[tip:smp/hotplug] POWERPC: Smp: remove call to ipi_call_lock()/ipi_call_unlock()

[tip-bot for Yong Zhang]

Commit-ID:  72ec61a9e8347375e37c05e23511173d8451c3d4
Gitweb:     http://git.kernel.org/tip/72ec61a9e8347375e37c05e23511173d8451c3d4
Author:     Yong Zhang <yong.zhang0@xxxxxxxxx>
AuthorDate: Tue, 29 May 2012 15:16:04 +0800
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Tue, 5 Jun 2012 17:27:13 +0200

POWERPC: Smp: remove call to ipi_call_lock()/ipi_call_unlock()

ipi_call_lock/unlock() lock resp. unlock call_function.lock. This lock
protects only the call_function data structure itself, but it's
completely unrelated to cpu_online_mask. The mask to which the IPIs
are sent is calculated before call_function.lock is taken in
smp_call_function_many(), so the locking around set_cpu_online() is
pointless and can be removed.

[ tglx: Massaged changelog ]

Signed-off-by: Yong Zhang <yong.zhang0@xxxxxxxxx>
Cc: ralf@xxxxxxxxxxxxxx
Cc: sshtylyov@xxxxxxxxxx
Cc: david.daney@xxxxxxxxxx
Cc: nikunj@xxxxxxxxxxxxxxxxxx
Cc: paulmck@xxxxxxxxxxxxxxxxxx
Cc: axboe@xxxxxxxxx
Cc: peterz@xxxxxxxxxxxxx
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1338275765-3217-10-git-send-email-yong.zhang0@xxxxxxxxx
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
Acked-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
 arch/powerpc/kernel/smp.c |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index e4cb343..e1417c4 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -571,7 +571,6 @@ void __devinit start_secondary(void *unused)
 	if (system_state == SYSTEM_RUNNING)
 		vdso_data->processorCount++;
 #endif
-	ipi_call_lock();
 	notify_cpu_starting(cpu);
 	set_cpu_online(cpu, true);
 	/* Update sibling maps */
@@ -601,7 +600,6 @@ void __devinit start_secondary(void *unused)
 		of_node_put(np);
 	}
 	of_node_put(l2_cache);
-	ipi_call_unlock();
 
 	local_irq_enable();
 
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