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Author SHA1 Message Date
Mauro Carvalho Chehab 151f4e2bdc docs: power: convert docs to ReST and rename to *.rst
Convert the PM documents to ReST, in order to allow them to
build with Sphinx.

The conversion is actually:
  - add blank lines and indentation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
2019-06-14 16:08:36 -05:00
Nicholas Piggin 9ca12ac04b kernel/cpu: Allow non-zero CPU to be primary for suspend / kexec freeze
This patch provides an arch option, ARCH_SUSPEND_NONZERO_CPU, to
opt-in to allowing suspend to occur on one of the housekeeping CPUs
rather than hardcoded CPU0.

This will allow CPU0 to be a nohz_full CPU with a later change.

It may be possible for platforms with hardware/firmware restrictions
on suspend/wake effectively support this by handing off the final
stage to CPU0 when kernel housekeeping is no longer required. Another
option is to make housekeeping / nohz_full mask dynamic at runtime,
but the complexity could not be justified at this time.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lkml.kernel.org/r/20190411033448.20842-4-npiggin@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-05-03 19:42:58 +02:00
Quentin Perret 27871f7a8a PM: Introduce an Energy Model management framework
Several subsystems in the kernel (task scheduler and/or thermal at the
time of writing) can benefit from knowing about the energy consumed by
CPUs. Yet, this information can come from different sources (DT or
firmware for example), in different formats, hence making it hard to
exploit without a standard API.

As an attempt to address this, introduce a centralized Energy Model
(EM) management framework which aggregates the power values provided
by drivers into a table for each performance domain in the system. The
power cost tables are made available to interested clients (e.g. task
scheduler or thermal) via platform-agnostic APIs. The overall design
is represented by the diagram below (focused on Arm-related drivers as
an example, but applicable to any architecture):

     +---------------+  +-----------------+  +-------------+
     | Thermal (IPA) |  | Scheduler (EAS) |  |    Other    |
     +---------------+  +-----------------+  +-------------+
             |                   | em_pd_energy()   |
             |                   | em_cpu_get()     |
             +-----------+       |         +--------+
                         |       |         |
                         v       v         v
                      +---------------------+
                      |                     |
                      |    Energy Model     |
                      |                     |
                      |     Framework       |
                      |                     |
                      +---------------------+
                         ^       ^       ^
                         |       |       | em_register_perf_domain()
              +----------+       |       +---------+
              |                  |                 |
      +---------------+  +---------------+  +--------------+
      |  cpufreq-dt   |  |   arm_scmi    |  |    Other     |
      +---------------+  +---------------+  +--------------+
              ^                  ^                 ^
              |                  |                 |
      +--------------+   +---------------+  +--------------+
      | Device Tree  |   |   Firmware    |  |      ?       |
      +--------------+   +---------------+  +--------------+

Drivers (typically, but not limited to, CPUFreq drivers) can register
data in the EM framework using the em_register_perf_domain() API. The
calling driver must provide a callback function with a standardized
signature that will be used by the EM framework to build the power
cost tables of the performance domain. This design should offer a lot of
flexibility to calling drivers which are free of reading information
from any location and to use any technique to compute power costs.
Moreover, the capacity states registered by drivers in the EM framework
are not required to match real performance states of the target. This
is particularly important on targets where the performance states are
not known by the OS.

The power cost coefficients managed by the EM framework are specified in
milli-watts. Although the two potential users of those coefficients (IPA
and EAS) only need relative correctness, IPA specifically needs to
compare the power of CPUs with the power of other components (GPUs, for
example), which are still expressed in absolute terms in their
respective subsystems. Hence, specifying the power of CPUs in
milli-watts should help transitioning IPA to using the EM framework
without introducing new problems by keeping units comparable across
sub-systems.
On the longer term, the EM of other devices than CPUs could also be
managed by the EM framework, which would enable to remove the absolute
unit. However, this is not absolutely required as a first step, so this
extension of the EM framework is left for later.

On the client side, the EM framework offers APIs to access the power
cost tables of a CPU (em_cpu_get()), and to estimate the energy
consumed by the CPUs of a performance domain (em_pd_energy()). Clients
such as the task scheduler can then use these APIs to access the shared
data structures holding the Energy Model of CPUs.

