[RFC PATCH 02/10] mn10300: smp: remove call to ipi_call_lock()/ipi_call_unlock()

[Yong Zhang]

From: Yong Zhang <yong.zhang@xxxxxxxxxxxxx>

1) call_function.lock used in smp_call_function_many() is just to protect
   call_function.queue and &data->refs, cpu_online_mask is outside of the
   lock. And it's not necessary to protect cpu_online_mask,
   because data->cpumask is pre-calculate and even if a cpu is brougt up
   when calling arch_send_call_function_ipi_mask(), it's harmless because
   validation test in generic_smp_call_function_interrupt() will take care
   of it.

2) For cpu down issue, stop_machine() will guarantee that no concurrent
   smp_call_fuction() is processing.

Signed-off-by: Yong Zhang <yong.zhang0@xxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Koichi Yasutake <yasutake.koichi@xxxxxxxxxxxxxxxx>
Cc: linux-am33-list@xxxxxxxxxx
---
 arch/mn10300/kernel/smp.c |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

diff --git a/arch/mn10300/kernel/smp.c b/arch/mn10300/kernel/smp.c
index 090d35d..e62c223 100644
--- a/arch/mn10300/kernel/smp.c
+++ b/arch/mn10300/kernel/smp.c
@@ -876,9 +876,7 @@ static void __init smp_online(void)
 
 	notify_cpu_starting(cpu);
 
-	ipi_call_lock();
 	set_cpu_online(cpu, true);
-	ipi_call_unlock();
 
 	local_irq_enable();
 }
-- 
1.7.5.4

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