2 files changed, 100 insertions, 51 deletions

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 71edc9cecd62..8a90ee42071a 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -11,10 +11,12 @@
 
 #include <linux/kernel.h>
 #include <linux/initrd.h>
+#include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
 #include <linux/string.h>
 #include <linux/errno.h>
+#include <linux/slab.h>
 
 #ifdef CONFIG_PPC
 #include <asm/machdep.h>
@@ -312,6 +314,94 @@ unsigned long unflatten_dt_node(struct boot_param_header *blob,
         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
+ */
+void __unflatten_device_tree(struct boot_param_header *blob,
+                             struct device_node **mynodes,
+                             void * (*dt_alloc)(u64 size, u64 align))
+{
+        unsigned long start, mem, size;
+        struct device_node **allnextp = mynodes;
+
+        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", be32_to_cpu(blob->magic));
+        pr_debug("size: %08x\n", be32_to_cpu(blob->totalsize));
+        pr_debug("version: %08x\n", be32_to_cpu(blob->version));
+
+        if (be32_to_cpu(blob->magic) != OF_DT_HEADER) {
+                pr_err("Invalid device tree blob header\n");
+                return;
+        }
+
+        /* First pass, scan for size */
+        start = ((unsigned long)blob) +
+                be32_to_cpu(blob->off_dt_struct);
+        size = unflatten_dt_node(blob, 0, &start, NULL, NULL, 0);
+        size = (size | 3) + 1;
+
+        pr_debug("  size is %lx, allocating...\n", size);
+
+        /* Allocate memory for the expanded device tree */
+        mem = (unsigned long)
+                dt_alloc(size + 4, __alignof__(struct device_node));
+
+        ((__be32 *)mem)[size / 4] = cpu_to_be32(0xdeadbeef);
+
+        pr_debug("  unflattening %lx...\n", mem);
+
+        /* Second pass, do actual unflattening */
+        start = ((unsigned long)blob) +
+                be32_to_cpu(blob->off_dt_struct);
+        unflatten_dt_node(blob, mem, &start, NULL, &allnextp, 0);
+        if (be32_to_cpup((__be32 *)start) != OF_DT_END)
+                pr_warning("Weird tag at end of tree: %08x\n", *((u32 *)start));
+        if (be32_to_cpu(((__be32 *)mem)[size / 4]) != 0xdeadbeef)
+                pr_warning("End of tree marker overwritten: %08x\n",
+                           be32_to_cpu(((__be32 *)mem)[size / 4]));
+        *allnextp = NULL;
+
+        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)
+{
+        struct boot_param_header *device_tree =
+                (struct boot_param_header *)blob;
+        __unflatten_device_tree(device_tree, 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;
@@ -569,6 +659,12 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
         return 1;
 }
 
+static void *__init early_device_tree_alloc(u64 size, u64 align)
+{
+        unsigned long mem = early_init_dt_alloc_memory_arch(size, align);
+        return __va(mem);
+}
+
 /**
  * unflatten_device_tree - create tree of device_nodes from flat blob
  *
@@ -579,62 +675,13 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
  */
 void __init unflatten_device_tree(void)
 {
-        unsigned long start, mem, size;
-        struct device_node **allnextp = &allnodes;
-
-        pr_debug(" -> unflatten_device_tree()\n");
-
-        if (!initial_boot_params) {
-                pr_debug("No device tree pointer\n");
-                return;
-        }
-
-        pr_debug("Unflattening device tree:\n");
-        pr_debug("magic: %08x\n", be32_to_cpu(initial_boot_params->magic));
-        pr_debug("size: %08x\n", be32_to_cpu(initial_boot_params->totalsize));
-        pr_debug("version: %08x\n", be32_to_cpu(initial_boot_params->version));
-
-        if (be32_to_cpu(initial_boot_params->magic) != OF_DT_HEADER) {
-                pr_err("Invalid device tree blob header\n");
-                return;
-        }
-
-        /* First pass, scan for size */
-        start = ((unsigned long)initial_boot_params) +
-                be32_to_cpu(initial_boot_params->off_dt_struct);
-        size = unflatten_dt_node(initial_boot_params, 0, &start,
-                                 NULL, NULL, 0);
-        size = (size | 3) + 1;
-
-        pr_debug("  size is %lx, allocating...\n", size);
-
-        /* Allocate memory for the expanded device tree */
-        mem = early_init_dt_alloc_memory_arch(size + 4,
-                        __alignof__(struct device_node));
-        mem = (unsigned long) __va(mem);
-
-        ((__be32 *)mem)[size / 4] = cpu_to_be32(0xdeadbeef);
-
-        pr_debug("  unflattening %lx...\n", mem);
-
-        /* Second pass, do actual unflattening */
-        start = ((unsigned long)initial_boot_params) +
-                be32_to_cpu(initial_boot_params->off_dt_struct);
-        unflatten_dt_node(initial_boot_params, mem, &start,
-                          NULL, &allnextp, 0);
-        if (be32_to_cpup((__be32 *)start) != OF_DT_END)
-                pr_warning("Weird tag at end of tree: %08x\n", *((u32 *)start));
-        if (be32_to_cpu(((__be32 *)mem)[size / 4]) != 0xdeadbeef)
-                pr_warning("End of tree marker overwritten: %08x\n",
-                           be32_to_cpu(((__be32 *)mem)[size / 4]));
-        *allnextp = NULL;
+        __unflatten_device_tree(initial_boot_params, &allnodes,
+                                early_device_tree_alloc);
 
         /* Get pointer to OF "/chosen" node for use everywhere */
         of_chosen = of_find_node_by_path("/chosen");
         if (of_chosen == NULL)
                 of_chosen = of_find_node_by_path("/chosen@0");
-
-        pr_debug(" <- unflatten_device_tree()\n");
 }
 
 #endif /* CONFIG_OF_EARLY_FLATTREE */
diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
index 70c5b736f0a3..9ce5dfd2186a 100644
--- a/include/linux/of_fdt.h
+++ b/include/linux/of_fdt.h
@@ -68,6 +68,8 @@ extern void *of_fdt_get_property(struct boot_param_header *blob,
 extern int of_fdt_is_compatible(struct boot_param_header *blob,
                                 unsigned long node,
                                 const char *compat);
+extern void of_fdt_unflatten_tree(unsigned long *blob,
+                               struct device_node **mynodes);
 
 /* TBD: Temporary export of fdt globals - remove when code fully merged */
 extern int __initdata dt_root_addr_cells;