 				ret = -EINVAL;  in add_changeset_property()
338 			return -EINVAL;  in add_changeset_property()
345 		return -ENOMEM;  in add_changeset_property()
348 		if (!target->in_livetree) {  in add_changeset_property()
349 			new_prop->next = target->np->deadprops;  in add_changeset_property()
350 			target->np->deadprops = new_prop;  in add_changeset_property()
352 		ret = of_changeset_add_property(&ovcs->cset, target->np,  in add_changeset_property()
355 		ret = of_changeset_update_property(&ovcs->cset, target->np,  in add_changeset_property()
359 	if (!of_node_check_flag(target->np, OF_OVERLAY))  in add_changeset_property()
361 		       target->np, new_prop->name);  in add_changeset_property()
369  * add_changeset_node() - add @node (and children) to overlay changeset
371  * @target:	where @node will be placed in live tree or changeset
383  * NOTE_1: A live devicetree created from a flattened device tree (FDT) will
384  *       not contain the full path in node->full_name.  Thus an overlay
386  *       node->full_name.  However, a live devicetree created from Open
387  *       Firmware may have the full path in node->full_name.
390  *       the full path in node->full_name.  Even though it expects the overlay
393  *       to nodes in the live devicetree so that it can apply an overlay to
394  *       a live devicetree created from Open Firmware.
398  * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
410 	node_kbasename = kbasename(node->full_name);  in add_changeset_node()
412 	for_each_child_of_node(target->np, tchild)  in add_changeset_node()
413 		if (!of_node_cmp(node_kbasename, kbasename(tchild->full_name)))  in add_changeset_node()
419 			return -ENOMEM;  in add_changeset_node()
421 		tchild->parent = target->np;  in add_changeset_node()
422 		tchild->name = __of_get_property(node, "name", NULL);  in add_changeset_node()
424 		if (!tchild->name)  in add_changeset_node()
425 			tchild->name = "<NULL>";  in add_changeset_node()
430 			tchild->phandle = be32_to_cpup(phandle);  in add_changeset_node()
434 		ret = of_changeset_attach_node(&ovcs->cset, tchild);  in add_changeset_node()
446 	if (node->phandle && tchild->phandle) {  in add_changeset_node()
447 		ret = -EINVAL;  in add_changeset_node()
450 		target_child.in_livetree = target->in_livetree;  in add_changeset_node()
459  * build_changeset_next_level() - add level of overlay changeset
461  * @target:		where to place @overlay_node in live tree
465  * @ovcs->cset changeset.  If an added node has child nodes, they will
470  * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
483 				 target->np, prop->name, ret);  in build_changeset_next_level()
492 				 target->np, child, ret);  in build_changeset_next_level()
501  * Add the properties from __overlay__ node to the @ovcs->cset changeset.
