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path: root/include/linux/cpuidle.h
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2021-04-07cpuidle: Use s64 as exit_latency_ns and target_residency_ns data typeRafael J. Wysocki
Subsequent changes will cause the exit_latency_ns and target_residency_ns fields in struct cpuidle_state to be used in computations in which data type conversions to u64 may turn a negative number close to zero into a verly large positive number leading to incorrect results. In preparation for that, change the data type of the fields mentioned above to s64, but ensure that they will not be negative themselves. No intentional functional impact. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-10-16cpuidle: Remove pointless stubDaniel Lezcano
The cpuidle.h header is declaring a function with an empty stub for the cpuidle disabled case, but that function is only called by cpuidle governors which depend on cpuidle anyway. In other words, the function is only called when cpuidle is enabled, so there is no need for the stub. Remove the pointless stub. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-09-23cpuidle: record state entry rejection statisticsLina Iyer
CPUs may fail to enter the chosen idle state if there was a pending interrupt, causing the cpuidle driver to return an error value. Record that and export it via sysfs along with the other idle state statistics. This could prove useful in understanding behavior of the governor and the system during usecases that involve multiple CPUs. Signed-off-by: Lina Iyer <ilina@codeaurora.org> [ rjw: Changelog and documentation edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-09-16cpuidle: Allow cpuidle drivers to take over RCU-idlePeter Zijlstra
Some drivers have to do significant work, some of which relies on RCU still being active. Instead of using RCU_NONIDLE in the drivers and flipping RCU back on, allow drivers to take over RCU-idle duty. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-08-26cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED genericPeter Zijlstra
This allows moving the leave_mm() call into generic code before rcu_idle_enter(). Gets rid of more trace_*_rcuidle() users. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Marco Elver <elver@google.com> Link: https://lkml.kernel.org/r/20200821085348.369441600@infradead.org
2020-07-29cpuidle: change enter_s2idle() prototypeNeal Liu
Control Flow Integrity(CFI) is a security mechanism that disallows changes to the original control flow graph of a compiled binary, making it significantly harder to perform such attacks. init_state_node() assign same function callback to different function pointer declarations. static int init_state_node(struct cpuidle_state *idle_state, const struct of_device_id *matches, struct device_node *state_node) { ... idle_state->enter = match_id->data; ... idle_state->enter_s2idle = match_id->data; } Function declarations: struct cpuidle_state { ... int (*enter) (struct cpuidle_device *dev, struct cpuidle_driver *drv, int index); void (*enter_s2idle) (struct cpuidle_device *dev, struct cpuidle_driver *drv, int index); }; In this case, either enter() or enter_s2idle() would cause CFI check failed since they use same callee. Align function prototype of enter() since it needs return value for some use cases. The return value of enter_s2idle() is no need currently. Signed-off-by: Neal Liu <neal.liu@mediatek.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-01-23Merge branch 'intel_idle+acpi'Rafael J. Wysocki
Merge changes updating the ACPI processor driver in order to export acpi_processor_evaluate_cst() to the code outside of it and adding ACPI support to the intel_idle driver based on that. * intel_idle+acpi: Documentation: admin-guide: PM: Add intel_idle document intel_idle: Use ACPI _CST on server systems intel_idle: Add module parameter to prevent ACPI _CST from being used intel_idle: Allow ACPI _CST to be used for selected known processors cpuidle: Allow idle states to be disabled by default intel_idle: Use ACPI _CST for processor models without C-state tables intel_idle: Refactor intel_idle_cpuidle_driver_init() ACPI: processor: Export acpi_processor_evaluate_cst() ACPI: processor: Make ACPI_PROCESSOR_CSTATE depend on ACPI_PROCESSOR ACPI: processor: Clean up acpi_processor_evaluate_cst() ACPI: processor: Introduce acpi_processor_evaluate_cst() ACPI: processor: Export function to claim _CST control
2020-01-09cpuidle: Drop unused cpuidle_driver_ref/unref() functionsRafael J. Wysocki
The cpuidle_driver_ref() and cpuidle_driver_unref() functions are not used and the refcnt field in struct cpuidle_driver operated by them is not updated anywhere else (so it is permanently equal to 0), so drop both of them along with refcnt. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2019-12-27cpuidle: Allow idle states to be disabled by defaultRafael J. Wysocki
