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path: root/drivers/cpufreq/cpufreq_stats.c
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2023-10-24cpufreq: stats: Fix buffer overflow detection in trans_stats()Christian Marangi
Commit 3c0897c180c6 ("cpufreq: Use scnprintf() for avoiding potential buffer overflow") switched from snprintf to the more secure scnprintf but never updated the exit condition for PAGE_SIZE. As the commit say and as scnprintf document, what scnprintf returns what is actually written not counting the '\0' end char. This results in the case of len exceeding the size, len set to PAGE_SIZE - 1, as it can be written at max PAGE_SIZE - 1 (as '\0' is not counted) Because of len is never set to PAGE_SIZE, the function never break early, never prints the warning and never return -EFBIG. Fix this by changing the condition to PAGE_SIZE - 1 to correctly trigger the error. Cc: 5.10+ <stable@vger.kernel.org> # 5.10+ Fixes: 3c0897c180c6 ("cpufreq: Use scnprintf() for avoiding potential buffer overflow") Signed-off-by: Christian Marangi <ansuelsmth@gmail.com> [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-08-21cpufreq: stats: Improve the performance of cpufreq_stats_create_table()Liao Chang
In the worst case, the freq_table of policy data is not sorted and contains duplicate frequencies, this means that it needs to iterate through the entire freq_table of policy to ensure each frequency is unique in the freq_table of stats data, this has a time complexity of O(N^2), where N is the number of frequencies in the freq_table of policy. However, if the policy.freq_table is already sorted and contains no duplicate frequencies, it can reduce the time complexity of creating stats.freq_table to O(N), the 'freq_table_sorted' field of policy data can be used to indicate whether the policy.freq_table is sorted. Signed-off-by: Liao Chang <liaochang1@huawei.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Dhruva Gole <d-gole@ti.com> [ rjw: Fix typo in changelog, remove redundant parens ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-12-06cpufreq: stats: Convert to use sysfs_emit_at() APIye xingchen
Follow the advice of the Documentation/filesystems/sysfs.rst and show() should only use sysfs_emit() or sysfs_emit_at() when formatting the value to be returned to user space. Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-06-07cpufreq: stats: Clean up local variable in cpufreq_stats_create_table()Shaokun Zhang
Local variable 'count' will be initialized and 'ret' is also not required, so remove the redundant initialization and get rid of 'ret'. Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-12-11cpufreq: stats: Use local_clock() instead of jiffiesViresh Kumar
local_clock() has better precision and accuracy as compared to jiffies, lets use it for time management in cpufreq stats. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-10-12cpufreq: stats: Fix string format specifier mismatchViresh Kumar
Fix following warning: drivers/cpufreq/cpufreq_stats.c:63:10: warning: %d in format string (no. 1) requires 'int' but the argument type is 'unsigned int' Fixes: 40c3bd4cfa6f ("cpufreq: stats: Defer stats update to cpufreq_stats_record_transition()") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-10-07cpufreq: stats: Add memory barrier to store_reset()Rafael J. Wysocki
There is nothing to prevent the CPU or the compiler from reordering the writes to stats->reset_time and stats->reset_pending in store_reset(), in which case the readers of stats->reset_time may see a stale value. Moreover, on 32-bit arches the write to reset_time cannot be completed in one go, so the readers of it may see a partially updated value in that case. To prevent that from happening, add a write memory barrier between the writes to stats->reset_time and stats->reset_pending in store_reset() and corresponding read memory barrier in the readers of stats->reset_time. Fixes: 40c3bd4cfa6f ("cpufreq: stats: Defer stats update to cpufreq_stats_record_transition()") Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-10-05cpufreq: stats: Enable stats for fast-switch as wellViresh Kumar
Now that all the blockers are gone for enabling stats in fast-switching case, enable it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-10-05cpufreq: stats: Mark few conditionals with unlikely()Viresh Kumar
Since this will be part of the scheduler's hotpath in some cases, use unlikely() for few of the obvious conditionals. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-10-05cpufreq: stats: Remove lockingViresh Kumar
The locking isn't required anymore as stats can get updated only from one place at a time. Remove it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-10-05cpufreq: stats: Defer stats update to cpufreq_stats_record_transition()Viresh Kumar