Signed-off-by: Quentin Perret <quentin.perret@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: adharmap@codeaurora.org
Cc: chris.redpath@arm.com
Cc: currojerez@riseup.net
Cc: dietmar.eggemann@arm.com
Cc: edubezval@gmail.com
Cc: gregkh@linuxfoundation.org
Cc: javi.merino@kernel.org
Cc: joel@joelfernandes.org
Cc: juri.lelli@redhat.com
Cc: morten.rasmussen@arm.com
Cc: patrick.bellasi@arm.com
Cc: pkondeti@codeaurora.org
Cc: skannan@codeaurora.org
Cc: smuckle@google.com
Cc: srinivas.pandruvada@linux.intel.com
Cc: thara.gopinath@linaro.org
Cc: tkjos@google.com
Cc: valentin.schneider@arm.com
Cc: vincent.guittot@linaro.org
Cc: viresh.kumar@linaro.org
Link: https://lkml.kernel.org/r/20181203095628.11858-4-quentin.perret@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-12-11 15:16:58 +01:00
zhangyi (F) 3df6f61fff PM / sleep: wakeup: Fix build error caused by missing SRCU support
Commit ea0212f40c (power: auto select CONFIG_SRCU) made the code in
drivers/base/power/wakeup.c use SRCU instead of RCU, but it forgot to
select CONFIG_SRCU in Kconfig, which leads to the following build
error if CONFIG_SRCU is not selected somewhere else:

drivers/built-in.o: In function `wakeup_source_remove':
(.text+0x3c6fc): undefined reference to `synchronize_srcu'
drivers/built-in.o: In function `pm_print_active_wakeup_sources':
(.text+0x3c7a8): undefined reference to `__srcu_read_lock'
drivers/built-in.o: In function `pm_print_active_wakeup_sources':
(.text+0x3c84c): undefined reference to `__srcu_read_unlock'
drivers/built-in.o: In function `device_wakeup_arm_wake_irqs':
(.text+0x3d1d8): undefined reference to `__srcu_read_lock'
drivers/built-in.o: In function `device_wakeup_arm_wake_irqs':
(.text+0x3d228): undefined reference to `__srcu_read_unlock'
drivers/built-in.o: In function `device_wakeup_disarm_wake_irqs':
(.text+0x3d24c): undefined reference to `__srcu_read_lock'
drivers/built-in.o: In function `device_wakeup_disarm_wake_irqs':
(.text+0x3d29c): undefined reference to `__srcu_read_unlock'
drivers/built-in.o:(.data+0x4158): undefined reference to `process_srcu'

Fix this error by selecting CONFIG_SRCU when PM_SLEEP is enabled.

Fixes: ea0212f40c (power: auto select CONFIG_SRCU)
Cc: 4.2+ <stable@vger.kernel.org> # 4.2+
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
[ rjw: Minor subject/changelog fixups ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-08-15 00:07:08 +02:00
Viresh Kumar 7813dd6fc7 PM / OPP: Move the OPP directory out of power/
The drivers/base/power/ directory is special and contains code related
to power management core like system suspend/resume, hibernation, etc.
It was fine to keep the OPP code inside it when we had just one file for
it, but it is growing now and already has a directory for itself.

Lets move it directly under drivers/ directory, just like cpufreq and
cpuidle.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-10-03 02:45:12 +02:00
Chen Yu 5b3f249c94 PM / sleep: Increase default DPM watchdog timeout to 120
Recently we have a new report that, the harddisk can not
resume on time due to firmware issues, and got a kernel
panic because of DPM watchdog timeout. So adjust the
default timeout from 60 to 120 to survive on this platform,
and make DPM_WATCHDOG depending on EXPERT.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=117971
Suggested-by: Pavel Machek <pavel@ucw.cz>
Suggested-by: Rafael J. Wysocki <rafael@kernel.org>
Reported-by: Higuita <higuita@gmx.net>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-09-13 02:15:58 +02:00
Arnd Bergmann 993e9fe1e7 PM: APM_EMULATION does not depend on PM
The APM emulation code does multiple things, and some of them depend on
PM_SLEEP, while the battery management does not. However, selecting
the symbol like SHARPSL_PM does causes a Kconfig warning:

warning: (SHARPSL_PM && PMAC_APM_EMU) selects APM_EMULATION which has unmet direct dependencies (PM && SYS_SUPPORTS_APM_EMULATION)

From all I can tell, this is completely harmless, and we can simply allow
APM_EMULATION to be enabled here, even if PM is not.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-01-27 23:20:14 +01:00
Len Brown 2fd77fff4b PM / suspend: make sync() on suspend-to-RAM build-time optional
The Linux kernel suspend path has traditionally invoked sys_sync()
before freezing user threads.

But sys_sync() can be expensive, and some user-space OS's do not want
the kernel to pay the cost of sys_sync() on every suspend -- preferring
invoke sync() from user-space if/when they want it.

So make sys_sync on suspend build-time optional.

The default is unchanged.

Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-07-31 23:46:05 +02:00
Takashi Iwai fff3b16d27 PM / sleep: Increase default DPM watchdog timeout to 60
Many harddisks (mostly WD ones) have firmware problems and take too
long, more than 10 seconds, to resume from suspend.  And this often
exceeds the default DPM watchdog timeout (12 seconds), resulting in a
kernel panic out of sudden.

