powerpc/fsl-booke: Fixup 64-bit PTE reading for SMP support

We need to create a false data dependency to ensure the loads of
the pte are done in the right order.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 21 insertions, 5 deletions

diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 3cb52fa0eda3..377e0c155c95 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -579,13 +579,19 @@ interrupt_base:
 
         FIND_PTE
         andc.   r13,r13,r11             /* Check permission */
-        bne     2f                      /* Bail if permission mismach */
 
 #ifdef CONFIG_PTE_64BIT
-        lwz     r13, 0(r12)
+#ifdef CONFIG_SMP
+        subf    r10,r11,r12             /* create false data dep */
+        lwzx    r13,r11,r10             /* Get upper pte bits */
+#else
+        lwz     r13,0(r12)              /* Get upper pte bits */
+#endif
 #endif
 
-         /* Jump to common tlb load */
+        bne     2f                      /* Bail if permission/valid mismach */
+
+        /* Jump to common tlb load */
         b       finish_tlb_load
 2:
         /* The bailout.  Restore registers to pre-exception conditions
@@ -640,10 +646,20 @@ interrupt_base:
 
         FIND_PTE
         andc.   r13,r13,r11             /* Check permission */
+
+#ifdef CONFIG_PTE_64BIT
+#ifdef CONFIG_SMP
+        subf    r10,r11,r12             /* create false data dep */
+        lwzx    r13,r11,r10             /* Get upper pte bits */
+#else
+        lwz     r13,0(r12)              /* Get upper pte bits */
+#endif
+#endif
+
         bne     2f                      /* Bail if permission mismach */
 
 #ifdef CONFIG_PTE_64BIT
-        lwz     r13, 0(r12)
+        lwz     r13,0(r12)
 #endif
 
         /* Jump to common TLB load point */
@@ -702,7 +718,7 @@ interrupt_base:
 /*
  * Both the instruction and data TLB miss get to this
  * point to load the TLB.
- *      r10 - EA of fault
+ *      r10 - available to use
  *      r11 - TLB (info from Linux PTE)
  *      r12 - available to use
  *      r13 - upper bits of PTE (if PTE_64BIT) or available to use