1 // SPDX-License-Identifier: GPL-2.0
3  * Functions for working with the Flattened Device Tree data format
37  * of_fdt_limit_memory - limit the number of regions in the /memory node
40  * Adjust the flattened device tree to have at most 'limit' number of
61 				"#address-cells", NULL);  in of_fdt_limit_memory()
66 				"#size-cells", NULL);  in of_fdt_limit_memory()
120 	pprev = &np->properties;  in populate_properties()
147 		/* We accept flattened tree phandles either in  in populate_properties()
148 		 * ePAPR-style "phandle" properties, or the  in populate_properties()
155 			if (!np->phandle)  in populate_properties()
156 				np->phandle = be32_to_cpup(val);  in populate_properties()
160 		 * used in pSeries dynamic device tree  in populate_properties()
164 			np->phandle = be32_to_cpup(val);  in populate_properties()
166 		pp->name   = (char *)pname;  in populate_properties()
167 		pp->length = sz;  in populate_properties()
168 		pp->value  = (__be32 *)val;  in populate_properties()
170 		pprev      = &pp->next;  in populate_properties()
190 		len = (pa - ps) + 1;  in populate_properties()
194 			pp->name   = "name";  in populate_properties()
195 			pp->length = len;  in populate_properties()
196 			pp->value  = pp + 1;  in populate_properties()
198 			memcpy(pp->value, ps, len - 1);  in populate_properties()
199 			((char *)pp->value)[len - 1] = 0;  in populate_properties()
200 			pr_debug("fixed up name for %s -> %s\n",  in populate_properties()
201 				 nodename, (char *)pp->value);  in populate_properties()
230 		np->full_name = fn = ((char *)np) + sizeof(*np);  in populate_node()
235 			np->parent = dad;  in populate_node()
236 			np->sibling = dad->child;  in populate_node()
237 			dad->child = np;  in populate_node()
243 		np->name = of_get_property(np, "name", NULL);  in populate_node()
244 		if (!np->name)  in populate_node()
245 			np->name = "<NULL>";  in populate_node()
256 	/* In-depth first */  in reverse_nodes()
257 	child = parent->child;  in reverse_nodes()
261 		child = child->sibling;  in reverse_nodes()
265 	child = parent->child;  in reverse_nodes()
266 	parent->child = NULL;  in reverse_nodes()
268 		next = child->sibling;  in reverse_nodes()
270 		child->sibling = parent->child;  in reverse_nodes()
271 		parent->child = child;  in reverse_nodes()
277  * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
278  * @blob: The parent device tree blob
279  * @mem: Memory chunk to use for allocating device nodes and properties
281  * @nodepp: The device_node tree created by the call
283  * Return: The size of unflattened device tree or error code
302 	 * We're unflattening device sub-tree if @dad is valid. There are  in unflatten_dt_nodes()
305 	 * immediately when negative @depth is found. Otherwise, the device  in unflatten_dt_nodes()
317 		if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH - 1))  in unflatten_dt_nodes()
335 	if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {  in unflatten_dt_nodes()
337 		return -EINVAL;  in unflatten_dt_nodes()
347 	return mem - base;  in unflatten_dt_nodes()
351  * __unflatten_device_tree - create tree of device_nodes from flat blob
353  * @dad: Parent device node
354  * @mynodes: The device_node tree created by the call
356  * for the resulting tree
359  * unflattens a device-tree, creating the tree of struct device_node. It also
360  * fills the "name" and "type" pointers of the nodes so the normal device-tree
364  * device tree on success.
