[POWERPC] Make sure interrupt enable gets restored properly

The lazy IRQ disable patch missed a couple of places where the
interrupt enable flags need to be restored correctly.  First, we
weren't restoring the paca->hard_enabled flag on interrupt exit.
Instead of saving it on entry, we compute it from the MSR_EE bit
in the MSR we are restoring at exit.  Secondly, the MMU hash miss
code was clearing both paca->soft_enabled and paca->hard_enabled
but not restoring them in the case where hash_page was able to
resolve the miss from the Linux page tables.

Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index efda48741b29..86e2bdd5afd6 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -489,6 +489,10 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
         andi.   r0,r3,MSR_RI
         beq-    unrecov_restore
 
+        /* extract EE bit and use it to restore paca->hard_enabled */
+        rldicl  r4,r3,49,63             /* r0 = (r3 >> 15) & 1 */
+        stb     r4,PACAHARDIRQEN(r13)
+
         andi.   r0,r3,MSR_PR
 
         /*