Since most distros just take the default as is, we should give a bit
more safer value.  This patch increases the default value from 12
seconds to one minute, which has been confirmed to be long enough for
such problematic disks.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=91921
Fixes: 70fea60d88 (PM / Sleep: Detect device suspend/resume lockup and log event)
Cc: 3.13+ <stable@vger.kernel.org> # 3.13+
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-06-25 00:35:16 +02:00
Pranith Kumar 83fe27ea53 rcu: Make SRCU optional by using CONFIG_SRCU
SRCU is not necessary to be compiled by default in all cases. For tinification
efforts not compiling SRCU unless necessary is desirable.

The current patch tries to make compiling SRCU optional by introducing a new
Kconfig option CONFIG_SRCU which is selected when any of the components making
use of SRCU are selected.

If we do not select CONFIG_SRCU, srcu.o will not be compiled at all.

   text    data     bss     dec     hex filename
   2007       0       0    2007     7d7 kernel/rcu/srcu.o

Size of arch/powerpc/boot/zImage changes from

   text    data     bss     dec     hex filename
 831552   64180   23944  919676   e087c arch/powerpc/boot/zImage : before
 829504   64180   23952  917636   e0084 arch/powerpc/boot/zImage : after

so the savings are about ~2000 bytes.

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: resolve conflict due to removal of arch/ia64/kvm/Kconfig. ]
2015-01-06 11:04:29 -08:00
Rafael J. Wysocki 464ed18ebd PM: Eliminate CONFIG_PM_RUNTIME
Having switched over all of the users of CONFIG_PM_RUNTIME to use
CONFIG_PM directly, turn the latter into a user-selectable option
and drop the former entirely from the tree.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
2014-12-19 22:55:06 +01:00
Rafael J. Wysocki e3d857e1ae Merge branch 'pm-runtime'
* pm-runtime: (25 commits)
  i2c-omap / PM: Drop CONFIG_PM_RUNTIME from i2c-omap.c
  dmaengine / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  drivers: sh / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  e1000e / igb / PM: Eliminate CONFIG_PM_RUNTIME
  MMC / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  MFD / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  misc / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  media / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  input / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  iio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  hsi / OMAP / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  i2c-hid / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  drm / exynos / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  gpio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  hwrandom / exynos / PM: Use CONFIG_PM in #ifdef
  block / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  USB / PM: Drop CONFIG_PM_RUNTIME from the USB core
  PM: Merge the SET*_RUNTIME_PM_OPS() macros
  PM / Kconfig: Do not select PM directly from Kconfig files
  PCI / PM: Drop CONFIG_PM_RUNTIME from the PCI core
  ...
2014-12-08 20:00:44 +01:00
Rafael J. Wysocki d30d819dc8 PM: Drop CONFIG_PM_RUNTIME from the driver core
After commit b2b49ccbdd (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is
selected) PM_RUNTIME is always set if PM is set, so quite a few
depend on CONFIG_PM or even may be dropped entirely in some cases.

Replace CONFIG_PM_RUNTIME with CONFIG_PM in the PM core code.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-12-04 00:46:58 +01:00
Rafael J. Wysocki b2b49ccbdd PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is selected
The number of and dependencies between high-level power management
Kconfig options make life much harder than necessary.  Several
conbinations of them have to be tested and supported, even though
some of those combinations are very rarely used in practice (if
they are used in practice at all).  Moreover, the fact that we
have separate independent Kconfig options for runtime PM and
system suspend is a serious obstacle for integration between
the two frameworks.

To overcome these difficulties, always select PM_RUNTIME if PM_SLEEP
is set.  Among other things, this will allow system suspend callbacks
provided by bus types and device drivers to rely on the runtime PM
framework regardless of the kernel configuration.

Enthusiastically-acked-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-18 23:41:40 +01:00
Pankaj Dubey 7d3dcd042c PM: Kconfig: fix unmet dependency for CPU_PM
If BL_SWITCHER is enabled but SUSPEND and CPU_IDLE is not enabled
we are getting following config warning.

warning: (BL_SWITCHER) selects CPU_PM which has unmet direct
dependencies (SUSPEND || CPU_IDLE)

It has been noticed that CPU_PM dependencies in this file are not really
required so let's remove these dependencies from CPU_PM.

Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-18 02:51:17 +01:00
Kevin Hilman 977d2fa6b2 PM / Runtime: Kconfig: move ia64 dependency to arch/ia64/Kconfig
The IA64_HP_SIM dependency on PM_RUNTIME should be done in the arch
Kconfig instead of in the PM core.  Move it accordingly.

NOTE: arch/ia64/Kconfig currently does a 'select PM', which since
commit 1eb208aea3 (PM: Make CONFIG_PM depend on (CONFIG_PM_SLEEP ||
CONFIG_PM_RUNTIME)) is effectively a noop unless PM_SLEEP or
PM_RUNTIME are set elsewhere.

