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2018-04-08Revert "cpufreq: Fix governor module removal race"Greg Kroah-Hartman
This reverts commit 3f7dfb7fcf98a7e73dee018c4a68537ce7fec646 which was commit a8b149d32b663c1a4105273295184b78f53d33cf upstream. The backport was not correct, so just drop it entirely. Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-22cpufreq: Fix governor module removal raceRafael J. Wysocki
[ Upstream commit a8b149d32b663c1a4105273295184b78f53d33cf ] It is possible to remove a cpufreq governor module after cpufreq_parse_governor() has returned success in store_scaling_governor() and before cpufreq_set_policy() acquires a reference to it, because the governor list is not protected during that period and nothing prevents the governor from being unregistered then. Prevent that from happening by acquiring an extra reference to the governor module temporarily in cpufreq_parse_governor(), under cpufreq_governor_mutex, and dropping it in store_scaling_governor(), when cpufreq_set_policy() returns. Note that the second cpufreq_parse_governor() call site is fine, because it only cares about the policy member of new_policy. 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> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-14cpufreq: cpufreq_register_driver() should return -ENODEV if init failsDavid Arcari
commit 6c77003677d5f1ce15f26d24360cb66c0bc07bb3 upstream. For a driver that does not set the CPUFREQ_STICKY flag, if all of the ->init() calls fail, cpufreq_register_driver() should return an error. This will prevent the driver from loading. Fixes: ce1bcfe94db8 (cpufreq: check cpufreq_policy_list instead of scanning policies for all CPUs) Signed-off-by: David Arcari <darcari@redhat.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-30cpufreq: Restore policy min/max limits on CPU onlineViresh Kumar
commit ff010472fb75670cb5c08671e820eeea3af59c87 upstream. On CPU online the cpufreq core restores the previous governor (or the previous "policy" setting for ->setpolicy drivers), but it does not restore the min/max limits at the same time, which is confusing, inconsistent and real pain for users who set the limits and then suspend/resume the system (using full suspend), in which case the limits are reset on all CPUs except for the boot one. Fix this by making cpufreq_online() restore the limits when an inactive policy is brought online. The commit log and patch are inspired from Rafael's earlier work. Reported-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-26cpufreq: Fix and clean up show_cpuinfo_cur_freq()Rafael J. Wysocki
commit 9b4f603e7a9f4282aec451063ffbbb8bb410dcd9 upstream. There is a missing newline in show_cpuinfo_cur_freq(), so add it, but while at it clean that function up somewhat too. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-02cpufreq: use last policy after online for drivers with ->setpolicySrinivas Pandruvada
For cpufreq drivers which use setpolicy interface, after offline->online the policy is set to default. This can be reproduced by setting the default policy of intel_pstate or longrun to ondemand and then change to "performance". After offline and online, the setpolicy will be called with the policy=ondemand. For drivers using governors this condition is handled by storing last_governor, during offline and restoring during online. The same should be done for drivers using setpolicy interface. Storing last_policy during offline and restoring during online. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-23cpufreq: Always remove sysfs cpuX/cpufreq link on ->remove_dev()Viresh Kumar
Subsys interface's ->remove_dev() is called when the cpufreq driver is unregistering or the CPU is getting physically removed. We keep removing the cpuX/cpufreq link for all CPUs except the last one, which is a mistake as all CPUs contain a link now. Because of this, one CPU from each policy will still contain a link (to an already removed policyX directory), after the cpufreq driver is unregistered. Fix that by removing the link first and then only see if the policy is required to be freed. That will make sure that no links are left out. Fixes: 96bdda61f58b ("cpufreq: create cpu/cpufreq/policyX directories") Reported-and-tested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-28cpufreq: postfix policy directory with the first CPU in related_cpusViresh Kumar
The sysfs policy directory is postfixed currently with the CPU number for which the policy was created, which isn't necessarily the first CPU in related_cpus mask. To make it more consistent and predictable, lets postfix the policy with the first cpu in related-cpus mask. Suggested-by: Saravana Kannan <skannan@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Saravana Kannan <skannan@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-28cpufreq: create cpu/cpufreq/policyX directoriesViresh Kumar
