Initial import

1 files changed, 1145 insertions, 0 deletions

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
new file mode 100644
index 000000000..cde35c5d0
--- /dev/null
+++ b/drivers/of/fdt.c
@@ -0,0 +1,1145 @@
+/*
+ * Functions for working with the Flattened Device Tree data format
+ *
+ * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
+ * benh@kernel.crashing.org
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ */
+
+#include <linux/crc32.h>
+#include <linux/kernel.h>
+#include <linux/initrd.h>
+#include <linux/memblock.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/sizes.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/libfdt.h>
+#include <linux/debugfs.h>
+#include <linux/serial_core.h>
+#include <linux/sysfs.h>
+
+#include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
+#include <asm/page.h>
+
+/*
+ * of_fdt_limit_memory - limit the number of regions in the /memory node
+ * @limit: maximum entries
+ *
+ * Adjust the flattened device tree to have at most 'limit' number of
+ * memory entries in the /memory node. This function may be called
+ * any time after initial_boot_param is set.
+ */
+void of_fdt_limit_memory(int limit)
+{
+	int memory;
+	int len;
+	const void *val;
+	int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
+	int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
+	const uint32_t *addr_prop;
+	const uint32_t *size_prop;
+	int root_offset;
+	int cell_size;
+
+	root_offset = fdt_path_offset(initial_boot_params, "/");
+	if (root_offset < 0)
+		return;
+
+	addr_prop = fdt_getprop(initial_boot_params, root_offset,
+				"#address-cells", NULL);
+	if (addr_prop)
+		nr_address_cells = fdt32_to_cpu(*addr_prop);
+
+	size_prop = fdt_getprop(initial_boot_params, root_offset,
+				"#size-cells", NULL);
+	if (size_prop)
+		nr_size_cells = fdt32_to_cpu(*size_prop);
+
+	cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
+
+	memory = fdt_path_offset(initial_boot_params, "/memory");
+	if (memory > 0) {
+		val = fdt_getprop(initial_boot_params, memory, "reg", &len);
+		if (len > limit*cell_size) {
+			len = limit*cell_size;
+			pr_debug("Limiting number of entries to %d\n", limit);
+			fdt_setprop(initial_boot_params, memory, "reg", val,
+					len);
+		}
+	}
+}
+
+/**
+ * of_fdt_is_compatible - Return true if given node from the given blob has
+ * compat in its compatible list
+ * @blob: A device tree blob
+ * @node: node to test
+ * @compat: compatible string to compare with compatible list.
+ *
+ * On match, returns a non-zero value with smaller values returned for more
+ * specific compatible values.
+ */
+int of_fdt_is_compatible(const void *blob,
+		      unsigned long node, const char *compat)
+{
+	const char *cp;
+	int cplen;
+	unsigned long l, score = 0;
+
+	cp = fdt_getprop(blob, node, "compatible", &cplen);
+	if (cp == NULL)
+		return 0;
+	while (cplen > 0) {
+		score++;
+		if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
+			return score;
+		l = strlen(cp) + 1;
+		cp += l;
+		cplen -= l;
+	}
+
+	return 0;
+}
+
+/**
+ * of_fdt_is_big_endian - Return true if given node needs BE MMIO accesses
+ * @blob: A device tree blob
+ * @node: node to test
+ *
+ * Returns true if the node has a "big-endian" property, or if the kernel
+ * was compiled for BE *and* the node has a "native-endian" property.
+ * Returns false otherwise.
