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2019-10-22cpufreq: Cancel policy update work scheduled before freeingSudeep Holla1-0/+3
Scheduled policy update work may end up racing with the freeing of the policy and unregistering the driver. One possible race is as below, where the cpufreq_driver is unregistered, but the scheduled work gets executed at later stage when, cpufreq_driver is NULL (i.e. after freeing the policy and driver). Unable to handle kernel NULL pointer dereference at virtual address 0000001c pgd = (ptrval) [0000001c] *pgd=80000080204003, *pmd=00000000 Internal error: Oops: 206 [#1] SMP THUMB2 Modules linked in: CPU: 0 PID: 34 Comm: kworker/0:1 Not tainted 5.4.0-rc3-00006-g67f5a8081a4b #86 Hardware name: ARM-Versatile Express Workqueue: events handle_update PC is at cpufreq_set_policy+0x58/0x228 LR is at dev_pm_qos_read_value+0x77/0xac Control: 70c5387d Table: 80203000 DAC: fffffffd Process kworker/0:1 (pid: 34, stack limit = 0x(ptrval)) (cpufreq_set_policy) from (refresh_frequency_limits.part.24+0x37/0x48) (refresh_frequency_limits.part.24) from (handle_update+0x2f/0x38) (handle_update) from (process_one_work+0x16d/0x3cc) (process_one_work) from (worker_thread+0xff/0x414) (worker_thread) from (kthread+0xff/0x100) (kthread) from (ret_from_fork+0x11/0x28) Fixes: 67d874c3b2c6 ("cpufreq: Register notifiers with the PM QoS framework") Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> [ rjw: Cancel the work before dropping the QoS requests ] Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-10-21cpufreq: Use per-policy frequency QoSRafael J. Wysocki1-33/+26
Replace the CPU device PM QoS used for the management of min and max frequency constraints in cpufreq (and its users) with per-policy frequency QoS to avoid problems with cpufreq policies covering more then one CPU. Namely, a cpufreq driver is registered with the subsys interface which calls cpufreq_add_dev() for each CPU, starting from CPU0, so currently the PM QoS notifiers are added to the first CPU in the policy (i.e. CPU0 in the majority of cases). In turn, when the cpufreq driver is unregistered, the subsys interface doing that calls cpufreq_remove_dev() for each CPU, starting from CPU0, and the PM QoS notifiers are only removed when cpufreq_remove_dev() is called for the last CPU in the policy, say CPUx, which as a rule is not CPU0 if the policy covers more than one CPU. Then, the PM QoS notifiers cannot be removed, because CPUx does not have them, and they are still there in the device PM QoS notifiers list of CPU0, which prevents new PM QoS notifiers from being registered for CPU0 on the next attempt to register the cpufreq driver. The same issue occurs when the first CPU in the policy goes offline before unregistering the driver. After this change it does not matter which CPU is the policy CPU at the driver registration time and whether or not it is online all the time, because the frequency QoS is per policy and not per CPU. Fixes: 67d874c3b2c6 ("cpufreq: Register notifiers with the PM QoS framework") Reported-by: Dmitry Osipenko <digetx@gmail.com> Tested-by: Dmitry Osipenko <digetx@gmail.com> Reported-by: Sudeep Holla <sudeep.holla@arm.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Diagnosed-by: Viresh Kumar <viresh.kumar@linaro.org> Link: https://lore.kernel.org/linux-pm/5ad2624194baa2f53acc1f1e627eb7684c577a19.1562210705.git.viresh.kumar@linaro.org/T/#md2d89e95906b8c91c15f582146173dce2e86e99f Link: https://lore.kernel.org/linux-pm/20191017094612.6tbkwoq4harsjcqv@vireshk-i7/T/#m30d48cc23b9a80467fbaa16e30f90b3828a5a29b Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-10-10cpufreq: Avoid cpufreq_suspend() deadlock on system shutdownRafael J. Wysocki1-10/+0
It is incorrect to set the cpufreq syscore shutdown callback pointer to cpufreq_suspend(), because that function cannot be run in the syscore stage of system shutdown for two reasons: (a) it may attempt to carry out actions depending on devices that have already been shut down at that point and (b) the RCU synchronization carried out by it may not be able to make progress then. The latter issue has been present since commit 45975c7d21a1 ("rcu: Define RCU-sched API in terms of RCU for Tree RCU PREEMPT builds"), but the former one has been there since commit 90de2a4aa9f3 ("cpufreq: suspend cpufreq governors on shutdown") regardless. Fix that by dropping cpufreq_syscore_ops altogether and making device_shutdown() call cpufreq_suspend() directly before shutting down devices, which is along the lines of what system-wide power management does. Fixes: 45975c7d21a1 ("rcu: Define RCU-sched API in terms of RCU for Tree RCU PREEMPT builds") Fixes: 90de2a4aa9f3 ("cpufreq: suspend cpufreq governors on shutdown") Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 4.0+ <stable@vger.kernel.org> # 4.0+
