linux-kernel - [PATCH v2] MIPS: entry: Remove unneeded need

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Date:   Fri, 15 Mar 2019 16:31:33 +0000
From:   Valentin Schneider <valentin.schneider@....com>
To:     linux-kernel@...r.kernel.org
Cc:     Ralf Baechle <ralf@...ux-mips.org>,
        Paul Burton <paul.burton@...s.com>,
        James Hogan <jhogan@...nel.org>, linux-mips@...r.kernel.org
Subject: [PATCH v2] MIPS: 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.

Note that commit a18815abcdfd ("Use preempt_schedule_irq.") initially
removed the existing loop, but missed the final branch to restore_all.
Commit cdaed73afb61 ("Fix preemption bug.") missed that and reintroduced
the loop.

Signed-off-by: Valentin Schneider <valentin.schneider@....com>
Cc: Ralf Baechle <ralf@...ux-mips.org>
Cc: Paul Burton <paul.burton@...s.com>
Cc: James Hogan <jhogan@...nel.org>
Cc: linux-mips@...r.kernel.org
---
 arch/mips/kernel/entry.S | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/mips/kernel/entry.S b/arch/mips/kernel/entry.S
index d7de8adcfcc8..5469d43b6966 100644
--- a/arch/mips/kernel/entry.S
+++ b/arch/mips/kernel/entry.S
@@ -58,15 +58,14 @@ resume_kernel:
 	local_irq_disable
 	lw	t0, TI_PRE_COUNT($28)
 	bnez	t0, restore_all
-need_resched:
 	LONG_L	t0, TI_FLAGS($28)
 	andi	t1, t0, _TIF_NEED_RESCHED
 	beqz	t1, restore_all
 	LONG_L	t0, PT_STATUS(sp)		# Interrupts off?
 	andi	t0, 1
 	beqz	t0, restore_all
-	jal	preempt_schedule_irq
-	b	need_resched
+	PTR_LA	ra, restore_all
+	j	preempt_schedule_irq
 #endif
 
 FEXPORT(ret_from_kernel_thread)
--
2.20.1