514 				 target->np, prop->name, ret);  in build_changeset_symbols_node()
529 	if (ce_1->action != OF_RECONFIG_ATTACH_NODE &&  in find_dup_cset_node_entry()
530 	    ce_1->action != OF_RECONFIG_DETACH_NODE)  in find_dup_cset_node_entry()
534 	list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) {  in find_dup_cset_node_entry()
535 		if ((ce_2->action != OF_RECONFIG_ATTACH_NODE &&  in find_dup_cset_node_entry()
536 		     ce_2->action != OF_RECONFIG_DETACH_NODE) ||  in find_dup_cset_node_entry()
537 		    of_node_cmp(ce_1->np->full_name, ce_2->np->full_name))  in find_dup_cset_node_entry()
540 		fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);  in find_dup_cset_node_entry()
541 		fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);  in find_dup_cset_node_entry()
547 			       ce_1->np);  in find_dup_cset_node_entry()
548 			return -EINVAL;  in find_dup_cset_node_entry()
562 	if (ce_1->action != OF_RECONFIG_ADD_PROPERTY &&  in find_dup_cset_prop()
563 	    ce_1->action != OF_RECONFIG_REMOVE_PROPERTY &&  in find_dup_cset_prop()
564 	    ce_1->action != OF_RECONFIG_UPDATE_PROPERTY)  in find_dup_cset_prop()
568 	list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) {  in find_dup_cset_prop()
569 		if ((ce_2->action != OF_RECONFIG_ADD_PROPERTY &&  in find_dup_cset_prop()
570 		     ce_2->action != OF_RECONFIG_REMOVE_PROPERTY &&  in find_dup_cset_prop()
571 		     ce_2->action != OF_RECONFIG_UPDATE_PROPERTY) ||  in find_dup_cset_prop()
572 		    of_node_cmp(ce_1->np->full_name, ce_2->np->full_name))  in find_dup_cset_prop()
575 		fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);  in find_dup_cset_prop()
576 		fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);  in find_dup_cset_prop()
581 		    !of_prop_cmp(ce_1->prop->name, ce_2->prop->name)) {  in find_dup_cset_prop()
583 			       ce_1->np, ce_1->prop->name);  in find_dup_cset_prop()
584 			return -EINVAL;  in find_dup_cset_prop()
592  * changeset_dup_entry_check() - check for duplicate entries
595  * Check changeset @ovcs->cset for multiple {add or delete} node entries for
599  * Return: 0 on success, or -EINVAL if duplicate changeset entry found.
606 	list_for_each_entry(ce_1, &ovcs->cset.entries, node) {  in changeset_dup_entry_check()
611 	return dup_entry ? -EINVAL : 0;  in changeset_dup_entry_check()
615  * build_changeset() - populate overlay changeset in @ovcs from @ovcs->fragments
618  * Create changeset @ovcs->cset to contain the nodes and properties of the
619  * overlay device tree fragments in @ovcs->fragments[].  If an error occurs,
621  * in @ovcs->cset.
623  * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
624  * invalid overlay in @ovcs->fragments[].
633 	 * if there is a symbols fragment in ovcs->fragments[i] it is  in build_changeset()
636 	if (ovcs->symbols_fragment)  in build_changeset()
637 		fragments_count = ovcs->count - 1;  in build_changeset()
639 		fragments_count = ovcs->count;  in build_changeset()
642 		fragment = &ovcs->fragments[i];  in build_changeset()
644 		target.np = fragment->target;  in build_changeset()
647 						 fragment->overlay);  in build_changeset()
650 				 fragment->target);  in build_changeset()
655 	if (ovcs->symbols_fragment) {  in build_changeset()
656 		fragment = &ovcs->fragments[ovcs->count - 1];  in build_changeset()
658 		target.np = fragment->target;  in build_changeset()
661 						   fragment->overlay);  in build_changeset()
664 				 fragment->target);  in build_changeset()
677  * 2) "target-path" property containing the path of the target
697 	ret = of_property_read_string(info_node, "target-path", &path);  in find_target()
725  * init_overlay_changeset() - initialize overlay changeset from overlay tree
