linux-kernel - [RFC PATCH 2/3] ARM: entry: Remove unneeded need

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Date:   Thu, 31 Jan 2019 18:23:38 +0000
From:   Valentin Schneider <valentin.schneider@....com>
To:     linux-kernel@...r.kernel.org
Cc:     Russell King <linux@...linux.org.uk>,
        Thomas Gleixner <tglx@...utronix.de>,
        Will Deacon <will.deacon@....com>,
        Julien Thierry <julien.thierry@....com>,
        linux-arm-kernel@...ts.infradead.org
Subject: [RFC PATCH 2/3] ARM: entry: Remove unneeded need_resched() loop

Since the enabling and disabling of IRQs within preempt_schedule_irq()
is contained in a need_resched() loop, we don't need the outer arch
code loop.

Signed-off-by: Valentin Schneider <valentin.schneider@....com>
Cc: Russell King <linux@...linux.org.uk>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Will Deacon <will.deacon@....com>
Cc: Julien Thierry <julien.thierry@....com>
Cc: linux-arm-kernel@...ts.infradead.org
---
 arch/arm/kernel/entry-armv.S | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index e85a3af9ddeb..a7ac22e09bb2 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -220,7 +220,7 @@ __irq_svc:
 	teq	r8, #0				@ if preempt count != 0
 	movne	r0, #0				@ force flags to 0
 	tst	r0, #_TIF_NEED_RESCHED
-	blne	svc_preempt
+	blne	preempt_schedule_irq            @ irq en/disable is done inside
 #endif
 
 	svc_exit r5, irq = 1			@ return from exception
@@ -229,16 +229,6 @@ ENDPROC(__irq_svc)
 
 	.ltorg
 
-#ifdef CONFIG_PREEMPT
-svc_preempt:
-	mov	r8, lr
-1:	bl	preempt_schedule_irq		@ irq en/disable is done inside
-	ldr	r0, [tsk, #TI_FLAGS]		@ get new tasks TI_FLAGS
-	tst	r0, #_TIF_NEED_RESCHED
-	reteq	r8				@ go again
-	b	1b
-#endif
-
 __und_fault:
 	@ Correct the PC such that it is pointing at the instruction
 	@ which caused the fault.  If the faulting instruction was ARM
-- 
2.20.1