In certain situations it may be useful to prevent some idle states from being used by default while allowing user space to enable them later on. For this purpose, introduce a new state flag, CPUIDLE_FLAG_OFF, to mark idle states that should be disabled by default, make the core set CPUIDLE_STATE_DISABLED_BY_USER for those states at the initialization time and add a new state attribute in sysfs, "default_status", to inform user space of the initial status of the given idle state ("disabled" if CPUIDLE_FLAG_OFF is set for it, "enabled" otherwise). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-29cpuidle: Drop disabled field from struct cpuidle_stateRafael J. Wysocki
After recent cpuidle updates the "disabled" field in struct cpuidle_state is only used by two drivers (intel_idle and shmobile cpuidle) for marking unusable idle states, but that may as well be achieved with the help of a state flag, so define an "unusable" idle state flag, CPUIDLE_FLAG_UNUSABLE, make the drivers in question use it instead of the "disabled" field and make the core set CPUIDLE_STATE_DISABLED_BY_DRIVER for the idle states with that flag set. After the above changes, the "disabled" field in struct cpuidle_state is not used any more, so drop it. No intentional functional impact. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-20cpuidle: Pass exit latency limit to cpuidle_use_deepest_state()Daniel Lezcano
Modify cpuidle_use_deepest_state() to take an additional exit latency limit argument to be passed to find_deepest_idle_state() and make cpuidle_idle_call() pass dev->forced_idle_latency_limit_ns to it for forced idle. Suggested-by: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> [ rjw: Rebase and rearrange code, subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-20cpuidle: Allow idle injection to apply exit latency limitDaniel Lezcano
In some cases it may be useful to specify an exit latency limit for the idle state to be used during CPU idle time injection. Instead of duplicating the information in struct cpuidle_device or propagating the latency limit in the call stack, replace the use_deepest_state field with forced_latency_limit_ns to represent that limit, so that the deepest idle state with exit latency within that limit is forced (i.e. no governors) when it is set. A zero exit latency limit for forced idle means to use governors in the usual way (analogous to use_deepest_state equal to "false" before this change). Additionally, add play_idle_precise() taking two arguments, the duration of forced idle and the idle state exit latency limit, both in nanoseconds, and redefine play_idle() as a wrapper around that new function. This change is preparatory, no functional impact is expected. Suggested-by: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> [ rjw: Subject, changelog, cpuidle_use_deepest_state() kerneldoc, whitespace ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-19cpuidle: Introduce cpuidle_driver_state_disabled() for driver quirksRafael J. Wysocki
Commit 99e98d3fb100 ("cpuidle: Consolidate disabled state checks") overlooked the fact that the imx6q and tegra20 cpuidle drivers use the "disabled" field in struct cpuidle_state for quirks which trigger after the initialization of cpuidle, so reading the initial value of that field is not sufficient for those drivers. In order to allow them to implement the quirks without using the "disabled" field in struct cpuidle_state, introduce a new helper function and modify them to use it. Fixes: 99e98d3fb100 ("cpuidle: Consolidate disabled state checks") Reported-by: Len Brown <lenb@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-11cpuidle: Use nanoseconds as the unit of timeRafael J. Wysocki
Currently, the cpuidle subsystem uses microseconds as the unit of time which (among other things) causes the idle loop to incur some integer division overhead for no clear benefit. In order to allow cpuidle to measure time in nanoseconds, add two new fields, exit_latency_ns and target_residency_ns, to represent the exit latency and target residency of an idle state in nanoseconds, respectively, to struct cpuidle_state and initialize them with the help of the corresponding values in microseconds provided by drivers. Additionally, change cpuidle_governor_latency_req() to return the idle state exit latency constraint in nanoseconds. Also meeasure idle state residency (last_residency_ns in struct cpuidle_device and time_ns in struct cpuidle_driver) in nanoseconds and update the cpuidle core and governors accordingly. However, the menu governor still computes typical intervals in microseconds to avoid integer overflows. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Doug Smythies <dsmythies@telus.net> Tested-by: Doug Smythies <dsmythies@telus.net>
2019-11-06cpuidle: Consolidate disabled state checksRafael J. Wysocki
