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2020-09-21cpuidle: psci: Fix suspicious RCU usageUlf Hansson
The commit eb1f00237aca ("lockdep,trace: Expose tracepoints"), started to expose us for tracepoints. This lead to the following RCU splat on an ARM64 Qcom board. [ 5.529634] WARNING: suspicious RCU usage [ 5.537307] sdhci-pltfm: SDHCI platform and OF driver helper [ 5.541092] 5.9.0-rc3 #86 Not tainted [ 5.541098] ----------------------------- [ 5.541105] ../include/trace/events/lock.h:37 suspicious rcu_dereference_check() usage! [ 5.541110] [ 5.541110] other info that might help us debug this: [ 5.541110] [ 5.541116] [ 5.541116] rcu_scheduler_active = 2, debug_locks = 1 [ 5.541122] RCU used illegally from extended quiescent state! [ 5.541129] no locks held by swapper/0/0. [ 5.541134] [ 5.541134] stack backtrace: [ 5.541143] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.9.0-rc3 #86 [ 5.541149] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT) [ 5.541157] Call trace: [ 5.568185] sdhci_msm 7864900.sdhci: Got CD GPIO [ 5.574186] dump_backtrace+0x0/0x1c8 [ 5.574206] show_stack+0x14/0x20 [ 5.574229] dump_stack+0xe8/0x154 [ 5.574250] lockdep_rcu_suspicious+0xd4/0xf8 [ 5.574269] lock_acquire+0x3f0/0x460 [ 5.574292] _raw_spin_lock_irqsave+0x80/0xb0 [ 5.574314] __pm_runtime_suspend+0x4c/0x188 [ 5.574341] psci_enter_domain_idle_state+0x40/0xa0 [ 5.574362] cpuidle_enter_state+0xc0/0x610 [ 5.646487] cpuidle_enter+0x38/0x50 [ 5.650651] call_cpuidle+0x18/0x40 [ 5.654467] do_idle+0x228/0x278 [ 5.657678] cpu_startup_entry+0x24/0x70 [ 5.661153] rest_init+0x1a4/0x278 [ 5.665061] arch_call_rest_init+0xc/0x14 [ 5.668272] start_kernel+0x508/0x540 Following the path in pm_runtime_put_sync_suspend() from psci_enter_domain_idle_state(), it seems like we end up using the RCU. Therefore, let's simply silence the splat by informing the RCU about it with RCU_NONIDLE. Note that, this is a temporary solution. Instead we should strive to avoid using RCU_NONIDLE (and similar), but rather push rcu_idle_enter|exit() further down, closer to the arch specific code. However, as the CPU PM notifiers are also using the RCU, additional rework is needed. Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-29cpuidle: psci: Fix error path via converting to a platform driverUlf Hansson
The current error paths for the cpuidle-psci driver, may leak memory or possibly leave CPU devices attached to their PM domains. These are quite harmless issues, but still deserves to be taken care of. Although, rather than fixing them by keeping track of allocations that needs to be freed, which tends to become a bit messy, let's convert into a platform driver. In this way, it gets easier to fix the memory leaks as we can rely on the devm_* functions. Moreover, converting to a platform driver also enables support for deferred probe, which subsequent changes takes benefit from. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-06-12Merge tag 'thermal-v5.8-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux Pull thermal updates from Daniel Lezcano: - Add the hwmon support on the i.MX SC (Anson Huang) - Thermal framework cleanups (self-encapsulation, pointless stubs, private structures) (Daniel Lezcano) - Use the PM QoS frequency changes for the devfreq cooling device (Matthias Kaehlcke) - Remove duplicate error messages from platform_get_irq() error handling (Markus Elfring) - Add support for the bandgap sensors (Keerthy) - Statically initialize .get_mode/.set_mode ops (Andrzej Pietrasiewicz) - Add Renesas R-Car maintainer entry (Niklas Söderlund) - Fix error checking after calling ti_bandgap_get_sensor_data() for the TI SoC thermal (Sudip Mukherjee) - Add latency constraint for the idle injection, the DT binding and the change the registering function (Daniel Lezcano) - Convert the thermal framework binding to the Yaml schema (Amit Kucheria) - Replace zero-length array with flexible-array on i.MX 8MM (Gustavo A. R. Silva) - Thermal framework cleanups (alphabetic order for heads, replace module.h by export.h, make file naming consistent) (Amit Kucheria) - Merge tsens-common into the tsens driver (Amit Kucheria) - Fix platform dependency for the Qoriq driver (Geert Uytterhoeven) - Clean up the rcar_thermal_update_temp() function in the rcar thermal driver (Niklas Söderlund) - Fix the TMSAR register for the TMUv2 on the Qoriq platform (Yuantian Tang) - Export GDDV, OEM vendor variables, and don't require IDSP for the int340x thermal driver - trivial conflicts fixed (Matthew Garrett) * tag 'thermal-v5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux: (48 commits) thermal/int340x_thermal: Don't require IDSP to exist thermal/int340x_thermal: Export OEM vendor variables thermal/int340x_thermal: Export GDDV thermal: qoriq: Update the settings for TMUv2 thermal: rcar_thermal: Clean up rcar_thermal_update_temp() thermal: qoriq: Add platform dependencies drivers: thermal: tsens: Merge tsens-common.c into tsens.c thermal/of: Rename of-thermal.c thermal/governors: Prefix all source files with gov_ thermal/drivers/user_space: Sort headers alphabetically thermal/drivers/of-thermal: Sort headers alphabetically thermal/drivers/cpufreq_cooling: Replace module.h with export.h thermal/drivers/cpufreq_cooling: Sort headers alphabetically thermal/drivers/clock_cooling: Include export.h thermal/drivers/clock_cooling: Sort headers alphabetically thermal/drivers/thermal_hwmon: Include export.h thermal/drivers/thermal_hwmon: Sort headers alphabetically thermal/drivers/thermal_helpers: Include export.h thermal/drivers/thermal_helpers: Sort headers alphabetically thermal/core: Replace module.h with export.h ...