+ */
+bool of_fdt_is_big_endian(const void *blob, unsigned long node)
+{
+	if (fdt_getprop(blob, node, "big-endian", NULL))
+		return true;
+	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
+	    fdt_getprop(blob, node, "native-endian", NULL))
+		return true;
+	return false;
+}
+
+/**
+ * of_fdt_match - Return true if node matches a list of compatible values
+ */
+int of_fdt_match(const void *blob, unsigned long node,
+                 const char *const *compat)
+{
+	unsigned int tmp, score = 0;
+
+	if (!compat)
+		return 0;
+
+	while (*compat) {
+		tmp = of_fdt_is_compatible(blob, node, *compat);
+		if (tmp && (score == 0 || (tmp < score)))
+			score = tmp;
+		compat++;
+	}
+
+	return score;
+}
+
+static void *unflatten_dt_alloc(void **mem, unsigned long size,
+				       unsigned long align)
+{
+	void *res;
+
+	*mem = PTR_ALIGN(*mem, align);
+	res = *mem;
+	*mem += size;
+
+	return res;
+}
+
+/**
+ * unflatten_dt_node - Alloc and populate a device_node from the flat tree
+ * @blob: The parent device tree blob
+ * @mem: Memory chunk to use for allocating device nodes and properties
+ * @p: pointer to node in flat tree
+ * @dad: Parent struct device_node
+ * @fpsize: Size of the node path up at the current depth.
+ */
+static void * unflatten_dt_node(void *blob,
+				void *mem,
+				int *poffset,
+				struct device_node *dad,
+				struct device_node **nodepp,
+				unsigned long fpsize,
+				bool dryrun)
+{
+	const __be32 *p;
+	struct device_node *np;
+	struct property *pp, **prev_pp = NULL;
+	const char *pathp;
+	unsigned int l, allocl;
+	static int depth = 0;
+	int old_depth;
+	int offset;
+	int has_name = 0;
+	int new_format = 0;
+
+	pathp = fdt_get_name(blob, *poffset, &l);
+	if (!pathp)
+		return mem;
+
+	allocl = ++l;
+
+	/* version 0x10 has a more compact unit name here instead of the full
+	 * path. we accumulate the full path size using "fpsize", we'll rebuild
+	 * it later. We detect this because the first character of the name is
+	 * not '/'.
+	 */
+	if ((*pathp) != '/') {
+		new_format = 1;
+		if (fpsize == 0) {
+			/* root node: special case. fpsize accounts for path
+			 * plus terminating zero. root node only has '/', so
+			 * fpsize should be 2, but we want to avoid the first
+			 * level nodes to have two '/' so we use fpsize 1 here
+			 */
+			fpsize = 1;
+			allocl = 2;
+			l = 1;
+			pathp = "";
+		} else {
+			/* account for '/' and path size minus terminal 0
+			 * already in 'l'
+			 */
+			fpsize += l;
+			allocl = fpsize;
+		}
+	}
+
+	np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
+				__alignof__(struct device_node));
+	if (!dryrun) {
+		char *fn;
+		of_node_init(np);
+		np->full_name = fn = ((char *)np) + sizeof(*np);
+		if (new_format) {
+			/* rebuild full path for new format */
+			if (dad && dad->parent) {
+				strcpy(fn, dad->full_name);
+#ifdef DEBUG
+				if ((strlen(fn) + l + 1) != allocl) {
+					pr_debug("%s: p: %d, l: %d, a: %d\n",
+						pathp, (int)strlen(fn),
+						l, allocl);
+				}
+#endif
+				fn += strlen(fn);
+			}
+			*(fn++) = '/';
+		}
+		memcpy(fn, pathp, l);
+
+		prev_pp = &np->properties;
+		if (dad != NULL) {
+			np->parent = dad;
+			np->sibling = dad->child;
+			dad->child = np;
+		}
+	}
+	/* process properties */