2019-09-05Merge branch 'pm-cpufreq-qos'Rafael J. Wysocki1-30/+21
* pm-cpufreq-qos: Documentation: cpufreq: Update policy notifier documentation cpufreq: Remove CPUFREQ_ADJUST and CPUFREQ_NOTIFY policy notifier events ACPI: cpufreq: Switch to QoS requests instead of cpufreq notifier video: pxafb: Remove cpufreq policy notifier video: sa1100fb: Remove cpufreq policy notifier arch_topology: Use CPUFREQ_CREATE_POLICY instead of CPUFREQ_NOTIFY cpufreq: powerpc_cbe: Switch to QoS requests for freq limits cpufreq: powerpc: macintosh: Switch to QoS requests for freq limits thermal: cpu_cooling: Switch to QoS requests for freq limits cpufreq: Add policy create/remove notifiers back
2019-09-02cpufreq: Remove CPUFREQ_ADJUST and CPUFREQ_NOTIFY policy notifier eventsViresh Kumar1-29/+7
No driver makes reference to these events now, remove them and the code related to them. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-08-22cpufreq: Print driver name if cpufreq_suspend() failsFlorian Fainelli1-2/+2
Instead of printing the policy, which is incidentally a kernel pointer, so with limited interest, print the cpufreq driver name that failed to be suspend, which is more useful for debugging. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-08-21cpufreq: remove redundant assignment to retColin Ian King1-1/+1
Variable ret is initialized to a value that is never read and it is re-assigned later. The initialization is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-08-10cpufreq: Add policy create/remove notifiers backViresh Kumar1-1/+14
This effectively reverts some changes made by commit f9f41e3ef99 ("cpufreq: Remove policy create/remove notifiers"). We have a new use case for policy create/remove notifiers (for allocating/freeing QoS requests per policy), so add them back. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-08-10cpufreq: dev_pm_qos_update_request() can return 1 on successViresh Kumar1-1/+1
dev_pm_qos_update_request() can return 1 on success, so don't treat it as an error. Fixes: 18c49926c4bf ("cpufreq: Add QoS requests for userspace constraints") Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-07-18Merge branch 'pm-cpufreq'Rafael J. Wysocki1-65/+151
* pm-cpufreq: cpufreq: Make cpufreq_generic_init() return void cpufreq: imx-cpufreq-dt: Add i.MX8MN support cpufreq: Add QoS requests for userspace constraints cpufreq: intel_pstate: Reuse refresh_frequency_limits() cpufreq: Register notifiers with the PM QoS framework PM / QoS: Add support for MIN/MAX frequency constraints PM / QOS: Pass request type to dev_pm_qos_read_value() PM / QOS: Rename __dev_pm_qos_read_value() and dev_pm_qos_raw_read_value() PM / QOS: Pass request type to dev_pm_qos_{add|remove}_notifier()
2019-07-16cpufreq: Make cpufreq_generic_init() return voidViresh Kumar1-3/+1
It always returns 0 (success) and its return type should really be void. Over that, many drivers have added error handling code based on its return value, which is not required at all. Change its return type to void and update all the callers. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-07-08cpufreq: Add QoS requests for userspace constraintsViresh Kumar1-43/+55
This implements QoS requests to manage userspace configuration of min and max frequency. Reviewed-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: syzbot <syzbot+de771ae9390dffed7266@syzkaller.appspotmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-07-08cpufreq: intel_pstate: Reuse refresh_frequency_limits()Viresh Kumar1-1/+2
The implementation of intel_pstate_update_max_freq() is quite similar to refresh_frequency_limits(), lets reuse it. Finding minimum of policy->user_policy.max and policy->cpuinfo.max_freq in intel_pstate_update_max_freq() is redundant as cpufreq_set_policy() will call the ->verify() callback of intel-pstate driver, which will do this comparison anyway and so dropping it from intel_pstate_update_max_freq() doesn't harm. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-07-08cpufreq: Register notifiers with the PM QoS frameworkViresh Kumar1-30/+105
Register notifiers for min/max frequency constraints with the PM QoS framework. The constraints are also taken into consideration in cpufreq_set_policy(). This also relocates cpufreq_policy_put_kobj() as it is required to be called from cpufreq_policy_alloc() now. refresh_frequency_limits() is updated to avoid calling cpufreq_set_policy() for inactive policies and handle_update() is updated to have proper locking in place. No constraints are added until now though. Reviewed-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-07-08Merge branch 'pm-cpufreq'Rafael J. Wysocki1-67/+54
