1 files changed, 35 insertions, 3 deletions

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index d50c8df0183e..294832a7e0a6 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -491,7 +491,12 @@ void __init finish_device_tree(void)
         size = 16;
         finish_node(allnodes, &size, 1);
         size -= 16;
-        end = start = (unsigned long) __va(lmb_alloc(size, 128));
+
+        if (0 == size)
+                end = start = 0;
+        else
+                end = start = (unsigned long)__va(lmb_alloc(size, 128));
+
         finish_node(allnodes, &end, 0);
         BUG_ON(end != start + size);
 
@@ -1398,8 +1403,8 @@ struct device_node *of_find_node_by_name(struct device_node *from,
 
         read_lock(&devtree_lock);
         np = from ? from->allnext : allnodes;
-        for (; np != 0; np = np->allnext)
-                if (np->name != 0 && strcasecmp(np->name, name) == 0
+        for (; np != NULL; np = np->allnext)
+                if (np->name != NULL && strcasecmp(np->name, name) == 0
                     && of_node_get(np))
                         break;
         if (from)
@@ -1917,3 +1922,30 @@ int prom_update_property(struct device_node *np,
 
         return 0;
 }
+
+#ifdef CONFIG_KEXEC
+/* We may have allocated the flat device tree inside the crash kernel region
+ * in prom_init. If so we need to move it out into regular memory. */
+void kdump_move_device_tree(void)
+{
+        unsigned long start, end;
+        struct boot_param_header *new;
+
+        start = __pa((unsigned long)initial_boot_params);
+        end = start + initial_boot_params->totalsize;
+
+        if (end < crashk_res.start || start > crashk_res.end)
+                return;
+
+        new = (struct boot_param_header*)
+                __va(lmb_alloc(initial_boot_params->totalsize, PAGE_SIZE));
+
+        memcpy(new, initial_boot_params, initial_boot_params->totalsize);
+
+        initial_boot_params = new;
+
+        DBG("Flat device tree blob moved to %p\n", initial_boot_params);
+
+        /* XXX should we unreserve the old DT? */
+}
+#endif /* CONFIG_KEXEC */