729  * Initialize @ovcs.  Populate @ovcs->fragments with node information from
734  * Return: 0 on success, -ENOMEM if memory allocation failure, -EINVAL if error
754 	 * Warn for some issues.  Can not return -EINVAL for these until  in init_overlay_changeset()
757 	if (!of_node_check_flag(ovcs->overlay_root, OF_DYNAMIC))  in init_overlay_changeset()
758 		pr_debug("%s() ovcs->overlay_root is not dynamic\n", __func__);  in init_overlay_changeset()
760 	if (!of_node_check_flag(ovcs->overlay_root, OF_DETACHED))  in init_overlay_changeset()
761 		pr_debug("%s() ovcs->overlay_root is not detached\n", __func__);  in init_overlay_changeset()
763 	if (!of_node_is_root(ovcs->overlay_root))  in init_overlay_changeset()
764 		pr_debug("%s() ovcs->overlay_root is not root\n", __func__);  in init_overlay_changeset()
769 	for_each_child_of_node(ovcs->overlay_root, node) {  in init_overlay_changeset()
777 	node = of_get_child_by_name(ovcs->overlay_root, "__symbols__");  in init_overlay_changeset()
785 		ret = -ENOMEM;  in init_overlay_changeset()
788 	ovcs->fragments = fragments;  in init_overlay_changeset()
791 	for_each_child_of_node(ovcs->overlay_root, node) {  in init_overlay_changeset()
797 		fragment->overlay = overlay_node;  in init_overlay_changeset()
798 		fragment->target = find_target(node, target_base);  in init_overlay_changeset()
799 		if (!fragment->target) {  in init_overlay_changeset()
800 			of_node_put(fragment->overlay);  in init_overlay_changeset()
801 			ret = -EINVAL;  in init_overlay_changeset()
810 	 * if there is a symbols fragment in ovcs->fragments[i] it is  in init_overlay_changeset()
813 	node = of_get_child_by_name(ovcs->overlay_root, "__symbols__");  in init_overlay_changeset()
815 		ovcs->symbols_fragment = 1;  in init_overlay_changeset()
817 		fragment->overlay = node;  in init_overlay_changeset()
818 		fragment->target = of_find_node_by_path("/__symbols__");  in init_overlay_changeset()
820 		if (!fragment->target) {  in init_overlay_changeset()
821 			pr_err("symbols in overlay, but not in live tree\n");  in init_overlay_changeset()
822 			ret = -EINVAL;  in init_overlay_changeset()
832 		ret = -EINVAL;  in init_overlay_changeset()
836 	ovcs->count = cnt;  in init_overlay_changeset()
850 	if (ovcs->cset.entries.next)  in free_overlay_changeset()
851 		of_changeset_destroy(&ovcs->cset);  in free_overlay_changeset()
853 	if (ovcs->id) {  in free_overlay_changeset()
854 		idr_remove(&ovcs_idr, ovcs->id);  in free_overlay_changeset()
855 		list_del(&ovcs->ovcs_list);  in free_overlay_changeset()
856 		ovcs->id = 0;  in free_overlay_changeset()
860 	for (i = 0; i < ovcs->count; i++) {  in free_overlay_changeset()
861 		of_node_put(ovcs->fragments[i].target);  in free_overlay_changeset()
862 		of_node_put(ovcs->fragments[i].overlay);  in free_overlay_changeset()
864 	kfree(ovcs->fragments);  in free_overlay_changeset()
867 	 * There should be no live pointers into ovcs->overlay_mem and  in free_overlay_changeset()
868 	 * ovcs->new_fdt due to the policy that overlay notifiers are not  in free_overlay_changeset()
876 	if (ovcs->notify_state == OF_OVERLAY_INIT ||  in free_overlay_changeset()
877 	    ovcs->notify_state == OF_OVERLAY_POST_REMOVE) {  in free_overlay_changeset()
878 		kfree(ovcs->overlay_mem);  in free_overlay_changeset()
879 		kfree(ovcs->new_fdt);  in free_overlay_changeset()
887  * of_overlay_apply() - Create and apply an overlay changeset
893  * If an error is returned by an overlay changeset pre-apply notifier
894  * then no further overlay changeset pre-apply notifier will be called.
896  * If an error is returned by an overlay changeset post-apply notifier
897  * then no further overlay changeset post-apply notifier will be called.