The cpufreq sysfs interface had been a bit inconsistent as one of the CPUs for a policy had a real directory within its sysfs 'cpuX' directory and all other CPUs had links to it. That also made the code a bit complex as we need to take care of moving the sysfs directory if the CPU containing the real directory is getting physically hot-unplugged. Solve this by creating 'policyX' directories (per-policy) in /sys/devices/system/cpu/cpufreq/ directory, where X is the CPU for which the policy was first created. This also removes the need of keeping kobj_cpu and we can remove it now. Suggested-by: Saravana Kannan <skannan@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Saravana Kannan <skannan@codeaurora.org> Acked-by: is more of a general agreement from the person that he is Reviewed-by: is a more strict tag and implies that the reviewer has Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-28cpufreq: remove cpufreq_sysfs_{create|remove}_file()Viresh Kumar
They don't do anything special now, remove the unnecessary wrapper. Reviewed-by: Saravana Kannan <skannan@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-28cpufreq: create cpu/cpufreq at boot timeViresh Kumar
Later patches will need to create policy specific directories in /sys/devices/system/cpu/cpufreq/ directory and so the cpufreq directory wouldn't be ever empty. And so no fun creating/destroying it on need basis anymore. Create it once on system boot. Reviewed-by: Saravana Kannan <skannan@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-28cpufreq: Use cpumask_copy instead of cpumask_or to copy a maskViresh Kumar
->related_cpus is empty at this point of time and copying ->cpus to it or orring ->related_cpus with ->cpus would result in the same value. But cpumask_copy makes it rather clear. Reviewed-by: Saravana Kannan <skannan@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-14cpufreq: Drop redundant check for inactive policiesViresh Kumar
We just made sure policy->cpu is online and this check will always fail as the policy is active. Drop it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Saravana Kannan <skannan@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-08cpufreq: prevent lockup on reading scaling_available_frequenciesSrinivas Pandruvada
When scaling_available_frequencies is read on an offlined cpu, then either lockup or junk values are displayed. This is caused by freed freq_table, which policy is using. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-16cpufreq: acpi-cpufreq: Use cpufreq_cpu_get_raw() in ->get()Rafael J. Wysocki
cpufreq_cpu_get() called by get_cur_freq_on_cpu() is overkill, because the ->get() callback is always invoked in a context in which all of the conditions checked by cpufreq_cpu_get() are guaranteed to be satisfied. Use cpufreq_cpu_get_raw() instead of it and drop the corresponding cpufreq_cpu_put() from get_cur_freq_on_cpu(). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2015-09-11Merge branch 'pm-cpufreq'Rafael J. Wysocki
* pm-cpufreq: intel_pstate: fix PCT_TO_HWP macro intel_pstate: Fix user input of min/max to legal policy region cpufreq-dt: add suspend frequency support cpufreq: allow cpufreq_generic_suspend() to work without suspend frequency cpufreq: Use __func__ to print function's name cpufreq: staticize cpufreq_cpu_get_raw() cpufreq: Add ARM_MT8173_CPUFREQ dependency on THERMAL cpufreq: dt: Tolerance applies on both sides of target voltage cpufreq: dt: Print error on failing to mark OPPs as shared cpufreq: dt: Check OPP count before marking them shared
2015-09-09cpufreq: allow cpufreq_generic_suspend() to work without suspend frequencyBartlomiej Zolnierkiewicz
Some cpufreq drivers may set suspend frequency only for selected setups but still would like to use the generic suspend handler. Thus don't treat !policy->suspend_freq condition as an incorrect one. Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-07cpufreq: Use __func__ to print function's nameViresh Kumar
Its better to use __func__ to print functions name instead of writing the name in the print statement. This also has the advantage that a change in function's name doesn't force us to change the print message as well. Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-07cpufreq: staticize cpufreq_cpu_get_raw()Viresh Kumar
cpufreq_cpu_get_raw() isn't used by any external users, staticize it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-03Merge branch 'pm-opp' into pm-cpufreqRafael J. Wysocki