There are two reasons why CPU idle states may be disabled: either because the driver has disabled them or because they have been disabled by user space via sysfs. In the former case, the state's "disabled" flag is set once during the initialization of the driver and it is never cleared later (it is read-only effectively). In the latter case, the "disable" field of the given state's cpuidle_state_usage struct is set and it may be changed via sysfs. Thus checking whether or not an idle state has been disabled involves reading these two flags every time. In order to avoid the additional check of the state's "disabled" flag (which is effectively read-only anyway), use the value of it at the init time to set a (new) flag in the "disable" field of that state's cpuidle_state_usage structure and use the sysfs interface to manipulate another (new) flag in it. This way the state is disabled whenever the "disable" field of its cpuidle_state_usage structure is nonzero, whatever the reason, and it is the only place to look into to check whether or not the state has been disabled. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2019-09-17Merge tag 'pm-5.4-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "These include a rework of the main suspend-to-idle code flow (related to the handling of spurious wakeups), a switch over of several users of cpufreq notifiers to QoS-based limits, a new devfreq driver for Tegra20, a new cpuidle driver and governor for virtualized guests, an extension of the wakeup sources framework to expose wakeup sources as device objects in sysfs, and more. Specifics: - Rework the main suspend-to-idle control flow to avoid repeating "noirq" device resume and suspend operations in case of spurious wakeups from the ACPI EC and decouple the ACPI EC wakeups support from the LPS0 _DSM support (Rafael Wysocki). - Extend the wakeup sources framework to expose wakeup sources as device objects in sysfs (Tri Vo, Stephen Boyd). - Expose system suspend statistics in sysfs (Kalesh Singh). - Introduce a new haltpoll cpuidle driver and a new matching governor for virtualized guests wanting to do guest-side polling in the idle loop (Marcelo Tosatti, Joao Martins, Wanpeng Li, Stephen Rothwell). - Fix the menu and teo cpuidle governors to allow the scheduler tick to be stopped if PM QoS is used to limit the CPU idle state exit latency in some cases (Rafael Wysocki). - Increase the resolution of the play_idle() argument to microseconds for more fine-grained injection of CPU idle cycles (Daniel Lezcano). - Switch over some users of cpuidle notifiers to the new QoS-based frequency limits and drop the CPUFREQ_ADJUST and CPUFREQ_NOTIFY policy notifier events (Viresh Kumar). - Add new cpufreq driver based on nvmem for sun50i (Yangtao Li). - Add support for MT8183 and MT8516 to the mediatek cpufreq driver (Andrew-sh.Cheng, Fabien Parent). - Add i.MX8MN support to the imx-cpufreq-dt cpufreq driver (Anson Huang). - Add qcs404 to cpufreq-dt-platdev blacklist (Jorge Ramirez-Ortiz). - Update the qcom cpufreq driver (among other things, to make it easier to extend and to use kryo cpufreq for other nvmem-based SoCs) and add qcs404 support to it (Niklas Cassel, Douglas RAILLARD, Sibi Sankar, Sricharan R). - Fix assorted issues and make assorted minor improvements in the cpufreq code (Colin Ian King, Douglas RAILLARD, Florian Fainelli, Gustavo Silva, Hariprasad Kelam). - Add new devfreq driver for NVidia Tegra20 (Dmitry Osipenko, Arnd Bergmann). - Add new Exynos PPMU events to devfreq events and extend that mechanism (Lukasz Luba). - Fix and clean up the exynos-bus devfreq driver (Kamil Konieczny). - Improve devfreq documentation and governor code, fix spelling typos in devfreq (Ezequiel Garcia, Krzysztof Kozlowski, Leonard Crestez, MyungJoo Ham, Gaël PORTAY). - Add regulators enable and disable to the OPP (operating performance points) framework (Kamil Konieczny). - Update the OPP framework to support multiple opp-suspend properties (Anson Huang). - Fix assorted issues and make assorted minor improvements in the OPP code (Niklas Cassel, Viresh Kumar, Yue Hu). - Clean up the generic power domains (genpd) framework (Ulf Hansson). - Clean up assorted pieces of power management code and documentation (Akinobu Mita, Amit Kucheria, Chuhong Yuan). - Update the pm-graph tool to version 5.5 including multiple fixes and improvements (Todd Brandt). - Update the cpupower utility (Benjamin Weis, Geert Uytterhoeven, Sébastien Szymanski)" * tag 'pm-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (126 commits) cpuidle-haltpoll: Enable kvm guest polling when dedicated physical CPUs are available cpuidle-haltpoll: do not set an owner to allow modunload cpuidle-haltpoll: return -ENODEV on modinit failure cpuidle-haltpoll: set haltpoll as preferred governor cpuidle: allow governor switch on cpuidle_register_driver() PM: runtime: Documentation: add runtime_status ABI document pm-graph: make setVal unbuffered again for python2 and python3 powercap: idle_inject: Use higher resolution for idle injection cpuidle: play_idle: Increase the resolution to usec cpuidle-haltpoll: vcpu hotplug support cpufreq: Add qcs404 to cpufreq-dt-platdev blacklist cpufreq: qcom: Add support for qcs404 on nvmem driver cpufreq: qcom: Refactor the driver to make it easier to extend cpufreq: qcom: Re-organise kryo cpufreq to use it for other nvmem based qcom socs dt-bindings: opp: Add qcom-opp bindings with properties needed for CPR dt-bindings: opp: qcom-nvmem: Support pstates provided by a power domain Documentation: cpufreq: Update policy notifier documentation cpufreq: Remove CPUFREQ_ADJUST and CPUFREQ_NOTIFY policy notifier events PM / Domains: Verify PM domain type in dev_pm_genpd_set_performance_state() PM / Domains: Simplify genpd_lookup_dev() ...
