[PATCH] powerpc: Reroute interrupts from 0 + offset to PHYSICAL_START + offset

Regardless of where the kernel's linked we always get interrupts at low
addresses. This patch creates a trampoline in the first 3 pages of memory,
where interrupts land, and patches those addresses to jump into the real
kernel code at PHYSICAL_START.

We also need to reserve the trampoline code and a bit more in prom.c

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 6509dd7..e67120e 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -34,6 +34,7 @@
 #include <linux/serial.h>
 #include <linux/serial_8250.h>
 #include <asm/io.h>
+#include <asm/kdump.h>
 #include <asm/prom.h>
 #include <asm/processor.h>
 #include <asm/pgtable.h>
@@ -268,6 +269,10 @@
 	}
 	ppc_md = **mach;
 
+#ifdef CONFIG_CRASH_DUMP
+	kdump_setup();
+#endif
+
 	DBG("Found, Initializing memory management...\n");
 
 	/*