* pm-cpufreq: cpufreq: Avoid calling cpufreq_verify_current_freq() from handle_update() cpufreq: Consolidate cpufreq_update_current_freq() and __cpufreq_get() cpufreq: Don't skip frequency validation for has_target() drivers cpufreq: Use has_target() instead of !setpolicy cpufreq: Remove redundant !setpolicy check cpufreq: Move the IS_ENABLED(CPU_THERMAL) macro into a stub cpufreq: s5pv210: Don't flood kernel log after cpufreq change cpufreq: pcc-cpufreq: Fail initialization if driver cannot be registered cpufreq: add driver for Raspberry Pi cpufreq: Switch imx7d to imx-cpufreq-dt for speed grading cpufreq: imx-cpufreq-dt: Remove global platform match list cpufreq: brcmstb-avs-cpufreq: Fix types for voltage/frequency cpufreq: brcmstb-avs-cpufreq: Fix initial command check cpufreq: armada-37xx: Remove set but not used variable 'freq' cpufreq: imx-cpufreq-dt: Fix no OPPs available on unfused parts dt-bindings: imx-cpufreq-dt: Document opp-supported-hw usage cpufreq: Add imx-cpufreq-dt driver
2019-06-28cpufreq: Avoid calling cpufreq_verify_current_freq() from handle_update()Viresh Kumar1-10/+16
On some occasions cpufreq_verify_current_freq() schedules a work whose callback is handle_update(), which further calls cpufreq_update_policy() which may end up calling cpufreq_verify_current_freq() again. On the other hand, when cpufreq_update_policy() is called from handle_update(), the pointer to the cpufreq policy is already available, but cpufreq_cpu_acquire() is still called to get it in cpufreq_update_policy(), which should be avoided as well. To fix these issues, create a new helper, refresh_frequency_limits(), and make both handle_update() call it cpufreq_update_policy(). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Rename reeval_frequency_limits() as refresh_frequency_limits() ] [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-06-28cpufreq: Consolidate cpufreq_update_current_freq() and __cpufreq_get()Viresh Kumar1-42/+28
Their implementations are quite similar, so modify cpufreq_update_current_freq() somewhat and call it from __cpufreq_get(). Also rename cpufreq_update_current_freq() to cpufreq_verify_current_freq(), as that's what it is doing. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-06-28cpufreq: Don't skip frequency validation for has_target() driversViresh Kumar1-8/+5
CPUFREQ_CONST_LOOPS was introduced in a very old commit from pre-2.6 kernel release by commit 6a4a93f9c0d5 ("[CPUFREQ] Fix 'out of sync' issue"). Basically, that commit does two things: - It adds the frequency verification code (which is quite similar to what we have today as well). - And it sets the CPUFREQ_CONST_LOOPS flag only for setpolicy drivers, rightly so based on the code we had then. The idea was to avoid frequency validation for setpolicy drivers as the cpufreq core doesn't know what frequency the hardware is running at and so no point in doing frequency verification. The problem happened when we started to use the same CPUFREQ_CONST_LOOPS flag for constant loops-per-jiffy thing as well and many has_target() drivers started using the same flag and unknowingly skipped the verification of frequency. There is no logical reason behind skipping frequency validation because of the presence of CPUFREQ_CONST_LOOPS flag otherwise. Fix this issue by skipping frequency validation only for setpolicy drivers and always doing it for has_target() drivers irrespective of the presence or absence of CPUFREQ_CONST_LOOPS flag. cpufreq_notify_transition() is only called for has_target() type driver and not for set_policy type, and the check is simply redundant. Remove it as well. Also remove () around freq comparison statement as they aren't required and checkpatch also warns for them. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-06-26cpufreq: Use has_target() instead of !setpolicyViresh Kumar1-3/+3
For code consistency, use has_target() instead of !setpolicy everywhere, as it is already done at several places. Maybe we should also use "!has_target()" instead of "cpufreq_driver->setpolicy" where we need to check if the driver supports setpolicy, so to use only one expression for this kind of differentiation. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-06-26cpufreq: Remove redundant !setpolicy checkViresh Kumar1-1/+1
cpufreq_start_governor() is only called for !setpolicy case, checking it again is not required. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-06-26cpufreq: Move the IS_ENABLED(CPU_THERMAL) macro into a stubDaniel Lezcano1-4/+2