Signed-off-by: Kevin Hilman <khilman@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-15 00:39:56 +01:00
Tomasz Figa a4a8c2c496 ARM: exynos: Move to generic PM domain DT bindings
This patch moves Exynos PM domain code to use the new generic PM domain
look-up framework introduced in previous patches, thus also allowing
the new code to be compiled with CONFIG_ARCH_EXYNOS.

This patch was originally submitted by Tomasz Figa when he was employed
by Samsung.

Link: http://marc.info/?l=linux-pm&m=139955336002083&w=2
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-22 15:57:40 +02:00
Tomasz Figa aa42240ab2 PM / Domains: Add generic OF-based PM domain look-up
This patch introduces generic code to perform PM domain look-up using
device tree and automatically bind devices to their PM domains.

Generic device tree bindings are introduced to specify PM domains of
devices in their device tree nodes.

Backwards compatibility with legacy Samsung-specific PM domain bindings
is provided, but for now the new code is not compiled when
CONFIG_ARCH_EXYNOS is selected to avoid collision with legacy code.
This will change as soon as the Exynos PM domain code gets converted to
use the generic framework in further patch.

This patch was originally submitted by Tomasz Figa when he was employed
by Samsung.

Link: http://marc.info/?l=linux-pm&m=139955349702152&w=2
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-22 15:57:40 +02:00
Mark Brown 78c5e0bb14 PM / OPP: Remove ARCH_HAS_OPP
Since the OPP layer is a kernel library which has been converted to be
directly selectable by its callers rather than user selectable and
requiring architectures to enable it explicitly the ARCH_HAS_OPP symbol
has become redundant and can be removed. Do so.

Signed-off-by: Mark Brown <broonie@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Nishanth Menon <nm@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Shawn Guo <shawn.guo@freescale.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-23 00:51:30 +02:00
Mark Brown 049d595a4d PM / OPP: Make OPP invisible to users in Kconfig
The OPP code is an in kernel library selected by its users, there is no
no architecture code required to implement it and enabling it without a
user just increases the kernel size. Since the users select rather than
depend on it just remove the ability to directly set the option from
Kconfig.

Signed-off-by: Mark Brown <broonie@linaro.org>
Acked-by: Nishanth Menon <nm@ti.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-19 23:03:31 +02:00
Benoit Goby 70fea60d88 PM / Sleep: Detect device suspend/resume lockup and log event
Rather than hard-lock the kernel, dump the suspend/resume thread stack
and panic() to capture a message in pstore when a driver takes too long
to suspend/resume. Default suspend/resume watchdog timeout is set to 12
seconds to be longer than the usbhid 10 second timeout, but could be
changed at compile time.

Exclude from the watchdog the time spent waiting for children that
are resumed asynchronously and time every device, whether or not they
resumed synchronously.

This patch is targeted for mobile devices where a suspend/resume lockup
could cause a system reboot. Information about failing device can be
retrieved in subsequent boot session by mounting pstore and inspecting
the log. Laptops with EFI-enabled pstore could also benefit from
this feature.

The hardware watchdog timer is likely suspended during this time and
couldn't be relied upon. The soft-lockup detector would eventually tell
that tasks are not scheduled, but would provide little context as to why.
The patch hence uses system timer and assumes it is still active while the
devices are suspended/resumed.

This feature can be enabled/disabled during kernel configuration.

This change is based on earlier work by San Mehat.

Signed-off-by: Benoit Goby <benoit@android.com>
Signed-off-by: Zoran Markovic <zoran.markovic@linaro.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-18 13:33:08 +02:00
Linus Torvalds f317ff9eed Merge branch 'for-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue changes from Tejun Heo:
 "Surprisingly, Lai and I didn't break too many things implementing
  custom pools and stuff last time around and there aren't any follow-up
  changes necessary at this point.

  The only change in this pull request is Viresh's patches to make some
  per-cpu workqueues to behave as unbound workqueues dependent on a boot
  param whose default can be configured via a config option.  This leads
  to higher processing overhead / lower bandwidth as more work items are
  bounced across CPUs; however, it can lead to noticeable powersave in
  certain configurations - ~10% w/ idlish constant workload on a
  big.LITTLE configuration according to Viresh.

  This is because per-cpu workqueues interfere with how the scheduler
  perceives whether or not each CPU is idle by forcing pinned tasks on
  them, which makes the scheduler's power-aware scheduling decisions
  less effective.

  Its effectiveness is likely less pronounced on homogenous
  configurations and this type of optimization can probably be made
  automatic; however, the changes are pretty minimal and the affected
  workqueues are clearly marked, so it's an easy gain for some
  configurations for the time being with pretty unintrusive changes."