918 	ret = of_resolve_phandles(ovcs->overlay_root);  in of_overlay_apply()
935 	ret = __of_changeset_apply_entries(&ovcs->cset, &ret_revert);  in of_overlay_apply()
945 	ret = __of_changeset_apply_notify(&ovcs->cset);  in of_overlay_apply()
962  * of_overlay_fdt_apply() - Create and apply an overlay changeset
995 		return -EBUSY;  in of_overlay_fdt_apply()
1001 		return -EINVAL;  in of_overlay_fdt_apply()
1006 		return -EINVAL;  in of_overlay_fdt_apply()
1010 		return -ENOMEM;  in of_overlay_fdt_apply()
1016 	 * ovcs->notify_state must be set to OF_OVERLAY_INIT before allocating  in of_overlay_fdt_apply()
1020 	ovcs->id = idr_alloc(&ovcs_idr, ovcs, 1, 0, GFP_KERNEL);  in of_overlay_fdt_apply()
1021 	if (ovcs->id <= 0) {  in of_overlay_fdt_apply()
1022 		ret = ovcs->id;  in of_overlay_fdt_apply()
1026 	INIT_LIST_HEAD(&ovcs->ovcs_list);  in of_overlay_fdt_apply()
1027 	list_add_tail(&ovcs->ovcs_list, &ovcs_list);  in of_overlay_fdt_apply()
1028 	of_changeset_init(&ovcs->cset);  in of_overlay_fdt_apply()
1036 		ret = -ENOMEM;  in of_overlay_fdt_apply()
1039 	ovcs->new_fdt = new_fdt;  in of_overlay_fdt_apply()
1045 					    &ovcs->overlay_root);  in of_overlay_fdt_apply()
1048 		ret = -EINVAL;  in of_overlay_fdt_apply()
1051 	ovcs->overlay_mem = overlay_mem;  in of_overlay_fdt_apply()
1060 	*ret_ovcs_id = ovcs->id;  in of_overlay_fdt_apply()
1107 		list_for_each_entry(ce, &ovcs->cset.entries, node) {  in node_overlaps_later_cs()
1108 			if (find_node(ce->np, remove_ce_node)) {  in node_overlaps_later_cs()
1110 					__func__, remove_ovcs->id, ovcs->id,  in node_overlaps_later_cs()
1114 			if (find_node(remove_ce_node, ce->np)) {  in node_overlaps_later_cs()
1116 					__func__, remove_ovcs->id, ovcs->id,  in node_overlaps_later_cs()
1127  * We can safely remove the overlay only if it's the top-most one.
1140 	list_for_each_entry(remove_ce, &remove_ovcs->cset.entries, node) {  in overlay_removal_is_ok()
1141 		if (node_overlaps_later_cs(remove_ovcs, remove_ce->np)) {  in overlay_removal_is_ok()
1142 			pr_err("overlay #%d is not topmost\n", remove_ovcs->id);  in overlay_removal_is_ok()
1151  * of_overlay_remove() - Revert and free an overlay changeset
1158  * then an attempt is made to re-apply any changeset entry that was
1159  * reverted.  If an error occurs on re-apply then the state of the device
1163  * A non-zero return value will not revert the changeset if error is from:
1164  *   - parameter checks
1165  *   - overlay changeset pre-remove notifier
1166  *   - overlay changeset entry revert
1168  * If an error is returned by an overlay changeset pre-remove notifier
1169  * then no further overlay changeset pre-remove notifier will be called.
1174  * A non-zero return value will revert the changeset if error is from:
1175  *   - overlay changeset entry notifier
1176  *   - overlay changeset post-remove notifier
1178  * If an error is returned by an overlay changeset post-remove notifier
1179  * then no further overlay changeset post-remove notifier will be called.
1191 		ret = -EBUSY;  in of_overlay_remove()
1199 		ret = -ENODEV;  in of_overlay_remove()
1205 		ret = -EBUSY;  in of_overlay_remove()
1214 	ret = __of_changeset_revert_entries(&ovcs->cset, &ret_apply);  in of_overlay_remove()
1221 	ret = __of_changeset_revert_notify(&ovcs->cset);  in of_overlay_remove()
1256  * of_overlay_remove_all() - Reverts and frees all overlay changesets
1269 		ret = of_overlay_remove(&ovcs->id);  in of_overlay_remove_all()