@@ -92,6 +92,12 @@ 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
@@ -105,12 +105,6 @@ int do_misaligned_access(unsigned long address, struct pt_regs *regs,
*/
void do_machine_check_fault(unsigned long address, struct pt_regs *regs)
{
- /*
- * Hardware auto-disables MMU upon this exception hence re-enabled
- * for ksym lookup in modules to work (in kernel vaddr space)
- */
- write_aux_reg(ARC_REG_PID, MMU_ENABLE | read_aux_reg(ARC_REG_PID));
-
die("Unhandled Machine Check Exception", regs, address);
}
@@ -908,9 +908,6 @@ void do_tlb_overlap_fault(unsigned long cause, unsigned long address,
local_irq_save(flags);
- /* re-enable the MMU */
- write_aux_reg(ARC_REG_PID, MMU_ENABLE | read_aux_reg(ARC_REG_PID));
-
/* loop thru all sets of TLB */
for (set = 0; set < mmu->sets; set++) {
Machine check Exception is handled in distinc ways depending on cause - Duplicate TLB Entry (relevent mostly for ARC700) - everything else Currently we re-enable MMU seperately for each of these cases, which can be consolidated by dign this before we fork off the handling in low level handler. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> --- arch/arc/kernel/entry.S | 6 ++++++ arch/arc/kernel/traps.c | 6 ------ arch/arc/mm/tlb.c | 3 --- 3 files changed, 6 insertions(+), 9 deletions(-)