1 // SPDX-License-Identifier: GPL-2.0
19  * Extra Boot Config (XBC) is given as tree-structured ascii text of
20  * key-value pairs on memory.
21  * xbc_parse() parses the text to build a simple tree. Each tree node is
22  * simply a key word or a value. A key node may have a next key node or/and
23  * a child node (both key and value). A value node may have a next value
24  * node (for array).
40 	xbc_err_pos = (int)(p - xbc_data);  in xbc_parse_error()
42 	return -EINVAL;  in xbc_parse_error()
46  * xbc_root_node() - Get the root node of extended boot config
48  * Return the address of root node of extended boot config. If the
60  * xbc_node_index() - Get the index of XBC node
61  * @node: A target node of getting index.
63  * Return the index number of @node in XBC node list.
65 int __init xbc_node_index(struct xbc_node *node)  in xbc_node_index()  argument
67 	return node - &xbc_nodes[0];  in xbc_node_index()
71  * xbc_node_get_parent() - Get the parent XBC node
72  * @node: An XBC node.
74  * Return the parent node of @node. If the node is top node of the tree,
77 struct xbc_node * __init xbc_node_get_parent(struct xbc_node *node)  in xbc_node_get_parent()  argument
79 	return node->parent == XBC_NODE_MAX ? NULL : &xbc_nodes[node->parent];  in xbc_node_get_parent()
83  * xbc_node_get_child() - Get the child XBC node
84  * @node: An XBC node.
86  * Return the first child node of @node. If the node has no child, return
89 struct xbc_node * __init xbc_node_get_child(struct xbc_node *node)  in xbc_node_get_child()  argument
91 	return node->child ? &xbc_nodes[node->child] : NULL;  in xbc_node_get_child()
95  * xbc_node_get_next() - Get the next sibling XBC node
96  * @node: An XBC node.
98  * Return the NEXT sibling node of @node. If the node has no next sibling,
99  * return NULL. Note that even if this returns NULL, it doesn't mean @node
100  * has no siblings. (You also has to check whether the parent's child node
101  * is @node or not.)
103 struct xbc_node * __init xbc_node_get_next(struct xbc_node *node)  in xbc_node_get_next()  argument
105 	return node->next ? &xbc_nodes[node->next] : NULL;  in xbc_node_get_next()
109  * xbc_node_get_data() - Get the data of XBC node
110  * @node: An XBC node.
112  * Return the data (which is always a null terminated string) of @node.
113  * If the node has invalid data, warn and return NULL.
115 const char * __init xbc_node_get_data(struct xbc_node *node)  in xbc_node_get_data()  argument
117 	int offset = node->data & ~XBC_VALUE;  in xbc_node_get_data()
126 xbc_node_match_prefix(struct xbc_node *node, const char **prefix)  in xbc_node_match_prefix()  argument
128 	const char *p = xbc_node_get_data(node);  in xbc_node_match_prefix()
145  * xbc_node_find_child() - Find a child node which matches given key
146  * @parent: An XBC node.
149  * Search a node under @parent which matches @key. The @key can contain
151  * node from whole tree. Return NULL if no node is matched.
156 	struct xbc_node *node;  in xbc_node_find_child()  local
159 		node = xbc_node_get_child(parent);  in xbc_node_find_child()
161 		node = xbc_root_node();  in xbc_node_find_child()
163 	while (node && xbc_node_is_key(node)) {  in xbc_node_find_child()
164 		if (!xbc_node_match_prefix(node, &key))  in xbc_node_find_child()
165 			node = xbc_node_get_next(node);  in xbc_node_find_child()
167 			node = xbc_node_get_child(node);  in xbc_node_find_child()
172 	return node;  in xbc_node_find_child()
176  * xbc_node_find_value() - Find a value node which matches given key
177  * @parent: An XBC node.
179  * @vnode: A container pointer of found XBC node.
181  * Search a value node under @parent whose (parent) key node matches @key,
184  * this searches the node from whole tree. Return the value string if a
185  * matched key found, return NULL if no node is matched.
186  * Note that this returns 0-length string and stores NULL in *@vnode if the
194 	struct xbc_node *node = xbc_node_find_child(parent, key);  in xbc_node_find_value()  local
196 	if (!node || !xbc_node_is_key(node))  in xbc_node_find_value()
199 	node = xbc_node_get_child(node);  in xbc_node_find_value()
200 	if (node && !xbc_node_is_value(node))  in xbc_node_find_value()
204 		*vnode = node;  in xbc_node_find_value()
206 	return node ? xbc_node_get_data(node) : "";  in xbc_node_find_value()
210  * xbc_node_compose_key_after() - Compose partial key string of the XBC node
211  * @root: Root XBC node
212  * @node: Target XBC node.