2015-09-01Merge tag 'pm+acpi-4.3-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management and ACPI updates from Rafael Wysocki: "From the number of commits perspective, the biggest items are ACPICA and cpufreq changes with the latter taking the lead (over 50 commits). On the cpufreq front, there are many cleanups and minor fixes in the core and governors, driver updates etc. We also have a new cpufreq driver for Mediatek MT8173 chips. ACPICA mostly updates its debug infrastructure and adds a number of fixes and cleanups for a good measure. The Operating Performance Points (OPP) framework is updated with new DT bindings and support for them among other things. We have a few updates of the generic power domains framework and a reorganization of the ACPI device enumeration code and bus type operations. And a lot of fixes and cleanups all over. Included is one branch from the MFD tree as it contains some PM-related driver core and ACPI PM changes a few other commits are based on. Specifics: - ACPICA update to upstream revision 20150818 including method tracing extensions to allow more in-depth AML debugging in the kernel and a number of assorted fixes and cleanups (Bob Moore, Lv Zheng, Markus Elfring). - ACPI sysfs code updates and a documentation update related to AML method tracing (Lv Zheng). - ACPI EC driver fix related to serialized evaluations of _Qxx methods and ACPI tools updates allowing the EC userspace tool to be built from the kernel source (Lv Zheng). - ACPI processor driver updates preparing it for future introduction of CPPC support and ACPI PCC mailbox driver updates (Ashwin Chaugule). - ACPI interrupts enumeration fix for a regression related to the handling of IRQ attribute conflicts between MADT and the ACPI namespace (Jiang Liu). - Fixes related to ACPI device PM (Mika Westerberg, Srinidhi Kasagar). - ACPI device registration code reorganization to separate the sysfs-related code and bus type operations from the rest (Rafael J Wysocki). - Assorted cleanups in the ACPI core (Jarkko Nikula, Mathias Krause, Andy Shevchenko, Rafael J Wysocki, Nicolas Iooss). - ACPI cpufreq driver and ia64 cpufreq driver fixes and cleanups (Pan Xinhui, Rafael J Wysocki). - cpufreq core cleanups on top of the previous changes allowing it to preseve its sysfs directories over system suspend/resume (Viresh Kumar, Rafael J Wysocki, Sebastian Andrzej Siewior). - cpufreq fixes and cleanups related to governors (Viresh Kumar). - cpufreq updates (core and the cpufreq-dt driver) related to the turbo/boost mode support (Viresh Kumar, Bartlomiej Zolnierkiewicz). - New DT bindings for Operating Performance Points (OPP), support for them in the OPP framework and in the cpufreq-dt driver plus related OPP framework fixes and cleanups (Viresh Kumar). - cpufreq powernv driver updates (Shilpasri G Bhat). - New cpufreq driver for Mediatek MT8173 (Pi-Cheng Chen). - Assorted cpufreq driver (speedstep-lib, sfi, integrator) cleanups and fixes (Abhilash Jindal, Andrzej Hajda, Cristian Ardelean). - intel_pstate driver updates including Skylake-S support, support for enabling HW P-states per CPU and an additional vendor bypass list entry (Kristen Carlson Accardi, Chen Yu, Ethan Zhao). - cpuidle core fixes related to the handling of coupled idle states (Xunlei Pang). - intel_idle driver updates including Skylake Client support and support for freeze-mode-specific idle states (Len Brown). - Driver core updates related to power management (Andy Shevchenko, Rafael J Wysocki). - Generic power domains framework fixes and cleanups (Jon Hunter, Geert Uytterhoeven, Rajendra Nayak, Ulf Hansson). - Device PM QoS framework update to allow the latency tolerance setting to be exposed to user space via sysfs (Mika Westerberg). - devfreq support for PPMUv2 in Exynos5433 and a fix for an incorrect exynos-ppmu DT binding (Chanwoo Choi, Javier Martinez Canillas). - System sleep support updates (Alan Stern, Len Brown, SungEun Kim). - rockchip-io AVS support updates (Heiko Stuebner). - PM core clocks support fixup (Colin Ian King). - Power capping RAPL driver update including support for Skylake H/S and Broadwell-H (Radivoje Jovanovic, Seiichi Ikarashi). - Generic device properties framework fixes related to the handling of static (driver-provided) property sets (Andy Shevchenko). - turbostat and cpupower updates (Len Brown, Shilpasri G Bhat, Shreyas B Prabhu)" * tag 'pm+acpi-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (180 commits) cpufreq: speedstep-lib: Use monotonic clock cpufreq: powernv: Increase the verbosity of OCC console messages cpufreq: sfi: use kmemdup rather than duplicating its implementation cpufreq: drop !cpufreq_driver check from cpufreq_parse_governor() cpufreq: rename cpufreq_real_policy as cpufreq_user_policy cpufreq: remove redundant 'policy' field from user_policy cpufreq: remove redundant 'governor' field from user_policy cpufreq: update user_policy.* on success cpufreq: use memcpy() to copy policy cpufreq: remove redundant CPUFREQ_INCOMPATIBLE notifier event cpufreq: mediatek: Add MT8173 cpufreq driver dt-bindings: mediatek: Add MT8173 CPU DVFS clock bindings PM / Domains: Fix typo in description of genpd_dev_pm_detach() PM / Domains: Remove unusable governor dummies PM / Domains: Make pm_genpd_init() available to modules PM / domains: Align column headers and data in pm_genpd_summary output powercap / RAPL: disable the 2nd power limit properly tools: cpupower: Fix error when running cpupower monitor PM / OPP: Drop unlikely before IS_ERR(_OR_NULL) PM / OPP: Fix static checker warning (broken 64bit big endian systems) ...
