[POWERPC] Fixes for the SLB shadow buffer code

On a machine with hardware 64kB pages and a kernel configured for a
64kB base page size, we need to change the vmalloc segment from 64kB
pages to 4kB pages if some driver creates a non-cacheable mapping in
the vmalloc area.  However, we never updated with SLB shadow buffer.
This fixes it.  Thanks to paulus for finding this.

Also added some write barriers to ensure the shadow buffer contents
are always consistent.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 9ef28da2c7fe..952eba6701f4 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -389,8 +389,11 @@ BEGIN_FTR_SECTION
         ld      r9,PACA_SLBSHADOWPTR(r13)
         li      r12,0
         std     r12,SLBSHADOW_STACKESID(r9) /* Clear ESID */
+        eieio
         std     r7,SLBSHADOW_STACKVSID(r9)  /* Save VSID */
+        eieio
         std     r0,SLBSHADOW_STACKESID(r9)  /* Save ESID */
+        eieio
 
         slbie   r6
         slbie   r6              /* Workaround POWER5 < DD2.1 issue */