powerpc/44x: No need to mask MSR:CE, ME or DE in _tlbil_va on 440

The handlers for Critical, Machine Check or Debug interrupts
will save and restore MMUCR nowadays, thus we only need to
disable normal interrupts when invalidating TLB entries.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 10 insertions, 9 deletions

diff --git a/arch/powerpc/mm/tlb_nohash_low.S b/arch/powerpc/mm/tlb_nohash_low.S
index 763c59fe0076..f900a39e6ec4 100644
--- a/arch/powerpc/mm/tlb_nohash_low.S
+++ b/arch/powerpc/mm/tlb_nohash_low.S
@@ -75,18 +75,19 @@ _GLOBAL(_tlbil_va)
         mfspr   r5,SPRN_MMUCR
         rlwimi  r5,r4,0,24,31                   /* Set TID */
 
-        /* We have to run the search with interrupts disabled, even critical
-         * and debug interrupts (in fact the only critical exceptions we have
-         * are debug and machine check).  Otherwise  an interrupt which causes
-         * a TLB miss can clobber the MMUCR between the mtspr and the tlbsx. */
+        /* We have to run the search with interrupts disabled, otherwise
+         * an interrupt which causes a TLB miss can clobber the MMUCR
+         * between the mtspr and the tlbsx.
+         *
+         * Critical and Machine Check interrupts take care of saving
+         * and restoring MMUCR, so only normal interrupts have to be
+         * taken care of.
+         */
         mfmsr   r4
-        lis     r6,(MSR_EE|MSR_CE|MSR_ME|MSR_DE)@ha
-        addi    r6,r6,(MSR_EE|MSR_CE|MSR_ME|MSR_DE)@l
-        andc    r6,r4,r6
-        mtmsr   r6
+        wrteei  0
         mtspr   SPRN_MMUCR,r5
         tlbsx.  r3, 0, r3
-        mtmsr   r4
+        wrtee   r4
         bne     1f
         sync
         /* There are only 64 TLB entries, so r3 < 64,