In order to prepare for lock-less stats update, add support to defer any updates to it until cpufreq_stats_record_transition() is called. The stats were updated from two places earlier: - show_time_in_state(): This can be easily deferred, all we need is to calculate the delta duration again in this routine to show the current state's time-in-state. - store_reset(): This is a bit tricky as we need to clear the stats here and avoid races with simultaneous call to cpufreq_stats_record_transition(). Fix that by deferring the reset of the stats (within the code) to the next call to cpufreq_stats_record_transition(), but since we need to keep showing the right stats until that time, we capture the reset time and account for the time since last time reset was called until the time cpufreq_stats_record_transition() update the stats. User space will continue seeing the stats correctly, everything will be 0 after the stats are reset, apart from the time-in-state of the current state, until the time a frequency switch happens. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Minor changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-03-14cpufreq: Use scnprintf() for avoiding potential buffer overflowTakashi Iwai
Since snprintf() returns the would-be-output size instead of the actual output size, the succeeding calls may go beyond the given buffer limit. Fix it by replacing with scnprintf(). Signed-off-by: Takashi Iwai <tiwai@suse.de> 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 Gleixner
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>
2019-04-09cpufreq: stats: Use lock by stat to replace global spin lockKyle Lin
Stats is updated by each policy, using the lock by stat can reduce the contention. Signed-off-by: Kyle Lin <linkyle0915@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-02-01cpufreq: stats: Fix concurrency issues while resetting statsViresh Kumar
It is possible for cpufreq_stats_clear_table() and cpufreq_stats_record_transition() to get called concurrently and they will try to update same variables simultaneously and may lead to corruption of data. Prevent that with the help of existing spinlock. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-02-01cpufreq: stats: Declare freq-attr right after their callbacksViresh Kumar
Freq attribute for "trans_table" is defined right after its callback (without any blank line between them), but the others are defined separately later on. Keep this consistent and define all attributes right after their callbacks. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-01-05cpufreq: stats: Change return type of cpufreq_stats_update() as voidViresh Kumar
It always returns 0 and none of its callers check its return value. Make it return void. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-11-08cpufreq: stats: Handle the case when trans_table goes beyond PAGE_SIZEGautham R. Shenoy
On platforms with large number of Pstates, the transition table, which is a NxN matrix, can overflow beyond the PAGE_SIZE boundary. This can be seen on POWER9 which has 100+ Pstates. As a result, each time the trans_table is read for any of the CPUs, we will get the following error. --------------------------------------------------- fill_read_buffer: show+0x0/0xa0 returned bad count --------------------------------------------------- This patch ensures that in case of an overflow, we print a warning once in the dmesg and return FILE TOO LARGE error for this and all subsequent accesses of trans_table. Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-07-14Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux Pull thermal management updates from Zhang Rui: - Improve thermal cpu_cooling interaction with cpufreq core. The cpu_cooling driver is designed to use CPU frequency scaling to avoid high thermal states for a platform. But it wasn't glued really well with cpufreq core. For example clipped-cpus is copied from the policy structure and its much better to use the policy->cpus (or related_cpus) fields directly as they may have got updated. Not that things were broken before this series, but they can be optimized a bit more. This series tries to improve interactions between cpufreq core and cpu_cooling driver and does some fixes/cleanups to the cpu_cooling driver. (Viresh Kumar) - A couple of fixes and cleanups in thermal core and imx, hisilicon, bcm_2835, int340x thermal drivers. (Arvind Yadav, Dan Carpenter, Sumeet Pawnikar, Srinivas Pandruvada, Willy WOLFF) * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux: (24 commits) thermal: bcm2835: fix an error code in probe() thermal: hisilicon: Handle return value of clk_prepare_enable thermal: imx: Handle return value of clk_prepare_enable thermal: int340x: check for sensor when PTYP is missing Thermal/int340x: Fix few typos and kernel-doc style thermal: fix source code documentation for parameters thermal: cpu_cooling: Replace kmalloc with kmalloc_array thermal: cpu_cooling: Rearrange struct cpufreq_cooling_device thermal: cpu_cooling: 'freq' can't be zero in cpufreq_state2power() thermal: cpu_cooling: don't store cpu_dev in cpufreq_cdev thermal: cpu_cooling: get_level() can't fail thermal: cpu_cooling: create structure for idle time stats thermal: cpu_cooling: merge frequency and power tables thermal: cpu_cooling: get rid of 'allowed_cpus' thermal: cpu_cooling: OPPs are registered for all CPUs thermal: cpu_cooling: store cpufreq policy cpufreq: create cpufreq_table_count_valid_entries() thermal: cpu_cooling: use cpufreq_policy to register cooling device thermal: cpu_cooling: get rid of a variable in cpufreq_set_cur_state() thermal: cpu_cooling: remove cpufreq_cooling_get_level() ...