2015-09-01Merge branch 'pm-opp'Rafael J. Wysocki
* pm-opp: PM / OPP: Drop unlikely before IS_ERR(_OR_NULL) PM / OPP: Fix static checker warning (broken 64bit big endian systems) PM / OPP: Free resources and properly return error on failure cpufreq-dt: make scaling_boost_freqs sysfs attr available when boost is enabled cpufreq: dt: Add support for turbo/boost mode cpufreq: dt: Add support for operating-points-v2 bindings cpufreq: Allow drivers to enable boost support after registering driver cpufreq: Update boost flag while initializing freq table from OPPs PM / OPP: add dev_pm_opp_is_turbo() helper PM / OPP: Add helpers for initializing CPU OPPs PM / OPP: Add support for opp-suspend PM / OPP: Add OPP sharing information to OPP library PM / OPP: Add clock-latency-ns support PM / OPP: Add support to parse "operating-points-v2" bindings PM / OPP: Break _opp_add_dynamic() into smaller functions PM / OPP: Allocate dev_opp from _add_device_opp() PM / OPP: Create _remove_device_opp() for freeing dev_opp PM / OPP: Relocate few routines PM / OPP: Create a directory for opp bindings PM / OPP: Update bindings to make opp-hz a 64 bit value
2015-09-01cpufreq: drop !cpufreq_driver check from cpufreq_parse_governor()Viresh Kumar
Driver is guaranteed to be present on a call to cpufreq_parse_governor() and there is no need to check for !cpufreq_driver. Drop it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-01cpufreq: remove redundant 'policy' field from user_policyViresh Kumar
Its always same as policy->policy, and there is no need to keep another copy of it. Remove it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-01cpufreq: remove redundant 'governor' field from user_policyViresh Kumar
Its always same as policy->governor, and there is no need to keep another copy of it. Remove it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-01cpufreq: update user_policy.* on successViresh Kumar
'user_policy' caches properties of a policy that are set by userspace. And these must be updated only if cpufreq core was successful in updating them based on request from user space. In store_scaling_governor(), we are updating user_policy.policy and user_policy.governor even if cpufreq_set_policy() failed. That's incorrect. Fix this by updating user_policy.* only if we were successful in updating the properties. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-01cpufreq: use memcpy() to copy policyViresh Kumar
cpufreq_get_policy() is useful if the pointer to policy isn't available in advance. But if it is available, then there is no need to call cpufreq_get_policy(). Directly use memcpy() to copy the policy. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-01cpufreq: remove redundant CPUFREQ_INCOMPATIBLE notifier eventViresh Kumar
What's being done from CPUFREQ_INCOMPATIBLE, can also be done with CPUFREQ_ADJUST. There is nothing special with CPUFREQ_INCOMPATIBLE notifier. Kill CPUFREQ_INCOMPATIBLE and fix its usage sites. This also updates the numbering of notifier events to remove holes. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-08-31Merge tag 'driver-core-4.3-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the new patches for the driver core / sysfs for 4.3-rc1. Very small number of changes here, all the details are in the shortlog, nothing major happening at all this kernel release, which is nice to see" * tag 'driver-core-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: bus: subsys: update return type of ->remove_dev() to void driver core: correct device's shutdown order driver core: fix docbook for device_private.device selftests: firmware: skip timeout checks for kernels without user mode helper kernel, cpu: Remove bogus __ref annotations cpu: Remove bogus __ref annotation of cpu_subsys_online() firmware: fix wrong memory deallocation in fw_add_devm_name() sysfs.txt: update show method notes about sprintf/snprintf/scnprintf usage devres: fix devres_get()
2015-08-07cpufreq: Allow drivers to enable boost support after registering driverViresh Kumar
In some cases it wouldn't be known at time of driver registration, if the driver needs to support boost frequencies. For example, while getting boost information from DT with opp-v2 bindings, we need to parse the bindings for all the CPUs to know if turbo/boost OPPs are supported or not. One way out to do that efficiently is to delay supporting boost mode (i.e. creating /sys/devices/system/cpu/cpufreq/boost file), until the time OPP bindings are parsed. At that point, the driver can enable boost support. This can be done at ->init(), where the frequency table is created. To do that, the driver requires few APIs from cpufreq core that let him do this. This patch provides these APIs. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-08-05bus: subsys: update return type of ->remove_dev() to voidViresh Kumar