* 'for-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  fbcon: queue work on power efficient wq
  block: queue work on power efficient wq
  PHYLIB: queue work on system_power_efficient_wq
  workqueue: Add system wide power_efficient workqueues
  workqueues: Introduce new flag WQ_POWER_EFFICIENT for power oriented workqueues
2013-07-02 19:53:30 -07:00
Stephen Rothwell 40b313608a Finally eradicate CONFIG_HOTPLUG
Ever since commit 45f035ab9b ("CONFIG_HOTPLUG should be always on"),
it has been basically impossible to build a kernel with CONFIG_HOTPLUG
turned off.  Remove all the remaining references to it.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-03 14:20:18 -07:00
Viresh Kumar cee22a1505 workqueues: Introduce new flag WQ_POWER_EFFICIENT for power oriented workqueues
Workqueues can be performance or power-oriented. Currently, most workqueues are
bound to the CPU they were created on. This gives good performance (due to cache
effects) at the cost of potentially waking up otherwise idle cores (Idle from
scheduler's perspective. Which may or may not be physically idle) just to
process some work. To save power, we can allow the work to be rescheduled on a
core that is already awake.

Workqueues created with the WQ_UNBOUND flag will allow some power savings.
However, we don't change the default behaviour of the system.  To enable
power-saving behaviour, a new config option CONFIG_WQ_POWER_EFFICIENT needs to
be turned on. This option can also be overridden by the
workqueue.power_efficient boot parameter.

tj: Updated config description and comments.  Renamed
    CONFIG_WQ_POWER_EFFICIENT to CONFIG_WQ_POWER_EFFICIENT_DEFAULT.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2013-05-14 10:50:06 -07:00
Rafael J. Wysocki 77f827de07 PM / Domains: Add power off/on function for system core suspend stage
Introduce function pm_genpd_syscore_switch() and two wrappers around
it, pm_genpd_syscore_poweroff() and pm_genpd_syscore_poweron(),
allowing the callers to let the generic PM domains framework know
that the given device is not necessary any more and its PM domain
can be turned off (the former) or that the given device will be
required immediately, so its PM domain has to be turned on (the
latter) during the system core (syscore) stage of system suspend
(or hibernation) and resume.

These functions will be used for handling devices registered as
clock sources and clock event devices that belong to PM domains.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-09-04 01:36:01 +02:00
Rafael J. Wysocki b2df1d4f8b PM / Sleep: Separate printing suspend times from initcall_debug
Change the behavior of the newly introduced
/sys/power/pm_print_times attribute so that its initial value
depends on initcall_debug, but setting it to 0 will cause device
suspend/resume times not to be printed, even if initcall_debug has
been set.  This way, the people who use initcall_debug for reasons
other than PM debugging will be able to switch the suspend/resume
times printing off, if need be.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-01 13:31:23 +02:00
Rafael J. Wysocki 4e585d25e1 PM / Sleep: User space wakeup sources garbage collector Kconfig option
Make it possible to configure out the user space wakeup sources
garbage collector for debugging and default Android builds.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Arve Hjønnevåg <arve@android.com>
2012-05-11 21:11:16 +02:00
Rafael J. Wysocki c73893e2ca PM / Sleep: Make the limit of user space wakeup sources configurable
Make it possible to configure out the check against the limit of
user space wakeup sources for debugging and default Android builds.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Arve Hjønnevåg <arve@android.com>
2012-05-11 21:11:02 +02:00
Rafael J. Wysocki b86ff9820f PM / Sleep: Add user space interface for manipulating wakeup sources, v3
Android allows user space to manipulate wakelocks using two
sysfs file located in /sys/power/, wake_lock and wake_unlock.
Writing a wakelock name and optionally a timeout to the wake_lock
file causes the wakelock whose name was written to be acquired (it
is created before is necessary), optionally with the given timeout.
Writing the name of a wakelock to wake_unlock causes that wakelock
to be released.

Implement an analogous interface for user space using wakeup sources.
Add the /sys/power/wake_lock and /sys/power/wake_unlock files
allowing user space to create, activate and deactivate wakeup
sources, such that writing a name and optionally a timeout to
wake_lock causes the wakeup source of that name to be activated,
optionally with the given timeout.  If that wakeup source doesn't
exist, it will be created and then activated.  Writing a name to
wake_unlock causes the wakeup source of that name, if there is one,
to be deactivated.  Wakeup sources created with the help of
wake_lock that haven't been used for more than 5 minutes are garbage
collected and destroyed.  Moreover, there can be only WL_NUMBER_LIMIT
wakeup sources created with the help of wake_lock present at a time.

The data type used to track wakeup sources created by user space is
called "struct wakelock" to indicate the origins of this feature.

