Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / of / fdt.c
diff --git a/kernel/drivers/of/fdt.c b/kernel/drivers/of/fdt.c
new file mode 100644 (file)
index 0000000..cde35c5
--- /dev/null
@@ -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 */