2019-09-11cpuidle: allow governor switch on cpuidle_register_driver()Joao Martins
The recently introduced haltpoll driver is largely only useful with haltpoll governor. To allow drivers to associate with a particular idle behaviour, add a @governor property to 'struct cpuidle_driver' and thus allow a cpuidle driver to switch to a *preferred* governor on idle driver registration. We save the previous governor, and when an idle driver is unregistered we switch back to that. The @governor can be overridden by cpuidle.governor= boot param or alternatively be ignored if the governor doesn't exist. Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-08-09PSCI: cpuidle: Refactor CPU suspend power_state parameter handlingLorenzo Pieralisi
Current PSCI code handles idle state entry through the psci_cpu_suspend_enter() API, that takes an idle state index as a parameter and convert the index into a previously initialized power_state parameter before calling the PSCI.CPU_SUSPEND() with it. This is unwieldly, since it forces the PSCI firmware layer to keep track of power_state parameter for every idle state so that the index->power_state conversion can be made in the PSCI firmware layer instead of the CPUidle driver implementations. Move the power_state handling out of drivers/firmware/psci into the respective ACPI/DT PSCI CPUidle backends and convert the psci_cpu_suspend_enter() API to get the power_state parameter as input, which makes it closer to its firmware interface PSCI.CPU_SUSPEND() API. A notable side effect is that the PSCI ACPI/DT CPUidle backends now can directly handle (and if needed update) power_state parameters before handing them over to the PSCI firmware interface to trigger PSCI.CPU_SUSPEND() calls. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Will Deacon <will@kernel.org>
2019-07-31cpuidle: header file stubs must be "static inline"Stephen Rothwell
An x86_64 allmodconfig build produces these errors: x86_64-linux-gnu-ld: kernel/sched/core.o: in function `cpuidle_poll_time': core.c:(.text+0x230): multiple definition of `cpuidle_poll_time'; arch/x86/= kernel/process.o:process.c:(.text+0xc0): first defined here (and more) Fixes: 259231a04561 ("cpuidle: add poll_limit_ns to cpuidle_device structure") Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-07-30governors: unify last_state_idxMarcelo Tosatti
Since this field is shared by all governors, move it to cpuidle device structure. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-07-30cpuidle: add poll_limit_ns to cpuidle_device structureMarcelo Tosatti
Add a poll_limit_ns variable to cpuidle_device structure. Calculate and configure it in the new cpuidle_poll_time function, in case its zero. Individual governors are allowed to override this value. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-04-10cpuidle: Export the next timer expiration for CPUsUlf Hansson
To be able to predict the sleep duration for a CPU entering idle, it is essential to know the expiration time of the next timer. Both the teo and the menu cpuidle governors already use this information for CPU idle state selection. Moving forward, a similar prediction needs to be made for a group of idle CPUs rather than for a single one and the following changes implement a new genpd governor for that purpose. In order to support that feature, add a new function called tick_nohz_get_next_hrtimer() that will return the next hrtimer expiration time of a given CPU to be invoked after deciding whether or not to stop the scheduler tick on that CPU. Make the cpuidle core call tick_nohz_get_next_hrtimer() right before invoking the ->enter() callback provided by the cpuidle driver for the given state and store its return value in the per-CPU struct cpuidle_device, so as to make it available to code outside of cpuidle. Note that at the point when cpuidle calls tick_nohz_get_next_hrtimer(), the governor's ->select() callback has already returned and indicated whether or not the tick should be stopped, so in fact the value returned by tick_nohz_get_next_hrtimer() always is the next hrtimer expiration time for the given CPU, possibly including the tick (if it hasn't been stopped). Co-developed-by: Lina Iyer <lina.iyer@linaro.org> Co-developed-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-01-17cpuidle: use BIT() for idle state flags and remove CPUIDLE_DRIVER_FLAGS_MASKYangtao Li
Use BIT() macro to do a small tidy-up. CPUIDLE_DRIVER_FLAGS_MASK is not used, so remove it. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-12-12cpuidle: Add 'above' and 'below' idle state metricsRafael J. Wysocki