+	for (offset = fdt_first_property_offset(blob, *poffset);
+	     (offset >= 0);
+	     (offset = fdt_next_property_offset(blob, offset))) {
+		const char *pname;
+		u32 sz;
+
+		if (!(p = fdt_getprop_by_offset(blob, offset, &pname, &sz))) {
+			offset = -FDT_ERR_INTERNAL;
+			break;
+		}
+
+		if (pname == NULL) {
+			pr_info("Can't find property name in list !\n");
+			break;
+		}
+		if (strcmp(pname, "name") == 0)
+			has_name = 1;
+		pp = unflatten_dt_alloc(&mem, sizeof(struct property),
+					__alignof__(struct property));
+		if (!dryrun) {
+			/* We accept flattened tree phandles either in
+			 * ePAPR-style "phandle" properties, or the
+			 * legacy "linux,phandle" properties.  If both
+			 * appear and have different values, things
+			 * will get weird.  Don't do that. */
+			if ((strcmp(pname, "phandle") == 0) ||
+			    (strcmp(pname, "linux,phandle") == 0)) {
+				if (np->phandle == 0)
+					np->phandle = be32_to_cpup(p);
+			}
+			/* And we process the "ibm,phandle" property
+			 * used in pSeries dynamic device tree
+			 * stuff */
+			if (strcmp(pname, "ibm,phandle") == 0)
+				np->phandle = be32_to_cpup(p);
+			pp->name = (char *)pname;
+			pp->length = sz;
+			pp->value = (__be32 *)p;
+			*prev_pp = pp;
+			prev_pp = &pp->next;
+		}
+	}
+	/* with version 0x10 we may not have the name property, recreate
+	 * it here from the unit name if absent
+	 */
+	if (!has_name) {
+		const char *p1 = pathp, *ps = pathp, *pa = NULL;
+		int sz;
+
+		while (*p1) {
+			if ((*p1) == '@')
+				pa = p1;
+			if ((*p1) == '/')
+				ps = p1 + 1;
+			p1++;
+		}
+		if (pa < ps)
+			pa = p1;
+		sz = (pa - ps) + 1;
+		pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
+					__alignof__(struct property));
+		if (!dryrun) {
+			pp->name = "name";
+			pp->length = sz;
+			pp->value = pp + 1;
+			*prev_pp = pp;
+			prev_pp = &pp->next;
+			memcpy(pp->value, ps, sz - 1);
+			((char *)pp->value)[sz - 1] = 0;
+			pr_debug("fixed up name for %s -> %s\n", pathp,
+				(char *)pp->value);
+		}
+	}
+	if (!dryrun) {
+		*prev_pp = NULL;
+		np->name = of_get_property(np, "name", NULL);
+		np->type = of_get_property(np, "device_type", NULL);
+
+		if (!np->name)
+			np->name = "<NULL>";
+		if (!np->type)
+			np->type = "<NULL>";
+	}
+
+	old_depth = depth;
+	*poffset = fdt_next_node(blob, *poffset, &depth);
+	if (depth < 0)
+		depth = 0;
+	while (*poffset > 0 && depth > old_depth)
+		mem = unflatten_dt_node(blob, mem, poffset, np, NULL,
+					fpsize, dryrun);
+
+	if (*poffset < 0 && *poffset != -FDT_ERR_NOTFOUND)
+		pr_err("unflatten: error %d processing FDT\n", *poffset);
+
+	/*
+	 * Reverse the child list. Some drivers assumes node order matches .dts
+	 * node order
+	 */
+	if (!dryrun && np->child) {
+		struct device_node *child = np->child;
+		np->child = NULL;
+		while (child) {
+			struct device_node *next = child->sibling;
+			child->sibling = np->child;
+			np->child = child;
+			child = next;
+		}
+	}
+
+	if (nodepp)
+		*nodepp = np;
+
+	return mem;
+}
+
+/**
+ * __unflatten_device_tree - create tree of device_nodes from flat blob
+ *
+ * unflattens a device-tree, creating the
+ * tree of struct device_node. It also fills the "name" and "type"
+ * pointers of the nodes so the normal device-tree walking functions
+ * can be used.
