[PATCH] powerpc/chrp: Fix enter_rtas() with CONFIG_VMAP_STACK

[Christophe Leroy]

With CONFIG_VMAP_STACK, data MMU has to be enabled
to read data on the stack.

Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr>
---
 arch/powerpc/kernel/entry_32.S | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 0713daa651d9..bc056d906b51 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -1354,12 +1354,17 @@ _GLOBAL(enter_rtas)
        mtspr   SPRN_SRR0,r8
        mtspr   SPRN_SRR1,r9
        RFI
-1:     tophys(r9,r1)
+1:     tophys_novmstack r9, r1
+#ifdef CONFIG_VMAP_STACK
+       li      r0, MSR_KERNEL & ~MSR_IR        /* can take DTLB miss */
+       mtmsr   r0
+       isync
+#endif
        lwz     r8,INT_FRAME_SIZE+4(r9) /* get return address */
        lwz     r9,8(r9)        /* original msr value */
        addi    r1,r1,INT_FRAME_SIZE
        li      r0,0
-       tophys(r7, r2)
+       tophys_novmstack r7, r2
        stw     r0, THREAD + RTAS_SP(r7)
        mtspr   SPRN_SRR0,r8
        mtspr   SPRN_SRR1,r9
-- 
2.25.0