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path: root/include/linux/cpufreq.h
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2015-01-23cpufreq: remove CPUFREQ_UPDATE_POLICY_CPU notificationsViresh Kumar
CPUFREQ_UPDATE_POLICY_CPU notifications were used only from cpufreq-stats which doesn't use it anymore. Remove them. This also decrements values of other notification macros defined after CPUFREQ_UPDATE_POLICY_CPU by 1 to remove gaps. Hopefully all users are using macro's instead of direct numbers and so they wouldn't break as macro values are changed now. 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: Remove (now) unused 'last_cpu' from struct cpufreq_policyViresh Kumar
'last_cpu' was used only from cpufreq-stats and isn't used anymore. Get rid of 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: 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>
2014-11-29cpufreq: Introduce ->ready() callback for cpufreq driversViresh Kumar
Currently there is no callback for cpufreq drivers which is called once the policy is ready to be used. There are some requirements where such a callback is required. One of them is registering a cooling device with the help of of_cpufreq_cooling_register(). This routine tries to get 'struct cpufreq_policy' for CPUs which isn't yet initialed at the time ->init() is called and so we face issues while registering the cooling device. Because we can't register cooling device from ->init(), we need a callback that is called after the policy is ready to be used and hence we introduce ->ready() callback. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Eduardo Valentin <edubezval@gmail.com> Tested-by: Eduardo Valentin <edubezval@gmail.com> Reviewed-by: Lukasz Majewski <l.majewski@samsung.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-29cpufreq: Fix formatting issues in 'struct cpufreq_driver'Viresh Kumar
Adding any new callback to 'struct cpufreq_driver' gives following checkpatch warning: WARNING: Unnecessary space before function pointer arguments + void (*ready) (struct cpufreq_policy *policy); This is because we have been using a tab spacing between function pointer name and its arguments and the new one tried to follow that. Though we normally don't try to fix every checkpatch warning, specially around formatting issues as that creates unnecessary noise over lists. But I thought we better fix this so that new additions don't generate these warnings plus it looks far better/symmetric now. So, remove these tab spacing issues in 'struct cpufreq_driver' only + fix alignment of all members. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Eduardo Valentin <edubezval@gmail.com> Tested-by: Eduardo Valentin <edubezval@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-10-21cpufreq: allow driver-specific dataThomas Petazzoni
This commit extends the cpufreq_driver structure with an additional 'void *driver_data' field that can be filled by the ->probe() function of a cpufreq driver to pass additional custom information to the driver itself. A new function called cpufreq_get_driver_data() is added to allow a cpufreq driver to retrieve those driver data, since they are typically needed from a cpufreq_policy->init() callback, which does not have access to the cpufreq_driver structure. This function call is similar to the existing cpufreq_get_current_driver() function call. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-09cpufreq: Add support for per-policy driver dataViresh Kumar
Drivers supporting multiple clusters or multiple 'struct cpufreq_policy' instances may need to keep per-policy data. If the core doesn't provide support for that, they might do it in the most unoptimized way: 'per-cpu' data. This patch adds another field in struct cpufreq_policy: 'driver_data'. It isn't accessed by core and is for driver's internal use only. Tested-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21cpufreq: Introduce new relation for freq selectionStratos Karafotis
Introduce CPUFREQ_RELATION_C for frequency selection. It selects the frequency with the minimum euclidean distance to target. In case of equal distance between 2 frequencies, it will select the greater frequency. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-18cpufreq: make table sentinel macros unsigned to match useBrian W Hart
