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Commit b4b2917c authored by Peter Watkins's avatar Peter Watkins Committed by Ralf Baechle
Browse files

[MIPS] Add smp_call_function_single() 



In the other archs, there is more factoring of smp call code, and more care
in the use of get_cpu(). That can be a follow-up MIPS patch.

Signed-off-by: default avatarPeter Watkins <pwatkins@sicortex.com>
Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 185bcd17

arch/mips/kernel/smp.c

+55 −0
Original line number Diff line number Diff line
@@ -194,6 +194,61 @@ void smp_call_function_interrupt(void) 
	}

}



int smp_call_function_single(int cpu, void (*func) (void *info), void *info,

			     int retry, int wait)

{

	struct call_data_struct data;

	int me;



	/*

	 * Can die spectacularly if this CPU isn't yet marked online

	 */

	if (!cpu_online(cpu))

		return 0;



	me = get_cpu();

	BUG_ON(!cpu_online(me));



	if (cpu == me) {

		local_irq_disable();

		func(info);

		local_irq_enable();

		put_cpu();

		return 0;

	}



	/* Can deadlock when called with interrupts disabled */

	WARN_ON(irqs_disabled());



	data.func = func;

	data.info = info;

	atomic_set(&data.started, 0);

	data.wait = wait;

	if (wait)

		atomic_set(&data.finished, 0);



	spin_lock(&smp_call_lock);

	call_data = &data;

	smp_mb();



	/* Send a message to the other CPU */

	core_send_ipi(cpu, SMP_CALL_FUNCTION);



	/* Wait for response */

	/* FIXME: lock-up detection, backtrace on lock-up */

	while (atomic_read(&data.started) != 1)

		barrier();



	if (wait)

		while (atomic_read(&data.finished) != 1)

			barrier();

	call_data = NULL;

	spin_unlock(&smp_call_lock);



	put_cpu();

	return 0;

}



static void stop_this_cpu(void *dummy)

{

	/*