2017-07-04cpufreq: cpufreq_stats: constify attribute_group structuresArvind Yadav
attribute_groups are not supposed to change at runtime. All functions working with attribute_groups provided by <linux/sysfs.h> work with const attribute_group. So mark the non-const structs as const. File size before: text data bss dec hex filename 1655 256 4 1915 77b drivers/cpufreq/cpufreq_stats.o File size After adding 'const': text data bss dec hex filename 1695 192 4 1891 763 drivers/cpufreq/cpufreq_stats.o Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-05-27cpufreq: create cpufreq_table_count_valid_entries()Viresh Kumar
We need such a routine at two places already, lets create one. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Tested-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2017-02-20Merge tag 'pm-4.11-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "The majority of changes go into the Operating Performance Points (OPP) framework and cpufreq this time, followed by devfreq and some scattered updates all over. The OPP changes are mostly related to switching over from RCU-based synchronization, that turned out to be overly complicated and problematic, to reference counting using krefs. In the cpufreq land there are core cleanups, documentation updates, a new driver for Broadcom BMIPS SoCs, a new cpufreq-dt sub-driver for TI SoCs that require special handling, ARM64 SoCs support for the qoriq driver, intel_pstate updates, powernv driver update and assorted fixes. The devfreq changes are mostly fixes related to the sysfs interface and some Exynos drivers updates. Apart from that, the cpuidle menu governor will support per-CPU PM QoS constraints for the wakeup latency now, some bugs in the wakeup IRQs framework are fixed, the generic power domains framework should handle asynchronous invocations of *noirq suspend/resume callbacks from now on, the analyze_suspend.py script is updated and there is a new tool for intel_pstate diagnostics. Specifics: - Operating Performance Points (OPP) framework fixes, cleanups and switch over from RCU-based synchronization to reference counting using krefs (Viresh Kumar, Wei Yongjun, Dave Gerlach) - cpufreq core cleanups and documentation updates (Viresh Kumar, Rafael Wysocki) - New cpufreq driver for Broadcom BMIPS SoCs (Markus Mayer) - New cpufreq-dt sub-driver for TI SoCs requiring special handling, like in the AM335x, AM437x, DRA7x, and AM57x families, along with new DT bindings for it (Dave Gerlach, Paul Gortmaker) - ARM64 SoCs support for the qoriq cpufreq driver (Tang Yuantian) - intel_pstate driver updates including a new sysfs knob to control the driver's operation mode and fixes related to the no_turbo sysfs knob and the hardware-managed P-states feature support (Rafael Wysocki, Srinivas Pandruvada) - New interface to export ultra-turbo frequencies for the powernv cpufreq driver (Shilpasri Bhat) - Assorted fixes for cpufreq drivers (Arnd Bergmann, Dan Carpenter, Wei Yongjun) - devfreq core fixes, mostly related to the sysfs interface exported by it (Chanwoo Choi, Chris Diamand) - Updates of the exynos-bus and exynos-ppmu devfreq drivers (Chanwoo Choi) - Device PM QoS extension to support CPUs and support for per-CPU wakeup (device resume) latency constraints in the cpuidle menu governor (Alex Shi) - Wakeup IRQs framework fixes (Grygorii Strashko) - Generic power domains framework update including a fix to make it handle asynchronous invocations of *noirq suspend/resume callbacks correctly (Ulf Hansson, Geert Uytterhoeven) - Assorted fixes and cleanups in the core suspend/hibernate code, PM QoS framework and x86 ACPI idle support code (Corentin Labbe, Geert Uytterhoeven, Geliang Tang, John Keeping, Nick Desaulniers) - Update of the analyze_suspend.py script is updated to version 4.5 offering multiple improvements (Todd Brandt) - New tool for intel_pstate diagnostics using the pstate_sample tracepoint (Doug Smythies)" * tag 'pm-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (85 commits) MAINTAINERS: cpufreq: add bmips-cpufreq.c PM / QoS: Fix memory leak on resume_latency.notifiers PM / Documentation: Spelling s/wrtie/write/ PM / sleep: Fix test_suspend after sleep state rework cpufreq: CPPC: add ACPI_PROCESSOR dependency cpufreq: make ti-cpufreq explicitly non-modular cpufreq: Do not clear real_cpus mask on policy init tools/power/x86: Debug utility for intel_pstate driver AnalyzeSuspend: fix drag and zoom bug in javascript PM / wakeirq: report a wakeup_event on dedicated wekup irq PM / wakeirq: Fix spurious wake-up events for dedicated wakeirqs PM / wakeirq: Enable dedicated wakeirq for suspend cpufreq: dt: Don't use generic platdev driver for ti-cpufreq platforms cpufreq: ti: Add cpufreq driver to determine available OPPs at runtime Documentation: dt: add bindings for ti-cpufreq PM / OPP: Expose _of_get_opp_desc_node as dev_pm_opp API cpufreq: qoriq: Don't look at clock implementation details cpufreq: qoriq: add ARM64 SoCs support PM / Domains: Provide dummy governors if CONFIG_PM_GENERIC_DOMAINS=n cpufreq: brcmstb-avs-cpufreq: remove unnecessary platform_set_drvdata() ...
