MN10300: AM34 erratum requires MMUCTR read and write on exception entry

An AM34 erratum requires MMUCTR read and write on entry to certain exceptions,
prior to EPSW.NMID being cleared to allow NMIs to happen.

Signed-off-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: Kiyoshi Owada <owada.kiyoshi@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/arch/mn10300/kernel/entry.S b/arch/mn10300/kernel/entry.S
index b82ce7b47fcb..355f68176771 100644
--- a/arch/mn10300/kernel/entry.S
+++ b/arch/mn10300/kernel/entry.S
@@ -251,6 +251,10 @@ double_fault_loop:
 ENTRY(raw_bus_error)
         add     -4,sp
         mov     d0,(sp)
+#if defined(CONFIG_ERRATUM_NEED_TO_RELOAD_MMUCTR)
+        mov     (MMUCTR),d0
+        mov     d0,(MMUCTR)
+#endif
         mov     (BCBERR),d0             # what
         btst    BCBERR_BEMR_DMA,d0      # see if it was an external bus error
         beq     __common_exception_aux  # it wasn't
@@ -282,6 +286,10 @@ ENTRY(nmi_handler)
 ENTRY(__common_exception)
         add     -4,sp
         mov     d0,(sp)
+#if defined(CONFIG_ERRATUM_NEED_TO_RELOAD_MMUCTR)
+        mov     (MMUCTR),d0
+        mov     d0,(MMUCTR)
+#endif
 
 __common_exception_aux:
         mov     (TBR),d0