This version of the patch includes an rbtree manipulation fix from John Stultz.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NeilBrown <neilb@suse.de>
2012-05-01 21:26:05 +02:00
Rafael J. Wysocki 7483b4a4d9 PM / Sleep: Implement opportunistic sleep, v2
Introduce a mechanism by which the kernel can trigger global
transitions to a sleep state chosen by user space if there are no
active wakeup sources.

It consists of a new sysfs attribute, /sys/power/autosleep, that
can be written one of the strings returned by reads from
/sys/power/state, an ordered workqueue and a work item carrying out
the "suspend" operations.  If a string representing the system's
sleep state is written to /sys/power/autosleep, the work item
triggering transitions to that state is queued up and it requeues
itself after every execution until user space writes "off" to
/sys/power/autosleep.

That work item enables the detection of wakeup events using the
functions already defined in drivers/base/power/wakeup.c (with one
small modification) and calls either pm_suspend(), or hibernate() to
put the system into a sleep state.  If a wakeup event is reported
while the transition is in progress, it will abort the transition and
the "system suspend" work item will be queued up again.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NeilBrown <neilb@suse.de>
2012-05-01 21:25:38 +02:00
Linus Torvalds 1fdb24e969 Merge branch 'devel-stable' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm
* 'devel-stable' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm: (178 commits)
  ARM: 7139/1: fix compilation with CONFIG_ARM_ATAG_DTB_COMPAT and large TEXT_OFFSET
  ARM: gic, local timers: use the request_percpu_irq() interface
  ARM: gic: consolidate PPI handling
  ARM: switch from NO_MACH_MEMORY_H to NEED_MACH_MEMORY_H
  ARM: mach-s5p64x0: remove mach/memory.h
  ARM: mach-s3c64xx: remove mach/memory.h
  ARM: plat-mxc: remove mach/memory.h
  ARM: mach-prima2: remove mach/memory.h
  ARM: mach-zynq: remove mach/memory.h
  ARM: mach-bcmring: remove mach/memory.h
  ARM: mach-davinci: remove mach/memory.h
  ARM: mach-pxa: remove mach/memory.h
  ARM: mach-ixp4xx: remove mach/memory.h
  ARM: mach-h720x: remove mach/memory.h
  ARM: mach-vt8500: remove mach/memory.h
  ARM: mach-s5pc100: remove mach/memory.h
  ARM: mach-tegra: remove mach/memory.h
  ARM: plat-tcc: remove mach/memory.h
  ARM: mach-mmp: remove mach/memory.h
  ARM: mach-cns3xxx: remove mach/memory.h
  ...

Fix up mostly pretty trivial conflicts in:
 - arch/arm/Kconfig
 - arch/arm/include/asm/localtimer.h
 - arch/arm/kernel/Makefile
 - arch/arm/mach-shmobile/board-ap4evb.c
 - arch/arm/mach-u300/core.c
 - arch/arm/mm/dma-mapping.c
 - arch/arm/mm/proc-v7.S
 - arch/arm/plat-omap/Kconfig
largely due to some CONFIG option renaming (ie CONFIG_PM_SLEEP ->
CONFIG_ARM_CPU_SUSPEND for the arm-specific suspend code etc) and
addition of NEED_MACH_MEMORY_H next to HAVE_IDE.
2011-10-28 12:02:27 -07:00
Bojan Smojver 081a9d043c PM / Hibernate: Improve performance of LZO/plain hibernation, checksum image
Use threads for LZO compression/decompression on hibernate/thaw.
Improve buffering on hibernate/thaw.
Calculate/verify CRC32 of the image pages on hibernate/thaw.

In my testing, this improved write/read speed by a factor of about two.

Signed-off-by: Bojan Smojver <bojan@rexursive.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-10-16 23:30:38 +02:00
Martin Schwidefsky 85055dd805 PM / Hibernate: Include storage keys in hibernation image on s390
For s390 there is one additional byte associated with each page,
the storage key. This byte contains the referenced and changed
bits and needs to be included into the hibernation image.
If the storage keys are not restored to their previous state all
original pages would appear to be dirty. This can cause
inconsistencies e.g. with read-only filesystems.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-10-16 23:27:46 +02:00
Colin Cross ab10023e00 cpu_pm: Add cpu power management notifiers
During some CPU power modes entered during idle, hotplug and
suspend, peripherals located in the CPU power domain, such as
the GIC, localtimers, and VFP, may be powered down.  Add a
notifier chain that allows drivers for those peripherals to
be notified before and after they may be reset.