2017-02-03cpufreq: Remove CONFIG_CPU_FREQ_STAT_DETAILS config optionViresh Kumar
This doesn't have any benefit apart from saving a small amount of memory when it is disabled. The ifdef hackery in the code makes it dirty unnecessarily. Clean it up by removing the Kconfig option completely. Few defconfigs are also updated and CONFIG_CPU_FREQ_STAT_DETAILS is replaced with CONFIG_CPU_FREQ_STAT now in them, as users wanted stats to be enabled. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> Acked-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-02-01sched/cputime: Convert kcpustat to nsecsFrederic Weisbecker
Kernel CPU stats are stored in cputime_t which is an architecture defined type, and hence a bit opaque and requiring accessors and mutators for any operation. Converting them to nsecs simplifies the code and is one step toward the removal of cputime_t in the core code. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1485832191-26889-4-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-11cpufreq: stats: New sysfs attribute for clearing statisticsMarkus Mayer
Allow CPUfreq statistics to be cleared by writing anything to /sys/.../cpufreq/stats/reset. Signed-off-by: Markus Mayer <mmayer@broadcom.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-09cpufreq: Remove cpufreq_frequency_get_table()Viresh Kumar
Most of the callers of cpufreq_frequency_get_table() already have the pointer to a valid 'policy' structure and they don't really need to go through the per-cpu variable first and then a check to validate the frequency, in order to find the freq-table for the policy. Directly use the policy->freq_table field instead for them. Only one user of that API is left after above changes, cpu_cooling.c and it accesses the freq_table in a racy way as the policy can get freed in between. Fix it by using cpufreq_cpu_get() properly. Since there are no more users of cpufreq_frequency_get_table() left, get rid of it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Javi Merino <javi.merino@arm.com> (cpu_cooling.c) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-02cpufreq: stats: Make the stats code non-modularRafael J. Wysocki
The modularity of cpufreq_stats is quite problematic. First off, the usage of policy notifiers for the initialization and cleanup in the cpufreq_stats module is inherently racy with respect to CPU offline/online and the initialization and cleanup of the cpufreq driver. Second, fast frequency switching (used by the schedutil governor) cannot be enabled if any transition notifiers are registered, so if the cpufreq_stats module (that registers a transition notifier for updating transition statistics) is loaded, the schedutil governor cannot use fast frequency switching. On the other hand, allowing cpufreq_stats to be built as a module doesn't really add much value. Arguably, there's not much reason for that code to be modular at all. For the above reasons, make the cpufreq stats code non-modular, modify the core to invoke functions provided by that code directly and drop the notifiers from it. Make the stats sysfs attributes appear empty if fast frequency switching is enabled as the statistics will not be updated in that case anyway (and returning -EBUSY from those attributes breaks powertop). While at it, clean up Kconfig help for the CPU_FREQ_STAT and CPU_FREQ_STAT_DETAILS options. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2015-01-23cpufreq: stats: drop unnecessary lockingViresh Kumar
There is no possibility of any race on updating last_index, trans_table or total_trans as these are updated only by cpufreq_stat_notifier_trans() which will be called sequentially. The only place where locking is still relevant is: cpufreq_stats_update(), which updates time_in_state and last_time. This can be called by two thread in parallel, that may result in races. The two threads being: - sysfs read of time_in_state - and frequency transition that calls cpufreq_stat_notifier_trans(). Remove locking from the first case mentioned above. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-23cpufreq: stats: don't update stats on false notifiersViresh Kumar
We need to call cpufreq_stats_update() to update 'time_in_state' for the last frequency. This is achieved by calling it from cpufreq_stat_notifier_trans(), which is called after frequency transition. But if we detect that the cpu's frequency haven't really changed and its a false POSTCHANGE notification, we don't really need to update time_in_state. It wouldn't cause any harm in calling cpufreq_stats_update() but we can avoid calling it here and call it when the frequency really changes. The result will be the same but more efficient. Reviewed-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-23cpufreq: stats: don't update stats from show_trans_table()Viresh Kumar
