From: Dave.Martin@arm.com (Dave Martin)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 0/3] MCPM/TC2 support for CPU powerdown synchronisation
Date: Mon, 30 Sep 2013 20:00:00 +0100 [thread overview]
Message-ID: <1380567603-21367-1-git-send-email-Dave.Martin@arm.com> (raw)
This series adds MCPM support for detecting when a CPU is safely powered
down, and provides an implementation for TC2.
It should be possible to implement the same thing for PSCI using the
AFFINITY_INFO call (I need to check the semantics with Charles)
This is sufficient to for working kexec with real power management on
TC2. To test it, you'll also need:
* CONFIG_KEXEC=y
* CONFIG_PROC_DEVICE_TREE=y
* CONFIG_MCPM=y
* CONFIG_ARCH_VEXPRESS_TC2_PM=y
* sufficiently new kexec-tools
(git://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git
v2.0.4 worked for me)
This build on Nico's patch
http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=7842/1
(MCPM: don't explode if invoked without being initialized first)
To prevent CPUs from running off into the weeds across kexec, this
series requires Lorenzo's patch
http://lists.infradead.org/pipermail/linux-arm-kernel/2013-September/200917.html
(arm: vexpress: tc2: fix hotplug/idle/kexec race on cluster power down).
Changes since RFC:
* Print a big fat warning instead of branching to null if the
power_down_finish() method is not supplied by the backend, or not
registered.
* Add a generous timeout of 1 second for the TC2 implementation.
* Relax the polling interval to 10ms for TC2, since the need to poll
more than once is rare and this is not a performance-critical path.
* Fix some silly typos.
Thanks Nico for these suggestions.
Dave Martin (3):
ARM: mcpm: Factor out logical-to-physical CPU translation
ARM: mcpm: Implement cpu_kill() to synchronise on powerdown
ARM: vexpress/TC2: Implement MCPM power_down_finish()
arch/arm/common/mcpm_entry.c | 15 +++++++++
arch/arm/common/mcpm_platsmp.c | 27 +++++++++++++---
arch/arm/include/asm/mcpm.h | 31 ++++++++++++++++++
arch/arm/mach-vexpress/spc.c | 39 +++++++++++++++++++++++
arch/arm/mach-vexpress/spc.h | 1 +
arch/arm/mach-vexpress/tc2_pm.c | 66 ++++++++++++++++++++++++++++++++++++---
6 files changed, 170 insertions(+), 9 deletions(-)
--
1.7.9.5
next reply other threads:[~2013-09-30 19:00 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-30 19:00 Dave Martin [this message]
2013-09-30 19:00 ` [PATCH 1/3] ARM: mcpm: Factor out logical-to-physical CPU translation Dave Martin
2013-09-30 19:00 ` [PATCH 2/3] ARM: mcpm: Implement cpu_kill() to synchronise on powerdown Dave Martin
2013-09-30 19:18 ` Nicolas Pitre
2013-10-01 9:29 ` Dave Martin
2013-09-30 19:00 ` [PATCH 3/3] ARM: vexpress/TC2: Implement MCPM power_down_finish() Dave Martin
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