+ * @blob: The blob to expand
+ * @mynodes: The device_node tree created by the call
+ * @dt_alloc: An allocator that provides a virtual address to memory
+ * for the resulting tree
+ */
+static void __unflatten_device_tree(void *blob,
+			     struct device_node **mynodes,
+			     void * (*dt_alloc)(u64 size, u64 align))
+{
+	unsigned long size;
+	int start;
+	void *mem;
+
+	pr_debug(" -> unflatten_device_tree()\n");
+
+	if (!blob) {
+		pr_debug("No device tree pointer\n");
+		return;
+	}
+
+	pr_debug("Unflattening device tree:\n");
+	pr_debug("magic: %08x\n", fdt_magic(blob));
+	pr_debug("size: %08x\n", fdt_totalsize(blob));
+	pr_debug("version: %08x\n", fdt_version(blob));
+
+	if (fdt_check_header(blob)) {
+		pr_err("Invalid device tree blob header\n");
+		return;
+	}
+
+	/* First pass, scan for size */
+	start = 0;
+	size = (unsigned long)unflatten_dt_node(blob, NULL, &start, NULL, NULL, 0, true);
+	size = ALIGN(size, 4);
+
+	pr_debug("  size is %lx, allocating...\n", size);
+
+	/* Allocate memory for the expanded device tree */
+	mem = dt_alloc(size + 4, __alignof__(struct device_node));
+	memset(mem, 0, size);
+
+	*(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
+
+	pr_debug("  unflattening %p...\n", mem);
+
+	/* Second pass, do actual unflattening */
+	start = 0;
+	unflatten_dt_node(blob, mem, &start, NULL, mynodes, 0, false);
+	if (be32_to_cpup(mem + size) != 0xdeadbeef)
+		pr_warning("End of tree marker overwritten: %08x\n",
+			   be32_to_cpup(mem + size));
+
+	pr_debug(" <- unflatten_device_tree()\n");
+}
+
+static void *kernel_tree_alloc(u64 size, u64 align)
+{
+	return kzalloc(size, GFP_KERNEL);
+}
+
+/**
+ * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
+ *
+ * unflattens the device-tree passed by the firmware, creating the
+ * tree of struct device_node. It also fills the "name" and "type"
+ * pointers of the nodes so the normal device-tree walking functions
+ * can be used.
+ */
+void of_fdt_unflatten_tree(unsigned long *blob,
+			struct device_node **mynodes)
+{
+	__unflatten_device_tree(blob, mynodes, &kernel_tree_alloc);
+}
+EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
+
+/* Everything below here references initial_boot_params directly. */
+int __initdata dt_root_addr_cells;
+int __initdata dt_root_size_cells;
+
+void *initial_boot_params;
+
+#ifdef CONFIG_OF_EARLY_FLATTREE
+
+static u32 of_fdt_crc32;
+
+/**
+ * res_mem_reserve_reg() - reserve all memory described in 'reg' property
+ */
+static int __init __reserved_mem_reserve_reg(unsigned long node,
+					     const char *uname)
+{
+	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
+	phys_addr_t base, size;
+	int len;
+	const __be32 *prop;
+	int nomap, first = 1;
+
+	prop = of_get_flat_dt_prop(node, "reg", &len);
+	if (!prop)
+		return -ENOENT;
+
+	if (len && len % t_len != 0) {
+		pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
+		       uname);
+		return -EINVAL;
+	}
+
+	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+
+	while (len >= t_len) {
+		base = dt_mem_next_cell(dt_root_addr_cells, &prop);
+		size = dt_mem_next_cell(dt_root_size_cells, &prop);
+
+		if (size &&
+		    early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
+			pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
+				uname, &base, (unsigned long)size / SZ_1M);
+		else
+			pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
+				uname, &base, (unsigned long)size / SZ_1M);
+
+		len -= t_len;
+		if (first) {
+			fdt_reserved_mem_save_node(node, uname, base, size);
+			first = 0;
+		}
+	}
+	return 0;
+}
+
+/**
+ * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
+ * in /reserved-memory matches the values supported by the current implementation,
+ * also check if ranges property has been provided
+ */
+static int __init __reserved_mem_check_root(unsigned long node)
+{
+	const __be32 *prop;
+
+	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
+	if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
+		return -EINVAL;
+
+	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
+	if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
+		return -EINVAL;
+
+	prop = of_get_flat_dt_prop(node, "ranges", NULL);
+	if (!prop)
+		return -EINVAL;
+	return 0;
+}
+
+/**
+ * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
+ */
+static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
+					  int depth, void *data)
+{
+	static int found;
+	const char *status;
+	int err;
+
+	if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
+		if (__reserved_mem_check_root(node) != 0) {
+			pr_err("Reserved memory: unsupported node format, ignoring\n");
+			/* break scan */
+			return 1;
+		}
+		found = 1;
+		/* scan next node */
+		return 0;
+	} else if (!found) {
+		/* scan next node */
+		return 0;
+	} else if (found && depth < 2) {
+		/* scanning of /reserved-memory has been finished */
+		return 1;
+	}
+
+	status = of_get_flat_dt_prop(node, "status", NULL);
+	if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
+		return 0;
+
+	err = __reserved_mem_reserve_reg(node, uname);
+	if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
+		fdt_reserved_mem_save_node(node, uname, 0, 0);
+
+	/* scan next node */
+	return 0;
+}
+
+/**
+ * early_init_fdt_scan_reserved_mem() - create reserved memory regions
+ *
+ * This function grabs memory from early allocator for device exclusive use
+ * defined in device tree structures. It should be called by arch specific code
+ * once the early allocator (i.e. memblock) has been fully activated.
