[PATCH v3 01/15] ARM: multi-cluster PM: secondary kernel entry code
From: Santosh Shilimkar <hidden>
Date: 2013-01-31 15:45:50
On Tuesday 29 January 2013 01:20 PM, Nicolas Pitre wrote:
CPUs in cluster based systems, such as big.LITTLE, have special needs when entering the kernel due to a hotplug event, or when resuming from a deep sleep mode. This is vectorized so multiple CPUs can enter the kernel in parallel without serialization. The mcpm prefix stands for "multi cluster power management", however this is usable on single cluster systems as well. Only the basic structure is introduced here. This will be extended with later patches. In order not to complexify things more than they currently have to, the planned work to make runtime adjusted MPIDR based indexing and dynamic memory allocation for cluster states is postponed to a later cycle. The MAX_NR_CLUSTERS and MAX_CPUS_PER_CLUSTER static definitions should be sufficient for those systems expected to be available in the near future.
'mcpm' sounds definitely better than 'bL' ;)
quoted hunk ↗ jump to hunk
Signed-off-by: Nicolas Pitre <redacted> --- arch/arm/Kconfig | 8 ++++ arch/arm/common/Makefile | 1 + arch/arm/common/mcpm_entry.c | 29 +++++++++++++ arch/arm/common/mcpm_head.S | 86 +++++++++++++++++++++++++++++++++++++++ arch/arm/include/asm/mcpm_entry.h | 35 ++++++++++++++++ 5 files changed, 159 insertions(+) create mode 100644 arch/arm/common/mcpm_entry.c create mode 100644 arch/arm/common/mcpm_head.S create mode 100644 arch/arm/include/asm/mcpm_entry.hdiff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 67874b82a4..200f559c1c 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig@@ -1584,6 +1584,14 @@ config HAVE_ARM_TWD help This options enables support for the ARM timer and watchdog unit +config CLUSTER_PM + bool "Cluster Power Management Infrastructure" + depends on CPU_V7 && SMP + help + This option provides the common power management infrastructure + for (multi-)cluster based systems, such as big.LITTLE based + systems. + choice prompt "Memory split" default VMSPLIT_3Gdiff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile index e8a4e58f1b..23e85b1fae 100644 --- a/arch/arm/common/Makefile +++ b/arch/arm/common/Makefile@@ -13,3 +13,4 @@ obj-$(CONFIG_SHARP_PARAM) += sharpsl_param.o obj-$(CONFIG_SHARP_SCOOP) += scoop.o obj-$(CONFIG_PCI_HOST_ITE8152) += it8152.o obj-$(CONFIG_ARM_TIMER_SP804) += timer-sp.o +obj-$(CONFIG_CLUSTER_PM) += mcpm_head.o mcpm_entry.odiff --git a/arch/arm/common/mcpm_entry.c b/arch/arm/common/mcpm_entry.c new file mode 100644 index 0000000000..3a6d7e70fd --- /dev/null +++ b/arch/arm/common/mcpm_entry.c@@ -0,0 +1,29 @@ +/* + * arch/arm/common/mcpm_entry.c -- entry point for multi-cluster PM + * + * Created by: Nicolas Pitre, March 2012 + * Copyright: (C) 2012-2013 Linaro Limited + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/init.h> + +#include <asm/mcpm_entry.h> +#include <asm/barrier.h> +#include <asm/proc-fns.h> +#include <asm/cacheflush.h> + +extern volatile unsigned long mcpm_entry_vectors[MAX_NR_CLUSTERS][MAX_CPUS_PER_CLUSTER]; + +void mcpm_set_entry_vector(unsigned cpu, unsigned cluster, void *ptr) +{ + unsigned long val = ptr ? virt_to_phys(ptr) : 0;
May be extra line would be good here. Patch looks fine to my eyes otherwise. Reviewed-by: Santosh Shilimkar <redacted>