powerpc/47x: Make sure mcsr is cleared before enabling machine check interrupts

Clear the machine check syndrom register before enabling machine check
interrupts.  The initial state of the tlb can lead to parity errors being
flagged early after a cold boot.

Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index 5ab484ef06a7..562305b40a8e 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -113,6 +113,10 @@ _ENTRY(_start);
         stw     r5, 0(r4)       /* Save abatron_pteptrs at a fixed location */
         stw     r6, 0(r5)
 
+        /* Clear the Machine Check Syndrome Register */
+        li      r0,0
+        mtspr   SPRN_MCSR,r0
+
         /* Let's move on */
         lis     r4,start_kernel@h
         ori     r4,r4,start_kernel@l