[ARM] move initrd code from kernel/setup.c to mm/init.c

This quietens some sparse warnings about phys_initrd_start and
phys_initrd_size.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 30a69d6..c70fb1d 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -27,8 +27,43 @@
 #include "mm.h"
 
 extern void _text, _etext, __data_start, _end, __init_begin, __init_end;
-extern unsigned long phys_initrd_start;
-extern unsigned long phys_initrd_size;
+
+static unsigned long phys_initrd_start __initdata = 0;
+static unsigned long phys_initrd_size __initdata = 0;
+
+static void __init early_initrd(char **p)
+{
+	unsigned long start, size;
+
+	start = memparse(*p, p);
+	if (**p == ',') {
+		size = memparse((*p) + 1, p);
+
+		phys_initrd_start = start;
+		phys_initrd_size = size;
+	}
+}
+__early_param("initrd=", early_initrd);
+
+static int __init parse_tag_initrd(const struct tag *tag)
+{
+	printk(KERN_WARNING "ATAG_INITRD is deprecated; "
+		"please update your bootloader.\n");
+	phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
+	phys_initrd_size = tag->u.initrd.size;
+	return 0;
+}
+
+__tagtable(ATAG_INITRD, parse_tag_initrd);
+
+static int __init parse_tag_initrd2(const struct tag *tag)
+{
+	phys_initrd_start = tag->u.initrd.start;
+	phys_initrd_size = tag->u.initrd.size;
+	return 0;
+}
+
+__tagtable(ATAG_INITRD2, parse_tag_initrd2);
 
 /*
  * This is used to pass memory configuration data from paging_init