1 // SPDX-License-Identifier: GPL-2.0
3  * Functions for working with the Flattened Device Tree data format
36  * of_fdt_limit_memory - limit the number of regions in the /memory node
39  * Adjust the flattened device tree to have at most 'limit' number of
60 				"#address-cells", NULL);  in of_fdt_limit_memory()
65 				"#size-cells", NULL);  in of_fdt_limit_memory()
119 	pprev = &np->properties;  in populate_properties()
146 		/* We accept flattened tree phandles either in  in populate_properties()
147 		 * ePAPR-style "phandle" properties, or the  in populate_properties()
154 			if (!np->phandle)  in populate_properties()
155 				np->phandle = be32_to_cpup(val);  in populate_properties()
159 		 * used in pSeries dynamic device tree  in populate_properties()
163 			np->phandle = be32_to_cpup(val);  in populate_properties()
165 		pp->name   = (char *)pname;  in populate_properties()
166 		pp->length = sz;  in populate_properties()
167 		pp->value  = (__be32 *)val;  in populate_properties()
169 		pprev      = &pp->next;  in populate_properties()
189 		len = (pa - ps) + 1;  in populate_properties()
193 			pp->name   = "name";  in populate_properties()
194 			pp->length = len;  in populate_properties()
195 			pp->value  = pp + 1;  in populate_properties()
197 			memcpy(pp->value, ps, len - 1);  in populate_properties()
198 			((char *)pp->value)[len - 1] = 0;  in populate_properties()
199 			pr_debug("fixed up name for %s -> %s\n",  in populate_properties()
200 				 nodename, (char *)pp->value);  in populate_properties()
229 		np->full_name = fn = ((char *)np) + sizeof(*np);  in populate_node()
234 			np->parent = dad;  in populate_node()
235 			np->sibling = dad->child;  in populate_node()
236 			dad->child = np;  in populate_node()
242 		np->name = of_get_property(np, "name", NULL);  in populate_node()
243 		if (!np->name)  in populate_node()
244 			np->name = "<NULL>";  in populate_node()
255 	/* In-depth first */  in reverse_nodes()
256 	child = parent->child;  in reverse_nodes()
260 		child = child->sibling;  in reverse_nodes()
264 	child = parent->child;  in reverse_nodes()
265 	parent->child = NULL;  in reverse_nodes()
267 		next = child->sibling;  in reverse_nodes()
269 		child->sibling = parent->child;  in reverse_nodes()
270 		parent->child = child;  in reverse_nodes()
276  * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
277  * @blob: The parent device tree blob
278  * @mem: Memory chunk to use for allocating device nodes and properties
280  * @nodepp: The device_node tree created by the call
282  * Return: The size of unflattened device tree or error code
301 	 * We're unflattening device sub-tree if @dad is valid. There are  in unflatten_dt_nodes()
304 	 * immediately when negative @depth is found. Otherwise, the device  in unflatten_dt_nodes()
334 	if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {  in unflatten_dt_nodes()
336 		return -EINVAL;  in unflatten_dt_nodes()
346 	return mem - base;  in unflatten_dt_nodes()
350  * __unflatten_device_tree - create tree of device_nodes from flat blob
352  * @dad: Parent device node
353  * @mynodes: The device_node tree created by the call
355  * for the resulting tree
358  * unflattens a device-tree, creating the tree of struct device_node. It also
359  * fills the "name" and "type" pointers of the nodes so the normal device-tree
363  * device tree on success.
378 	pr_debug(" -> unflatten_device_tree()\n");  in __unflatten_device_tree()
381 		pr_debug("No device tree pointer\n");  in __unflatten_device_tree()
385 	pr_debug("Unflattening device tree:\n");  in __unflatten_device_tree()
391 		pr_err("Invalid device tree blob header\n");  in __unflatten_device_tree()
403 	/* Allocate memory for the expanded device tree */  in __unflatten_device_tree()
418 		pr_warn("End of tree marker overwritten: %08x\n",  in __unflatten_device_tree()
426 		pr_debug("unflattened tree is detached\n");  in __unflatten_device_tree()
429 	pr_debug(" <- unflatten_device_tree()\n");  in __unflatten_device_tree()
441  * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
442  * @blob: Flat device tree blob
443  * @dad: Parent device node
444  * @mynodes: The device tree created by the call
446  * unflattens the device-tree passed by the firmware, creating the
447  * tree of struct device_node. It also fills the "name" and "type"
448  * pointers of the nodes so the normal device-tree walking functions
452  * device tree on success.
488 			return -EBUSY;  in early_init_dt_reserve_memory_arch()
496  * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property
510 		return -ENOENT;  in __reserved_mem_reserve_reg()
515 		return -EINVAL;  in __reserved_mem_reserve_reg()
518 	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;  in __reserved_mem_reserve_reg()
532 		len -= t_len;  in __reserved_mem_reserve_reg()
542  * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
543  * in /reserved-memory matches the values supported by the current implementation,
550 	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);  in __reserved_mem_check_root()
552 		return -EINVAL;  in __reserved_mem_check_root()
554 	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);  in __reserved_mem_check_root()
556 		return -EINVAL;  in __reserved_mem_check_root()
560 		return -EINVAL;  in __reserved_mem_check_root()
565  * __fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
573 	if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {  in __fdt_scan_reserved_mem()
586 		/* scanning of /reserved-memory has been finished */  in __fdt_scan_reserved_mem()
594 	if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))  in __fdt_scan_reserved_mem()
602  * fdt_reserve_elfcorehdr() - reserves memory for elf core header
605  * described in the device tree. This region contains all the
626  * early_init_fdt_scan_reserved_mem() - create reserved memory regions
628  * This function grabs memory from early allocator for device exclusive use
629  * defined in device tree structures. It should be called by arch specific code
654  * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
668  * of_scan_flat_dt - scan flattened tree blob and call callback on each.