cpufreq_stats_update() updates time_in_state and nothing else. It should ideally be updated only in two cases: - User requested for the current value of time_in_state. - We have switched states and so need to update time for the last state. Currently, we are also doing this while user asks for the transition table of frequencies. It wouldn't do any harm, but no good as well. Its useless here. Remove it. Reviewed-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-23cpufreq: stats: time_in_state can't be NULL in cpufreq_stats_update()Viresh Kumar
'time_in_state' can't be NULL if 'stats' is valid. These are allocated together and only if time_in_state is allocated successfully, we update policy->stats. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-23cpufreq: stats: create sysfs group once we are readyViresh Kumar
Userspace is free to read value of any file from cpufreq/stats directory once they are created. __cpufreq_stats_create_table() is creating the sysfs files first and then allocating resources for them. Though it would be quite difficult to trigger the racy situation here, but for the sake of keeping sensible code lets create sysfs entries only after we are ready to go. This also does some makeup to the routine to make it look better. Reviewed-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-23cpufreq: stats: drop 'cpu' field of struct cpufreq_statsViresh Kumar
'cpu' field of struct cpufreq_stats isn't used anymore and so can be dropped. This change makes cpufreq_stats_update_policy_cpu() empty and so that is removed as well. Reviewed-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-23cpufreq: stats: rename 'struct cpufreq_stats' objects as 'stats'Viresh Kumar
Currently we name objects of 'struct cpufreq_stats' as 'stat' and 'stats'. Use 'stats' to make it consistent. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-23cpufreq: stats: get rid of per-cpu cpufreq_stats_tableViresh Kumar
All CPUs sharing a cpufreq policy share stats too. For this reason, add a stats pointer to struct cpufreq_policy and drop per-CPU variable cpufreq_stats_table used for accessing cpufreq stats so as to reduce code complexity. Reviewed-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-23cpufreq: stats: pass 'stat' to cpufreq_stats_update()Viresh Kumar
It is better to pass a struct cpufreq_stats pointer to cpufreq_stats_update() instead of a CPU number, because that's all it needs. Even if we pass a cpu number to cpufreq_stats_update(), it reads the per-cpu variable to get 'stats' out of it. So we are doing these operations unnecessarily: - First getting the cpu number to pass to cpufreq_stats_update(), stat->cpu. - And then getting stats from the cpu, per_cpu(cpufreq_stats_table, cpu). Reviewed-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-23cpufreq: stats: don't check for freq table while freeing statsViresh Kumar
While we allocate stats, we do need to check if freq-table is present or not as we need to use it then. But while freeing stats, all we need to know is if stats holds a valid pointer value. There is no use of testing if cpufreq table is present or not. Don't check it. Reviewed-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-23cpufreq: stats: initialize 'cur_time' on its definitionViresh Kumar
'cur_time' is defined in the first line and is then assigned a value in the next line. Initialize it while defining it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-23cpufreq: stats: remove unused cpufreq_stats_attributeViresh Kumar
It was never used, but is there since the first commit. Remove it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-23cpufreq: stats: return -EEXIST when stats are already allocatedViresh Kumar
__cpufreq_stats_create_table() is called from: - cpufreq notifier on creation of a new policy. Stats will always be NULL here. - cpufreq_stats_init() for all CPUs as cpufreq-stats might have been initialized after cpufreq driver. For any policy, 'stats' will be NULL for the first CPU only and will be valid for all other CPUs managed by the same policy. While we return for other CPUs, we don't return the right error value. It's not that we would fail with -EBUSY. But generally, this is what these return values mean: - EBUSY: we are busy right now, try again. And the retry attempt might be immediate. - EEXIST: We already have what you are trying to create and there is no need to create it again, and so no more tries are required. Reviewed-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-23cpufreq: stats: Improve module description stringViresh Kumar
The MODULE_DESCRIPTION() string is just too long and then is broken into multiple lines just to make checkpatch happy. Rewrite it to make it more precise. Reviewed-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-30cpufreq: Use cpufreq_for_each_* macros for frequency table iterationStratos Karafotis
