Pull SMP hotplug updates from Thomas Gleixner:
"This update is primarily a cleanup of the CPU hotplug locking code.
The hotplug locking mechanism is an open coded RWSEM, which allows
recursive locking. The main problem with that is the recursive nature
as it evades the full lockdep coverage and hides potential deadlocks.
The rework replaces the open coded RWSEM with a percpu RWSEM and
establishes full lockdep coverage that way.
The bulk of the changes fix up recursive locking issues and address
the now fully reported potential deadlocks all over the place. Some of
these deadlocks have been observed in the RT tree, but on mainline the
probability was low enough to hide them away."
* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
cpu/hotplug: Constify attribute_group structures
powerpc: Only obtain cpu_hotplug_lock if called by rtasd
ARM/hw_breakpoint: Fix possible recursive locking for arch_hw_breakpoint_init
cpu/hotplug: Remove unused check_for_tasks() function
perf/core: Don't release cred_guard_mutex if not taken
cpuhotplug: Link lock stacks for hotplug callbacks
acpi/processor: Prevent cpu hotplug deadlock
sched: Provide is_percpu_thread() helper
cpu/hotplug: Convert hotplug locking to percpu rwsem
s390: Prevent hotplug rwsem recursion
arm: Prevent hotplug rwsem recursion
arm64: Prevent cpu hotplug rwsem recursion
kprobes: Cure hotplug lock ordering issues
jump_label: Reorder hotplug lock and jump_label_lock
perf/tracing/cpuhotplug: Fix locking order
ACPI/processor: Use cpu_hotplug_disable() instead of get_online_cpus()
PCI: Replace the racy recursion prevention
PCI: Use cpu_hotplug_disable() instead of get_online_cpus()
perf/x86/intel: Drop get_online_cpus() in intel_snb_check_microcode()
x86/perf: Drop EXPORT of perf_check_microcode
...
Conflicts:
kernel/sched/Makefile
Pick up the waitqueue related renames - it didn't get much feedback,
so it appears to be uncontroversial. Famous last words? ;-)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit 27ed3cd2eb (cpufreq: conservative: Fix the logic in frequency
decrease checking) removed the 10 point substraction when comparing the
load against down_threshold but did not remove the related limit for the
down_threshold value. As a result, down_threshold lower than 11 is not
allowed even though values from 1 to 10 do work correctly too. The
comment ("cannot be lower than 11 otherwise freq will not fall") also
does not apply after removing the substraction.
For this reason, allow down_threshold to take any value from 1 to 99
and fix the related comment.
Fixes: 27ed3cd2eb (cpufreq: conservative: Fix the logic in frequency decrease checking)
Signed-off-by: Tomasz Wilczyński <twilczynski@naver.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 3.10+ <stable@vger.kernel.org> # 3.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit c5a2ee7dde (cpufreq: intel_pstate: Active mode P-state
limits rework) incorrectly assumed that pstate.turbo_pstate would
always be nonzero for CPU0 in min_perf_pct_min() if
cpufreq_register_driver() had succeeded which may not be the case
in virtualized environments.
If that assumption doesn't hold, it leads to an early crash on boot
in intel_pstate_register_driver(), so add a sanity check to
min_perf_pct_min() to prevent the crash from happening.
Fixes: c5a2ee7dde (cpufreq: intel_pstate: Active mode P-state limits rework)
Reported-and-tested-by: Jongman Heo <jongman.heo@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* pm-cpufreq:
cpufreq: kirkwood-cpufreq:- Handle return value of clk_prepare_enable()
cpufreq: cpufreq_register_driver() should return -ENODEV if init fails
clk_prepare_enable() can fail here and we must check its return value.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
For a driver that does not set the CPUFREQ_STICKY flag, if all of the
->init() calls fail, cpufreq_register_driver() should return an error.
This will prevent the driver from loading.
Fixes: ce1bcfe94d (cpufreq: check cpufreq_policy_list instead of scanning policies for all CPUs)
Cc: 4.0+ <stable@vger.kernel.org> # 4.0+
Signed-off-by: David Arcari <darcari@redhat.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq holds get_online_cpus() while invoking cpuhp_setup_state_nocalls()
to make subsys_interface_register() and the registration of hotplug calls
atomic versus cpu hotplug.
cpuhp_setup_state_nocalls() invokes get_online_cpus() as well. This is
correct, but prevents the conversion of the hotplug locking to a percpu
rwsem.
