powerpc/8xx: Add missing Guarded setting in DTLB Error.

only DTLB Miss did set this bit, DTLB Error needs too otherwise
the setting is lost when the page becomes dirty.

Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index c00120d..1a28ee8 100644 (file)
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -552,9 +552,16 @@ DARFixed:/* Return from dcbx instruction bug workaround, r10 holds value of DAR
         */
        ori     r11, r11, 1             /* Set valid bit in physical L2 page */
        DO_8xx_CPU6(0x3b80, r3)
-       mtspr   SPRN_MD_TWC, r11                /* Load pte table base address */
-       mfspr   r11, SPRN_MD_TWC                /* ....and get the pte address */
-       lwz     r10, 0(r11)             /* Get the pte */
+       mtspr   SPRN_MD_TWC, r11        /* Load pte table base address */
+       mfspr   r10, SPRN_MD_TWC        /* ....and get the pte address */
+       lwz     r10, 0(r10)             /* Get the pte */
+       /* Insert the Guarded flag into the TWC from the Linux PTE.
+        * It is bit 27 of both the Linux PTE and the TWC
+        */
+       rlwimi  r11, r10, 0, 27, 27
+       DO_8xx_CPU6(0x3b80, r3)
+       mtspr   SPRN_MD_TWC, r11
+       mfspr   r11, SPRN_MD_TWC        /* get the pte address again */
 
        ori     r10, r10, _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_HWWRITE
        stw     r10, 0(r11)             /* and update pte in table */