[PATCH] arm64: hw-breakpoint: Remove superfluous SMP function call

From	Anna-Maria Gleixner <anna-maria@linutronix.de>
Newsgroups	linux.kernel
Subject	[PATCH] arm64: hw-breakpoint: Remove superfluous SMP function call
Date	2016-04-04 12:50 +0200
Message-ID	<rkaf0-1J2-11@gated-at.bofh.it> (permalink)
Organization	linux.* mail to news gateway

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Since commit 1cf4f629d9d2 ("cpu/hotplug: Move online calls to
hotplugged cpu") it is ensured that callbacks of CPU_ONLINE and
CPU_DOWN_PREPARE are processed on the hotplugged cpu. Due to this SMP
function calls are no longer required.

Replace smp_call_function_single() with a direct call of
hw_breakpoint_reset(). To keep the calling convention, interrupts are
explicitely disabled around the call.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
---
 arch/arm64/kernel/hw_breakpoint.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -886,9 +886,11 @@ static int hw_breakpoint_reset_notify(st
 						unsigned long action,
 						void *hcpu)
 {
-	int cpu = (long)hcpu;
-	if ((action & ~CPU_TASKS_FROZEN) == CPU_ONLINE)
-		smp_call_function_single(cpu, hw_breakpoint_reset, NULL, 1);
+	if ((action & ~CPU_TASKS_FROZEN) == CPU_ONLINE) {
+		local_irq_disable();
+		hw_breakpoint_reset(NULL);
+		local_irq_enable();
+	}
 	return NOTIFY_OK;
 }

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[PATCH] arm64: hw-breakpoint: Remove superfluous SMP function call Anna-Maria Gleixner <anna-maria@linutronix.de> - 2016-04-04 12:50 +0200
  Re: [PATCH] arm64: hw-breakpoint: Remove superfluous SMP function  call Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> - 2016-04-04 16:10 +0200
  Re: [PATCH] arm64: hw-breakpoint: Remove superfluous SMP function  call "Suzuki K. Poulose" <Suzuki.Poulose@arm.com> - 2016-04-05 11:30 +0200
    Re: [PATCH] arm64: hw-breakpoint: Remove superfluous SMP function  call Anna-Maria Gleixner <anna-maria@linutronix.de> - 2016-04-05 11:40 +0200

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