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>

diff --git a/arch/mn10300/Kconfig b/arch/mn10300/Kconfig
index 21e2a53..dd7b570 100644 (file)
--- a/arch/mn10300/Kconfig
+++ b/arch/mn10300/Kconfig
@@ -20,6 +20,9 @@ config AM34_2
        select MN10300_HAS_ATOMIC_OPS_UNIT
        select MN10300_HAS_CACHE_SNOOP
 
+config ERRATUM_NEED_TO_RELOAD_MMUCTR
+       def_bool y if AM33_3 || AM34_2
+
 config MMU
        def_bool y
 

diff --git a/arch/mn10300/kernel/entry.S b/arch/mn10300/kernel/entry.S
index b82ce7b..355f681 100644 (file)
--- 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

diff --git a/arch/mn10300/mm/tlb-mn10300.S b/arch/mn10300/mm/tlb-mn10300.S
index 7095147..ccf6229 100644 (file)
--- a/arch/mn10300/mm/tlb-mn10300.S
+++ b/arch/mn10300/mm/tlb-mn10300.S
@@ -27,7 +27,6 @@
 ###############################################################################
        .type   itlb_miss,@function
 ENTRY(itlb_miss)
-       and     ~EPSW_NMID,epsw
 #ifdef CONFIG_GDBSTUB
        movm    [d2,d3,a2],(sp)
 #else
@@ -38,6 +37,12 @@ ENTRY(itlb_miss)
        nop
 #endif
 
+#if defined(CONFIG_ERRATUM_NEED_TO_RELOAD_MMUCTR)
+       mov     (MMUCTR),d2
+       mov     d2,(MMUCTR)
+#endif
+
+       and     ~EPSW_NMID,epsw
        mov     (IPTEU),d3
        mov     (PTBR),a2
        mov     d3,d2
@@ -79,7 +84,6 @@ itlb_miss_fault:
 ###############################################################################
        .type   dtlb_miss,@function
 ENTRY(dtlb_miss)
-       and     ~EPSW_NMID,epsw
 #ifdef CONFIG_GDBSTUB
        movm    [d2,d3,a2],(sp)
 #else
@@ -90,6 +94,12 @@ ENTRY(dtlb_miss)
        nop
 #endif
 
+#if defined(CONFIG_ERRATUM_NEED_TO_RELOAD_MMUCTR)
+       mov     (MMUCTR),d2
+       mov     d2,(MMUCTR)
+#endif
+
+       and     ~EPSW_NMID,epsw
        mov     (DPTEU),d3
        mov     (PTBR),a2
        mov     d3,d2
@@ -130,9 +140,15 @@ dtlb_miss_fault:
 ###############################################################################
        .type   itlb_aerror,@function
 ENTRY(itlb_aerror)
-       and     ~EPSW_NMID,epsw
        add     -4,sp
        SAVE_ALL
+
+#if defined(CONFIG_ERRATUM_NEED_TO_RELOAD_MMUCTR)
+       mov     (MMUCTR),d1
+       mov     d1,(MMUCTR)
+#endif
+
+       and     ~EPSW_NMID,epsw
        add     -4,sp                           # need to pass three params
 
        # calculate the fault code
@@ -148,7 +164,6 @@ ENTRY(itlb_aerror)
        clr     d0
        mov     d0,(IPTEL)
 
-       and     ~EPSW_NMID,epsw
        or      EPSW_IE,epsw
        mov     fp,d0
        call    do_page_fault[],0               # do_page_fault(regs,code,addr
@@ -163,10 +178,16 @@ ENTRY(itlb_aerror)
 ###############################################################################
        .type   dtlb_aerror,@function
 ENTRY(dtlb_aerror)
-       and     ~EPSW_NMID,epsw
        add     -4,sp
        SAVE_ALL
+
+#if defined(CONFIG_ERRATUM_NEED_TO_RELOAD_MMUCTR)
+       mov     (MMUCTR),d1
+       mov     d1,(MMUCTR)
+#endif
+
        add     -4,sp                           # need to pass three params
+       and     ~EPSW_NMID,epsw
 
        # calculate the fault code
        movhu   (MMUFCR_DFC),d1
@@ -180,7 +201,6 @@ ENTRY(dtlb_aerror)
        clr     d0
        mov     d0,(DPTEL)
 
-       and     ~EPSW_NMID,epsw
        or      EPSW_IE,epsw
        mov     fp,d0
        call    do_page_fault[],0               # do_page_fault(regs,code,addr