linux-stable.git/drivers/cpuidle, branch linux-3.19.y Linux kernel stable tree cpuidle: remove state_count field from struct cpuidle_device 2015-04-19T08:10:21+00:00 Bartlomiej Zolnierkiewicz b.zolnierkie@samsung.com 2015-03-31T18:15:09+00:00 67b4228ed87b17801c8822f6d4ebe949493949cc commit d75e4af14e228bbe3f86e29bcecb8e6be98d4e04 upstream. Thomas Schlichter reports the following issue on his Samsung NC20: "The C-states C1 and C2 to the OS when connected to AC, and additionally provides the C3 C-state when disconnected from AC. However, the number of C-states shown in sysfs is fixed to the number of C-states present at boot. If I boot with AC connected, I always only see the C-states up to C2 even if I disconnect AC. The reason is commit 130a5f692425 (ACPI / cpuidle: remove dev->state_count setting). It removes the update of dev->state_count, but sysfs uses exactly this variable to show the C-states. The fix is to use drv->state_count in sysfs. As this is currently the last user of dev->state_count, this variable can be completely removed." Remove dev->state_count as per the above. Reported-by: Thomas Schlichter <thomas.schlichter@web.de> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d75e4af14e228bbe3f86e29bcecb8e6be98d4e04 upstream.

Thomas Schlichter reports the following issue on his Samsung NC20:

"The C-states C1 and C2 to the OS when connected to AC, and additionally
 provides the C3 C-state when disconnected from AC.  However, the number
 of C-states shown in sysfs is fixed to the number of C-states present
 at boot.
   If I boot with AC connected, I always only see the C-states up to C2
   even if I disconnect AC.

   The reason is commit 130a5f692425 (ACPI / cpuidle: remove dev->state_count
   setting).  It removes the update of dev->state_count, but sysfs uses
   exactly this variable to show the C-states.

   The fix is to use drv->state_count in sysfs.  As this is currently the
   last user of dev->state_count, this variable can be completely removed."

Remove dev->state_count as per the above.

Reported-by: Thomas Schlichter <thomas.schlichter@web.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cpuidle: mvebu: Fix the CPU PM notifier usage 2015-04-13T12:03:53+00:00 Gregory CLEMENT gregory.clement@free-electrons.com 2015-02-26T17:20:48+00:00 9ce9d3fb7754af5f731499ec87b842739db4d03a commit 43b68879de27b1993518687fbc6013da80cdcbfe upstream. As stated in kernel/cpu_pm.c, "Platform is responsible for ensuring that cpu_pm_enter is not called twice on the same CPU before cpu_pm_exit is called.". In the current code in case of failure when calling mvebu_v7_cpu_suspend, the function cpu_pm_exit() is never called whereas cpu_pm_enter() was called just before. This patch moves the cpu_pm_exit() in order to balance the cpu_pm_enter() calls. Reported-by: Fulvio Benini <fbf@libero.it> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 43b68879de27b1993518687fbc6013da80cdcbfe upstream.

As stated in kernel/cpu_pm.c, "Platform is responsible for ensuring
that cpu_pm_enter is not called twice on the same CPU before
cpu_pm_exit is called.". In the current code in case of failure when
calling mvebu_v7_cpu_suspend, the function cpu_pm_exit() is never
called whereas cpu_pm_enter() was called just before.

This patch moves the cpu_pm_exit() in order to balance the
cpu_pm_enter() calls.