Notified drivers can include VFP co-processor, interrupt controller
and it's PM extensions, local CPU timers context save/restore which
shouldn't be interrupted. Hence CPU PM event APIs  must be called
with interrupts disabled.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-and-Acked-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Kevin Hilman <khilman@ti.com>
Tested-by: Vishwanath BS <vishwanath.bs@ti.com>
2011-09-23 12:05:29 +05:30
Rafael J. Wysocki 17f2ae7f67 PM / Domains: Fix build for CONFIG_PM_RUNTIME unset
Function genpd_queue_power_off_work() is not defined for
CONFIG_PM_RUNTIME, so pm_genpd_poweroff_unused() causes a build
error to happen in that case.  Fix the problem by making
pm_genpd_poweroff_unused() depend on CONFIG_PM_RUNTIME too.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-14 13:34:31 +02:00
Linus Torvalds d3ec4844d4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits)
  fs: Merge split strings
  treewide: fix potentially dangerous trailing ';' in #defined values/expressions
  uwb: Fix misspelling of neighbourhood in comment
  net, netfilter: Remove redundant goto in ebt_ulog_packet
  trivial: don't touch files that are removed in the staging tree
  lib/vsprintf: replace link to Draft by final RFC number
  doc: Kconfig: `to be' -> `be'
  doc: Kconfig: Typo: square -> squared
  doc: Konfig: Documentation/power/{pm => apm-acpi}.txt
  drivers/net: static should be at beginning of declaration
  drivers/media: static should be at beginning of declaration
  drivers/i2c: static should be at beginning of declaration
  XTENSA: static should be at beginning of declaration
  SH: static should be at beginning of declaration
  MIPS: static should be at beginning of declaration
  ARM: static should be at beginning of declaration
  rcu: treewide: Do not use rcu_read_lock_held when calling rcu_dereference_check
  Update my e-mail address
  PCIe ASPM: forcedly -> forcibly
  gma500: push through device driver tree
  ...

Fix up trivial conflicts:
 - arch/arm/mach-ep93xx/dma-m2p.c (deleted)
 - drivers/gpio/gpio-ep93xx.c (renamed and context nearby)
 - drivers/net/r8169.c (just context changes)
2011-07-25 13:56:39 -07:00
Michael Witten 2dc98fd320 doc: Konfig: Documentation/power/{pm => apm-acpi}.txt
Signed-off-by: Michael Witten <mfwitten@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-07-11 14:20:07 +02:00
Rafael J. Wysocki b7b95920aa PM: Allow the clocks management code to be used during system suspend
The common clocks management code in drivers/base/power/clock_ops.c
is going to be used during system-wide power transitions as well as
for runtime PM, so it shouldn't depend on CONFIG_PM_RUNTIME.
However, the suspend/resume functions provided by it for
CONFIG_PM_RUNTIME unset, to be used during system-wide power
transitions, should not behave in the same way as their counterparts
defined for CONFIG_PM_RUNTIME set, because in that case the clocks
are managed differently at run time.

The names of the functions still contain the word "runtime" after
this change, but that is going to be modified by a separate patch
later.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Kevin Hilman <khilman@ti.com>
2011-07-02 14:29:56 +02:00
Rafael J. Wysocki f721889ff6 PM / Domains: Support for generic I/O PM domains (v8)
Introduce common headers, helper functions and callbacks allowing
platforms to use simple generic power domains for runtime power
management.

Introduce struct generic_pm_domain to be used for representing
power domains that each contain a number of devices and may be
parent domains or subdomains with respect to other power domains.
Among other things, this structure includes callbacks to be
provided by platforms for performing specific tasks related to
power management (i.e. ->stop_device() may disable a device's
clocks, while ->start_device() may enable them, ->power_off() is
supposed to remove power from the entire power domain
and ->power_on() is supposed to restore it).

Introduce functions that can be used as power domain runtime PM
callbacks, pm_genpd_runtime_suspend() and pm_genpd_runtime_resume(),
as well as helper functions for the initialization of a power
domain represented by a struct generic_power_domain object,
adding a device to or removing a device from it and adding or
removing subdomains.

Introduce configuration option CONFIG_PM_GENERIC_DOMAINS to be
selected by the platforms that want to use the new code.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Reviewed-by: Kevin Hilman <khilman@ti.com>
2011-07-02 14:29:55 +02:00
Rafael J. Wysocki c650da23d5 PM: Remove CONFIG_PM_VERBOSE
Now that we have CONFIG_DYNAMIC_DEBUG there is no need for yet
another flag causing dev_dbg() and pr_debug() statements in the
core PM code to produce output.  Moreover, CONFIG_PM_VERBOSE
causes so much output to be generated that it's not really useful
and almost no one sets it.

References: https://bugzilla.kernel.org/show_bug.cgi?id=23182
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-05-17 23:25:10 +02:00
Rafael J. Wysocki 85eb8c8d0b PM / Runtime: Generic clock manipulation rountines for runtime PM (v6)
Many different platforms and subsystems may want to disable device
clocks during suspend and enable them during resume which is going to
be done in a very similar way in all those cases.  For this reason,
provide generic routines for the manipulation of device clocks during
suspend and resume.