cpufreq_online() and cpufreq_offline() [un]register the driver as a cooling device. This is done if the driver is flagged as a cooling device in addition with an IS_ENABLED() check to compile out the branching code. Group this test in a stub function added in the cpufreq header instead of having the IS_ENABLED() in the code. Suggested-by: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner1-4/+1
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-15Merge tag 'pm-5.2-rc1-2' of ↵Linus Torvalds1-60/+80
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more power management updates from Rafael Wysocki: "These fix a recent regression causing kernels built with CONFIG_PM unset to crash on systems that support the Performance and Energy Bias Hint (EPB), clean up the cpufreq core and some users of transition notifiers and introduce a new power domain flag into the generic power domains framework (genpd). Specifics: - Fix recent regression causing kernels built with CONFIG_PM unset to crash on systems that support the Performance and Energy Bias Hint (EPB) by avoiding to compile the EPB-related code depending on CONFIG_PM when it is unset (Rafael Wysocki). - Clean up the transition notifier invocation code in the cpufreq core and change some users of cpufreq transition notifiers accordingly (Viresh Kumar). - Change MAINTAINERS to cover the schedutil governor as part of cpufreq (Viresh Kumar). - Simplify cpufreq_init_policy() to avoid redundant computations (Yue Hu). - Add explanatory comment to the cpufreq core (Rafael Wysocki). - Introduce a new flag, GENPD_FLAG_RPM_ALWAYS_ON, to the generic power domains (genpd) framework along with the first user of it (Leonard Crestez)" * tag 'pm-5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: soc: imx: gpc: Use GENPD_FLAG_RPM_ALWAYS_ON for ERR009619 PM / Domains: Add GENPD_FLAG_RPM_ALWAYS_ON flag cpufreq: Update MAINTAINERS to include schedutil governor cpufreq: Don't find governor for setpolicy drivers in cpufreq_init_policy() cpufreq: Explain the kobject_put() in cpufreq_policy_alloc() cpufreq: Call transition notifier only once for each policy x86: intel_epb: Take CONFIG_PM into account
2019-05-13cpufreq: Don't find governor for setpolicy drivers in cpufreq_init_policy()Yue Hu1-51/+65
In cpufreq_init_policy() we will check if there's last_governor for target and setpolicy type. However last_governor is set only if has_target() is true in cpufreq_offline(). That means find last_governor for setpolicy type is pointless. Also new_policy.governor will not be used if ->setpolicy callback is set in cpufreq_set_policy(). Moreover, there's duplicate ->setpolicy check in using default policy path. Let's add a new helper function to avoid it. Also update comments. Signed-off-by: Yue Hu <huyue2@yulong.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-05-13cpufreq: Explain the kobject_put() in cpufreq_policy_alloc()Rafael J. Wysocki1-0/+5
It may not be particularly clear why the kobject_put() after failing kobject_init_and_add() in cpufreq_policy_alloc() is not redundant, so add a comment to explain that. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-05-10cpufreq: Call transition notifier only once for each policyViresh Kumar1-9/+10
Currently, the notifiers are called once for each CPU of the policy->cpus cpumask. It would be more optimal if the notifier can be called only once and all the relevant information be provided to it. Out of the 23 drivers that register for the transition notifiers today, only 4 of them do per-cpu updates and the callback for the rest can be called only once for the policy without any impact. This would also avoid multiple function calls to the notifier callbacks and reduce multiple iterations of notifier core's code (which does locking as well). This patch adds pointer to the cpufreq policy to the struct cpufreq_freqs, so the notifier callback has all the information available to it with a single call. The five drivers which perform per-cpu updates are updated to use the cpufreq policy. The freqs->cpu field is redundant now and is removed. Acked-by: David S. Miller <davem@davemloft.net> (sparc) Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-05-07Merge tag 'printk-for-5.2' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Allow state reset of printk_once() calls. - Prevent crashes when dereferencing invalid pointers in vsprintf(). Only the first byte is checked for simplicity. - Make vsprintf warnings consistent and inlined. - Treewide conversion of obsolete %pf, %pF to %ps, %pF printf modifiers. - Some clean up of vsprintf and test_printf code. * tag 