2020-05-19thermal: cpuidle: Register cpuidle cooling deviceDaniel Lezcano
The cpuidle driver can be used as a cooling device by injecting idle cycles. When the property is set, register the cpuidle driver with the idle state node pointer as a cooling device. The thermal framework will do the association automatically with the thermal zone via the cooling-device defined in the device tree cooling-maps section. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Link: https://lore.kernel.org/r/20200429103644.5492-4-daniel.lezcano@linaro.org
2020-05-15cpuidle: psci: Fixup execution order when entering a domain idle stateUlf Hansson
Moving forward, platforms are going to need to execute specific "last-man" operations before a domain idle state can be entered. In one way or the other, these operations needs to be triggered while walking the hierarchical topology via runtime PM and genpd, as it's at that point the last-man becomes known. Moreover, executing last-man operations needs to be done after the CPU PM notifications are sent through cpu_pm_enter(), as otherwise it's likely that some notifications would fail. Therefore, let's re-order the sequence in psci_enter_domain_idle_state(), so cpu_pm_enter() gets called prior pm_runtime_put_sync(). Fixes: ce85aef570df ("cpuidle: psci: Manage runtime PM in the idle path") Reported-by: Lina Iyer <ilina@codeaurora.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-03-14cpuidle: psci: Split psci_dt_cpu_init_idle()Ulf Hansson
To make the code a bit more readable, let's move the OSI specific initialization out of the psci_dt_cpu_init_idle() and into a separate function. Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-01-02cpuidle: psci: Add support for PM domains by using genpdUlf Hansson
When the hierarchical CPU topology layout is used in DT and the PSCI OSI mode is supported by the PSCI FW, let's initialize a corresponding PM domain topology by using genpd. This enables a CPU and a group of CPUs, when attached to the topology, to be power-managed accordingly. To trigger the attempt to initialize the genpd data structures let's use a subsys_initcall, which should be early enough to allow CPUs, but also other devices to be attached. The initialization consists of parsing the PSCI OF node for the topology and the "domain idle states" DT bindings. In case the idle states are compatible with "domain-idle-state", the initialized genpd becomes responsible of selecting an idle state for the PM domain, via assigning it a genpd governor. Note that, a successful initialization of the genpd data structures, is followed by a call to psci_set_osi_mode(), as to try to enable the OSI mode in the PSCI FW. In case this fails, we fall back into a degraded mode rather than bailing out and returning error codes. Co-developed-by: Lina Iyer <lina.iyer@linaro.org> Signed-off-by: Lina Iyer <lina.iyer@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Rafael J. Wysocki <rafael@kernel.org>
2020-01-02cpuidle: psci: Support CPU hotplug for the hierarchical modelUlf Hansson
When the hierarchical CPU topology is used and when a CPU is put offline, that CPU prevents its PM domain from being powered off, which is because genpd observes the corresponding attached device as being active from a runtime PM point of view. Furthermore, any potential master PM domains are also prevented from being powered off. To address this limitation, let's add add a new CPU hotplug state (CPUHP_AP_CPU_PM_STARTING) and register up/down callbacks for it, which allows us to deal with runtime PM accordingly. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Rafael J. Wysocki <rafael@kernel.org>
2020-01-02cpuidle: psci: Manage runtime PM in the idle pathUlf Hansson
In case we have succeeded to attach a CPU to its PM domain, let's deploy runtime PM support for the corresponding attached device, to allow the CPU to be powered-managed accordingly. The triggering point for when runtime PM reference counting should be done, has been selected to the deepest idle state for the CPU. However, from the hierarchical point view, there may be good reasons to do runtime PM reference counting even on shallower idle states, but at this point this isn't supported, mainly due to limitations set by the generic PM domain. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Rafael J. Wysocki <rafael@kernel.org>
2020-01-02cpuidle: psci: Prepare to use OS initiated suspend mode via PM domainsUlf Hansson