The cpufreq core now supports the cpufreq_for_each_entry and cpufreq_for_each_valid_entry macros helpers for iteration over the cpufreq_frequency_table, so use them. It should have no functional changes. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-01Merge tag 'pm+acpi-3.15-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI and power management updates from Rafael Wysocki: "The majority of this material spent some time in linux-next, some of it even several weeks. There are a few relatively fresh commits in it, but they are mostly fixes and simple cleanups. ACPI took the lead this time, both in terms of the number of commits and the number of modified lines of code, cpufreq follows and there are a few changes in the PM core and in cpuidle too. A new feature that already got some LWN.net's attention is the device PM QoS extension allowing latency tolerance requirements to be propagated from leaf devices to their ancestors with hardware interfaces for specifying latency tolerance. That should help systems with hardware-driven power management to avoid going too far with it in cases when there are latency tolerance constraints. There also are some significant changes in the ACPI core related to the way in which hotplug notifications are handled. They affect PCI hotplug (ACPIPHP) and the ACPI dock station code too. The bottom line is that all those notification now go through the root notify handler and are propagated to the interested subsystems by means of callbacks instead of having to install a notify handler for each device object that we can potentially get hotplug notifications for. In addition to that ACPICA will now advertise "Windows 2013" compatibility for _OSI, because some systems out there don't work correctly if that is not done (some of them don't even boot). On the system suspend side of things, all of the device suspend and resume callbacks, except for ->prepare() and ->complete(), are now going to be executed asynchronously as that turns out to speed up system suspend and resume on some platforms quite significantly and we have a few more optimizations in that area. Apart from that, there are some new device IDs and fixes and cleanups all over. In particular, the system suspend and resume handling by cpufreq should be improved and the cpuidle menu governor should be a bit more robust now. Specifics: - Device PM QoS support for latency tolerance constraints on systems with hardware interfaces allowing such constraints to be specified. That is necessary to prevent hardware-driven power management from becoming overly aggressive on some systems and to prevent power management features leading to excessive latencies from being used in some cases. - Consolidation of the handling of ACPI hotplug notifications for device objects. This causes all device hotplug notifications to go through the root notify handler (that was executed for all of them anyway before) that propagates them to individual subsystems, if necessary, by executing callbacks provided by those subsystems (those callbacks are associated with struct acpi_device objects during device enumeration). As a result, the code in question becomes both smaller in size and more straightforward and all of those changes should not affect users. - ACPICA update, including fixes related to the handling of _PRT in cases when it is broken and the addition of "Windows 2013" to the list of supported "features" for _OSI (which is necessary to support systems that work incorrectly or don't even boot without it). Changes from Bob Moore and Lv Zheng. - Consolidation of ACPI _OST handling from Jiang Liu. - ACPI battery and AC fixes allowing unusual system configurations to be handled by that code from Alexander Mezin. - New device IDs for the ACPI LPSS driver from Chiau Ee Chew. - ACPI fan and thermal optimizations related to system suspend and resume from Aaron Lu. - Cleanups related to ACPI video from Jean Delvare. - Assorted ACPI fixes and cleanups from Al Stone, Hanjun Guo, Lan Tianyu, Paul Bolle, Tomasz Nowicki. - Intel RAPL (Running Average Power Limits) driver cleanups from Jacob Pan. - intel_pstate fixes and cleanups from Dirk Brandewie. - cpufreq fixes related to system suspend/resume handling from Viresh Kumar. - cpufreq core fixes and cleanups from Viresh Kumar, Stratos Karafotis, Saravana Kannan, Rashika Kheria, Joe Perches. - cpufreq drivers updates from Viresh Kumar, Zhuoyu Zhang, Rob Herring. - cpuidle fixes related to the menu governor from Tuukka Tikkanen. - cpuidle fix related to coupled CPUs handling from Paul Burton. - Asynchronous execution of all device suspend and resume callbacks, except for ->prepare and ->complete, during system suspend and resume from Chuansheng