Reported-by: Fulvio Benini <fbf@libero.it>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge branches 'pm-cpufreq' and 'pm-cpuidle' 2014-12-29T20:23:41+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2014-12-29T20:23:41+00:00 ff23ab2441e7ba5089e8631bad3a6569e7b6d5b8 * pm-cpufreq: cpufreq: fix a NULL pointer dereference in __cpufreq_governor() cpufreq-dt: defer probing if OPP table is not ready * pm-cpuidle: cpuidle / ACPI: remove unused CPUIDLE_FLAG_TIME_INVALID cpuidle: ladder: Better idle duration measurement without using CPUIDLE_FLAG_TIME_INVALID cpuidle: menu: Better idle duration measurement without using CPUIDLE_FLAG_TIME_INVALID 
* pm-cpufreq:
  cpufreq: fix a NULL pointer dereference in __cpufreq_governor()
  cpufreq-dt: defer probing if OPP table is not ready

* pm-cpuidle:
  cpuidle / ACPI: remove unused CPUIDLE_FLAG_TIME_INVALID
  cpuidle: ladder: Better idle duration measurement without using CPUIDLE_FLAG_TIME_INVALID
  cpuidle: menu: Better idle duration measurement without using CPUIDLE_FLAG_TIME_INVALID
Merge tag 'powerpc-3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux 2014-12-19T20:57:45+00:00 Linus Torvalds torvalds@linux-foundation.org 2014-12-19T20:57:45+00:00 34b85e3574424beb30e4cd163e6da2e2282d2683 Pull second batch of powerpc updates from Michael Ellerman: "The highlight is the series that reworks the idle management on powernv, which allows us to use deeper idle states on those machines. There's the fix from Anton for the "BUG at kernel/smpboot.c:134!" problem. An i2c driver for powernv. This is acked by Wolfram Sang, and he asked that we take it through the powerpc tree. A fix for audit from rgb at Red Hat, acked by Paul Moore who is one of the audit maintainers. A patch from Ben to export the symbol map of our OPAL firmware as a sysfs file, so that tools can use it. Also some CXL fixes, a couple of powerpc perf fixes, a fix for smt-enabled, and the patch to add __force to get_user() so we can use bitwise types" * tag 'powerpc-3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: powerpc/powernv: Ignore smt-enabled on Power8 and later powerpc/uaccess: Allow get_user() with bitwise types powerpc/powernv: Expose OPAL firmware symbol map powernv/powerpc: Add winkle support for offline cpus powernv/cpuidle: Redesign idle states management powerpc/powernv: Enable Offline CPUs to enter deep idle states powerpc/powernv: Switch off MMU before entering nap/sleep/rvwinkle mode i2c: Driver to expose PowerNV platform i2c busses powerpc: add little endian flag to syscall_get_arch() power/perf/hv-24x7: Use kmem_cache_free() instead of kfree powerpc/perf/hv-24x7: Use per-cpu page buffer cxl: Unmap MMIO regions when detaching a context cxl: Add timeout to process element commands cxl: Change contexts_lock to a mutex to fix sleep while atomic bug powerpc: Secondary CPUs must set cpu_callin_map after setting active and online 
Pull second batch of powerpc updates from Michael Ellerman:
 "The highlight is the series that reworks the idle management on
  powernv, which allows us to use deeper idle states on those machines.

  There's the fix from Anton for the "BUG at kernel/smpboot.c:134!"
  problem.

  An i2c driver for powernv.  This is acked by Wolfram Sang, and he
  asked that we take it through the powerpc tree.

  A fix for audit from rgb at Red Hat, acked by Paul Moore who is one of
  the audit maintainers.

  A patch from Ben to export the symbol map of our OPAL firmware as a
  sysfs file, so that tools can use it.

  Also some CXL fixes, a couple of powerpc perf fixes, a fix for
  smt-enabled, and the patch to add __force to get_user() so we can use
  bitwise types"

