[RFC PATCH 0/5] arm64: initial CPU_HOTPLUG support

[mark.rutland@arm.com (Mark Rutland)]

Hi Catalin, Paul,

I've realised these patches are going to conflict with Paul's "arm64:
delete __cpuinit usage from all users", so I'd like to rebase this
series atop of it (removing my cpuinit additions as I do so).

Catalin, would you be happy to create a stable branch at some point soon
with Paul's arm64 patch for me to work atop of?

Thanks,
Mark.

On Wed, Jul 10, 2013 at 11:11:14PM +0100, Mark Rutland wrote:
> The following patches add basic CPU_HOTPLUG support to arm64, which
> combined with appropriate firmware (e.g. [1]) can be used to power CPUs
> up and down dynamically. From discussions at connect it seemed that
> several people were interested in working in this area, so I thought I'd
> make my current implementation public now that I've managed to regain
> access to my inbox.
> 
> I've tested this series with the bootwrapper PSCI implementation I've
> placed on linux-arm.org [1] and a modified foundation model dts with a
> psci node and each CPU's enable-method set to "psci", using a shell
> while repeatedly cycling all cpus off and on:
> 
> for C in $(seq 0 3); do
> 	./cyclichotplug.sh $C >/dev/null 2>&1 &
> done
> 
> ---->8----
> #!/bin/sh
> # cyclichotplug.sh
> 
> CPU=$1;
> 
> if [ -z "$CPU" ]; then
> 	printf "Usage: $0 <cpu id>\n";
> 	exit 1;
> fi
> 
> ONLINEFILE=/sys/devices/system/cpu/cpu$CPU/online;
> 
> while true; do
> 	echo 0 > $ONLINEFILE;
> 	echo 1 > $ONLINEFILE;
> done
> ---->8----
> 
> Patches are based on v3.10.
> 
> Thanks,
> Mark.
> 
> [1] http://linux-arm.org/git?p=boot-wrapper-aarch64.git;a=shortlog;h=refs/tags/simple-psci
> 
> Mark Rutland (5):
>   arm64: reorganise smp_enable_ops
>   arm64: factor out spin-table boot method
>   arm64: read enable-method for CPU0
>   arm64: add CPU_HOTPLUG infrastructure
>   arm64: add PSCI CPU_OFF-based hotplug support
> 
>  arch/arm64/Kconfig                 |    7 ++
>  arch/arm64/include/asm/irq.h       |    1 +
>  arch/arm64/include/asm/smp.h       |   37 +++++--
>  arch/arm64/kernel/cputable.c       |    2 +-
>  arch/arm64/kernel/head.S           |   12 +-
>  arch/arm64/kernel/irq.c            |   61 ++++++++++
>  arch/arm64/kernel/process.c        |    7 ++
>  arch/arm64/kernel/smp.c            |  215 ++++++++++++++++++++++--------------
>  arch/arm64/kernel/smp_psci.c       |   54 +++++++--
>  arch/arm64/kernel/smp_spin_table.c |   85 +++++++++++++-
>  arch/arm64/kernel/vmlinux.lds.S    |    1 -
>  11 files changed, 375 insertions(+), 107 deletions(-)
> 
> -- 
> 1.7.9.5
>