+ */
+void __init early_init_fdt_scan_reserved_mem(void)
+{
+	int n;
+	u64 base, size;
+
+	if (!initial_boot_params)
+		return;
+
+	/* Reserve the dtb region */
+	early_init_dt_reserve_memory_arch(__pa(initial_boot_params),
+					  fdt_totalsize(initial_boot_params),
+					  0);
+
+	/* Process header /memreserve/ fields */
+	for (n = 0; ; n++) {
+		fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
+		if (!size)
+			break;
+		early_init_dt_reserve_memory_arch(base, size, 0);
+	}
+
+	of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
+	fdt_init_reserved_mem();
+}
+
+/**
+ * of_scan_flat_dt - scan flattened tree blob and call callback on each.
+ * @it: callback function
+ * @data: context data pointer
+ *
+ * This function is used to scan the flattened device-tree, it is
+ * used to extract the memory information at boot before we can
+ * unflatten the tree
+ */
+int __init of_scan_flat_dt(int (*it)(unsigned long node,
+				     const char *uname, int depth,
+				     void *data),
+			   void *data)
+{
+	const void *blob = initial_boot_params;
+	const char *pathp;
+	int offset, rc = 0, depth = -1;
+
+        for (offset = fdt_next_node(blob, -1, &depth);
+             offset >= 0 && depth >= 0 && !rc;
+             offset = fdt_next_node(blob, offset, &depth)) {
+
+		pathp = fdt_get_name(blob, offset, NULL);
+		if (*pathp == '/')
+			pathp = kbasename(pathp);
+		rc = it(offset, pathp, depth, data);
+	}
+	return rc;
+}
+
+/**
+ * of_get_flat_dt_root - find the root node in the flat blob
+ */
+unsigned long __init of_get_flat_dt_root(void)
+{
+	return 0;
+}
+
+/**
+ * of_get_flat_dt_size - Return the total size of the FDT
+ */
+int __init of_get_flat_dt_size(void)
+{
+	return fdt_totalsize(initial_boot_params);
+}
+
+/**
+ * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
+ *
+ * This function can be used within scan_flattened_dt callback to get
+ * access to properties
+ */
+const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
+				       int *size)
+{
+	return fdt_getprop(initial_boot_params, node, name, size);
+}
+
+/**
+ * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
+ * @node: node to test
+ * @compat: compatible string to compare with compatible list.
+ */
+int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
+{
+	return of_fdt_is_compatible(initial_boot_params, node, compat);
+}
+
+/**
+ * of_flat_dt_match - Return true if node matches a list of compatible values
+ */
+int __init of_flat_dt_match(unsigned long node, const char *const *compat)
+{
+	return of_fdt_match(initial_boot_params, node, compat);
+}
+
+struct fdt_scan_status {
+	const char *name;
+	int namelen;
+	int depth;
+	int found;
+	int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
+	void *data;
+};
+
+const char * __init of_flat_dt_get_machine_name(void)
+{
+	const char *name;
+	unsigned long dt_root = of_get_flat_dt_root();
+
+	name = of_get_flat_dt_prop(dt_root, "model", NULL);
+	if (!name)
+		name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
+	return name;
+}
+
+/**
+ * of_flat_dt_match_machine - Iterate match tables to find matching machine.