The per CPU variable psci_power_state, contains an array of fixed values, which reflects the corresponding arm,psci-suspend-param parsed from DT, for each of the available CPU idle states. This isn't sufficient when using the hierarchical CPU topology in DT, in combination with having PSCI OS initiated (OSI) mode enabled. More precisely, in OSI mode, Linux is responsible of telling the PSCI FW what idle state the cluster (a group of CPUs) should enter, while in PSCI Platform Coordinated (PC) mode, each CPU independently votes for an idle state of the cluster. For this reason, introduce a per CPU variable called domain_state and implement two helper functions to read/write its value. Then let the domain_state take precedence over the regular selected state, when entering and idle state. To avoid executing the above OSI specific code in the ->enter() callback, while operating in the default PSCI Platform Coordinated mode, let's also add a new enter-function and use it for OSI. Co-developed-by: Lina Iyer <lina.iyer@linaro.org> Signed-off-by: Lina Iyer <lina.iyer@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Rafael J. Wysocki <rafael@kernel.org>
2020-01-02cpuidle: psci: Attach CPU devices to their PM domainsUlf Hansson
In order to enable a CPU to be power managed through its PM domain, let's try to attach it by calling psci_dt_attach_cpu() during the cpuidle initialization. psci_dt_attach_cpu() returns a pointer to the attached struct device, which later should be used for runtime PM, hence we need to store it somewhere. Rather than adding yet another per CPU variable, let's create a per CPU struct to collect the relevant per CPU variables. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Rafael J. Wysocki <rafael@kernel.org>
2020-01-02cpuidle: psci: Support hierarchical CPU idle statesUlf Hansson
Currently CPU's idle states are represented using the flattened model. Let's add support for the hierarchical layout, via converting to use of_get_cpu_state_node(). Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Rafael J. Wysocki <rafael@kernel.org>
2020-01-02cpuidle: psci: Simplify OF parsing of CPU idle state nodesUlf Hansson
Iterating through the idle state nodes in DT, to find out the number of states that needs to be allocated is unnecessary, as it has already been done from dt_init_idle_driver(). Therefore, drop the iteration and use the number we already have at hand. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Rafael J. Wysocki <rafael@kernel.org>
2020-01-02cpuidle: psci: Align psci_power_state count with idle state countSudeep Holla
Instead of allocating 'n-1' states in psci_power_state to manage 'n' idle states which include "ARM WFI" state, it would be simpler to have 1:1 mapping between psci_power_state and cpuidle driver states. ARM WFI state(i.e. idx == 0) is handled specially in the generic macro CPU_PM_CPU_IDLE_ENTER_PARAM and hence state[-1] is not possible. However for sake of code readability, it is better to have 1:1 mapping and not use [idx - 1] to access psci_power_state corresponding to driver cpuidle state for idx. psci_power_state[0] is default initialised to 0 and is never accessed while entering WFI state. Reported-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Rafael J. Wysocki <rafael@kernel.org>
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>
2019-08-09ARM: psci: cpuidle: Introduce PSCI CPUidle driverLorenzo Pieralisi
PSCI firmware is the standard power management control for all ARM64 based platforms and it is also deployed on some ARM 32 bit platforms to date. Idle state entry in PSCI is currently achieved by calling arm_cpuidle_init() and arm_cpuidle_suspend() in a generic idle driver, which in turn relies on ARM/ARM64 CPUidle back-end to relay the call into PSCI firmware if PSCI is the boot method. Given that PSCI is the standard idle entry method on ARM64 systems (which means that no other CPUidle driver are expected on ARM64 platforms - so PSCI is already a generic idle driver), in order to simplify idle entry and code maintenance, it makes sense to have a PSCI specific idle driver so that idle code that it is currently living in drivers/firmware directory can be hoisted out of it and moved where it belongs, into a full-fledged PSCI driver, leaving PSCI code in drivers/firmware as a pure firmware interface, as it should be. Implement a PSCI CPUidle driver. By default it is a silent Kconfig entry which is left unselected, since it selection would clash with the generic ARM CPUidle driver that provides a PSCI based idle driver through the arm/arm64 arches back-ends CPU operations. 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: Ulf Hansson <ulf.hansson@linaro.org> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Will Deacon <will@kernel.org>