Add two new metrics for CPU idle states, "above" and "below", to count the number of times the given state had been asked for (or entered from the kernel's perspective), but the observed idle duration turned out to be too short or too long for it (respectively). These metrics help to estimate the quality of the CPU idle governor in use. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-10-04cpuidle: menu: Fix wakeup statistics updates for polling stateRafael J. Wysocki
If the CPU exits the "polling" state due to the time limit in the loop in poll_idle(), this is not a real wakeup and it just means that the "polling" state selection was not adequate. The governor mispredicted short idle duration, but had a more suitable state been selected, the CPU might have spent more time in it. In fact, there is no reason to expect that there would have been a wakeup event earlier than the next timer in that case. Handling such cases as regular wakeups in menu_update() may cause the menu governor to make suboptimal decisions going forward, but ignoring them altogether would not be correct either, because every time menu_select() is invoked, it makes a separate new attempt to predict the idle duration taking distinct time to the closest timer event as input and the outcomes of all those attempts should be recorded. For this reason, make menu_update() always assume that if the "polling" state was exited due to the time limit, the next proper wakeup event for the CPU would be the next timer event (not including the tick). Fixes: a37b969a61c1 "cpuidle: poll_state: Add time limit to poll_idle()" Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2018-09-18cpuidle: Remove unnecessary wrapper cpuidle_get_last_residency()Fieah Lim
cpuidle_get_last_residency() is just a wrapper for retrieving the last_residency member of struct cpuidle_device. It's also weirdly the only wrapper function for accessing cpuidle_* struct member (by my best guess is it could be a leftover from v2.x). Anyhow, since the only two users (the ladder and menu governors) can access dev->last_residency directly, and it's more intuitive to do it that way, let's just get rid of the wrapper. This patch tidies up CPU idle code a bit without functional changes. Signed-off-by: Fieah Lim <kw@fieahl.im> [ rjw: Changelog cleanup ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-05-30cpuidle: governors: Consolidate PM QoS handlingRafael J. Wysocki
There is some code duplication related to the PM QoS handling between the existing cpuidle governors, so move that code to a common helper function and call that from the governors. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-04-06cpuidle: Return nohz hint from cpuidle_select()Rafael J. Wysocki
Add a new pointer argument to cpuidle_select() and to the ->select cpuidle governor callback to allow a boolean value indicating whether or not the tick should be stopped before entering the selected state to be returned from there. Make the ladder governor ignore that pointer (to preserve its current behavior) and make the menu governor return 'false" through it if: (1) the idle exit latency is constrained at 0, or (2) the selected state is a polling one, or (3) the expected idle period duration is within the tick period range. In addition to that, the correction factor computations in the menu governor need to take the possibility that the tick may not be stopped into account to avoid artificially small correction factor values. To that end, add a mechanism to record tick wakeups, as suggested by Peter Zijlstra, and use it to modify the menu_update() behavior when tick wakeup occurs. Namely, if the CPU is woken up by the tick and the return value of tick_nohz_get_sleep_length() is not within the tick boundary, the predicted idle duration is likely too short, so make menu_update() try to compensate for that by updating the governor statistics as though the CPU was idle for a long time. Since the value returned through the new argument pointer of cpuidle_select() is not used by its caller yet, this change by itself is not expected to alter the functionality of the code. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2018-03-29PM: cpuidle/suspend: Add s2idle usage and time state attributesRafael J. Wysocki
Add a new attribute group called "s2idle" under the sysfs directory of each cpuidle state that supports the ->enter_s2idle callback and put two new attributes, "usage" and "time", into that group to represent the number of times the given state was requested for suspend-to-idle and the total time spent in suspend-to-idle after requesting that state, respectively. That will allow diagnostic information related to suspend-to-idle to be collected without enabling advanced debug features and analyzing dmesg output. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-02-15Merge branches 'pm-cpuidle' and 'pm-opp'Rafael J. Wysocki
