[IA64-SGI] Fix SN PTC deadlock recovery

The patch that added support for a new platform chipset (shub2) broke
PTC deadlock recovery on older versions of the chipset. (PTCs are the
SN platform-specific method for doing a global TLB purge). This
patch fixes deadlock recovery so that it works on both the old & new
chipsets.

Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/arch/ia64/sn/kernel/sn2/ptc_deadlock.S b/arch/ia64/sn/kernel/sn2/ptc_deadlock.S
index 3fa95065a446..bebbcc4f8dd4 100644
--- a/arch/ia64/sn/kernel/sn2/ptc_deadlock.S
+++ b/arch/ia64/sn/kernel/sn2/ptc_deadlock.S
@@ -39,9 +39,13 @@ sn2_ptc_deadlock_recovery_core:
         mov     r8=r0
 
 1:
+        cmp.ne  p8,p9=r0,ptc1           // Test for shub type (ptc1 non-null on shub1)
+                                        // p8 = 1 if shub1, p9 = 1 if shub2
+
         add     scr2=ALIAS_OFFSET,piowc // Address of WRITE_STATUS alias register 
-        ;;
-        ld8.acq scr1=[scr2];;
+        mov     scr1=7;;                // Clear DEADLOCK, WRITE_ERROR, MULTI_WRITE_ERROR
+(p8)    st8.rel [scr2]=scr1;;
+(p9)    ld8.acq scr1=[scr2];;
 
 5:      ld8.acq scr1=[piowc];;          // Wait for PIOs to complete.
         hint    @pause