672  * This function is used to scan the flattened device-tree, it is
674  * unflatten the tree
683 	int offset, rc = 0, depth = -1;  in of_scan_flat_dt()
688 	for (offset = fdt_next_node(blob, -1, &depth);  in of_scan_flat_dt()
699  * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
704  * This function is used to scan sub-nodes of a node.
728  * of_get_flat_dt_subnode_by_name - get the subnode by given name
732  * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
741  * of_get_flat_dt_root - find the root node in the flat blob
749  * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
761  * of_fdt_is_compatible - Return true if given node from the given blob has
763  * @blob: A device tree blob
767  * Return: a non-zero value on match with smaller values returned for more
786 		cplen -= l;  in of_fdt_is_compatible()
793  * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
803  * of_flat_dt_match - Return true if node matches a list of compatible values
823  * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle
851  * of_flat_dt_match_machine - Iterate match tables to find matching machine.
880 		pr_err("\n unrecognized device tree list:\n[ ");  in of_flat_dt_match_machine()
886 				size -= strlen(prop) + 1;  in of_flat_dt_match_machine()
915  * early_init_dt_check_for_initrd - Decode initrd location from flat tree
929 	prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);  in early_init_dt_check_for_initrd()
934 	prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);  in early_init_dt_check_for_initrd()
941 	phys_initrd_size = end - start;  in early_init_dt_check_for_initrd()
947  * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat
948  * tree
976  * early_init_dt_check_for_usable_mem_range - Decode usable memory range
977  * location from flat tree
985 	pr_debug("Looking for usable-memory-range property... ");  in early_init_dt_check_for_usable_mem_range()
987 	prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len);  in early_init_dt_check_for_usable_mem_range()
1012 		return -ENOENT;  in early_init_dt_scan_chosen_stdout()
1014 	p = fdt_getprop(fdt, offset, "stdout-path", &l);  in early_init_dt_scan_chosen_stdout()
1016 		p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);  in early_init_dt_scan_chosen_stdout()
1018 		return -ENOENT;  in early_init_dt_scan_chosen_stdout()
1023 	l = q - p;  in early_init_dt_scan_chosen_stdout()
1025 	/* Get the node specified by stdout-path */  in early_init_dt_scan_chosen_stdout()
1028 		pr_warn("earlycon: stdout-path %.*s not found\n", l, p);  in early_init_dt_scan_chosen_stdout()
1033 		if (!match->compatible[0])  in early_init_dt_scan_chosen_stdout()
1036 		if (fdt_node_check_compatible(fdt, offset, match->compatible))  in early_init_dt_scan_chosen_stdout()
1042 	return -ENODEV;  in early_init_dt_scan_chosen_stdout()
1047  * early_init_dt_scan_root - fetch the top level address and size cells
1060 	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);  in early_init_dt_scan_root()
1065 	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);  in early_init_dt_scan_root()
1083  * early_init_dt_scan_memory - Look for and parse memory nodes
1097 	reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);  in early_init_dt_scan_memory()
1108 	while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {  in early_init_dt_scan_memory()
1116 		pr_debug(" - %llx, %llx\n", base, size);  in early_init_dt_scan_memory()
1124 			pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",  in early_init_dt_scan_memory()
1173 	rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);  in early_init_dt_scan_chosen()
1178 		fdt_nop_property(initial_boot_params, node, "rng-seed");  in early_init_dt_scan_chosen()
1200 	if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {  in early_init_dt_add_memory_arch()
1201 		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",  in early_init_dt_add_memory_arch()
1207 		size -= PAGE_SIZE - (base & ~PAGE_MASK);  in early_init_dt_add_memory_arch()
1213 		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",  in early_init_dt_add_memory_arch()
1218 	if (base + size - 1 > MAX_MEMBLOCK_ADDR) {  in early_init_dt_add_memory_arch()
1219 		pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",  in early_init_dt_add_memory_arch()
1221 		size = MAX_MEMBLOCK_ADDR - base + 1;  in early_init_dt_add_memory_arch()
1225 		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",  in early_init_dt_add_memory_arch()
1230 		pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",  in early_init_dt_add_memory_arch()
1232 		size -= phys_offset - base;  in early_init_dt_add_memory_arch()
1254 	/* check device tree validity */  in early_init_dt_verify()
1258 	/* Setup flat device-tree pointer */  in early_init_dt_verify()
1270 	/* Initialize {size,address}-cells info */  in early_init_dt_scan_nodes()
1281 	/* Handle linux,usable-memory-range property */  in early_init_dt_scan_nodes()
1298  * unflatten_device_tree - create tree of device_nodes from flat blob
1300  * unflattens the device-tree passed by the firmware, creating the
1301  * tree of struct device_node. It also fills the "name" and "type"
1302  * pointers of the nodes so the normal device-tree walking functions
1317  * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1319  * Copies and unflattens the device-tree passed by the firmware, creating the
1320  * tree of struct device_node. It also fills the "name" and "type"
1321  * pointers of the nodes so the normal device-tree walking functions
1323  * reserved such is the case when the FDT is built-in to the kernel init
1333 		pr_warn("No valid device tree found, continuing without\n");  in unflatten_and_copy_device_tree()