[PATCH 3.10 18/48] ARC: Entry Handler tweaks: Simplify branch for in-kernel preemption

From: Greg Kroah-Hartman
Date: Sun May 11 2014 - 15:47:35 EST


3.10-stable review patch. If anyone has any objections, please let me know.

------------------

From: Vineet Gupta <vgupta@xxxxxxxxxxxx>

commit 147aece29b15051173eb1e767018135361cdba89 upstream.

Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/arc/kernel/entry.S | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -589,11 +589,7 @@ ARC_ENTRY ret_from_exception
; Pre-{IRQ,Trap,Exception} K/U mode from pt_regs->status32
ld r8, [sp, PT_status32] ; returning to User/Kernel Mode

-#ifdef CONFIG_PREEMPT
bbit0 r8, STATUS_U_BIT, resume_kernel_mode
-#else
- bbit0 r8, STATUS_U_BIT, restore_regs
-#endif

; Before returning to User mode check-for-and-complete any pending work
; such as rescheduling/signal-delivery etc.
@@ -653,10 +649,10 @@ resume_user_mode_begin:
b resume_user_mode_begin ; unconditionally back to U mode ret chks
; for single exit point from this block

-#ifdef CONFIG_PREEMPT
-
resume_kernel_mode:

+#ifdef CONFIG_PREEMPT
+
; Can't preempt if preemption disabled
GET_CURR_THR_INFO_FROM_SP r10
ld r8, [r10, THREAD_INFO_PREEMPT_COUNT]


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