+ *
+ * @default_match: A machine specific ptr to return in case of no match.
+ * @get_next_compat: callback function to return next compatible match table.
+ *
+ * Iterate through machine match tables to find the best match for the machine
+ * compatible string in the FDT.
+ */
+const void * __init of_flat_dt_match_machine(const void *default_match,
+		const void * (*get_next_compat)(const char * const**))
+{
+	const void *data = NULL;
+	const void *best_data = default_match;
+	const char *const *compat;
+	unsigned long dt_root;
+	unsigned int best_score = ~1, score = 0;
+
+	dt_root = of_get_flat_dt_root();
+	while ((data = get_next_compat(&compat))) {
+		score = of_flat_dt_match(dt_root, compat);
+		if (score > 0 && score < best_score) {
+			best_data = data;
+			best_score = score;
+		}
+	}
+	if (!best_data) {
+		const char *prop;
+		int size;
+
+		pr_err("\n unrecognized device tree list:\n[ ");
+
+		prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
+		if (prop) {
+			while (size > 0) {
+				printk("'%s' ", prop);
+				size -= strlen(prop) + 1;
+				prop += strlen(prop) + 1;
+			}
+		}
+		printk("]\n\n");
+		return NULL;
+	}
+
+	pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
+
+	return best_data;
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+/**
+ * early_init_dt_check_for_initrd - Decode initrd location from flat tree
+ * @node: reference to node containing initrd location ('chosen')
+ */
+static void __init early_init_dt_check_for_initrd(unsigned long node)
+{
+	u64 start, end;
+	int len;
+	const __be32 *prop;
+
+	pr_debug("Looking for initrd properties... ");
+
+	prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
+	if (!prop)
+		return;
+	start = of_read_number(prop, len/4);
+
+	prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
+	if (!prop)
+		return;
+	end = of_read_number(prop, len/4);
+
+	initrd_start = (unsigned long)__va(start);
+	initrd_end = (unsigned long)__va(end);
+	initrd_below_start_ok = 1;
+
+	pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n",
+		 (unsigned long long)start, (unsigned long long)end);
+}
+#else
+static inline void early_init_dt_check_for_initrd(unsigned long node)
+{
+}
+#endif /* CONFIG_BLK_DEV_INITRD */
+
+#ifdef CONFIG_SERIAL_EARLYCON
+extern struct of_device_id __earlycon_of_table[];
+
+static int __init early_init_dt_scan_chosen_serial(void)
+{
+	int offset;
+	const char *p;
+	int l;
+	const struct of_device_id *match = __earlycon_of_table;
+	const void *fdt = initial_boot_params;
+
+	offset = fdt_path_offset(fdt, "/chosen");
+	if (offset < 0)
+		offset = fdt_path_offset(fdt, "/chosen@0");
+	if (offset < 0)
+		return -ENOENT;
+
+	p = fdt_getprop(fdt, offset, "stdout-path", &l);
+	if (!p)
+		p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
+	if (!p || !l)
+		return -ENOENT;
+
+	/* Get the node specified by stdout-path */
+	offset = fdt_path_offset(fdt, p);
+	if (offset < 0)
+		return -ENODEV;
+
+	while (match->compatible[0]) {
+		unsigned long addr;
+		if (fdt_node_check_compatible(fdt, offset, match->compatible)) {
+			match++;
+			continue;
+		}
+
+		addr = fdt_translate_address(fdt, offset);
+		if (!addr)
+			return -ENXIO;
+
+		of_setup_earlycon(addr, match->data);
+		return 0;
+	}
+	return -ENODEV;
+}
+
+static int __init setup_of_earlycon(char *buf)
+{
+	if (buf)
+		return 0;
+
+	return early_init_dt_scan_chosen_serial();
+}
+early_param("earlycon", setup_of_earlycon);
+#endif
+
+/**
+ * early_init_dt_scan_root - fetch the top level address and size cells
+ */
+int __init early_init_dt_scan_root(unsigned long node, const char *uname,
+				   int depth, void *data)
+{
+	const __be32 *prop;
+
+	if (depth != 0)
+		return 0;
+
+	dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
+	dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
+
+	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
+	if (prop)
+		dt_root_size_cells = be32_to_cpup(prop);
+	pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
+
+	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
+	if (prop)
+		dt_root_addr_cells = be32_to_cpup(prop);
+	pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
+
+	/* break now */
+	return 1;
+}
+
+u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
+{
+	const __be32 *p = *cellp;
+
+	*cellp = p + s;
+	return of_read_number(p, s);
+}
+
+/**
+ * early_init_dt_scan_memory - Look for an parse memory nodes
+ */
+int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
+				     int depth, void *data)
+{
+	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+	const __be32 *reg, *endp;
+	int l;
+
+	/* We are scanning "memory" nodes only */
+	if (type == NULL) {
+		/*
+		 * The longtrail doesn't have a device_type on the
+		 * /memory node, so look for the node called /memory@0.