216  * Compose the partial key of the @node into @buf, which is starting right
218  * key words of @node.
219  * Returns the total length of the key stored in @buf. Returns -EINVAL
220  * if @node is NULL or @root is not the ancestor of @node or @root is @node,
221  * or returns -ERANGE if the key depth is deeper than max depth.
222  * This is expected to be used with xbc_find_node() to list up all (child)
226 				      struct xbc_node *node,  in xbc_node_compose_key_after()  argument
232 	if (!node || node == root)  in xbc_node_compose_key_after()
233 		return -EINVAL;  in xbc_node_compose_key_after()
235 	if (xbc_node_is_value(node))  in xbc_node_compose_key_after()
236 		node = xbc_node_get_parent(node);  in xbc_node_compose_key_after()
238 	while (node && node != root) {  in xbc_node_compose_key_after()
239 		keys[depth++] = xbc_node_index(node);  in xbc_node_compose_key_after()
241 			return -ERANGE;  in xbc_node_compose_key_after()
242 		node = xbc_node_get_parent(node);  in xbc_node_compose_key_after()
244 	if (!node && root)  in xbc_node_compose_key_after()
245 		return -EINVAL;  in xbc_node_compose_key_after()
247 	while (--depth >= 0) {  in xbc_node_compose_key_after()
248 		node = xbc_nodes + keys[depth];  in xbc_node_compose_key_after()
249 		ret = snprintf(buf, size, "%s%s", xbc_node_get_data(node),  in xbc_node_compose_key_after()
256 			size -= ret;  in xbc_node_compose_key_after()
266  * xbc_node_find_next_leaf() - Find the next leaf node under given node
267  * @root: An XBC root node
268  * @node: An XBC node which starts from.
270  * Search the next leaf node (which means the terminal key node) of @node
271  * under @root node (including @root node itself).
272  * Return the next node or NULL if next leaf node is not found.
275 						 struct xbc_node *node)  in xbc_node_find_next_leaf()  argument
280 	if (!node) {	/* First try */  in xbc_node_find_next_leaf()
281 		node = root;  in xbc_node_find_next_leaf()
282 		if (!node)  in xbc_node_find_next_leaf()
283 			node = xbc_nodes;  in xbc_node_find_next_leaf()
285 		if (node == root)	/* @root was a leaf, no child node. */  in xbc_node_find_next_leaf()
288 		while (!node->next) {  in xbc_node_find_next_leaf()
289 			node = xbc_node_get_parent(node);  in xbc_node_find_next_leaf()
290 			if (node == root)  in xbc_node_find_next_leaf()
292 			/* User passed a node which is not uder parent */  in xbc_node_find_next_leaf()
293 			if (WARN_ON(!node))  in xbc_node_find_next_leaf()
296 		node = xbc_node_get_next(node);  in xbc_node_find_next_leaf()
299 	while (node && !xbc_node_is_leaf(node))  in xbc_node_find_next_leaf()
300 		node = xbc_node_get_child(node);  in xbc_node_find_next_leaf()
302 	return node;  in xbc_node_find_next_leaf()
306  * xbc_node_find_next_key_value() - Find the next key-value pair nodes
307  * @root: An XBC root node
308  * @leaf: A container pointer of XBC node which starts from.
310  * Search the next leaf node (which means the terminal key node) of *@leaf
311  * under @root node. Returns the value and update *@leaf if next leaf node
312  * is found, or NULL if no next leaf node is found.