Its return value is not used by the subsys core and nothing meaningful can be done with it, even if we want to use it. The subsys device is anyway getting removed. Update prototype of ->remove_dev() to make its return type as void. Fix all usage sites as well. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-31cpufreq: Correct a freq check in cpufreq_set_policy()Pan Xinhui
This check was originally added by commit 9c9a43ed2734 ("[CPUFREQ] return error when failing to set minfreq").It attempt to return an error on obviously incorrect limits when we echo xxx >.../scaling_max,min_freq Actually we just need check if new_policy->min > new_policy->max. Because at least one of max/min is copied from cpufreq_get_policy(). For example, when we echo xxx > .../scaling_min_freq, new_policy is copied from policy in cpufreq_get_policy. new_policy->max is same with policy->max. new_policy->min is set to a new value. Let me explain it in deduction method, first statement in if (): new_policy->min > policy->max policy->max == new_policy->max ==> new_policy->min > new_policy->max second statement in if(): new_policy->max < policy->min policy->max < policy->min ==>new_policy->min > new_policy->max (induction method) So we have proved that we only need check if new_policy->min > new_policy->max. After apply this patch, we can also modify ->min and ->max at same time if new freq range is very much different from current freq range. For example, if current freq range is 480000-960000, then we want to set this range to 1120000-2240000, we would fail in the past because new_policy->min > policy->max. As long as the cpufreq range is valid, we has no reason to reject the user. So correct the check to avoid such case. Signed-off-by: Pan Xinhui <xinhuix.pan@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-07-31cpufreq: Lock CPU online/offline in cpufreq_register_driver()Rafael J. Wysocki
To protect against races with concurrent CPU online/offline, call get_online_cpus() before registering a cpufreq driver. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2015-07-31cpufreq: Replace recover_policy with new_policy in cpufreq_online()Rafael J. Wysocki
The recover_policy is unsed in cpufreq_online() to indicate whether a new policy object is created or an existing one is reinitialized. The "recover" part of the name is slightly confusing (it should be "reinitialization" rather than "recovery") and the logical not (!) operator is applied to it in almost all of the checks it is used in, so replace that variable with a new one called "new_policy" that will be true in the case of a new policy creation. While at it, drop one of the labels that is jumped to from only one spot. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2015-07-31cpufreq: Separate CPU device registration from CPU onlineRafael J. Wysocki
To separate the CPU online interface from the CPU device registration, split cpufreq_online() out of cpufreq_add_dev() and make cpufreq_cpu_callback() call the former, while cpufreq_add_dev() itself will only be used as the CPU device addition subsystem interface callback. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Suggested-by: Russell King <linux@arm.linux.org.uk> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2015-07-28cpufreq: Pass CPU number to cpufreq_policy_alloc()Rafael J. Wysocki
Change cpufreq_policy_alloc() to take a CPU number instead of a CPU device pointer as its argument, as it is the only function called by cpufreq_add_dev() taking a device pointer argument at this point. That will allow us to split the CPU online part from cpufreq_add_dev() more cleanly going forward. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2015-07-28cpufreq: Do not update related_cpus on every policy activationRafael J. Wysocki
The related_cpus mask includes CPUs whose cpufreq_cpu_data per-CPU pointers have been set the the given policy. Since those pointers are only set at the policy creation time and unset when the policy is deleted, the related_cpus should not be updated between those two operations. For this reason, avoid updating it whenever the first of the "related" CPUs goes online. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2015-07-28cpufreq: Drop unused dev argument from two functionsRafael J. Wysocki
The dev argument of cpufreq_add_policy_cpu() and cpufreq_add_dev_interface() is not used by any of them, so drop it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2015-07-28cpufreq: Drop unnecessary label from cpufreq_add_dev()Rafael J. Wysocki
The leftover out_release_rwsem label in cpufreq_add_dev() is not necessary any more and confusing, so drop it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2015-07-28cpufreq: Drop cpufreq_policy_restore()Rafael J. Wysocki