+		 */
+		if (!IS_ENABLED(CONFIG_PPC32) || depth != 1 || strcmp(uname, "memory@0") != 0)
+			return 0;
+	} else if (strcmp(type, "memory") != 0)
+		return 0;
+
+	reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
+	if (reg == NULL)
+		reg = of_get_flat_dt_prop(node, "reg", &l);
+	if (reg == NULL)
+		return 0;
+
+	endp = reg + (l / sizeof(__be32));
+
+	pr_debug("memory scan node %s, reg size %d,\n", uname, l);
+
+	while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
+		u64 base, size;
+
+		base = dt_mem_next_cell(dt_root_addr_cells, &reg);
+		size = dt_mem_next_cell(dt_root_size_cells, &reg);
+
+		if (size == 0)
+			continue;
+		pr_debug(" - %llx ,  %llx\n", (unsigned long long)base,
+		    (unsigned long long)size);
+
+		early_init_dt_add_memory_arch(base, size);
+	}
+
+	return 0;
+}
+
+int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
+				     int depth, void *data)
+{
+	int l;
+	const char *p;
+
+	pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
+
+	if (depth != 1 || !data ||
+	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
+		return 0;
+
+	early_init_dt_check_for_initrd(node);
+
+	/* Retrieve command line */
+	p = of_get_flat_dt_prop(node, "bootargs", &l);
+	if (p != NULL && l > 0)
+		strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
+
+	/*
+	 * CONFIG_CMDLINE is meant to be a default in case nothing else
+	 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
+	 * is set in which case we override whatever was found earlier.
+	 */
+#ifdef CONFIG_CMDLINE
+#ifndef CONFIG_CMDLINE_FORCE
+	if (!((char *)data)[0])
+#endif
+		strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
+#endif /* CONFIG_CMDLINE */
+
+	pr_debug("Command line is: %s\n", (char*)data);
+
+	/* break now */
+	return 1;
+}
+
+#ifdef CONFIG_HAVE_MEMBLOCK
+#define MAX_PHYS_ADDR	((phys_addr_t)~0)
+
+void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
+{
+	const u64 phys_offset = __pa(PAGE_OFFSET);
+
+	if (!PAGE_ALIGNED(base)) {
+		if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
+			pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
+				base, base + size);
+			return;
+		}
+		size -= PAGE_SIZE - (base & ~PAGE_MASK);
+		base = PAGE_ALIGN(base);
+	}
+	size &= PAGE_MASK;
+
+	if (base > MAX_PHYS_ADDR) {
+		pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
+				base, base + size);
+		return;
+	}
+
+	if (base + size - 1 > MAX_PHYS_ADDR) {
+		pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
+				((u64)MAX_PHYS_ADDR) + 1, base + size);
+		size = MAX_PHYS_ADDR - base + 1;
+	}
+
+	if (base + size < phys_offset) {
+		pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
+			   base, base + size);
+		return;
+	}
+	if (base < phys_offset) {
+		pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
+			   base, phys_offset);
+		size -= phys_offset - base;
+		base = phys_offset;
+	}
+	memblock_add(base, size);
+}
+
+int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
+					phys_addr_t size, bool nomap)
+{
+	if (nomap)
+		return memblock_remove(base, size);
+	return memblock_reserve(base, size);
+}
+
+/*
+ * called from unflatten_device_tree() to bootstrap devicetree itself
+ * Architectures can override this definition if memblock isn't used
+ */
+void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
+{
+	return __va(memblock_alloc(size, align));
+}
+#else
+int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
+					phys_addr_t size, bool nomap)
+{
