1 // SPDX-License-Identifier: GPL-2.0
3  * Functions for working with the Flattened Device Tree data format
42  * of_fdt_limit_memory - limit the number of regions in the /memory node
45  * Adjust the flattened device tree to have at most 'limit' number of
104 	pprev = &np->properties;  in populate_properties()
131 		/* We accept flattened tree phandles either in  in populate_properties()
132 		 * ePAPR-style "phandle" properties, or the  in populate_properties()
139 			if (!np->phandle)  in populate_properties()
140 				np->phandle = be32_to_cpup(val);  in populate_properties()
144 		 * used in pSeries dynamic device tree  in populate_properties()
148 			np->phandle = be32_to_cpup(val);  in populate_properties()
150 		pp->name   = (char *)pname;  in populate_properties()
151 		pp->length = sz;  in populate_properties()
152 		pp->value  = (__be32 *)val;  in populate_properties()
154 		pprev      = &pp->next;  in populate_properties()
174 		len = (pa - ps) + 1;  in populate_properties()
178 			pp->name   = "name";  in populate_properties()
179 			pp->length = len;  in populate_properties()
180 			pp->value  = pp + 1;  in populate_properties()
182 			memcpy(pp->value, ps, len - 1);  in populate_properties()
183 			((char *)pp->value)[len - 1] = 0;  in populate_properties()
184 			pr_debug("fixed up name for %s -> %s\n",  in populate_properties()
185 				 nodename, (char *)pp->value);  in populate_properties()
214 		np->full_name = fn = ((char *)np) + sizeof(*np);  in populate_node()
219 			np->parent = dad;  in populate_node()
220 			np->sibling = dad->child;  in populate_node()
221 			dad->child = np;  in populate_node()
227 		np->name = of_get_property(np, "name", NULL);  in populate_node()
228 		if (!np->name)  in populate_node()
229 			np->name = "<NULL>";  in populate_node()
240 	/* In-depth first */  in reverse_nodes()
241 	child = parent->child;  in reverse_nodes()
245 		child = child->sibling;  in reverse_nodes()
249 	child = parent->child;  in reverse_nodes()
250 	parent->child = NULL;  in reverse_nodes()
252 		next = child->sibling;  in reverse_nodes()
254 		child->sibling = parent->child;  in reverse_nodes()
255 		parent->child = child;  in reverse_nodes()
261  * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
262  * @blob: The parent device tree blob
263  * @mem: Memory chunk to use for allocating device nodes and properties
265  * @nodepp: The device_node tree created by the call
267  * Return: The size of unflattened device tree or error code
286 	 * We're unflattening device sub-tree if @dad is valid. There are  in unflatten_dt_nodes()
289 	 * immediately when negative @depth is found. Otherwise, the device  in unflatten_dt_nodes()
301 		if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH - 1))  in unflatten_dt_nodes()
319 	if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {  in unflatten_dt_nodes()
321 		return -EINVAL;  in unflatten_dt_nodes()
331 	return mem - base;  in unflatten_dt_nodes()
335  * __unflatten_device_tree - create tree of device_nodes from flat blob
337  * @dad: Parent device node
338  * @mynodes: The device_node tree created by the call
340  * for the resulting tree
343  * unflattens a device-tree, creating the tree of struct device_node. It also
344  * fills the "name" and "type" pointers of the nodes so the normal device-tree
348  * device tree on success.
363 	pr_debug(" -> unflatten_device_tree()\n");  in __unflatten_device_tree()
366 		pr_debug("No device tree pointer\n");  in __unflatten_device_tree()
370 	pr_debug("Unflattening device tree:\n");  in __unflatten_device_tree()
376 		pr_err("Invalid device tree blob header\n");  in __unflatten_device_tree()
388 	/* Allocate memory for the expanded device tree */  in __unflatten_device_tree()
403 		pr_warn("End of tree marker overwritten: %08x\n",  in __unflatten_device_tree()
411 		pr_debug("unflattened tree is detached\n");  in __unflatten_device_tree()
414 	pr_debug(" <- unflatten_device_tree()\n");  in __unflatten_device_tree()
426  * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
427  * @blob: Flat device tree blob
428  * @dad: Parent device node
429  * @mynodes: The device tree created by the call
431  * unflattens the device-tree passed by the firmware, creating the
432  * tree of struct device_node. It also fills the "name" and "type"
433  * pointers of the nodes so the normal device-tree walking functions
437  * device tree on success.
466  * fdt_reserve_elfcorehdr() - reserves memory for elf core header
469  * described in the device tree. This region contains all the
490  * early_init_fdt_scan_reserved_mem() - create reserved memory regions
492  * This function grabs memory from early allocator for device exclusive use
493  * defined in device tree structures. It should be called by arch specific code
522  * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
535  * of_scan_flat_dt - scan flattened tree blob and call callback on each.
539  * This function is used to scan the flattened device-tree, it is
541  * unflatten the tree
550 	int offset, rc = 0, depth = -1;  in of_scan_flat_dt()
555 	for (offset = fdt_next_node(blob, -1, &depth);  in of_scan_flat_dt()
566  * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
571  * This function is used to scan sub-nodes of a node.