Commit 5eeaf1f18973 (cpufreq: Fix build error on some platforms that use cpufreq_for_each_*) moved function cpufreq_next_valid() to a public header. Warnings are now generated when objects including that header are built with -Wsign-compare (as an out-of-tree module might be): .../include/linux/cpufreq.h: In function ‘cpufreq_next_valid’: .../include/linux/cpufreq.h:519:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while ((*pos)->frequency != CPUFREQ_TABLE_END) ^ .../include/linux/cpufreq.h:520:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if ((*pos)->frequency != CPUFREQ_ENTRY_INVALID) ^ Constants CPUFREQ_ENTRY_INVALID and CPUFREQ_TABLE_END are signed, but are used with unsigned member 'frequency' of cpufreq_frequency_table. Update the macro definitions to be explicitly unsigned to match their use. This also corrects potentially wrong behavior of clk_rate_table_iter() if unsigned long is wider than usigned int. Fixes: 5eeaf1f18973 (cpufreq: Fix build error on some platforms that use cpufreq_for_each_*) Signed-off-by: Brian W Hart <hartb@linux.vnet.ibm.com> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-05cpufreq: add support for intermediate (stable) frequenciesViresh Kumar
Douglas Anderson, recently pointed out an interesting problem due to which udelay() was expiring earlier than it should. While transitioning between frequencies few platforms may temporarily switch to a stable frequency, waiting for the main PLL to stabilize. For example: When we transition between very low frequencies on exynos, like between 200MHz and 300MHz, we may temporarily switch to a PLL running at 800MHz. No CPUFREQ notification is sent for that. That means there's a period of time when we're running at 800MHz but loops_per_jiffy is calibrated at between 200MHz and 300MHz. And so udelay behaves badly. To get this fixed in a generic way, introduce another set of callbacks get_intermediate() and target_intermediate(), only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION unset. get_intermediate() should return a stable intermediate frequency platform wants to switch to, and target_intermediate() should set CPU to that frequency, before jumping to the frequency corresponding to 'index'. Core will take care of sending notifications and driver doesn't have to handle them in target_intermediate() or target_index(). NOTE: ->target_index() should restore to policy->restore_freq in case of failures as core would send notifications for that. Tested-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-08cpufreq: Fix build error on some platforms that use cpufreq_for_each_*Stratos Karafotis
On platforms that use cpufreq_for_each_* macros, build fails if CONFIG_CPU_FREQ=n, e.g. ARM/shmobile/koelsch/non-multiplatform: drivers/built-in.o: In function `clk_round_parent': clkdev.c:(.text+0xcf168): undefined reference to `cpufreq_next_valid' drivers/built-in.o: In function `clk_rate_table_find': clkdev.c:(.text+0xcf820): undefined reference to `cpufreq_next_valid' make[3]: *** [vmlinux] Error 1 Fix this making cpufreq_next_valid function inline and move it to cpufreq.h. Fixes: 27e289dce297 (cpufreq: Introduce macros for cpufreq_frequency_table iteration) Reported-and-tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-07PM / OPP: Move cpufreq specific OPP functions out of generic OPP libraryNishanth Menon
CPUFreq specific helper functions for OPP (Operating Performance Points) now use generic OPP functions that allow CPUFreq to be be moved back into CPUFreq framework. This allows for independent modifications or future enhancements as needed isolated to just CPUFreq framework alone. Here, we just move relevant code and documentation to make this part of CPUFreq infrastructure. Cc: Kevin Hilman <khilman@deeprootsystems.com> Signed-off-by: Nishanth Menon <nm@ti.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-07cpufreq: Catch double invocations of cpufreq_freq_transition_begin/endSrivatsa S. Bhat
Some cpufreq drivers were redundantly invoking the _begin() and _end() APIs around frequency transitions, and this double invocation (one from the cpufreq core and the other from the cpufreq driver) used to result in a self-deadlock, leading to system hangs during boot. (The _begin() API makes contending callers wait until the previous invocation is complete. Hence, the cpufreq driver would end up waiting on itself!). Now all such drivers have been fixed, but debugging this issue was not very straight-forward (even lockdep didn't catch this). So let us add a debug infrastructure to the cpufreq core to catch such issues more easily in the future. We add a new field called 'transition_task' to the policy structure, to keep track of the task which is performing the frequency transition. Using this field, we make note of this task during _begin() and print