Use cpuhp_setup/remove_state_nocalls_cpuslocked() to avoid the nested
call. Convert *_online_cpus() to the new interfaces while at it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-pm@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081547.731628408@linutronix.de
To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.
Adjust the system_state check in pas_cpufreq_cpu_exit() to handle the extra
states.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20170516184735.620023128@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
* intel_pstate:
cpufreq: intel_pstate: Document the current behavior and user interface
* pm-cpufreq:
cpufreq: dbx500: add a Kconfig symbol
* pm-cpufreq-sched:
cpufreq: schedutil: use now as reference when aggregating shared policy requests
Moving the cooling code into the cpufreq driver caused a possible build failure
when the cpu_thermal helper code is a loadable module or disabled:
drivers/cpufreq/dbx500-cpufreq.o: In function `dbx500_cpufreq_ready':
dbx500-cpufreq.c:(.text.dbx500_cpufreq_ready+0x4): undefined reference to `cpufreq_cooling_register'
This adds the same dependency that we have in other cpufreq drivers,
forcing the driver to be disabled when we can't possibly link it.
Fixes: 19678ffb9f (cpufreq: dbx500: Manage cooling device from cpufreq driver)
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Merge tag 'hwparam-20170420' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull hw lockdown support from David Howells:
"Annotation of module parameters that configure hardware resources
including ioports, iomem addresses, irq lines and dma channels.
This allows a future patch to prohibit the use of such module
parameters to prevent that hardware from being abused to gain access
to the running kernel image as part of locking the kernel down under
UEFI secure boot conditions.
Annotations are made by changing:
module_param(n, t, p)
module_param_named(n, v, t, p)
module_param_array(n, t, m, p)
to:
module_param_hw(n, t, hwtype, p)
module_param_hw_named(n, v, t, hwtype, p)
module_param_hw_array(n, t, hwtype, m, p)
where the module parameter refers to a hardware setting
hwtype specifies the type of the resource being configured. This can
be one of:
ioport Module parameter configures an I/O port
iomem Module parameter configures an I/O mem address
ioport_or_iomem Module parameter could be either (runtime set)
irq Module parameter configures an I/O port
dma Module parameter configures a DMA channel
dma_addr Module parameter configures a DMA buffer address
other Module parameter configures some other value
Note that the hwtype is compile checked, but not currently stored (the
lockdown code probably won't require it). It is, however, there for
future use.
A bonus is that the hwtype can also be used for grepping.
The intention is for the kernel to ignore or reject attempts to set
annotated module parameters if lockdown is enabled. This applies to
options passed on the boot command line, passed to insmod/modprobe or
direct twiddling in /sys/module/ parameter files.
The module initialisation then needs to handle the parameter not being
set, by (1) giving an error, (2) probing for a value or (3) using a
reasonable default.
What I can't do is just reject a module out of hand because it may
take a hardware setting in the module parameters. Some important
modules, some ipmi stuff for instance, both probe for hardware and
allow hardware to be manually specified; if the driver is aborts with
any error, you don't get any ipmi hardware.
Further, trying to do this entirely in the module initialisation code
doesn't protect against sysfs twiddling.
[!] Note that in and of itself, this series of patches should have no
effect on the the size of the kernel or code execution - that is
left to a patch in the next series to effect. It does mark
annotated kernel parameters with a KERNEL_PARAM_FL_HWPARAM flag in
an already existing field"
* tag 'hwparam-20170420' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (38 commits)
Annotate hardware config module parameters in sound/pci/
Annotate hardware config module parameters in sound/oss/
Annotate hardware config module parameters in sound/isa/
Annotate hardware config module parameters in sound/drivers/
Annotate hardware config module parameters in fs/pstore/
Annotate hardware config module parameters in drivers/watchdog/
Annotate hardware config module parameters in drivers/video/
Annotate hardware config module parameters in drivers/tty/
Annotate hardware config module parameters in drivers/staging/vme/
Annotate hardware config module parameters in drivers/staging/speakup/
Annotate hardware config module parameters in drivers/staging/media/
Annotate hardware config module parameters in drivers/scsi/
Annotate hardware config module parameters in drivers/pcmcia/
Annotate hardware config module parameters in drivers/pci/hotplug/
Annotate hardware config module parameters in drivers/parport/
Annotate hardware config module parameters in drivers/net/wireless/
Annotate hardware config module parameters in drivers/net/wan/
Annotate hardware config module parameters in drivers/net/irda/
Annotate hardware config module parameters in drivers/net/hamradio/
Annotate hardware config module parameters in drivers/net/ethernet/
...
