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authorNicolas Pitre <nicolas.pitre@linaro.org>2014-04-22 00:25:35 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2014-04-22 22:23:59 +0100
commit4530e4b6a450af14973c2b0703edfb02d66cbd41 (patch)
tree20ad0784be6feed9e2869a0961e468d82bfe333c /arch/arm
parent56b700fd6f1e49149880fb1b6ffee0dca5be45fb (diff)
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: Nicolas Pitre <nico@linaro.org> Tested-by: Abhilash Kesavan <kesavan.abhilash@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/common/bL_switcher.c6
-rw-r--r--arch/arm/common/mcpm_entry.c5
-rw-r--r--arch/arm/include/asm/mcpm.h7
3 files changed, 14 insertions, 4 deletions
diff --git a/arch/arm/common/bL_switcher.c b/arch/arm/common/bL_switcher.c
index 5774b6ea7ad..f01c0ee0c87 100644
--- a/arch/arm/common/bL_switcher.c
+++ b/arch/arm/common/bL_switcher.c
@@ -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);
diff --git a/arch/arm/common/mcpm_entry.c b/arch/arm/common/mcpm_entry.c
index 1e361abc29e..86fd60fefbc 100644
--- a/arch/arm/common/mcpm_entry.c
+++ b/arch/arm/common/mcpm_entry.c
@@ -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)
diff --git a/arch/arm/include/asm/mcpm.h b/arch/arm/include/asm/mcpm.h
index 608516ebabf..a5ff410dcdb 100644
--- a/arch/arm/include/asm/mcpm.h
+++ b/arch/arm/include/asm/mcpm.h
@@ -54,6 +54,13 @@ void mcpm_set_early_poke(unsigned cpu, unsigned cluster,
*/
/**
+ * 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
*
* @cpu: CPU number within given cluster