'printk-for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: lib/vsprintf: Make function pointer_string static vsprintf: Limit the length of inlined error messages vsprintf: Avoid confusion between invalid address and value vsprintf: Prevent crash when dereferencing invalid pointers vsprintf: Consolidate handling of unknown pointer specifiers vsprintf: Factor out %pO handler as kobject_string() vsprintf: Factor out %pV handler as va_format() vsprintf: Factor out %p[iI] handler as ip_addr_string() vsprintf: Do not check address of well-known strings vsprintf: Consistent %pK handling for kptr_restrict == 0 vsprintf: Shuffle restricted_pointer() printk: Tie printk_once / printk_deferred_once into .data.once for reset treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively lib/test_printf: Switch to bitmap_zalloc()
2019-04-30cpufreq: Fix kobject memleakViresh Kumar1-0/+1
Currently the error return path from kobject_init_and_add() is not followed by a call to kobject_put() - which means we are leaking the kobject. Fix it by adding a call to kobject_put() in the error path of kobject_init_and_add(). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Tobin C. Harding <tobin@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-04-23cpufreq: Move ->get callback check outside of __cpufreq_get()Yue Hu1-2/+3
Currenly, __cpufreq_get() called by show_cpuinfo_cur_freq() will check ->get callback. That is needless since cpuinfo_cur_freq attribute will not be created if ->get is not set. So let's drop it in __cpufreq_get(). Also keep this check in cpufreq_get(). Signed-off-by: Yue Hu <huyue2@yulong.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-04-16cpufreq: Remove needless bios_limit check in show_bios_limit()Yue Hu1-5/+3
Initially, bios_limit attribute will be created if driver->bios_limit is set in cpufreq_add_dev_interface(). So remove the redundant check for latter show operation. Signed-off-by: Yue Hu <huyue2@yulong.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-04-09treewide: Switch printk users from %pf and %pF to %ps and %pS, respectivelySakari Ailus1-1/+1
%pF and %pf are functionally equivalent to %pS and %ps conversion specifiers. The former are deprecated, therefore switch the current users to use the preferred variant. The changes have been produced by the following command: git grep -l '%p[fF]' | grep -v '^\(tools\|Documentation\)/' | \ while read i; do perl -i -pe 's/%pf/%ps/g; s/%pF/%pS/g;' $i; done And verifying the result. Link: http://lkml.kernel.org/r/20190325193229.23390-1-sakari.ailus@linux.intel.com Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: linux-arm-kernel@lists.infradead.org Cc: sparclinux@vger.kernel.org Cc: linux-um@lists.infradead.org Cc: xen-devel@lists.xenproject.org Cc: linux-acpi@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: drbd-dev@lists.linbit.com Cc: linux-block@vger.kernel.org Cc: linux-mmc@vger.kernel.org Cc: linux-nvdimm@lists.01.org Cc: linux-pci@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: linux-btrfs@vger.kernel.org Cc: linux-f2fs-devel@lists.sourceforge.net Cc: linux-mm@kvack.org Cc: ceph-devel@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Acked-by: David Sterba <dsterba@suse.com> (for btrfs) Acked-by: Mike Rapoport <rppt@linux.ibm.com> (for mm/memblock.c) Acked-by: Bjorn Helgaas <bhelgaas@google.com> (for drivers/pci) Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-09cpufreq: Remove cpufreq_driver check in cpufreq_boost_supported()Yue Hu1-1/+1
Currently there are three calling paths for cpufreq_boost_supported() in all as below, we can see the cpufreq_driver null check is needless since it is already checked before. <path1> cpufreq_enable_boost_support() |-> if (!cpufreq_driver) |-> cpufreq_boost_supported() <path2> cpufreq_register_driver() |-> if (!driver_data ... |-> cpufreq_driver = driver_data |-> cpufreq_boost_supported() |-> remove_boost_sysfs_file() |-> cpufreq_boost_supported() <path3> cpufreq_unregister_driver() |-> if (!cpufreq_driver ... |-> remove_boost_sysfs_file() |-> cpufreq_boost_supported() Signed-off-by: Yue Hu <huyue2@yulong.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-04-08cpufreq: intel_pstate: Update max frequency on global turbo changesRafael J. Wysocki1-12/+4
