In the more likely case of returning to kernel from perf interrupt, do a fast path returning w/o bothering about CONFIG_PREEMPT etc However, if returning to user space, need do go thru the usual gyrations, as check for pending signals is an absolute must. Signed-off-by: Vineet Gupta <vgupta at synopsys.com> --- arch/arc/include/asm/entry-arcv2.h | 2 ++ arch/arc/kernel/entry-arcv2.S | 23 ++++++++++++++++++++++- 2 files changed, 24 insertions(+), 1 deletion(-) diff --git a/arch/arc/include/asm/entry-arcv2.h b/arch/arc/include/asm/entry-arcv2.h index 257a68f3c2fe..8b49b327b1f9 100644 --- a/arch/arc/include/asm/entry-arcv2.h +++ b/arch/arc/include/asm/entry-arcv2.h @@ -58,6 +58,8 @@ /*------------------------------------------------------------------------*/ .macro INTERRUPT_EPILOGUE called_from + ; Assumes STATUS32.Z bit set if return to K + .ifnc \called_from, exception add sp, sp, 12 ; skip BTA/ECR/orig_r0 placeholderss .endif diff --git a/arch/arc/kernel/entry-arcv2.S b/arch/arc/kernel/entry-arcv2.S index cc558a25b8fa..9ca1d146426b 100644 --- a/arch/arc/kernel/entry-arcv2.S +++ b/arch/arc/kernel/entry-arcv2.S @@ -51,7 +51,7 @@ VECTOR handle_interrupt ; (16) Timer0 VECTOR handle_interrupt ; unused (Timer1) VECTOR handle_interrupt ; unused (WDT) VECTOR handle_interrupt ; (19) Inter core Interrupt (IPI) -VECTOR handle_interrupt ; (20) perf Interrupt +VECTOR handle_interrupt_pct ; (20) perf Interrupt VECTOR handle_interrupt ; (21) Software Triggered Intr (Self IPI) VECTOR handle_interrupt ; unused VECTOR handle_interrupt ; (23) unused @@ -97,6 +97,26 @@ ENTRY(handle_interrupt) END(handle_interrupt) +ENTRY(handle_interrupt_pct) + + INTERRUPT_PROLOGUE irq + + IRQ_DISABLE + + lr r0, [ICAUSE] + + bl.d arch_do_IRQ + mov r1, sp + + ld r0, [sp, PT_status32] ; returning to User/Kernel Mode + btst r0, STATUS_U_BIT + bnz resume_user_mode_begin + + clri + b .Lisr_ret_fast_path_to_k + +END(handle_interrupt_pct) + ;################### Non TLB Exception Handling ############################# ENTRY(EV_SWI) @@ -224,6 +244,7 @@ debug_marker_l1: bset.nz r11, r11, AUX_IRQ_ACT_BIT_U ; NZ means U sr r11, [AUX_IRQ_ACT] +.Lisr_ret_fast_path_to_k: INTERRUPT_EPILOGUE irq rtie -- 2.7.4
