2 files changed, 11 insertions, 2 deletions

diff --git a/arch/powerpc/include/asm/pte-8xx.h b/arch/powerpc/include/asm/pte-8xx.h
index 68ba861331ee..d44826e4ff97 100644
--- a/arch/powerpc/include/asm/pte-8xx.h
+++ b/arch/powerpc/include/asm/pte-8xx.h
@@ -35,11 +35,12 @@
 #define _PAGE_SPECIAL   0x0008  /* SW entry, forced to 0 by the TLB miss */
 #define _PAGE_DIRTY     0x0100  /* C: page changed */
 
-/* These 3 software bits must be masked out when the entry is loaded
- * into the TLB, 2 SW bits left.
+/* These 4 software bits must be masked out when the entry is loaded
+ * into the TLB, 1 SW bit left(0x0080).
  */
 #define _PAGE_GUARDED   0x0010  /* software: guarded access */
 #define _PAGE_ACCESSED  0x0020  /* software: page referenced */
+#define _PAGE_WRITETHRU 0x0040  /* software: caching is write through */
 
 /* Setting any bits in the nibble with the follow two controls will
  * require a TLB exception handler change.  It is assumed unused bits
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 1a28ee8ca318..c4ae85b8f8c0 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -422,6 +422,10 @@ DataStoreTLBMiss:
          * above.
          */
         rlwimi  r11, r10, 0, 27, 27
+        /* Insert the WriteThru flag into the TWC from the Linux PTE.
+         * It is bit 25 in the Linux PTE and bit 30 in the TWC
+         */
+        rlwimi  r11, r10, 32-5, 30, 30
         DO_8xx_CPU6(0x3b80, r3)
         mtspr   SPRN_MD_TWC, r11
 
@@ -559,6 +563,10 @@ DARFixed:/* Return from dcbx instruction bug workaround, r10 holds value of DAR
          * It is bit 27 of both the Linux PTE and the TWC
          */
         rlwimi  r11, r10, 0, 27, 27
+        /* Insert the WriteThru flag into the TWC from the Linux PTE.
+         * It is bit 25 in the Linux PTE and bit 30 in the TWC
+         */
+        rlwimi  r11, r10, 32-5, 30, 30
         DO_8xx_CPU6(0x3b80, r3)
         mtspr   SPRN_MD_TWC, r11
         mfspr   r11, SPRN_MD_TWC        /* get the pte address again */