While the cpuinfo.max_freq value doesn't really matter for intel_pstate in the active mode, in the passive mode it is used by governors as the maximum physical frequency of the CPU and the results of governor computations generally depend on it. Also it is made available to user space via sysfs and it should match the current HW configuration. For this reason, make intel_pstate update cpuinfo.max_freq for all CPUs if it detects a global change of turbo frequency settings from "disable" to "enable" or the other way associated with a _PPC change notification from the platform firmware. Note that policy_is_inactive(), cpufreq_cpu_acquire(), cpufreq_cpu_release(), and cpufreq_set_policy() need to be made available to it for this purpose. Link: https://bugzilla.kernel.org/show_bug.cgi?id=200759 Reported-by: Gabriele Mazzotta <gabriele.mzt@gmail.com> Tested-by: Gabriele Mazzotta <gabriele.mzt@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-04-01cpufreq: Add cpufreq_cpu_acquire() and cpufreq_cpu_release()Rafael J. Wysocki1-9/+47
It sometimes is necessary to find a cpufreq policy for a given CPU and acquire its rwsem (for writing) immediately after that, so introduce cpufreq_cpu_acquire() as a helper for that and the complementary cpufreq_cpu_release(). Make cpufreq_update_policy() use the new functions. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-04-01cpufreq: intel_pstate: Driver-specific handling of _PPC updatesRafael J. Wysocki1-0/+16
In some cases, the platform firmware disables or enables turbo frequencies for all CPUs globally before triggering a _PPC change notification for one of them. Obviously, that global change affects all CPUs, not just the notified one, and it needs to be acted upon by cpufreq. The intel_pstate driver is able to detect such global changes of the settings, but it also needs to update policy limits for all CPUs if that happens, in particular if turbo frequencies are enabled globally - to allow them to be used. For this reason, introduce a new cpufreq driver callback to be invoked on _PPC notifications, if present, instead of simply calling cpufreq_update_policy() for the notified CPU and make intel_pstate use it to trigger policy updates for all CPUs in the system if global settings change. Link: https://bugzilla.kernel.org/show_bug.cgi?id=200759 Reported-by: Gabriele Mazzotta <gabriele.mzt@gmail.com> Tested-by: Gabriele Mazzotta <gabriele.mzt@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-03-07cpufreq: Improve kerneldoc comments for cpufreq_cpu_get/put()Rafael J. Wysocki1-15/+9
Fix the formatting of the cpufreq_cpu_get() and cpufreq_cpu_put() kerneldoc comments and rework them to be somewhat easier to follow. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-02-20cpufreq: Pass updated policy to driver ->setpolicy() callbackRafael J. Wysocki1-1/+1
The invocation of the ->setpolicy() cpufreq driver callback should be equivalent to calling cpufreq_governor_limits(policy) for drivers with internal governors, but in fact it isn't so, because the temporary new_policy object is passed to it instead of the updated policy. That is a bit confusing, so make cpufreq_set_policy() pass the updated policy to the driver ->setpolicy() callback. No intentional changes of behavior. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-02-20cpufreq: Fix two debug messages in cpufreq_set_policy()Rafael J. Wysocki1-2/+2
Remove the redundant "cpufreq:" prefix from two debug messages in cpufreq_set_policy(). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-02-20cpufreq: Reorder and simplify cpufreq_update_policy()Rafael J. Wysocki1-12/+7
In cpufreq_update_policy(), instead of updating new_policy.cur separately, which is kind of confusing, because cpufreq_set_policy() doesn't take that value into account directly anyway, make the copy of the existing policy after calling cpufreq_update_current_freq(). No intentional changes of behavior. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-02-20cpufreq: Add kerneldoc comments for two core functionsRafael J. Wysocki1-8/+24
Add kerneldoc comments describing cpufreq_set_policy() and cpufreq_update_policy() as they have not been properly documented so far and they really need to be documented. While at it, fix white space around the cpufreq_set_policy() header. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-02-14cpufreq: Replace double NOT (!!) with single NOT (!)Viresh Kumar1-1/+1
Double NOT (!!) operation is normally done to convert a non-zero value to 1 and keep zero as is, but that isn't the requirement in this case. All we wanted was to make sure that only one of the two routines isn't set, i.e. either both function pointers are set or both are unset. This can be done with a single NOT (!) operation as well. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-02-12cpufreq: Allow light-weight tear down and bring up of CPUsViresh Kumar1-20/+38
