diff options
Diffstat (limited to 'arch/arc/kernel/entry-arcv2.S')
| -rw-r--r-- | arch/arc/kernel/entry-arcv2.S | 58 |
1 files changed, 10 insertions, 48 deletions
diff --git a/arch/arc/kernel/entry-arcv2.S b/arch/arc/kernel/entry-arcv2.S index 0fc408ec0814..12d5f12d10d2 100644 --- a/arch/arc/kernel/entry-arcv2.S +++ b/arch/arc/kernel/entry-arcv2.S @@ -79,7 +79,7 @@ ENTRY(handle_interrupt) # # Note this disable is only for consistent book-keeping as further interrupts # will be disabled anyways even w/o this. Hardware tracks active interrupts - # seperately in AUX_IRQ_ACTIVE.active and will not take new interrupts + # seperately in AUX_IRQ_ACT.active and will not take new interrupts # unless this one returns (or higher prio becomes pending in 2-prio scheme) IRQ_DISABLE @@ -200,17 +200,18 @@ restore_regs: ld r0, [sp, PT_status32] ; U/K mode at time of entry lr r10, [AUX_IRQ_ACT] - bmsk r11, r10, 15 ; AUX_IRQ_ACT.ACTIVE + bmsk r11, r10, 15 ; extract AUX_IRQ_ACT.active breq r11, 0, .Lexcept_ret ; No intr active, ret from Exception ;####### Return from Intr ####### +.Lisr_ret: + debug_marker_l1: ; bbit1.nt r0, STATUS_DE_BIT, .Lintr_ret_to_delay_slot btst r0, STATUS_DE_BIT ; Z flag set if bit clear bnz .Lintr_ret_to_delay_slot ; branch if STATUS_DE_BIT set -.Lisr_ret_fast_path: ; Handle special case #1: (Entry via Exception, Return via IRQ) ; ; Exception in U mode, preempted in kernel, Intr taken (K mode), orig @@ -244,8 +245,8 @@ debug_marker_syscall: ; ; IRQ RTIE won't reliably restore DE bit and/or BTA, needs workaround ; -; Solution is return from Intr w/o any delay slot quirks into a kernel trampoline -; and from pure kernel mode return to delay slot which handles DS bit/BTA correctly +; Solution is to drop out of interrupt context into pure kernel mode +; and return from pure kernel mode which does right things for delay slot .Lintr_ret_to_delay_slot: debug_marker_ds: @@ -254,48 +255,9 @@ debug_marker_ds: add r2, r2, 1 st r2, [@intr_to_DE_cnt] - ld r2, [sp, PT_ret] - ld r3, [sp, PT_status32] - - ; STAT32 for Int return created from scratch - ; (No delay dlot, disable Further intr in trampoline) - - bic r0, r3, STATUS_U_MASK|STATUS_DE_MASK|STATUS_IE_MASK|STATUS_L_MASK - st r0, [sp, PT_status32] - - mov r1, .Lintr_ret_to_delay_slot_2 - st r1, [sp, PT_ret] - - ; Orig exception PC/STAT32 safekept @orig_r0 and @event stack slots - st r2, [sp, 0] - st r3, [sp, 4] - - b .Lisr_ret_fast_path - -.Lintr_ret_to_delay_slot_2: - ; Trampoline to restore orig exception PC/STAT32/BTA/AUX_USER_SP - sub sp, sp, SZ_PT_REGS - st r9, [sp, -4] - - ld r9, [sp, 0] - sr r9, [eret] - - ld r9, [sp, 4] - sr r9, [erstatus] - - ; restore AUX_USER_SP if returning to U mode - bbit0 r9, STATUS_U_BIT, 1f - ld r9, [sp, PT_sp] - sr r9, [AUX_USER_SP] - -1: - ld r9, [sp, 8] - sr r9, [erbta] - - ld r9, [sp, -4] - add sp, sp, SZ_PT_REGS - - ; return from pure kernel mode to delay slot - rtie + ; drop out of interrupt context (clear AUX_IRQ_ACT.active) + bmskn r11, r10, 15 + sr r11, [AUX_IRQ_ACT] + b .Lexcept_ret END(ret_from_exception) |