* pm-cpuidle: PM: cpuidle: Fix cpuidle_poll_state_init() prototype Documentation/ABI: update cpuidle sysfs documentation * pm-opp: opp: cpu: Replace GFP_ATOMIC with GFP_KERNEL in dev_pm_opp_init_cpufreq_table
2018-02-12PM: cpuidle: Fix cpuidle_poll_state_init() prototypeRafael J. Wysocki
Commit f85942207516 (x86: PM: Make APM idle driver initialize polling state) made apm_init() call cpuidle_poll_state_init(), but that only is defined for CONFIG_CPU_IDLE set, so make the empty stub of it available for CONFIG_CPU_IDLE unset too to fix the resulting build issue. Fixes: f85942207516 (x86: PM: Make APM idle driver initialize polling state) Cc: 4.14+ <stable@vger.kernel.org> # 4.14+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-01-02cpuidle: Add new macro to enter a retention idle statePrashanth Prakash
If a CPU is entering a low power idle state where it doesn't lose any context, then there is no need to call cpu_pm_enter()/cpu_pm_exit(). Add a new macro(CPU_PM_CPU_IDLE_ENTER_RETENTION) to be used by cpuidle drivers when they are entering retention state. By not calling cpu_pm_enter and cpu_pm_exit we reduce the latency involved in entering and exiting the retention idle states. CPU_PM_CPU_IDLE_ENTER_RETENTION assumes that no state is lost and hence CPU PM notifiers will not be called. We may need a broader change if we need to support partial retention states effeciently. On ARM64 based Qualcomm Server Platform we measured below overhead for for calling cpu_pm_enter and cpu_pm_exit for retention states. workload: stress --hdd #CPUs --hdd-bytes 32M -t 30 Average overhead of cpu_pm_enter - 1.2us Average overhead of cpu_pm_exit - 3.1us Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-09-04Merge branch 'pm-sleep'Rafael J. Wysocki
* pm-sleep: ACPI / PM: Check low power idle constraints for debug only PM / s2idle: Rename platform operations structure PM / s2idle: Rename ->enter_freeze to ->enter_s2idle PM / s2idle: Rename freeze_state enum and related items PM / s2idle: Rename PM_SUSPEND_FREEZE to PM_SUSPEND_TO_IDLE ACPI / PM: Prefer suspend-to-idle over S3 on some systems platform/x86: intel-hid: Wake up Dell Latitude 7275 from suspend-to-idle PM / suspend: Define pr_fmt() in suspend.c PM / suspend: Use mem_sleep_labels[] strings in messages PM / sleep: Put pm_test under CONFIG_PM_SLEEP_DEBUG PM / sleep: Check pm_wakeup_pending() in __device_suspend_noirq() PM / core: Add error argument to dpm_show_time() PM / core: Split dpm_suspend_noirq() and dpm_resume_noirq() PM / s2idle: Rearrange the main suspend-to-idle loop PM / timekeeping: Print debug messages when requested PM / sleep: Mark suspend/hibernation start and finish PM / sleep: Do not print debug messages by default PM / suspend: Export pm_suspend_target_state
2017-08-30cpuidle: Make drivers initialize polling stateRafael J. Wysocki
Make the drivers that want to include the polling state into their states table initialize it explicitly and drop the initialization of it (which in fact is conditional, but that is not obvious from the code) from the core. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-08-30cpuidle: Move polling state initialization code to separate fileRafael J. Wysocki
Move the polling state initialization code to a separate file built conditionally on CONFIG_ARCH_HAS_CPU_RELAX to get rid of the #ifdef in driver.c. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-08-30cpuidle: Eliminate the CPUIDLE_DRIVER_STATE_START symbolRafael J. Wysocki
On some architectures the first (index 0) idle state is a polling one and it doesn't really save energy, so there is the CPUIDLE_DRIVER_STATE_START symbol allowing some pieces of cpuidle code to avoid using that state. However, this makes the code rather hard to follow. It is better to explicitly avoid the polling state, so add a new cpuidle state flag CPUIDLE_FLAG_POLLING to mark it and make the relevant code check that flag for the first state instead of using the CPUIDLE_DRIVER_STATE_START symbol. In the ACPI processor driver that cannot always rely on the state flags (like before the states table has been set up) define a new internal symbol ACPI_IDLE_STATE_START equivalent to the CPUIDLE_DRIVER_STATE_START one and drop the latter. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2017-08-11PM / s2idle: Rename ->enter_freeze to ->enter_s2idleRafael J. Wysocki
