From 8f19e3daf3fffee9e18a8812067a6a4b538ae6c8 Mon Sep 17 00:00:00 2001 From: Akira Takeuchi Date: Wed, 27 Oct 2010 17:28:48 +0100 Subject: [PATCH] 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 Signed-off-by: Kiyoshi Owada Signed-off-by: David Howells --- arch/mn10300/Kconfig | 3 +++ arch/mn10300/kernel/entry.S | 8 ++++++++ arch/mn10300/mm/tlb-mn10300.S | 32 ++++++++++++++++++++++++++------ 3 files changed, 37 insertions(+), 6 deletions(-) diff --git a/arch/mn10300/Kconfig b/arch/mn10300/Kconfig index 21e2a534d98e..dd7b5700358b 100644 --- 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 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 diff --git a/arch/mn10300/mm/tlb-mn10300.S b/arch/mn10300/mm/tlb-mn10300.S index 7095147dcb8b..ccf622999a5b 100644 --- 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