a warning if we find a case where the same task is calling _begin() again, before completing the previous frequency transition using the corresponding _end(). We have left out ASYNC_NOTIFICATION drivers from this debug infrastructure for 2 reasons: 1. At the moment, we have no way to avoid a particular scenario where this debug infrastructure can emit false-positive warnings for such drivers. The scenario is depicted below: Task A Task B /* 1st freq transition */ Invoke _begin() { ... ... } Change the frequency /* 2nd freq transition */ Invoke _begin() { ... //waiting for B to ... //finish _end() for ... //the 1st transition ... | Got interrupt for successful ... | change of frequency (1st one). ... | ... | /* 1st freq transition */ ... | Invoke _end() { ... | ... ... V } ... ... } This scenario is actually deadlock-free because, once Task A changes the frequency, it is Task B's responsibility to invoke the corresponding _end() for the 1st frequency transition. Hence it is perfectly legal for Task A to go ahead and attempt another frequency transition in the meantime. (Of course it won't be able to proceed until Task B finishes the 1st _end(), but this doesn't cause a deadlock or a hang). The debug infrastructure cannot handle this scenario and will treat it as a deadlock and print a warning. To avoid this, we exclude such drivers from the purview of this code. 2. Luckily, we don't _need_ this infrastructure for ASYNC_NOTIFICATION drivers at all! The cpufreq core does not automatically invoke the _begin() and _end() APIs during frequency transitions in such drivers. Thus, the driver alone is responsible for invoking _begin()/_end() and hence there shouldn't be any conflicts which lead to double invocations. So, we can skip these drivers, since the probability that such drivers will hit this problem is extremely low, as outlined above. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-30cpufreq: Introduce macros for cpufreq_frequency_table iterationStratos Karafotis
Many cpufreq drivers need to iterate over the cpufreq_frequency_table for various tasks. This patch introduces two macros which can be used for iteration over cpufreq_frequency_table keeping a common coding style across drivers: - cpufreq_for_each_entry: iterate over each entry of the table - cpufreq_for_each_valid_entry: iterate over each entry that contains a valid frequency. 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>
2014-04-07cpufreq: create another field .flags in cpufreq_frequency_tableViresh Kumar
Currently cpufreq frequency table has two fields: frequency and driver_data. driver_data is only for drivers' internal use and cpufreq core shouldn't use it at all. But with the introduction of BOOST frequencies, this assumption was broken and we started using it as a flag instead. There are two problems due to this: - It is against the description of this field, as driver's data is used by the core now. - if drivers fill it with -3 for any frequency, then those frequencies are never considered by cpufreq core as it is exactly same as value of CPUFREQ_BOOST_FREQ, i.e. ~2. The best way to get this fixed is by creating another field flags which will be used for such flags. This patch does that. Along with that various drivers need modifications due to the change of struct cpufreq_frequency_table. Reviewed-by: Gautham R Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-26cpufreq: Make cpufreq_notify_transition & cpufreq_notify_post_transition staticViresh Kumar
cpufreq_notify_transition() and cpufreq_notify_post_transition() shouldn't be called directly by cpufreq drivers anymore and so these should be marked static. Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-26cpufreq: Make sure frequency transitions are serializedSrivatsa S. Bhat
Whenever we change the frequency of a CPU, we call the PRECHANGE and POSTCHANGE notifiers. They must be serialized, i.e. PRECHANGE and POSTCHANGE notifiers should strictly alternate, thereby preventing two different sets of PRECHANGE or POSTCHANGE notifiers from interleaving arbitrarily. The following examples illustrate why this is important: Scenario 1: ----------- A thread reading the value of cpuinfo_cur_freq, will call __cpufreq_cpu_get()->cpufreq_out_of_sync()->cpufreq_notify_transition() The ondemand governor can decide to change the frequency of the CPU at the same time and hence it can end up sending the notifications via ->target(). If the notifiers are not serialized, the following sequence can occur: - PRECHANGE Notification for freq A (from cpuinfo_cur_freq) - PRECHANGE