[PATCH] free initrds boot option

[Michael Neuling <mikey@neuling.org>]

Add free_initrd= option to control freeing of initrd memory after
extraction.  By default, free memory as previously.

Signed-off-by: Michael Neuling <mikey@neuling.org>
---
Useful for kexec when you want to reuse the same initrd.  Testing on
POWERPC with CPIOs 

 init/initramfs.c |   18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

Index: linux-2.6-ozlabs/init/initramfs.c
===================================================================
--- linux-2.6-ozlabs.orig/init/initramfs.c
+++ linux-2.6-ozlabs/init/initramfs.c
@@ -487,6 +487,17 @@ static char * __init unpack_to_rootfs(ch
 	return message;
 }
 
+static int do_free_initrd = 1;
+
+int __init free_initrd_param(char *p)
+{
+	if (p && strncmp(p, "0", 1) == 0)
+		do_free_initrd = 0;
+
+	return 0;
+}
+early_param("free_initrd", free_initrd_param);
+
 extern char __initramfs_start[], __initramfs_end[];
 #ifdef CONFIG_BLK_DEV_INITRD
 #include <linux/initrd.h>
@@ -494,10 +505,13 @@ extern char __initramfs_start[], __initr
 
 static void __init free_initrd(void)
 {
-#ifdef CONFIG_KEXEC
 	unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
 	unsigned long crashk_end   = (unsigned long)__va(crashk_res.end);
 
+	if (!do_free_initrd)
+		goto skip;
+
+#ifdef CONFIG_KEXEC
 	/*
 	 * If the initrd region is overlapped with crashkernel reserved region,
 	 * free only memory that is not part of crashkernel region.
@@ -515,7 +529,7 @@ static void __init free_initrd(void)
 	} else
 #endif
 		free_initrd_mem(initrd_start, initrd_end);
-
+skip:
 	initrd_start = 0;
 	initrd_end = 0;
 }