[IA64] Failure to resume after INIT in user space

The OS INIT handler is loading incorrect values into cr.ifa on exit.
This shows up as a hang when resuming after an INIT that is delivered
while a cpu is in user space.  Correct the value loaded into cr.ifa.
Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/kernel/mca_asm.S

@@ -827,7 +827,7 @@ ia64_state_restore:
 	ld8 r9=[temp2],16	// sal_gp
 	;;
 	ld8 r22=[temp1],16	// pal_min_state, virtual
-	ld8 r21=[temp2],16	// prev_IA64_KR_CURRENT
+	ld8 r13=[temp2],16	// prev_IA64_KR_CURRENT
 	;;
 	ld8 r16=[temp1],16	// prev_IA64_KR_CURRENT_STACK
 	ld8 r20=[temp2],16	// prev_task
@@ -848,7 +848,7 @@ ia64_state_restore:
 	mov cr.iim=temp3
 	mov cr.iha=temp4
 	dep r22=0,r22,62,1	// pal_min_state, physical, uncached
-	mov IA64_KR(CURRENT)=r21
+	mov IA64_KR(CURRENT)=r13
 	ld8 r8=[temp1]		// os_status
 	ld8 r10=[temp2]		// context
 
@@ -856,7 +856,7 @@ ia64_state_restore:
 	 * avoid any dependencies on the algorithm in ia64_switch_to(), just
 	 * purge any existing CURRENT_STACK mapping and insert the new one.
 	 *
-	 * r16 contains prev_IA64_KR_CURRENT_STACK, r21 contains
+	 * r16 contains prev_IA64_KR_CURRENT_STACK, r13 contains
 	 * prev_IA64_KR_CURRENT, these values may have been changed by the C
 	 * code.  Do not use r8, r9, r10, r22, they contain values ready for
 	 * the return to SAL.
@@ -873,7 +873,7 @@ ia64_state_restore:
 	;;
 	srlz.d
 
-	extr.u r19=r21,61,3			// r21 = prev_IA64_KR_CURRENT
+	extr.u r19=r13,61,3			// r13 = prev_IA64_KR_CURRENT
 	shl r20=r16,IA64_GRANULE_SHIFT		// r16 = prev_IA64_KR_CURRENT_STACK
 	movl r21=PAGE_KERNEL			// page properties
 	;;
@@ -883,7 +883,7 @@ ia64_state_restore:
 (p6)	br.spnt 1f				// the dreaded cpu 0 idle task in region 5:(
 	;;
 	mov cr.itir=r18
-	mov cr.ifa=r21
+	mov cr.ifa=r13
 	mov r20=IA64_TR_CURRENT_STACK
 	;;
 	itr.d dtr[r20]=r21