Convert the ARM shmobile platform to using the new routines.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-04-30 00:25:44 +02:00
Shriram Rajagopalan d419e4c0f7 fix XEN_SAVE_RESTORE Kconfig dependencies
Make XEN_SAVE_RESTORE select HIBERNATE_CALLBACKS.
Remove XEN_SAVE_RESTORE dependency from PM_SLEEP.

Signed-off-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-04-11 22:54:48 +02:00
Rafael J. Wysocki 1f112cee07 PM / Hibernate: Introduce CONFIG_HIBERNATE_CALLBACKS
Xen save/restore is going to use hibernate device callbacks for
quiescing devices and putting them back to normal operations and it
would need to select CONFIG_HIBERNATION for this purpose.  However,
that also would cause the hibernate interfaces for user space to be
enabled, which might confuse user space, because the Xen kernels
don't support hibernation.  Moreover, it would be wasteful, as it
would make the Xen kernels include a substantial amount of code that
they would never use.

To address this issue introduce new power management Kconfig option
CONFIG_HIBERNATE_CALLBACKS, such that it will only select the code
that is necessary for the hibernate device callbacks to work and make
CONFIG_HIBERNATION select it.  Then, Xen save/restore will be able to
select CONFIG_HIBERNATE_CALLBACKS without dragging the entire
hibernate code along with it.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
2011-04-11 22:54:42 +02:00
Jan Beulich cf4fb80ca3 PM: Simplify kernel/power/Kconfig
'n' defaults are pretty pointless and actually bogus when used with
prompt-less config options.

The "bool"/"default y" pair with no prompt can be expressed more
compactly using def_bool.

[rjw: Rebased on top of earlier patches modifying this file.]

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15 00:43:17 +01:00
Rafael J. Wysocki 88a6f33e4d PM: Clean up PM_TRACE dependencies and drop unnecessary Kconfig option
CONFIG_PM_SLEEP_ADVANCED_DEBUG is not used any more, so drop it
and CONFIG_CAN_PM_TRACE need not depend on EXPERIMENTAL, so remove
that dependency.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15 00:43:15 +01:00
Rafael J. Wysocki aa33860158 PM: Remove CONFIG_PM_OPS
After redefining CONFIG_PM to depend on (CONFIG_PM_SLEEP ||
CONFIG_PM_RUNTIME) the CONFIG_PM_OPS option is redundant and can be
replaced with CONFIG_PM.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15 00:43:15 +01:00
Rafael J. Wysocki 196ec24322 PM: Reorder power management Kconfig options
Reorder configuration options in kernel/power/Kconfig so that
the options depended on are at the top of the list.

This patch doesn't introduce any functional changes.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15 00:43:15 +01:00
Rafael J. Wysocki 1eb208aea3 PM: Make CONFIG_PM depend on (CONFIG_PM_SLEEP || CONFIG_PM_RUNTIME)
From the users' point of view CONFIG_PM is really only used for
making it possible to set CONFIG_SUSPEND, CONFIG_HIBERNATION,
CONFIG_PM_RUNTIME and (surprisingly enough) CONFIG_XEN_SAVE_RESTORE
(CONFIG_PM_OPP also depends on CONFIG_PM, but quite artificially).
However, both CONFIG_SUSPEND and CONFIG_HIBERNATION require platform
support (independent of CONFIG_PM) and it is not quite obvious that
CONFIG_PM has to be set for CONFIG_XEN_SAVE_RESTORE to be available.
Thus, from the users' point of view, it would be more logical to
automatically select CONFIG_PM if any of the above options depending
on it are set.

Make CONFIG_PM depend on (CONFIG_PM_SLEEP || CONFIG_PM_RUNTIME),
which will cause it to be selected when any of CONFIG_SUSPEND,
CONFIG_HIBERNATION, CONFIG_PM_RUNTIME, CONFIG_XEN_SAVE_RESTORE is
set and will clarify its meaning.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15 00:43:15 +01:00
Rafael J. Wysocki 976513dbfc PM / ACPI: Move NVS saving and restoring code to drivers/acpi
The saving of the ACPI NVS area during hibernation and suspend and
restoring it during the subsequent resume is entirely specific to
ACPI, so move it to drivers/acpi and drop the CONFIG_SUSPEND_NVS
configuration option which is redundant.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
2011-01-07 00:36:55 -05:00
Mark Brown 43e60861fe PM / OPP: Hide OPP configuration when SoCs do not provide an implementation
Since the OPP API is only useful with an appropraite SoC-specific
implementation there is no point in offering the ability to enable
the API on general systems. Provide an ARCH_HAS OPP Kconfig symbol
which masks out the option unless selected by an implementation.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Nishanth Menon <nm@ti.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-11-11 01:51:26 +01:00