+	pr_err("Reserved memory not supported, ignoring range 0x%pa - 0x%pa%s\n",
+		  &base, &size, nomap ? " (nomap)" : "");
+	return -ENOSYS;
+}
+#endif
+
+bool __init early_init_dt_verify(void *params)
+{
+	if (!params)
+		return false;
+
+	/* check device tree validity */
+	if (fdt_check_header(params))
+		return false;
+
+	/* Setup flat device-tree pointer */
+	initial_boot_params = params;
+	of_fdt_crc32 = crc32_be(~0, initial_boot_params,
+				fdt_totalsize(initial_boot_params));
+	return true;
+}
+
+
+void __init early_init_dt_scan_nodes(void)
+{
+	/* Retrieve various information from the /chosen node */
+	of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
+
+	/* Initialize {size,address}-cells info */
+	of_scan_flat_dt(early_init_dt_scan_root, NULL);
+
+	/* Setup memory, calling early_init_dt_add_memory_arch */
+	of_scan_flat_dt(early_init_dt_scan_memory, NULL);
+}
+
+bool __init early_init_dt_scan(void *params)
+{
+	bool status;
+
+	status = early_init_dt_verify(params);
+	if (!status)
+		return false;
+
+	early_init_dt_scan_nodes();
+	return true;
+}
+
+/**
+ * unflatten_device_tree - create tree of device_nodes from flat blob
+ *
+ * unflattens the device-tree passed by the firmware, creating the
+ * tree of struct device_node. It also fills the "name" and "type"
+ * pointers of the nodes so the normal device-tree walking functions
+ * can be used.
+ */
+void __init unflatten_device_tree(void)
+{
+	__unflatten_device_tree(initial_boot_params, &of_root,
+				early_init_dt_alloc_memory_arch);
+
+	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
+	of_alias_scan(early_init_dt_alloc_memory_arch);
+}
+
+/**
+ * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
+ *
+ * Copies and unflattens the device-tree passed by the firmware, creating the
+ * tree of struct device_node. It also fills the "name" and "type"
+ * pointers of the nodes so the normal device-tree walking functions
+ * can be used. This should only be used when the FDT memory has not been
+ * reserved such is the case when the FDT is built-in to the kernel init
+ * section. If the FDT memory is reserved already then unflatten_device_tree
+ * should be used instead.
+ */
+void __init unflatten_and_copy_device_tree(void)
+{
+	int size;
+	void *dt;
+
+	if (!initial_boot_params) {
+		pr_warn("No valid device tree found, continuing without\n");
+		return;
+	}
+
+	size = fdt_totalsize(initial_boot_params);
+	dt = early_init_dt_alloc_memory_arch(size,
+					     roundup_pow_of_two(FDT_V17_SIZE));
+
+	if (dt) {
+		memcpy(dt, initial_boot_params, size);
+		initial_boot_params = dt;
+	}
+	unflatten_device_tree();
+}
+
+#ifdef CONFIG_SYSFS
+static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
+			       struct bin_attribute *bin_attr,
+			       char *buf, loff_t off, size_t count)
+{
+	memcpy(buf, initial_boot_params + off, count);
+	return count;
+}
+
+static int __init of_fdt_raw_init(void)
+{
+	static struct bin_attribute of_fdt_raw_attr =
+		__BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
+
+	if (!initial_boot_params)
+		return 0;
+
+	if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
+				     fdt_totalsize(initial_boot_params))) {
+		pr_warn("fdt: not creating '/sys/firmware/fdt': CRC check failed\n");
+		return 0;
+	}
+	of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
+	return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
+}
+late_initcall(of_fdt_raw_init);
+#endif
+
+#endif /* CONFIG_OF_EARLY_FLATTREE */