* tag 'powerpc-3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux:
  powerpc/powernv: Ignore smt-enabled on Power8 and later
  powerpc/uaccess: Allow get_user() with bitwise types
  powerpc/powernv: Expose OPAL firmware symbol map
  powernv/powerpc: Add winkle support for offline cpus
  powernv/cpuidle: Redesign idle states management
  powerpc/powernv: Enable Offline CPUs to enter deep idle states
  powerpc/powernv: Switch off MMU before entering nap/sleep/rvwinkle mode
  i2c: Driver to expose PowerNV platform i2c busses
  powerpc: add little endian flag to syscall_get_arch()
  power/perf/hv-24x7: Use kmem_cache_free() instead of kfree
  powerpc/perf/hv-24x7: Use per-cpu page buffer
  cxl: Unmap MMIO regions when detaching a context
  cxl: Add timeout to process element commands
  cxl: Change contexts_lock to a mutex to fix sleep while atomic bug
  powerpc: Secondary CPUs must set cpu_callin_map after setting active and online
cpuidle: ladder: Better idle duration measurement without using CPUIDLE_FLAG_TIME_INVALID 2014-12-17T01:26:28+00:00 Len Brown len.brown@intel.com 2014-12-16T06:52:07+00:00 b73026b9c959600bcd65eeae7a5f7ac00ded886f When the ladder governor sees the CPUIDLE_FLAG_TIME_INVALID flag, it unconditionally causes a state promotion by setting last_residency to a number higher than the state's promotion_time: last_residency = last_state->threshold.promotion_time + 1 It does this for fear that cpuidle_get_last_residency() will be in-accurate, because cpuidle_enter_state() invoked a state with CPUIDLE_FLAG_TIME_INVALID. But the only state with CPUIDLE_FLAG_TIME_INVALID is acpi_safe_halt(), which may return well after its actual idle duration because it enables interrupts, so cpuidle_enter_state() also measures interrupt service time. So what? In ladder, a huge invalid last_residency has exactly the same effect as the current code -- it unconditionally causes a state promotion. In the case where the idle residency plus measured interrupt handling time is less than the state's demotion_time -- we should use that timestamp to give ladder a chance to demote, rather than unconditionally promoting. This can be done by simply ignoring the CPUIDLE_FLAG_TIME_INVALID, and using the "invalid" time, as it is either equal to what we are doing today, or better. Signed-off-by: Len Brown <len.brown@intel.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
When the ladder governor sees the CPUIDLE_FLAG_TIME_INVALID flag,
it unconditionally causes a state promotion by setting last_residency
to a number higher than the state's promotion_time:

last_residency = last_state->threshold.promotion_time + 1

It does this for fear that cpuidle_get_last_residency()
will be in-accurate, because cpuidle_enter_state() invoked
a state with CPUIDLE_FLAG_TIME_INVALID.

But the only state with CPUIDLE_FLAG_TIME_INVALID is
acpi_safe_halt(), which may return well after its actual
idle duration because it enables interrupts, so cpuidle_enter_state()
also measures interrupt service time.

So what?  In ladder, a huge invalid last_residency has exactly
the same effect as the current code -- it unconditionally
causes a state promotion.

In the case where the idle residency plus measured interrupt
handling time is less than the state's demotion_time -- we should
use that timestamp to give ladder a chance to demote, rather than
unconditionally promoting.

This can be done by simply ignoring the CPUIDLE_FLAG_TIME_INVALID,
and using the "invalid" time, as it is either equal to what we are
doing today, or better.

Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuidle: menu: Better idle duration measurement without using CPUIDLE_FLAG_TIME_INVALID 2014-12-17T01:26:28+00:00 Len Brown len.brown@intel.com 2014-12-16T06:52:06+00:00 4108b3d96273784f697dd6d8e59ef9203a10a02d When menu sees CPUIDLE_FLAG_TIME_INVALID, it ignores its timestamps, and assumes that idle lasted as long as the time till next predicted timer expiration. But if an interrupt was seen and serviced before that duration, it would actually be more accurate to use the measured time rather than rounding up to the next predicted timer expiration. And if an interrupt is seen and serviced such that the mesured time exceeds the time till next predicted timer expiration, then truncating to that expiration is the right thing to do -- since we can never stay idle past that timer expiration. So the code can do a better job without checking for CPUIDLE_FLAG_TIME_INVALID. Signed-off-by: Len Brown <len.brown@intel.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
When menu sees CPUIDLE_FLAG_TIME_INVALID, it ignores its timestamps,
and assumes that idle lasted as long as the time till next predicted
timer expiration.