379 	pr_debug(" -> unflatten_device_tree()\n");  in __unflatten_device_tree()
382 		pr_debug("No device tree pointer\n");  in __unflatten_device_tree()
386 	pr_debug("Unflattening device tree:\n");  in __unflatten_device_tree()
392 		pr_err("Invalid device tree blob header\n");  in __unflatten_device_tree()
404 	/* Allocate memory for the expanded device tree */  in __unflatten_device_tree()
419 		pr_warn("End of tree marker overwritten: %08x\n",  in __unflatten_device_tree()
427 		pr_debug("unflattened tree is detached\n");  in __unflatten_device_tree()
430 	pr_debug(" <- unflatten_device_tree()\n");  in __unflatten_device_tree()
442  * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
443  * @blob: Flat device tree blob
444  * @dad: Parent device node
445  * @mynodes: The device tree created by the call
447  * unflattens the device-tree passed by the firmware, creating the
448  * tree of struct device_node. It also fills the "name" and "type"
449  * pointers of the nodes so the normal device-tree walking functions
453  * device tree on success.
491 			return -EBUSY;  in early_init_dt_reserve_memory()
499  * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property
513 		return -ENOENT;  in __reserved_mem_reserve_reg()
518 		return -EINVAL;  in __reserved_mem_reserve_reg()
521 	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;  in __reserved_mem_reserve_reg()
538 		len -= t_len;  in __reserved_mem_reserve_reg()
548  * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
549  * in /reserved-memory matches the values supported by the current implementation,
556 	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);  in __reserved_mem_check_root()
558 		return -EINVAL;  in __reserved_mem_check_root()
560 	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);  in __reserved_mem_check_root()
562 		return -EINVAL;  in __reserved_mem_check_root()
566 		return -EINVAL;  in __reserved_mem_check_root()
571  * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
578 	node = fdt_path_offset(fdt, "/reserved-memory");  in fdt_scan_reserved_mem()
580 		return -ENODEV;  in fdt_scan_reserved_mem()
584 		return -EINVAL;  in fdt_scan_reserved_mem()
597 		if (err == -ENOENT && of_get_flat_dt_prop(child, "size", NULL))  in fdt_scan_reserved_mem()
604  * fdt_reserve_elfcorehdr() - reserves memory for elf core header
607  * described in the device tree. This region contains all the
628  * early_init_fdt_scan_reserved_mem() - create reserved memory regions
630  * This function grabs memory from early allocator for device exclusive use
631  * defined in device tree structures. It should be called by arch specific code
656  * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
669  * of_scan_flat_dt - scan flattened tree blob and call callback on each.
673  * This function is used to scan the flattened device-tree, it is
675  * unflatten the tree
684 	int offset, rc = 0, depth = -1;  in of_scan_flat_dt()
689 	for (offset = fdt_next_node(blob, -1, &depth);  in of_scan_flat_dt()
700  * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
705  * This function is used to scan sub-nodes of a node.
729  * of_get_flat_dt_subnode_by_name - get the subnode by given name
733  * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
742  * of_get_flat_dt_root - find the root node in the flat blob
750  * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
762  * of_fdt_is_compatible - Return true if given node from the given blob has
764  * @blob: A device tree blob
768  * Return: a non-zero value on match with smaller values returned for more
787 		cplen -= l;  in of_fdt_is_compatible()
794  * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
804  * of_flat_dt_match - Return true if node matches a list of compatible values
824  * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle
843  * of_flat_dt_match_machine - Iterate match tables to find matching machine.
872 		pr_err("\n unrecognized device tree list:\n[ ");  in of_flat_dt_match_machine()
878 				size -= strlen(prop) + 1;  in of_flat_dt_match_machine()
907  * early_init_dt_check_for_initrd - Decode initrd location from flat tree
921 	prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);  in early_init_dt_check_for_initrd()
926 	prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);  in early_init_dt_check_for_initrd()
935 	phys_initrd_size = end - start;  in early_init_dt_check_for_initrd()
941  * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat
942  * tree
966 static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
969  * The main usage of linux,usable-memory-range is for crash dump kernel.
970  * Originally, the number of usable-memory regions is one. Now there may
972  * To make compatibility with existing user-space and older kdump, the low
973  * region is always the last range of linux,usable-memory-range if exist.