Liu. - Delayed resuming of runtime-suspended devices during system suspend for the PCI bus type and ACPI PM domain. - New set of PM helper routines to allow device runtime PM callbacks to be used during system suspend and resume more easily from Ulf Hansson. - Assorted fixes and cleanups in the PM core from Geert Uytterhoeven, Prabhakar Lad, Philipp Zabel, Rashika Kheria, Sebastian Capella. - devfreq fix from Saravana Kannan" * tag 'pm+acpi-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (162 commits) PM / devfreq: Rewrite devfreq_update_status() to fix multiple bugs PM / sleep: Correct whitespace errors in <linux/pm.h> intel_pstate: Set core to min P state during core offline cpufreq: Add stop CPU callback to cpufreq_driver interface cpufreq: Remove unnecessary braces cpufreq: Fix checkpatch errors and warnings cpufreq: powerpc: add cpufreq transition latency for FSL e500mc SoCs MAINTAINERS: Reorder maintainer addresses for PM and ACPI PM / Runtime: Update runtime_idle() documentation for return value meaning video / output: Drop display output class support fujitsu-laptop: Drop unneeded include acer-wmi: Stop selecting VIDEO_OUTPUT_CONTROL ACPI / gpu / drm: Stop selecting VIDEO_OUTPUT_CONTROL ACPI / video: fix ACPI_VIDEO dependencies cpufreq: remove unused notifier: CPUFREQ_{SUSPENDCHANGE|RESUMECHANGE} cpufreq: Do not allow ->setpolicy drivers to provide ->target cpufreq: arm_big_little: set 'physical_cluster' for each CPU cpufreq: arm_big_little: make vexpress driver depend on bL core driver ACPI / button: Add ACPI Button event via netlink routine ACPI: Remove duplicate definitions of PREFIX ...
2014-03-13cputime: Default implementation of nsecs -> cputime conversionFrederic Weisbecker
The architectures that override cputime_t (s390, ppc) don't provide any version of nsecs_to_cputime(). Indeed this cputime_t implementation by backend only happens when CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y under which the core code doesn't make any use of nsecs_to_cputime(). At least for now. We are going to make a broader use of it so lets provide a default version with a per usecs granularity. It should be good enough for most usecases. Cc: Ingo Molnar <mingo@kernel.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2014-03-02cpufreq: stats: Refactor common code into __cpufreq_stats_create_table()Saravana Kannan
cpufreq_frequency_get_table() is called from all callers of __cpufreq_stats_create_table(). So, move it inside. Suggested-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Saravana Kannan <skannan@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-02cpufreq: stats: Fix error handling in __cpufreq_stats_create_table()Saravana Kannan
Remove sysfs group if __cpufreq_stats_create_table() fails after creating one. Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Saravana Kannan <skannan@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-02cpufreq: stats: Remove redundant cpufreq_cpu_get() callSaravana Kannan
__cpufreq_stats_create_table always gets pass the valid and real policy struct. So, there's no need to call cpufreq_cpu_get() to get the policy again. Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Saravana Kannan <skannan@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-01-17cpufreq: stats: create sysfs entries when cpufreq_stats is a moduleViresh Kumar
When cpufreq_stats is compiled in as a module, cpufreq driver would have already been registered. And so the CPUFREQ_CREATE_POLICY notifiers wouldn't be called for it. Hence no sysfs entries for stats. :( This patch calls cpufreq_stats_create_table() for each online CPU from cpufreq_stats_init() and so if policy is already created for CPUx then we will register sysfs stats for it. When its not compiled as module, we will return early as policy wouldn't be found for any of the CPUs. Acked-by: Nicolas Pitre <nico@linaro.org> Tested-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-01-17cpufreq: stats: free table and remove sysfs entry in a single routineViresh Kumar
We don't have code paths now where we need to do these two things separately, so it is better do them in a single routine. Just as they are allocated in a single routine. Acked-by: Nicolas Pitre <nico@linaro.org> Tested-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-01-17cpufreq: stats: remove hotplug notifiersViresh Kumar
Either CPUs are hot-unplugged or suspend/resume occurs, cpufreq core will send notifications to cpufreq-stats and stats structure and sysfs entries would be correctly handled.. And so we don't actually need hotcpu notifiers in cpufreq-stats anymore. We were only handling cpu hot-unplug events here and that are already taken care of by POLICY notifiers. Acked-by: Nicolas Pitre <nico@linaro.org> Tested-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>