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Commit 4530e4b6 authored by Nicolas Pitre's avatar Nicolas Pitre Committed by Russell King
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ARM: 8032/1: bL_switcher: fix validation check before its activation 



The switcher should not depend on MAX_CLUSTER to determine ifit should
be activated or not. In a multiplatform kernel binary it is possible to
have dual-cluster and quad-cluster platforms configured in. In that case
MAX_CLUSTER which is a build time limit should be 4 and that shouldn't
prevent the switcher from working if the kernel is booted on a b.L
dual-cluster system.

In bL_switcher_halve_cpus() we already have a runtime validation check
to make sure we're dealing with only two clusters, so booting on a quad
cluster system will be caught and switcher activation aborted.

However, the b.L switcher must ensure the MCPM layer is initialized on
the booted hardware before doing anything.  The mcpm_is_available()
function is added to that effect.

Signed-off-by: default avatarNicolas Pitre <nico@linaro.org>
Tested-by: default avatarAbhilash Kesavan <kesavan.abhilash@gmail.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 56b700fd

arch/arm/common/bL_switcher.c

+2 −4
Original line number Diff line number Diff line
@@ -797,10 +797,8 @@ static int __init bL_switcher_init(void) 
{

	int ret;



	if (MAX_NR_CLUSTERS != 2) {

		pr_err("%s: only dual cluster systems are supported\n", __func__);

		return -EINVAL;

	}

	if (!mcpm_is_available())

		return -ENODEV;



	cpu_notifier(bL_switcher_hotplug_callback, 0);

arch/arm/common/mcpm_entry.c

+5 −0
Original line number Diff line number Diff line
@@ -48,6 +48,11 @@ int __init mcpm_platform_register(const struct mcpm_platform_ops *ops) 
	return 0;

}



bool mcpm_is_available(void)

{

	return (platform_ops) ? true : false;

}



int mcpm_cpu_power_up(unsigned int cpu, unsigned int cluster)

{

	if (!platform_ops)

arch/arm/include/asm/mcpm.h

+7 −0
Original line number Diff line number Diff line
@@ -53,6 +53,13 @@ void mcpm_set_early_poke(unsigned cpu, unsigned cluster, 
 * CPU/cluster power operations API for higher subsystems to use.

 */



/**

 * mcpm_is_available - returns whether MCPM is initialized and available

 *

 * This returns true or false accordingly.

 */

bool mcpm_is_available(void);



/**

 * mcpm_cpu_power_up - make given CPU in given cluster runable

 *