While examining output from trial builds with -Wformat-security enabled,
many strings were found that should be defined as "const", or as a char
array instead of char pointer. This makes some static analysis easier,
by producing fewer false positives.
As these are all trivial changes, it seemed best to put them all in a
single patch rather than chopping them up per maintainer.
Link: http://lkml.kernel.org/r/20170405214711.GA5711@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Jes Sorensen <jes@trained-monkey.org> [runner.c]
Cc: Tony Lindgren <tony@atomide.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Yisen Zhuang <yisen.zhuang@huawei.com>
Cc: Salil Mehta <salil.mehta@huawei.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Mugunthan V N <mugunthanvnm@ti.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: Jarod Wilson <jarod@redhat.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Antonio Quartulli <a@unstable.cc>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Kejian Yan <yankejian@huawei.com>
Cc: Daode Huang <huangdaode@hisilicon.com>
Cc: Qianqian Xie <xieqianqian@huawei.com>
Cc: Philippe Reynes <tremyfr@gmail.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Christian Gromm <christian.gromm@microchip.com>
Cc: Andrey Shvetsov <andrey.shvetsov@k2l.de>
Cc: Jason Litzinger <jlitzingerdev@gmail.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This typo is quite common. Fix it and add it to the spelling file so
that checkpatch catches it earlier.
Link: http://lkml.kernel.org/r/20170317011131.6881-2-sboyd@codeaurora.org
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When the kernel is running in secure boot mode, we lock down the kernel to
prevent userspace from modifying the running kernel image. Whilst this
includes prohibiting access to things like /dev/mem, it must also prevent
access by means of configuring driver modules in such a way as to cause a
device to access or modify the kernel image.
To this end, annotate module_param* statements that refer to hardware
configuration and indicate for future reference what type of parameter they
specify. The parameter parser in the core sees this information and can
skip such parameters with an error message if the kernel is locked down.
The module initialisation then runs as normal, but just sees whatever the
default values for those parameters is.
Note that we do still need to do the module initialisation because some
drivers have viable defaults set in case parameters aren't specified and
some drivers support automatic configuration (e.g. PNP or PCI) in addition
to manually coded parameters.
This patch annotates drivers in drivers/cpufreq/.
Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
cc: linux-pm@vger.kernel.org
Add a new cpufreq driver for Tegra186 (and likely later).
The CPUs are organized into two clusters, Denver and A57,
with two and four cores respectively. CPU frequency can be
adjusted by writing the desired rate divisor and a voltage
hint to a special per-core register.
The frequency of each core can be set individually; however,
this is just a hint as all CPUs in a cluster will run at
the maximum rate of non-idle CPUs in the cluster.
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
According to the previous error handling code, it is likely that
'goto out_free_opp' is expected here in order to avoid a memory leak in
error handling path.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If the cpufreq driver tries to modify voltage/freq during suspend/resume
it might need to control an external PMIC via I2C or SPI but those
devices might be already suspended. This issue is likely to happen
whenever the LDOs have their vin-supply set.
To avoid this scenario we just increase cpufreq to the maximum before
suspend.
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If there are any errors in getting the cpu0 regulators, the driver returns
-ENOENT. In case the regulators are not yet available, the devm_regulator_get
calls will return -EPROBE_DEFER, so that the driver can be probed later.
If we return -ENOENT, the driver will fail its initialization and will
not try to probe again (when the regulators become available).
Return the actual error received from regulator_get in probe. Print a
differentiated message in case we need to probe the device later and
in case we actually failed. Also add a message to inform when the
driver has been successfully registered.
Signed-off-by: Irina Tirdea <irina.tirdea@nxp.com>
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Make the schedutil governor take the initial (default) value of the
rate_limit_us sysfs attribute from the (new) transition_delay_us
policy parameter (to be set by the scaling driver).
That will allow scaling drivers to make schedutil use smaller default
values of rate_limit_us and reduce the default average time interval
between consecutive frequency changes.