313  * Note that this returns 0-length string if the key has no value, or
326 	if ((*leaf)->child)  in xbc_node_find_next_key_value()
334 static int __init xbc_init_node(struct xbc_node *node, char *data, u32 flag)  in xbc_init_node()  argument
336 	unsigned long offset = data - xbc_data;  in xbc_init_node()
339 		return -EINVAL;  in xbc_init_node()
341 	node->data = (u16)offset | flag;  in xbc_init_node()
342 	node->child = 0;  in xbc_init_node()
343 	node->next = 0;  in xbc_init_node()
350 	struct xbc_node *node;  in xbc_add_node()  local
355 	node = &xbc_nodes[xbc_node_num++];  in xbc_add_node()
356 	if (xbc_init_node(node, data, flag) < 0)  in xbc_add_node()
359 	return node;  in xbc_add_node()
362 static inline __init struct xbc_node *xbc_last_sibling(struct xbc_node *node)  in xbc_last_sibling()  argument
364 	while (node->next)  in xbc_last_sibling()
365 		node = xbc_node_get_next(node);  in xbc_last_sibling()
367 	return node;  in xbc_last_sibling()
372 	struct xbc_node *sib, *node = xbc_add_node(data, flag);  in xbc_add_sibling()  local
374 	if (node) {  in xbc_add_sibling()
376 			node->parent = XBC_NODE_MAX;  in xbc_add_sibling()
378 			sib->next = xbc_node_index(node);  in xbc_add_sibling()
380 			node->parent = xbc_node_index(last_parent);  in xbc_add_sibling()
381 			if (!last_parent->child) {  in xbc_add_sibling()
382 				last_parent->child = xbc_node_index(node);  in xbc_add_sibling()
386 				sib->next = xbc_node_index(node);  in xbc_add_sibling()
392 	return node;  in xbc_add_sibling()
397 	struct xbc_node *node = xbc_add_sibling(data, flag);  in xbc_add_child()  local
399 	if (node)  in xbc_add_child()
400 		last_parent = node;  in xbc_add_child()
402 	return node;  in xbc_add_child()
410 	while (isalnum(*key) || *key == '-' || *key == '_')  in xbc_valid_keyword()
448 	brace_index--;  in __xbc_close_brace()
456 		last_parent = &xbc_nodes[open_brace[brace_index - 1]];  in __xbc_close_brace()
462  * Return delimiter or error, no node added. As same as lib/cmdline.c,
479 	p = v - 1;  in __xbc_parse_value()
516 	struct xbc_node *node;  in xbc_parse_array()  local
525 		node = xbc_add_sibling(*__v, XBC_VALUE);  in xbc_parse_array()
526 		if (!node)  in xbc_parse_array()
527 			return -ENOMEM;  in xbc_parse_array()
530 	node->next = 0;  in xbc_parse_array()
536 struct xbc_node *find_match_node(struct xbc_node *node, char *k)  in find_match_node()  argument
538 	while (node) {  in find_match_node()
539 		if (!strcmp(xbc_node_get_data(node), k))  in find_match_node()
541 		node = xbc_node_get_next(node);  in find_match_node()
543 	return node;  in find_match_node()
548 	struct xbc_node *node, *child;  in __xbc_add_key()  local
557 		node = find_match_node(xbc_nodes, k);  in __xbc_add_key()
559 		child = xbc_node_get_child(last_parent);  in __xbc_add_key()
560 		if (child && xbc_node_is_value(child))  in __xbc_add_key()
562 		node = find_match_node(child, k);  in __xbc_add_key()
565 	if (node)  in __xbc_add_key()
566 		last_parent = node;  in __xbc_add_key()
569 		node = xbc_add_child(k, XBC_KEY);  in __xbc_add_key()
570 		if (!node)  in __xbc_add_key()
571 			return -ENOMEM;  in __xbc_add_key()
596 	struct xbc_node *child;  in xbc_parse_kv()  local
604 	child = xbc_node_get_child(last_parent);  in xbc_parse_kv()
605 	if (child) {  in xbc_parse_kv()
606 		if (xbc_node_is_key(child))  in xbc_parse_kv()
616 	if (op == ':' && child) {  in xbc_parse_kv()
617 		xbc_init_node(child, v, XBC_VALUE);  in xbc_parse_kv()
619 		return -ENOMEM;  in xbc_parse_kv()
630 		ret = __xbc_close_brace(next - 1);  in xbc_parse_kv()
666 	return __xbc_open_brace(n - 1);  in xbc_open_brace()
678 	return __xbc_close_brace(n - 1);  in xbc_close_brace()
696 		return -ENOENT;  in xbc_verify_tree()
727 		len -= wlen;  in xbc_verify_tree()
733 			len -= strlen(xbc_node_get_data(n)) + 1;  in xbc_verify_tree()
734 			depth--;  in xbc_verify_tree()
744  * xbc_destroy_all() - Clean up all parsed bootconfig
761  * xbc_init() - Parse given XBC file and build XBC internal tree
768  * Return the number of stored nodes (>0) if succeeded, or -errno
772  * of @buf. If the error is not a parser error, @epos will be -1.
780 		*epos = -1;  in xbc_init()
785 		return -EBUSY;  in xbc_init()
789 	if (ret > XBC_DATA_MAX - 1 || ret == 0) {  in xbc_init()
793 		return -ERANGE;  in xbc_init()
801 		return -ENOMEM;  in xbc_init()
827 							q - 2);  in xbc_init()
866  * xbc_debug_dump() - Dump current XBC node list
868  * Dump the current XBC node list on printk buffer for debug.
875 		pr_debug("[%d] %s (%s) .next=%d, .child=%d .parent=%d\n", i,  in xbc_debug_dump()
878 			xbc_nodes[i].next, xbc_nodes[i].child,  in xbc_debug_dump()