Notice that when cpufreq_policy_restore() is called, its per-CPU cpufreq_cpu_data variable has been already dereferenced and if that variable is not NULL, the policy local pointer in cpufreq_add_dev() contains its value. Therefore it is not necessary to dereference it again and the policy pointer can be used directly. Moreover, if that pointer is not NULL, the policy is inactive (or the previous check would have made us return from cpufreq_add_dev()) so the restoration code from cpufreq_policy_restore() can be moved to that point in cpufreq_add_dev(). Do that and drop cpufreq_policy_restore(). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2015-07-28cpufreq: Rework two functions related to CPU offlineRafael J. Wysocki
Since __cpufreq_remove_dev_prepare() and __cpufreq_remove_dev_finish() are about CPU offline rather than about CPU removal, rename them to cpufreq_offline_prepare() and cpufreq_offline_finish(), respectively. Also change their argument from a struct device pointer to a CPU number, because they use the CPU number only internally anyway and make them void as their return values are ignored. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2015-07-28Merge back earlier cpufreq material for v4.3.Rafael J. Wysocki
2015-07-28cpufreq: Avoid attempts to create duplicate symbolic linksRafael J. Wysocki
After commit 87549141d516 (cpufreq: Stop migrating sysfs files on hotplug) there is a problem with CPUs that share cpufreq policy objects with other CPUs and are initially offline. Say CPU1 shares a policy with CPU0 which is online and is registered first. As part of the registration process, cpufreq_add_dev() is called for it. It creates the policy object and a symbolic link to it from the CPU1's sysfs directory. If CPU1 is registered subsequently and it is offline at that time, cpufreq_add_dev() will attempt to create a symbolic link to the policy object for it, but that link is present already, so a warning about that will be triggered. To avoid that warning, make cpufreq use an additional CPU mask containing related CPUs that are actually present for each policy object. That mask is initialized when the policy object is populated after its creation (for the first online CPU using it) and it includes CPUs from the "policy CPUs" mask returned by the cpufreq driver's ->init() callback that are physically present at that time. Symbolic links to the policy are created only for the CPUs in that mask. If cpufreq_add_dev() is invoked for an offline CPU, it checks the new mask and only creates the symlink if the CPU was not in it (the CPU is added to the mask at the same time). In turn, cpufreq_remove_dev() drops the given CPU from the new mask, removes its symlink to the policy object and returns, unless it is the CPU owning the policy object. In that case, the policy object is moved to a new CPU's sysfs directory or deleted if the CPU being removed was the last user of the policy. While at it, notice that cpufreq_remove_dev() can't fail, because its return value is ignored, so make it ignore return values from __cpufreq_remove_dev_prepare() and __cpufreq_remove_dev_finish() and prevent these functions from aborting on errors returned by __cpufreq_governor(). Also drop the now unused sif argument from them. Fixes: 87549141d516 (cpufreq: Stop migrating sysfs files on hotplug) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reported-and-tested-by: Russell King <linux@arm.linux.org.uk> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2015-07-25cpufreq: Remove cpufreq_rwsemSebastian Andrzej Siewior
cpufreq_rwsem was introduced in commit 6eed9404ab3c4 ("cpufreq: Use rwsem for protecting critical sections) in order to replace try_module_get() on the cpu-freq driver. That try_module_get() worked well until the refcount was so heavily used that module removal became more or less impossible. Though when looking at the various (undocumented) protection mechanisms in that code, the randomly sprinkeled around cpufreq_rwsem locking sites are superfluous. The policy, which is acquired in cpufreq_cpu_get() and released in cpufreq_cpu_put() is sufficiently protected already. cpufreq_cpu_get(cpu) /* Protects against concurrent driver removal */ read_lock_irqsave(&cpufreq_driver_lock, flags); policy = per_cpu(cpufreq_cpu_data, cpu); kobject_get(&policy->kobj); read_unlock_irqrestore(&cpufreq_driver_lock, flags); The reference on the policy serializes versus module unload already: cpufreq_unregister_driver() subsys_interface_unregister() __cpufreq_remove_dev_finish() per_cpu(cpufreq_cpu_data) = NULL; cpufreq_policy_put_kobj() If there is a reference held on the policy, i.e. obtained prior to the unregister call, then cpufreq_policy_put_kobj() will wait until that reference is dropped. So once subsys_interface_unregister() returns there is no policy pointer in flight and no new reference can be obtained. So that rwsem protection is useless. The other usage of cpufreq_rwsem in show()/store() of the sysfs interface is redundant as well because sysfs already does the proper kobject_get()/put() pairs. That leaves CPU hotplug versus module removal. The current down_write() around the write_lock() in cpufreq_unregister_driver() is silly at best as it protects actually nothing. The trivial solution to this is to prevent hotplug across cpufreq_unregister_driver completely. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-07-21cpufreq: propagate errors returned from __cpufreq_governor()Viresh Kumar
