From 4530e4b6a450af14973c2b0703edfb02d66cbd41 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Tue, 22 Apr 2014 00:25:35 +0100 Subject: [PATCH] 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 Tested-by: Abhilash Kesavan Signed-off-by: Russell King --- arch/arm/common/bL_switcher.c | 6 ++---- arch/arm/common/mcpm_entry.c | 5 +++++ arch/arm/include/asm/mcpm.h | 7 +++++++ 3 files changed, 14 insertions(+), 4 deletions(-) diff --git a/arch/arm/common/bL_switcher.c b/arch/arm/common/bL_switcher.c index 5774b6ea7ad5..f01c0ee0c87e 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 1e361abc29eb..86fd60fefbc9 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 608516ebabfe..a5ff410dcdb6 100644 --- a/arch/arm/include/asm/mcpm.h +++ b/arch/arm/include/asm/mcpm.h @@ -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 * -- 2.20.1