Rename the ->enter_freeze cpuidle driver callback to ->enter_s2idle to make it clear that it is used for entering suspend-to-idle and rename the related functions, variables and so on accordingly. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-01-31cpuidle:powernv: Add helper function to populate powernv idle states.Gautham R. Shenoy
In the current code for powernv_add_idle_states, there is a lot of code duplication while initializing an idle state in powernv_states table. Add an inline helper function to populate the powernv_states[] table for a given idle state. Invoke this for populating the "Nap", "Fastsleep" and the stop states in powernv_add_idle_states. Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-29cpuidle: Allow enforcing deepest idle state selectionJacob Pan
When idle injection is used to cap power, we need to override the governor's choice of idle states. For this reason, make it possible the deepest idle state selection to be enforced by setting a flag on a given CPU to achieve the maximum potential power draw reduction. Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-21cpuidle: governors: Remove remaining old module codeDaniel Lezcano
The governor's code use try_module_get() and put_module() to refcount the governor's module. But the governors are not compiled as module. The refcount does not prevent to switch the governor or unload a module as they aren't compiled as modules. The code is pointless, so remove it. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-07-21cpuidle: introduce CPU_PM_CPU_IDLE_ENTER macro for ARM{32, 64}Sudeep Holla
The function arm_enter_idle_state is exactly the same in both generic ARM{32,64} CPUIdle driver and will be the same even on ARM64 backend for ACPI processor idle driver. So we can unify it and move it to a common place by introducing CPU_PM_CPU_IDLE_ENTER macro that can be used in all places avoiding duplication. This is in preparation of reuse of the generic cpuidle entry function for ACPI LPI support on ARM64. Suggested-by: Rafael J. Wysocki <rjw@rjwysocki.net> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-02cpuidle: Do not access cpuidle_devices when !CONFIG_CPU_IDLECatalin Marinas
The cpuidle_devices per-CPU variable is only defined when CPU_IDLE is enabled. Commit c8cc7d4de7a4 ("sched/idle: Reorganize the idle loop") removed the #ifdef CONFIG_CPU_IDLE around cpuidle_idle_call() with the compiler optimising away __this_cpu_read(cpuidle_devices). However, with CONFIG_UBSAN && !CONFIG_CPU_IDLE, this optimisation no longer happens and the kernel fails to link since cpuidle_devices is not defined. This patch introduces an accessor function for the current CPU cpuidle device (returning NULL when !CONFIG_CPU_IDLE) and uses it in cpuidle_idle_call(). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: 4.5+ <stable@vger.kernel.org> # 4.5+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-08-28cpuidle/coupled: Remove cpuidle_device::safe_state_indexXunlei Pang
cpuidle_device::safe_state_index need to be initialized before use, it should be the same as cpuidle_driver::safe_state_index. We tackled this issue by removing the safe_state_index from the cpuidle_device structure and use the one in the cpuidle_driver structure instead. Suggested-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-06-19Merge branches 'pm-sleep' and 'pm-runtime'Rafael J. Wysocki
* pm-sleep: PM / sleep: trace_device_pm_callback coverage in dpm_prepare/complete PM / wakeup: add a dummy wakeup_source to record statistics PM / sleep: Make suspend-to-idle-specific code depend on CONFIG_SUSPEND PM / sleep: Return -EBUSY from suspend_enter() on wakeup detection PM / tick: Add tracepoints for suspend-to-idle diagnostics PM / sleep: Fix symbol name in a comment in kernel/power/main.c leds / PM: fix hibernation on arm when gpio-led used with CPU led trigger ARM: omap-device: use SET_NOIRQ_SYSTEM_SLEEP_PM_OPS bus: omap_l3_noc: add missed callbacks for suspend-to-disk PM / sleep: Add macro to define common noirq system PM callbacks PM / sleep: Refine diagnostic messages in enter_state() PM / wakeup: validate wakeup source before activating it. * pm-runtime: PM / Runtime: Update last_busy in rpm_resume PM / runtime: add note about re-calling in during device probe()
2015-05-19PM / sleep: Make suspend-to-idle-specific code depend on CONFIG_SUSPENDRafael J. Wysocki
Since idle_should_freeze() is defined to always return 'false' for CONFIG_SUSPEND unset, all of the code depending on it in cpuidle_idle_call() is not necessary in that case. Make that code depend on CONFIG_SUSPEND too to avoid building it when it is not going to be used. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-14sched / idle: Call default_idle_call() from cpuidle_enter_state()Rafael J. Wysocki
