I believe a few words here would be useful even for the future version of yourself ;-) On Tue, Aug 10, 2021 at 05:42:51PM -0700, Vineet Gupta wrote: > Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxx> > --- > arch/arc/kernel/entry.S | 6 ------ > arch/arc/mm/tlb.c | 3 +++ > 2 files changed, 3 insertions(+), 6 deletions(-) > > diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S > index 2cb8dfe866b6..684efd094520 100644 > --- a/arch/arc/kernel/entry.S > +++ b/arch/arc/kernel/entry.S > @@ -101,12 +101,6 @@ ENTRY(EV_MachineCheck) > lr r0, [efa] > mov r1, sp > > - ; hardware auto-disables MMU, re-enable it to allow kernel vaddr > - ; access for say stack unwinding of modules for crash dumps > - lr r3, [ARC_REG_PID] > - or r3, r3, MMU_ENABLE > - sr r3, [ARC_REG_PID] > - > lsr r3, r2, 8 > bmsk r3, r3, 7 > brne r3, ECR_C_MCHK_DUP_TLB, 1f > diff --git a/arch/arc/mm/tlb.c b/arch/arc/mm/tlb.c > index b68d5798327b..34f16e0b41e6 100644 > --- a/arch/arc/mm/tlb.c > +++ b/arch/arc/mm/tlb.c > @@ -813,5 +813,8 @@ void do_tlb_overlap_fault(unsigned long cause, unsigned long address, > } > } > > + /* Re-enable MMU as hardware may have auto-disabled it upon exception */ > + write_aux_reg(ARC_REG_PID, read_aux_reg(ARC_REG_PID) | MMU_ENABLE); > + > local_irq_restore(flags); > } > -- > 2.25.1 > -- Sincerely yours, Mike.
