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Commit 3a36d1e4 authored by Glauber Costa's avatar Glauber Costa Committed by Ingo Molnar
Browse files

x86: provide __smp_call_function 



This function is used in smp_send_stop(). It's like
smp_call_function_mask, but always go to all online cpus,
and does not take any locks.

It is added to x86_64, but will soon be unified in a common file

Signed-off-by: default avatarGlauber Costa <gcosta@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent e32640a2

arch/x86/kernel/smp_64.c

+33 −1
Original line number Diff line number Diff line
@@ -322,6 +322,38 @@ void unlock_ipi_call_lock(void) 
	spin_unlock_irq(&call_lock);

}



static void __smp_call_function(void (*func) (void *info), void *info,

				int nonatomic, int wait)

{

	struct call_data_struct data;

	int cpus = num_online_cpus() - 1;



	if (!cpus)

		return;



	data.func = func;

	data.info = info;

	atomic_set(&data.started, 0);

	data.wait = wait;

	if (wait)

		atomic_set(&data.finished, 0);



	call_data = &data;

	mb();



	/* Send a message to all other CPUs and wait for them to respond */

	send_IPI_allbutself(CALL_FUNCTION_VECTOR);



	/* Wait for response */

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

		cpu_relax();



	if (wait)

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

			cpu_relax();

}





/*

 * this function sends a 'generic call function' IPI to all other CPU

 * of the system defined in the mask.
@@ -424,7 +456,7 @@ void smp_send_stop(void) 
	/* Don't deadlock on the call lock in panic */

	nolock = !spin_trylock(&call_lock);

	local_irq_save(flags);

	__smp_call_function_mask(cpu_online_map, stop_this_cpu, NULL, 0);

	__smp_call_function(stop_this_cpu, NULL, 0, 0);

	if (!nolock)

		spin_unlock(&call_lock);

	disable_local_APIC();