[PATCH] PPC64 iSeries fails to boot

Jeremy Katz of Red Hat reported that his iSeries machine would not boot
with 2.6.7 based kernels.

It appears that with the inclusion of Paul Mackerras' patch "Optimize
exception/syscall entry/exit" a small previous patch got reverted.  Here
is that patch again.  The lack of this patch does not stop all iSeries
machines booting, but it does stop some.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/ppc64/kernel/head.S

@@ -631,6 +631,9 @@ SystemCall_Iseries:
 	.globl SystemReset_Iseries
 SystemReset_Iseries:
 	mfspr	r13,SPRG3		/* Get paca address */
+	mfmsr	r24
+	ori	r24,r24,MSR_RI
+	mtmsrd	r24			/* RI on */
 	lhz	r24,PACAPACAINDEX(r13)	/* Get processor # */
 	cmpwi	0,r24,0			/* Are we processor 0? */
 	beq	.__start_initialization_iSeries	/* Start up the first processor */