595  * of_get_flat_dt_subnode_by_name - get the subnode by given name
599  * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
608  * of_get_flat_dt_root - find the root node in the flat blob
616  * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
628  * of_fdt_is_compatible - Return true if given node from the given blob has
630  * @blob: A device tree blob
634  * Return: a non-zero value on match with smaller values returned for more
653 		cplen -= l;  in of_fdt_is_compatible()
660  * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
670  * of_flat_dt_match - Return true if node matches a list of compatible values
690  * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle
709  * of_flat_dt_match_machine - Iterate match tables to find matching machine.
738 		pr_err("\n unrecognized device tree list:\n[ ");  in of_flat_dt_match_machine()
744 				size -= strlen(prop) + 1;  in of_flat_dt_match_machine()
774  * early_init_dt_check_for_initrd - Decode initrd location from flat tree
788 	prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);  in early_init_dt_check_for_initrd()
793 	prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);  in early_init_dt_check_for_initrd()
802 	phys_initrd_size = end - start;  in early_init_dt_check_for_initrd()
808  * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat
809  * tree
833 static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
836  * The main usage of linux,usable-memory-range is for crash dump kernel.
837  * Originally, the number of usable-memory regions is one. Now there may
839  * To make compatibility with existing user-space and older kdump, the low
840  * region is always the last range of linux,usable-memory-range if exist.
845  * early_init_dt_check_for_usable_mem_range - Decode usable memory range
846  * location from flat tree
858 	pr_debug("Looking for usable-memory-range property... ");  in early_init_dt_check_for_usable_mem_range()
860 	prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len);  in early_init_dt_check_for_usable_mem_range()
893 		return -ENOENT;  in early_init_dt_scan_chosen_stdout()
895 	p = fdt_getprop(fdt, offset, "stdout-path", &l);  in early_init_dt_scan_chosen_stdout()
897 		p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);  in early_init_dt_scan_chosen_stdout()
899 		return -ENOENT;  in early_init_dt_scan_chosen_stdout()
904 	l = q - p;  in early_init_dt_scan_chosen_stdout()
906 	/* Get the node specified by stdout-path */  in early_init_dt_scan_chosen_stdout()
909 		pr_warn("earlycon: stdout-path %.*s not found\n", l, p);  in early_init_dt_scan_chosen_stdout()
914 		if (!match->compatible[0])  in early_init_dt_scan_chosen_stdout()
917 		if (fdt_node_check_compatible(fdt, offset, match->compatible))  in early_init_dt_scan_chosen_stdout()
921 		if (!ret || ret == -EALREADY)  in early_init_dt_scan_chosen_stdout()
924 	return -ENODEV;  in early_init_dt_scan_chosen_stdout()
929  * early_init_dt_scan_root - fetch the top level address and size cells
938 		return -ENODEV;  in early_init_dt_scan_root()
943 	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);  in early_init_dt_scan_root()
944 	if (!WARN(!prop, "No '#size-cells' in root node\n"))  in early_init_dt_scan_root()
948 	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);  in early_init_dt_scan_root()
949 	if (!WARN(!prop, "No '#address-cells' in root node\n"))  in early_init_dt_scan_root()
965  * early_init_dt_scan_memory - Look for and parse memory nodes
985 		reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);  in early_init_dt_scan_memory()
997 		while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {  in early_init_dt_scan_memory()
1005 			pr_debug(" - %llx, %llx\n", base, size);  in early_init_dt_scan_memory()
1015 				pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",  in early_init_dt_scan_memory()
1041 	rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);  in early_init_dt_scan_chosen()
1046 		fdt_nop_property(initial_boot_params, node, "rng-seed");  in early_init_dt_scan_chosen()
1093 	if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {  in early_init_dt_add_memory_arch()
1094 		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",  in early_init_dt_add_memory_arch()
1100 		size -= PAGE_SIZE - (base & ~PAGE_MASK);  in early_init_dt_add_memory_arch()
1106 		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",  in early_init_dt_add_memory_arch()
1111 	if (base + size - 1 > MAX_MEMBLOCK_ADDR) {  in early_init_dt_add_memory_arch()
1112 		pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",  in early_init_dt_add_memory_arch()
1114 		size = MAX_MEMBLOCK_ADDR - base + 1;  in early_init_dt_add_memory_arch()
1118 		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",  in early_init_dt_add_memory_arch()
1123 		pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",  in early_init_dt_add_memory_arch()
1125 		size -= phys_offset - base;  in early_init_dt_add_memory_arch()
1141 	/* check device tree validity */  in early_init_dt_verify()
1145 	/* Setup flat device-tree pointer */  in early_init_dt_verify()
1151 	/* Initialize {size,address}-cells info */  in early_init_dt_verify()
1170 	/* Handle linux,usable-memory-range property */  in early_init_dt_scan_nodes()
1202  * unflatten_device_tree - create tree of device_nodes from flat blob
1204  * unflattens the device-tree passed by the firmware, creating the
1205  * tree of struct device_node. It also fills the "name" and "type"
1206  * pointers of the nodes so the normal device-tree walking functions
1213 	/* Save the statically-placed regions in the reserved_mem array */  in unflatten_device_tree()
1221 		    __dtb_empty_root_end - __dtb_empty_root_begin) {  in unflatten_device_tree()
1239  * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1241  * Copies and unflattens the device-tree passed by the firmware, creating the
1242  * tree of struct device_node. It also fills the "name" and "type"
1243  * pointers of the nodes so the normal device-tree walking functions
1245  * reserved such is the case when the FDT is built-in to the kernel init