Return codes aren't honored properly in cpufreq_set_policy(). This can lead to two problems: - wrong errors propagated to sysfs - we try to do next state-change even if the previous one failed cpufreq_governor_dbs() now returns proper errors on all invalid state-transition requests and this code should honor that. Reviewed-and-tested-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-07-16cpufreq: Properly handle errors from cpufreq_init_policy()Viresh Kumar
cpufreq_init_policy() can fail, and we don't do anything except a call to ->exit() on that. The policy should be freed if this happens. Do it properly. Reported-and-tested-by: "Jon Medhurst (Tixy)" <tixy@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-07-16cpufreq: cpufreq_add_dev: name goto labels based on what they doViresh Kumar
These labels are are named in two ways normally: - Based on what caused to jump to such labels - Based on what we do under such labels We follow the first naming convention today and that leads to multiple labels for doing the same work. Fix it by switching to the second way of naming them. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-07-10cpufreq: Allow freq_table to be obtained for offline CPUsViresh Kumar
Users of freq table may want to access it for any CPU from policy->related_cpus mask. One such user is cpu-cooling layer. It gets a list of 'clip_cpus' (equivalent to policy->related_cpus) during registration and tries to get freq_table for the first CPU of this mask. If the CPU, for which it tries to fetch freq_table, is offline, cpufreq_frequency_get_table() fails. This happens because it relies on cpufreq_cpu_get_raw() for its functioning which returns policy only for online CPUs. The fix is to access the policy data structure for the given CPU directly (which also returns a valid policy for offline CPUs), but the policy itself has to be active (meaning that at least one CPU using it is online) for the frequency table to be returned. Because we will be using 'cpufreq_cpu_data' now, which is internal to the cpufreq core, move cpufreq_frequency_get_table() to cpufreq.c. Reported-and-tested-by: Pi-Cheng Chen <pi-cheng.chen@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-07-10cpufreq: Initialize the governor again while restoring policyViresh Kumar
When all CPUs of a policy are hot-unplugged, we EXIT the governor but don't mark policy->governor as NULL. This was done in order to keep last used governor's information intact in sysfs, while the CPUs are offline. But we also need to clear policy->governor when restoring the policy. Because policy->governor still points to the last governor while policy is restored, following sequence of event happens: - cpufreq_init_policy() called while restoring policy - find_governor() matches last_governor string for present governors and returns last used governor's pointer, say ondemand. policy->governor already has the same address, unless the governor was removed in between. - cpufreq_set_policy() is called with both old/new policies governor set as ondemand. - Because governors matched, we skip governor initialization and return after calling __cpufreq_governor(CPUFREQ_GOV_LIMITS). Because the governor wasn't initialized for this policy, it returned -EBUSY. - cpufreq_init_policy() exits the policy on this error, but doesn't destroy it properly (should be fixed separately). - And so we enter a scenario where the policy isn't completely initialized but used. Fix this by setting policy->governor to NULL while restoring the policy. Reported-and-tested-by: Pi-Cheng Chen <pi-cheng.chen@linaro.org> Reported-and-tested-by: "Jon Medhurst (Tixy)" <tixy@linaro.org> Reported-and-tested-by: Steven Rostedt <rostedt@goodmis.org> Fixes: 18bf3a124ef8 (cpufreq: Mark policy->governor = NULL for inactive policies) Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-06-11cpufreq: Remove cpufreq_update_policy()Viresh Kumar
cpufreq_update_policy() was kept as a separate routine earlier as it was handling migration of sysfs directories, which isn't the case anymore. It is only updating policy->cpu now and is called by a single caller. The WARN_ON() isn't really required anymore, as we are just updating the cpu now, not moving the sysfs directories. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>