The check of the cpuidle_enter() return value against -EBUSY made in call_cpuidle() will not be necessary any more if cpuidle_enter_state() calls default_idle_call() directly when it is about to return -EBUSY, so make that happen and eliminate the check. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Tested-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Kevin Hilman <khilman@linaro.org>
2015-05-14sched / idle: Call idle_set_state() from cpuidle_enter_state()Rafael J. Wysocki
Introduce a wrapper function around idle_set_state() called sched_idle_set_state() that will pass this_rq() to it as the first argument and make cpuidle_enter_state() call the new function before and after entering the target state. At the same time, remove direct invocations of idle_set_state() from call_cpuidle(). This will allow the invocation of default_idle_call() to be moved from call_cpuidle() to cpuidle_enter_state() safely and call_cpuidle() to be simplified a bit as a result. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Tested-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Kevin Hilman <khilman@linaro.org>
2015-04-03cpuidle: remove state_count field from struct cpuidle_deviceBartlomiej Zolnierkiewicz
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> Cc: 3.14+ <stable@vger.kernel.org> # 3.14+ [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-03-05cpuidle / sleep: Use broadcast timer for states that stop local timerRafael J. Wysocki
Commit 381063133246 (PM / sleep: Re-implement suspend-to-idle handling) overlooked the fact that entering some sufficiently deep idle states by CPUs may cause their local timers to stop and in those cases it is necessary to switch over to a broadcast timer prior to entering the idle state. If the cpuidle driver in use does not provide the new ->enter_freeze callback for any of the idle states, that problem affects suspend-to-idle too, but it is not taken into account after the changes made by commit 381063133246. Fix that by changing the definition of cpuidle_enter_freeze() and re-arranging of the code in cpuidle_idle_call(), so the former does not call cpuidle_enter() any more and the fallback case is handled by cpuidle_idle_call() directly. Fixes: 381063133246 (PM / sleep: Re-implement suspend-to-idle handling) Reported-and-tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2015-02-15PM / sleep: Make it possible to quiesce timers during suspend-to-idleRafael J. Wysocki
The efficiency of suspend-to-idle depends on being able to keep CPUs in the deepest available idle states for as much time as possible. Ideally, they should only be brought out of idle by system wakeup interrupts. However, timer interrupts occurring periodically prevent that from happening and it is not practical to chase all of the "misbehaving" timers in a whack-a-mole fashion. A much more effective approach is to suspend the local ticks for all CPUs and the entire timekeeping along the lines of what is done during full suspend, which also helps to keep suspend-to-idle and full suspend reasonably similar. The idea is to suspend the local tick on each CPU executing cpuidle_enter_freeze() and to make the last of them suspend the entire timekeeping. That should prevent timer interrupts from triggering until an IO interrupt wakes up one of the CPUs. It needs to be done with interrupts disabled on all of the CPUs, though, because otherwise the suspended clocksource might be accessed by an interrupt handler which might lead to fatal consequences. Unfortunately, the existing ->enter callbacks provided by cpuidle drivers generally cannot be used for implementing that, because some of them re-enable interrupts temporarily and some idle entry methods cause interrupts to be re-enabled automatically on exit. Also some of these callbacks manipulate local clock event devices of the CPUs which really shouldn't be done after suspending their ticks. To overcome that difficulty, introduce a new cpuidle state callback, ->enter_freeze, that will be guaranteed (1) to keep interrupts disabled all the time (and return with interrupts disabled) and (2) not to touch the CPU timer devices. Modify cpuidle_enter_freeze() to look for the deepest available idle state with ->enter_freeze present and to make the CPU execute that callback with suspended tick (and the last of the online CPUs to execute it with suspended timekeeping). Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>