The cpufreq core doesn't remove the cpufreq policy anymore on CPU offline operation, rather that happens when the CPU device gets unregistered from the kernel. This allows faster recovery when the CPU comes back online. This is also very useful during system wide suspend/resume where we offline all non-boot CPUs during suspend and then bring them back on resume. This commit takes the same idea a step ahead to allow drivers to do light weight tear-down and bring-up during CPU offline and online operations. A new set of callbacks is introduced, online/offline(). online() gets called when the first CPU of an inactive policy is brought up and offline() gets called when all the CPUs of a policy are offlined. The existing init/exit() callback get called on policy creation/destruction. They also get called instead of online/offline() callbacks if the online/offline() callbacks aren't provided. This also moves around some code to get executed only for the new-policy case going forward. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-01-30cpufreq: Auto-register the driver as a thermal cooling device if askedAmit Kucheria1-0/+11
All cpufreq drivers do similar things to register as a cooling device. Provide a cpufreq driver flag so drivers can just ask the cpufreq core to register the cooling device on their behalf. This allows us to get rid of duplicated code in the drivers. In order to allow this, we add a struct thermal_cooling_device pointer to struct cpufreq_policy so that drivers don't need to store it in a private data structure. Suggested-by: Stephen Boyd <swboyd@chromium.org> Suggested-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org> Reviewed-by: Matthias Kaehlcke <mka@chromium.org> Tested-by: Matthias Kaehlcke <mka@chromium.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-01-29cpufreq: Use struct kobj_attribute instead of struct global_attrViresh Kumar1-3/+3
The cpufreq_global_kobject is created using kobject_create_and_add() helper, which assigns the kobj_type as dynamic_kobj_ktype and show/store routines are set to kobj_attr_show() and kobj_attr_store(). These routines pass struct kobj_attribute as an argument to the show/store callbacks. But all the cpufreq files created using the cpufreq_global_kobject expect the argument to be of type struct attribute. Things work fine currently as no one accesses the "attr" argument. We may not see issues even if the argument is used, as struct kobj_attribute has struct attribute as its first element and so they will both get same address. But this is logically incorrect and we should rather use struct kobj_attribute instead of struct global_attr in the cpufreq core and drivers and the show/store callbacks should take struct kobj_attribute as argument instead. This bug is caught using CFI CLANG builds in android kernel which catches mismatch in function prototypes for such callbacks. Reported-by: Donghee Han <dh.han@samsung.com> Reported-by: Sangkyu Kim <skwith.kim@samsung.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-01-15cpufreq: Don't update new_policy on failuresViresh Kumar1-2/+0
The local variable "new_policy" hasn't been used in the error path of cpufreq_online() since commit f9f41e3ef99a (cpufreq: Remove policy create/remove notifiers). Don't update it in that error path. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-01-11Merge branches 'pm-cpuidle', 'pm-cpufreq' and 'pm-sleep'Rafael J. Wysocki1-8/+4
* pm-cpuidle: doc: trace: fix reference to cpuidle documentation file cpuidle / Documentation: Update cpuidle MAINTAINERS entry * pm-cpufreq: cpufreq: scmi: Fix frequency invariance in slow path cpufreq: check if policy is inactive early in __cpufreq_get() cpufreq: scpi/scmi: Fix freeing of dynamic OPPs cpufreq / Documentation: Update cpufreq MAINTAINERS entry * pm-sleep: PM: sleep: call devfreq suspend/resume
2019-01-08cpufreq: check if policy is inactive early in __cpufreq_get()Sudeep Holla1-8/+4
cpuinfo_cur_freq gets current CPU frequency as detected by hardware while scaling_cur_freq last known CPU frequency. Some platforms may not allow checking the CPU frequency of an offline CPU or the associated resources may have been released via cpufreq_exit when the CPU gets offlined, in which case the policy would have been invalidated already. If we attempt to get current frequency from the hardware, it may result in hang or crash. For example on Juno, I see: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000188 [0000000000000188] pgd=0000000000000000 Internal error: Oops: 96000004 [#1] PREEMPT SMP Modules linked in: CPU: 5 PID: 4202 Comm: cat Not tainted 4.20.0-08251-ga0f2c0318a15-dirty #87 Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform pstate: 40000005 (nZcv daif -PAN -UAO) pc : scmi_cpufreq_get_rate+0x34/0xb0 lr : scmi_cpufreq_get_rate+0x34/0xb0 Call trace: scmi_cpufreq_get_rate+0x34/0xb0 __cpufreq_get+0x34/0xc0 show_cpuinfo_cur_freq+0x24/0x78 show+0x40/0x60 sysfs_kf_seq_show+0xc0/0x148 kernfs_seq_show+0x44/0x50 seq_read+0xd4/0x480 kernfs_fop_read+0x15c/0x208 __vfs_read+0x60/0x188 vfs_read+0x94/0x150 ksys_read+0x6c/0xd8 __arm64_sys_read+0x24/0x30 el0_svc_common+0x78/0x100 el0_svc_handler+0x38/0x78 el0_svc+0x8/0xc ---[ end trace 3d1024e58f77f6b2 ]--- So fix the issue by checking if the policy is invalid early in __cpufreq_get before attempting to get the current frequency. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-12-11sched/topology: Make Energy Aware Scheduling depend on schedutilQuentin Perret1-0/+1