Make intel_pstate set transition_delay_us to 500.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
The access to the HBIRD_ESTAR_MODE register in the cpu frequency control
functions must happen on the target CPU. This is achieved by temporarily
setting the affinity of the calling user space thread to the requested CPU
and reset it to the original affinity afterwards.
That's racy vs. CPU hotplug and concurrent affinity settings for that
thread resulting in code executing on the wrong CPU and overwriting the
new affinity setting.
Replace it by a straight forward smp function call.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: linux-pm@vger.kernel.org
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Len Brown <lenb@kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1704131020280.2408@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The access to the safari config register in the CPU frequency functions
must be executed on the target CPU. This is achieved by temporarily setting
the affinity of the calling user space thread to the requested CPU and
reset it to the original affinity afterwards.
That's racy vs. CPU hotplug and concurrent affinity settings for that
thread resulting in code executing on the wrong CPU and overwriting the
new affinity setting.
Replace it by a straight forward smp function call.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: linux-pm@vger.kernel.org
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Len Brown <lenb@kernel.org>
Link: http://lkml.kernel.org/r/20170412201043.047558840@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The target() callback must run on the affected cpu. This is achieved by
temporarily setting the affinity of the calling thread to the requested CPU
and reset it to the original affinity afterwards.
That's racy vs. concurrent affinity settings for that thread resulting in
code executing on the wrong CPU.
Replace it by work_on_cpu(). All call pathes which invoke the callbacks are
already protected against CPU hotplug.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: linux-pm@vger.kernel.org
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Len Brown <lenb@kernel.org>
Link: http://lkml.kernel.org/r/20170412201042.958216363@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The get() and target() callbacks must run on the affected cpu. This is
achieved by temporarily setting the affinity of the calling thread to the
requested CPU and reset it to the original affinity afterwards.
That's racy vs. concurrent affinity settings for that thread resulting in
code executing on the wrong CPU and overwriting the new affinity setting.
Replace it by work_on_cpu(). All call pathes which invoke the callbacks are
already protected against CPU hotplug.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: linux-pm@vger.kernel.org
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Len Brown <lenb@kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1704122231100.2548@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
There is a report that after commit 27622b061e ("cpufreq: Convert
to hotplug state machine"), the normal CPU offline/online cycle
fails on some platforms.
According to the ftrace result, this problem was triggered on
platforms using acpi-cpufreq as the default cpufreq driver,
and due to the lack of some ACPI freq method (eg. _PCT),
cpufreq_online() failed and returned a negative value, so the CPU
hotplug state machine rolled back the CPU online process. Actually,
from the user's perspective, the failure of cpufreq_online() should
not prevent that CPU from being brought up, although cpufreq might
not work on that CPU.
BTW, during system startup cpufreq_online() is not invoked via CPU
online but by the cpufreq device creation process, so the APs can be
brought up even though cpufreq_online() fails in that stage.
This patch ignores the return value of cpufreq_online/offline() and
lets the cpufreq framework deal with the failure. cpufreq_online()
itself will do a proper rollback in that case and if _PCT is missing,
the ACPI cpufreq driver will print a warning if the corresponding
debug options have been enabled.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=194581
Fixes: 27622b061e ("cpufreq: Convert to hotplug state machine")
Reported-and-tested-by: Tomasz Maciej Nowak <tmn505@gmail.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.9+ <stable@vger.kernel.org> # 4.9+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It is pure mystery to me why we need to be on a specific CPU while
looking up a value in an array.
My best shot at this is that before commit d4019f0a92 ("cpufreq: move
freq change notifications to cpufreq core") it was required to invoke
cpufreq_notify_transition() on a special CPU.
Since it looks like a waste, remove it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: tglx@linutronix.de
Cc: linux-pm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15888/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Use same parameters as INTEL_FAM6_ATOM_GOLDMONT to enable
Gemini Lake.
Signed-off-by: Box, David E <david.e.box@intel.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Some computations in intel_pstate_get_min_max() are not necessary
and one of its two callers doesn't even use the full result.
First off, the fixed-point value of cpu->max_perf represents a
non-negative number between 0 and 1 inclusive and cpu->min_perf
cannot be greater than cpu->max_perf. It is not necessary to check
those conditions every time the numbers in question are used.