978  * early_init_dt_check_for_usable_mem_range - Decode usable memory range
979  * location from flat tree
991 	pr_debug("Looking for usable-memory-range property... ");  in early_init_dt_check_for_usable_mem_range()
993 	prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len);  in early_init_dt_check_for_usable_mem_range()
1026 		return -ENOENT;  in early_init_dt_scan_chosen_stdout()
1028 	p = fdt_getprop(fdt, offset, "stdout-path", &l);  in early_init_dt_scan_chosen_stdout()
1030 		p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);  in early_init_dt_scan_chosen_stdout()
1032 		return -ENOENT;  in early_init_dt_scan_chosen_stdout()
1037 	l = q - p;  in early_init_dt_scan_chosen_stdout()
1039 	/* Get the node specified by stdout-path */  in early_init_dt_scan_chosen_stdout()
1042 		pr_warn("earlycon: stdout-path %.*s not found\n", l, p);  in early_init_dt_scan_chosen_stdout()
1047 		if (!match->compatible[0])  in early_init_dt_scan_chosen_stdout()
1050 		if (fdt_node_check_compatible(fdt, offset, match->compatible))  in early_init_dt_scan_chosen_stdout()
1054 		if (!ret || ret == -EALREADY)  in early_init_dt_scan_chosen_stdout()
1057 	return -ENODEV;  in early_init_dt_scan_chosen_stdout()
1062  * early_init_dt_scan_root - fetch the top level address and size cells
1071 		return -ENODEV;  in early_init_dt_scan_root()
1076 	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);  in early_init_dt_scan_root()
1081 	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);  in early_init_dt_scan_root()
1098  * early_init_dt_scan_memory - Look for and parse memory nodes
1118 		reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);  in early_init_dt_scan_memory()
1130 		while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {  in early_init_dt_scan_memory()
1138 			pr_debug(" - %llx, %llx\n", base, size);  in early_init_dt_scan_memory()
1146 				pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",  in early_init_dt_scan_memory()
1164 		return -ENOENT;  in early_init_dt_scan_chosen()
1196 	rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);  in early_init_dt_scan_chosen()
1201 		fdt_nop_property(initial_boot_params, node, "rng-seed");  in early_init_dt_scan_chosen()
1222 	if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {  in early_init_dt_add_memory_arch()
1223 		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",  in early_init_dt_add_memory_arch()
1229 		size -= PAGE_SIZE - (base & ~PAGE_MASK);  in early_init_dt_add_memory_arch()
1235 		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",  in early_init_dt_add_memory_arch()
1240 	if (base + size - 1 > MAX_MEMBLOCK_ADDR) {  in early_init_dt_add_memory_arch()
1241 		pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",  in early_init_dt_add_memory_arch()
1243 		size = MAX_MEMBLOCK_ADDR - base + 1;  in early_init_dt_add_memory_arch()
1247 		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",  in early_init_dt_add_memory_arch()
1252 		pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",  in early_init_dt_add_memory_arch()
1254 		size -= phys_offset - base;  in early_init_dt_add_memory_arch()
1276 	/* check device tree validity */  in early_init_dt_verify()
1280 	/* Setup flat device-tree pointer */  in early_init_dt_verify()
1292 	/* Initialize {size,address}-cells info */  in early_init_dt_scan_nodes()
1303 	/* Handle linux,usable-memory-range property */  in early_init_dt_scan_nodes()
1320  * unflatten_device_tree - create tree of device_nodes from flat blob
1322  * unflattens the device-tree passed by the firmware, creating the
1323  * tree of struct device_node. It also fills the "name" and "type"
1324  * pointers of the nodes so the normal device-tree walking functions
1339  * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1341  * Copies and unflattens the device-tree passed by the firmware, creating the
1342  * tree of struct device_node. It also fills the "name" and "type"
1343  * pointers of the nodes so the normal device-tree walking functions
1345  * reserved such is the case when the FDT is built-in to the kernel init
1355 		pr_warn("No valid device tree found, continuing without\n");  in unflatten_and_copy_device_tree()