Energy Aware Scheduling (EAS) is designed with the assumption that frequencies of CPUs follow their utilization value. When using a CPUFreq governor other than schedutil, the chances of this assumption being true are small, if any. When schedutil is being used, EAS' predictions are at least consistent with the frequency requests. Although those requests have no guarantees to be honored by the hardware, they should at least guide DVFS in the right direction and provide some hope in regards to the EAS model being accurate. To make sure EAS is only used in a sane configuration, create a strong dependency on schedutil being used. Since having sugov compiled-in does not provide that guarantee, make CPUFreq call a scheduler function on governor changes hence letting it rebuild the scheduling domains, check the governors of the online CPUs, and enable/disable EAS accordingly. Signed-off-by: Quentin Perret <quentin.perret@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: adharmap@codeaurora.org Cc: chris.redpath@arm.com Cc: currojerez@riseup.net Cc: dietmar.eggemann@arm.com Cc: edubezval@gmail.com Cc: gregkh@linuxfoundation.org Cc: javi.merino@kernel.org Cc: joel@joelfernandes.org Cc: juri.lelli@redhat.com Cc: morten.rasmussen@arm.com Cc: patrick.bellasi@arm.com Cc: pkondeti@codeaurora.org Cc: skannan@codeaurora.org Cc: smuckle@google.com Cc: srinivas.pandruvada@linux.intel.com Cc: thara.gopinath@linaro.org Cc: tkjos@google.com Cc: valentin.schneider@arm.com Cc: vincent.guittot@linaro.org Cc: viresh.kumar@linaro.org Link: https://lkml.kernel.org/r/20181203095628.11858-9-quentin.perret@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-09-10cpufreq: remove unnecessary unlikely()Igor Stoppa1-1/+1
WARN_ON() already contains an unlikely(), so it's not necessary to wrap it into another. Signed-off-by: Igor Stoppa <igor.stoppa@huawei.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-07-26cpufreq: Fix a circular lock dependency problemWaiman Long1-1/+6
With lockdep turned on, the following circular lock dependency problem was reported: [ 57.470040] ====================================================== [ 57.502900] WARNING: possible circular locking dependency detected [ 57.535208] 4.18.0-0.rc3.1.el8+7.x86_64+debug #1 Tainted: G [ 57.577761] ------------------------------------------------------ [ 57.609714] tuned/1505 is trying to acquire lock: [ 57.633808] 00000000559deec5 (cpu_hotplug_lock.rw_sem){++++}, at: store+0x27/0x120 [ 57.672880] [ 57.672880] but task is already holding lock: [ 57.702184] 000000002136ca64 (kn->count#118){++++}, at: kernfs_fop_write+0x1d0/0x410 [ 57.742176] [ 57.742176] which lock already depends on the new lock. [ 57.742176] [ 57.785220] [ 57.785220] the existing dependency chain (in reverse order) is: : [ 58.932512] other info that might help us debug this: [ 58.932512] [ 58.973344] Chain exists of: [ 58.973344] cpu_hotplug_lock.rw_sem --> subsys mutex#5 --> kn->count#118 [ 58.973344] [ 59.030795] Possible unsafe locking scenario: [ 59.030795] [ 59.061248] CPU0 CPU1 [ 59.085377] ---- ---- [ 59.108160] lock(kn->count#118); [ 59.124935] lock(subsys mutex#5); [ 59.156330] lock(kn->count#118); [ 59.186088] lock(cpu_hotplug_lock.rw_sem); [ 59.208541] [ 59.208541] *** DEADLOCK *** In the cpufreq_register_driver() function, the lock sequence is: cpus_read_lock --> kn->count For the cpufreq sysfs store method, the lock sequence is: kn->count --> cpus_read_lock These sequences are actually safe as they are taking a share lock on cpu_hotplug_lock. However, the current lockdep code doesn't check for share locking when detecting circular lock dependency. Fixing that could be a substantial effort. Instead, we can work around this problem by using cpus_read_trylock() in the store method which is much simpler. The chance of not getting the read lock is very small. If that happens, the userspace application that writes the sysfs file will get an error. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>