Commit ea925a72 authored Mar 25, 2015 by Andrew Bresticker Committed by Ralf Baechle Apr 01, 2015

MIPS: smp: Make stop_this_cpu() actually stop the CPU



Since cpu_wait() enables interrupts upon return, CPUs which have
entered stop_this_cpu() may still end up handling interrupts.
This can lead to the softlockup detector firing on a panic or
restart/poweroff/halt.  Just disable interrupts and spin to ensure
nothing else runs on the CPU once it has entered stop_this_cpu().

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9601/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

parent c1bed31f

arch/mips/kernel/smp.c

+2 −4

Original line number	Original line	Diff line number	Diff line
	@@ -176,10 +176,8 @@ static void stop_this_cpu(void *dummy)
	* Remove this CPU:		* Remove this CPU:
	*/		*/
	set_cpu_online(smp_processor_id(), false);		set_cpu_online(smp_processor_id(), false);
	for (;;) {		local_irq_disable();
	if (cpu_wait)		while (1);
	(cpu_wait)(); / Wait if available. */
	}
	}		}

	void smp_send_stop(void)		void smp_send_stop(void)