But if an interrupt was seen and serviced before that duration,
it would actually be more accurate to use the measured time
rather than rounding up to the next predicted timer expiration.

And if an interrupt is seen and serviced such that the mesured time
exceeds the time till next predicted timer expiration, then
truncating to that expiration is the right thing to do --
since we can never stay idle past that timer expiration.

So the code can do a better job without
checking for CPUIDLE_FLAG_TIME_INVALID.

Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core 2014-12-15T00:10:09+00:00 Linus Torvalds torvalds@linux-foundation.org 2014-12-15T00:10:09+00:00 e6b5be2be4e30037eb551e0ed09dd97bd00d85d3 Pull driver core update from Greg KH: "Here's the set of driver core patches for 3.19-rc1. They are dominated by the removal of the .owner field in platform drivers. They touch a lot of files, but they are "simple" changes, just removing a line in a structure. Other than that, a few minor driver core and debugfs changes. There are some ath9k patches coming in through this tree that have been acked by the wireless maintainers as they relied on the debugfs changes. Everything has been in linux-next for a while" * tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits) Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries" fs: debugfs: add forward declaration for struct device type firmware class: Deletion of an unnecessary check before the function call "vunmap" firmware loader: fix hung task warning dump devcoredump: provide a one-way disable function device: Add dev_<level>_once variants ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries ath: use seq_file api for ath9k debugfs files debugfs: add helper function to create device related seq_file drivers/base: cacheinfo: remove noisy error boot message Revert "core: platform: add warning if driver has no owner" drivers: base: support cpu cache information interface to userspace via sysfs drivers: base: add cpu_device_create to support per-cpu devices topology: replace custom attribute macros with standard DEVICE_ATTR* cpumask: factor out show_cpumap into separate helper function driver core: Fix unbalanced device reference in drivers_probe driver core: fix race with userland in device_add() sysfs/kernfs: make read requests on pre-alloc files use the buffer. sysfs/kernfs: allow attributes to request write buffer be pre-allocated. fs: sysfs: return EGBIG on write if offset is larger than file size ... 
Pull driver core update from Greg KH:
 "Here's the set of driver core patches for 3.19-rc1.

  They are dominated by the removal of the .owner field in platform
  drivers.  They touch a lot of files, but they are "simple" changes,
  just removing a line in a structure.

  Other than that, a few minor driver core and debugfs changes.  There
  are some ath9k patches coming in through this tree that have been
  acked by the wireless maintainers as they relied on the debugfs
  changes.

  Everything has been in linux-next for a while"

* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
  Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
  fs: debugfs: add forward declaration for struct device type
  firmware class: Deletion of an unnecessary check before the function call "vunmap"
  firmware loader: fix hung task warning dump
  devcoredump: provide a one-way disable function
  device: Add dev_<level>_once variants
  ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
  ath: use seq_file api for ath9k debugfs files
  debugfs: add helper function to create device related seq_file
  drivers/base: cacheinfo: remove noisy error boot message
  Revert "core: platform: add warning if driver has no owner"
  drivers: base: support cpu cache information interface to userspace via sysfs
  drivers: base: add cpu_device_create to support per-cpu devices
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  cpumask: factor out show_cpumap into separate helper function
  driver core: Fix unbalanced device reference in drivers_probe
  driver core: fix race with userland in device_add()
  sysfs/kernfs: make read requests on pre-alloc files use the buffer.
  sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
  fs: sysfs: return EGBIG on write if offset is larger than file size
  ...
powernv/cpuidle: Redesign idle states management 2014-12-14T23:46:40+00:00 Shreyas B. Prabhu shreyas@linux.vnet.ibm.com 2014-12-09T18:56:52+00:00 7cba160ad789a3ad7e68b92bf20eaad6ed171f80 Deep idle states like sleep and winkle are per core idle states. A core enters these states only when all the threads enter either the particular idle state or a deeper one. There are tasks like fastsleep hardware bug workaround and hypervisor core state save which have to be done only by the last thread of the core entering deep idle state and similarly tasks like timebase resync, hypervisor core register restore that have to be done only by the first thread waking up from these state. The current idle state management does not have a way to distinguish the first/last thread of the core waking/entering idle states. Tasks like timebase resync are done for all the threads. This is not only is suboptimal, but can cause functionality issues when subcores and kvm is involved. This patch adds the necessary infrastructure to track idle states of threads in a per-core structure. It uses this info to perform tasks like fastsleep workaround and timebase resync only once per core. Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com> Originally-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: linux-pm@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
Deep idle states like sleep and winkle are per core idle states. A core
enters these states only when all the threads enter either the
particular idle state or a deeper one. There are tasks like fastsleep
hardware bug workaround and hypervisor core state save which have to be
done only by the last thread of the core entering deep idle state and
similarly tasks like timebase resync, hypervisor core register restore
that have to be done only by the first thread waking up from these
state.

The current idle state management does not have a way to distinguish the
first/last thread of the core waking/entering idle states. Tasks like
timebase resync are done for all the threads. This is not only is
suboptimal, but can cause functionality issues when subcores and kvm is
involved.

This patch adds the necessary infrastructure to track idle states of
threads in a per-core structure. It uses this info to perform tasks like
fastsleep workaround and timebase resync only once per core.

Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Originally-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/powernv: Enable Offline CPUs to enter deep idle states 2014-12-14T23:46:40+00:00 Shreyas B. Prabhu shreyas@linux.vnet.ibm.com 2014-12-09T18:56:51+00:00 8eb8ac89a364305d05ad16be983b7890eb462cc3 The secondary threads should enter deep idle states so as to gain maximum powersavings when the entire core is offline. To do so the offline path must be made aware of the available deepest idle state. Hence probe the device tree for the possible idle states in powernv core code and expose the deepest idle state through flags. Since the device tree is probed by the cpuidle driver as well, move the parameters required to discover the idle states into an appropriate common place to both the driver and the powernv core code. Another point is that fastsleep idle state may require workarounds in the kernel to function properly. This workaround is introduced in the subsequent patches. However neither the cpuidle driver or the hotplug path need be bothered about this workaround. They will be taken care of by the core powernv code. Originally-by: Srivatsa S. Bhat <srivatsa@mit.edu> Signed-off-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com> Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com> Reviewed-by: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: linux-pm@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
The secondary threads should enter deep idle states so as to gain maximum
powersavings when the entire core is offline. To do so the offline path
must be made aware of the available deepest idle state. Hence probe the
device tree for the possible idle states in powernv core code and
expose the deepest idle state through flags.

Since the  device tree is probed by the cpuidle driver as well, move
the parameters required to discover the idle states into an appropriate
common place to both the driver and the powernv core code.

Another point is that fastsleep idle state may require workarounds in
the kernel to function properly. This workaround is introduced in the
subsequent patches. However neither the cpuidle driver or the hotplug
path need be bothered about this workaround.

They will be taken care of by the core powernv code.

Originally-by: Srivatsa S. Bhat <srivatsa@mit.edu>
Signed-off-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Reviewed-by: Paul Mackerras <paulus@samba.org>

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Merge back earlier cpuidle material for 3.19-rc1. 2014-11-21T15:31:42+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2014-11-21T15:31:42+00:00 0a924200ae5fcf7b3d237d92a110545b6db6aa18 Conflicts: drivers/cpuidle/dt_idle_states.c 
Conflicts:
	drivers/cpuidle/dt_idle_states.c