Elide the need to re-read ECR in Trap handler by ensuring that EXCEPTION_PROLOGUE does that at the very end just before returning to Trap handler ARCv2 EXCEPTION_PROLOGUE already did that, so same for ARcompact and the common trap handler adjusted to use cached ECR Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx> --- arch/arc/include/asm/entry-compact.h | 5 +++-- arch/arc/kernel/entry.S | 4 ++-- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/arc/include/asm/entry-compact.h b/arch/arc/include/asm/entry-compact.h index 6c0a81b598d2..8b65eb36655a 100644 --- a/arch/arc/include/asm/entry-compact.h +++ b/arch/arc/include/asm/entry-compact.h @@ -181,8 +181,6 @@ /* ARC700 doesn't provide auto-stack switching */ SWITCH_TO_KERNEL_STK - lr r9, [ecr] - st r9, [sp, 8] /* ECR */ st r0, [sp, 4] /* orig_r0, needed only for sys calls */ /* Restore r9 used to code the early prologue */ @@ -198,6 +196,9 @@ PUSHAX lp_end PUSHAX lp_start PUSHAX erbta + + lr r9, [ecr] + st r9, [sp, PT_event] /* EV_Trap expects r9 to have ECR */ .endm /*-------------------------------------------------------------- diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S index 603266eb75e1..f7a82fd4d601 100644 --- a/arch/arc/kernel/entry.S +++ b/arch/arc/kernel/entry.S @@ -258,8 +258,8 @@ ENTRY(EV_Trap) EXCEPTION_PROLOGUE ;============ TRAP 1 :breakpoints - lr r10, [ecr] - bmsk.f 0, r10, 7 + ; Check ECR for trap with arg (PROLOGUE ensures r9 has ECR) + bmsk.f 0, r9, 7 bnz trap_with_param ;============ TRAP (no param): syscall top level -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