Moreover, since intel_pstate_max_within_limits() only needs the
upper boundary, it doesn't make sense to compute the lower one in
there and returning min and max from intel_pstate_get_min_max()
via pointers doesn't look particularly nice.
For the above reasons, drop intel_pstate_get_min_max(), add a helper
to get the base P-state for min/max computations and carry out them
directly in the previous callers of intel_pstate_get_min_max().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
intel_pstate_hwp_set() is the only function walking policy->cpus
in intel_pstate. The rest of the code simply assumes one CPU per
policy, including the initialization code.
Therefore it doesn't make sense for intel_pstate_hwp_set() to
walk policy->cpus as it is guaranteed to have only one bit set
for policy->cpu.
For this reason, rearrange intel_pstate_hwp_set() to take the CPU
number as the argument and drop the loop over policy->cpus from it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add a new function pid_in_use() to return the information on whether
or not the PID-based P-state selection algorithm is in use.
That allows a couple of complicated conditions in the code to be
reduced to simple checks against the new function's return value.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpu_defaults structure is redundant, because it only contains
one member of type struct pstate_funcs which can be used directly
instead of struct cpu_defaults.
For this reason, drop struct cpu_defaults, use struct pstate_funcs
directly instead of it where applicable and rename all of the
variables of that type accordingly.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Move the definitions of the cpu_defaults structures after the
definitions of utilization update callback routines to avoid
extra declarations of the latter.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Avoid using extra function pointers during P-state selection by
dropping the get_target_pstate member from struct pstate_funcs,
adding a new update_util callback to it (to be registered with
the CPU scheduler as the utilization update callback in the active
mode) and reworking the utilization update callback routines to
invoke specific P-state selection functions directly.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Notice that some overhead in the utilization update callbacks
registered by intel_pstate in the active mode can be avoided if
those callbacks are tailored to specific configurations of the
driver. For example, the utilization update callback for the HWP
enabled case only needs to update the average CPU performance
periodically whereas the utilization update callback for the
PID-based algorithm does not need to take IO-wait boosting into
account and so on.
With that in mind, define three utilization update callbacks for
three different use cases: HWP enabled, the CPU load "powersave"
P-state selection algorithm and the PID-based "powersave" P-state
selection algorithm and modify the driver initialization to
choose the callback matching its current configuration.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
One of the checks in intel_pstate_update_status() implicitly relies
on the information that there are only two struct cpufreq_driver
objects available, but it is better to do it directly against the
value it really is about (to make the code easier to follow if
nothing else).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The driver_registered variable in intel_pstate is used for checking
whether or not the driver has been registered, but intel_pstate_driver
can be used for that too (with the rule that the driver is not
registered as long as it is NULL).
That is a bit more straightforward and the code may be simplified
a bit this way, so modify the driver accordingly.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PID controller parameters only need to be initialized if the
get_target_pstate_use_performance() P-state selection routine
is going to be used. It is not necessary to initialize them
otherwise, so don't do that.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In the HWP enabled case pid_params.sample_rate_ns only needs to be
updated once, because it is global, so do that when setting hwp_active
instead of doing it during the initialization of every CPU.
Moreover, pid_params.sample_rate_ms is never used if HWP is enabled,
so do not update it at all then.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
intel_pstate_busy_pid_reset() is the only caller of pid_reset(),
pid_p_gain_set(), pid_i_gain_set(), and pid_d_gain_set(). Moreover,
it passes constants as two parameters of pid_reset() and all of
the other routines above essentially contain the same code, so
fold all of them into the caller and drop unnecessary computations.
Introduce percent_fp() for converting integer values in percent
to fixed-point fractions and use it in the above code cleanup.
Finally, rename intel_pstate_busy_pid_reset() to
intel_pstate_pid_reset() as it also is used for the
initialization of PID parameters for every CPU and the
meaning of the "busy" part of the name is not particularly
clear.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There is only one caller of intel_pstate_reset_all_pid(), which is
pid_param_set() used in the debugfs interface only, and having that
code split does not make it particularly convenient to follow.
For this reason, move the body of intel_pstate_reset_all_pid() into
its caller and drop that function.
Also change the loop from for_each_online_cpu() (which is obviously
racy with respect to CPU offline/online) to for_each_possible_cpu(),
so that all PID parameters are reset for all CPUs regardless of their
online/offline status (to prevent, for example, a previously offline
CPU from going online with a stale set of PID parameters).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
