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ARM: 8032/1: bL_switcher: fix validation check before its activation

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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: Nicolas Pitre <nico@linaro.org>
Tested-by: Abhilash Kesavan <kesavan.abhilash@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Nicolas Pitre 2014-04-22 00:25:35 +01:00 committed by Russell King
parent 56b700fd6f
commit 4530e4b6a4
3 changed files with 14 additions and 4 deletions
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6
arch/arm/common/bL_switcher.c
View file

@ -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);

5
arch/arm/common/mcpm_entry.c
View file

@ -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)

7
arch/arm/include/asm/mcpm.h
View file

@ -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
*