Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f9a69931 authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Thomas Gleixner
Browse files

powerpc/powernv: Use stop_machine_cpuslocked() 



set_subcores_per_core() holds get_online_cpus() while invoking stop_machine().

stop_machine() invokes get_online_cpus() as well. This is correct, but
prevents the conversion of the hotplug locking to a percpu rwsem.

Use stop_machine_cpuslocked() to avoid the nested call. Convert
*_online_cpus() to the new interfaces while at it.

Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20170524081548.331016542@linutronix.de
parent 2337e879

arch/powerpc/platforms/powernv/subcore.c

+4 −3
Original line number Diff line number Diff line
@@ -348,7 +348,7 @@ static int set_subcores_per_core(int new_mode) 
		state->master = 0;

	}



	get_online_cpus();

	cpus_read_lock();



	/* This cpu will update the globals before exiting stop machine */

	this_cpu_ptr(&split_state)->master = 1;
@@ -356,9 +356,10 @@ static int set_subcores_per_core(int new_mode) 
	/* Ensure state is consistent before we call the other cpus */

	mb();



	stop_machine(cpu_update_split_mode, &new_mode, cpu_online_mask);

	stop_machine_cpuslocked(cpu_update_split_mode, &new_mode,

				cpu_online_mask);



	put_online_cpus();

	cpus_read_unlock();



	return 0;

}