From: AMEET M. PARANJAPE <aparanja@redhat.com>
Date: Fri, 24 Oct 2008 15:45:39 -0400
Subject: [ppc64] ptcal has to be disabled to use kexec on QS21
Message-id: 20081024194520.27751.78159.sendpatchset@squad5-lp1.lab.bos.redhat.com
O-Subject: [PATCH 1/2 RHEL5.3 BZ462744] ptcal has to be disabled to use kexec on QS21
Bugzilla: 462744

RHBZ#:
======
https://bugzilla.redhat.com/show_bug.cgi?id=462744

Description:
===========
When kexec is disabled, the crash_shutdown_{un,}register functions are not
available in the kernel. This provides dummy inline functions for those so that
the callers don't have to worry about it.

RHEL Version Found:
================
RHEL 5.2

kABI Status:
============
No symbols were harmed.

Brew:
=====
Built on all platforms.
http://brewweb.devel.redhat.com/brew/taskinfo?taskID=1540066

Upstream Status:
================
http://kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.26-rc8/2.6.26-rc8-mm1/broken-out/linux-next.patch

commit aee10c6145199f872bc51f811b115a4b686b2426
Author: Arnd Bergmann <arnd@arndb.de>
Date:   Thu Jun 12 19:14:34 2008 +1000

    powerpc: Provide dummy crash_shutdown_register

    Signed-off-by: Arnd Bergmann <arnd@arndb.de>
    Signed-off-by: Paul Mackerras <paulus@samba.org>

Test Status:
============
Without the patch the QS21 shows a "cpu internal fault" and reboots.  With this
patch the message is not seen.
===============================================================
Ameet Paranjape 978-392-3903 ext 23903
IBM on-site partner

Proposed Patch:
===============

diff --git a/include/asm-powerpc/kexec.h b/include/asm-powerpc/kexec.h
index a6178dd..ad17fe0 100644
--- a/include/asm-powerpc/kexec.h
+++ b/include/asm-powerpc/kexec.h
@@ -34,6 +34,8 @@
 #ifndef __ASSEMBLY__
 #include <linux/cpumask.h>
 
+typedef void (*crash_shutdown_t)(void);
+
 #ifdef CONFIG_KEXEC
 
 #ifdef __powerpc64__
@@ -125,7 +127,6 @@ struct pt_regs;
 extern void default_machine_kexec(struct kimage *image);
 extern int default_machine_kexec_prepare(struct kimage *image);
 extern void default_machine_crash_shutdown(struct pt_regs *regs);
-typedef void (*crash_shutdown_t)(void);
 extern int crash_shutdown_register(crash_shutdown_t handler);
 extern int crash_shutdown_unregister(crash_shutdown_t handler);
 
@@ -145,6 +146,16 @@ static inline int overlaps_crashkernel(unsigned long start, unsigned long size)
 
 static inline void reserve_crashkernel(void) { ; }
 
+static inline int crash_shutdown_register(crash_shutdown_t handler)
+{
+	return 0;
+}
+
+static inline int crash_shutdown_unregister(crash_shutdown_t handler)
+{
+	return 0;
+}
+
 #endif /* CONFIG_KEXEC */
 #endif /* ! __ASSEMBLY__ */
 #endif /* __KERNEL__ */