Notification for freq B (from target()) - Freq changed by target() to B - POSTCHANGE Notification for freq B - POSTCHANGE Notification for freq A We can see from the above that the last POSTCHANGE Notification happens for freq A but the hardware is set to run at freq B. Where would we break then?: adjust_jiffies() in cpufreq.c & cpufreq_callback() in arch/arm/kernel/smp.c (which also adjusts the jiffies). All the loops_per_jiffy calculations will get messed up. Scenario 2: ----------- The governor calls __cpufreq_driver_target() to change the frequency. At the same time, if we change scaling_{min|max}_freq from sysfs, it will end up calling the governor's CPUFREQ_GOV_LIMITS notification, which will also call __cpufreq_driver_target(). And hence we end up issuing concurrent calls to ->target(). Typically, platforms have the following logic in their ->target() routines: (Eg: cpufreq-cpu0, omap, exynos, etc) A. If new freq is more than old: Increase voltage B. Change freq C. If new freq is less than old: decrease voltage Now, if the two concurrent calls to ->target() are X and Y, where X is trying to increase the freq and Y is trying to decrease it, we get the following race condition: X.A: voltage gets increased for larger freq Y.A: nothing happens Y.B: freq gets decreased Y.C: voltage gets decreased X.B: freq gets increased X.C: nothing happens Thus we can end up setting a freq which is not supported by the voltage we have set. That will probably make the clock to the CPU unstable and the system might not work properly anymore. This patch introduces a set of synchronization primitives to serialize frequency transitions, which are to be used as shown below: cpufreq_freq_transition_begin(); //Perform the frequency change cpufreq_freq_transition_end(); The _begin() call sends the PRECHANGE notification whereas the _end() call sends the POSTCHANGE notification. Also, all the necessary synchronization is handled within these calls. In particular, even drivers which set the ASYNC_NOTIFICATION flag can also use these APIs for performing frequency transitions (ie., you can call _begin() from one task, and call the corresponding _end() from a different task). The actual synchronization underneath is not that complicated: The key challenge is to allow drivers to begin the transition from one thread and end it in a completely different thread (this is to enable drivers that do asynchronous POSTCHANGE notification from bottom-halves, to also use the same interface). To achieve this, a 'transition_ongoing' flag, a 'transition_lock' spinlock and a wait-queue are added per-policy. The flag and the wait-queue are used in conjunction to create an "uninterrupted flow" from _begin() to _end(). The spinlock is used to ensure that only one such "flow" is in flight at any given time. Put together, this provides us all the necessary synchronization. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-20cpufreq: Add stop CPU callback to cpufreq_driver interfaceDirk Brandewie
This callback allows the driver to do clean up before the CPU is completely down and its state cannot be modified. This is used by the intel_pstate driver to reduce the requested P state prior to the core going away. This is required because the requested P state of the offline core is used to select the package P state. This effectively sets the floor package P state to the requested P state on the offline core. Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> [rjw: Minor modifications] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-19cpufreq: remove unused notifier: CPUFREQ_{SUSPENDCHANGE|RESUMECHANGE}Viresh Kumar
Two cpufreq notifiers CPUFREQ_RESUMECHANGE and CPUFREQ_SUSPENDCHANGE have not been used for some time, so remove them to clean up code a bit. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> [rjw: Changelog] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-12cpufreq: Remove cpufreq_generic_exit()Viresh Kumar
cpufreq_generic_exit() is empty now and can be deleted. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-12cpufreq: add 'freq_table' in struct cpufreq_policyViresh Kumar
freq table is not per CPU but per policy, so it makes more sense to keep it within struct cpufreq_policy instead of a per-cpu variable. This patch does it. Over that, there is no need to set policy->freq_table to NULL in ->exit(), as policy structure is going to be freed soon. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-06cpufreq: Implement cpufreq_generic_suspend()Viresh Kumar
Multiple platforms need to set CPUs to a particular frequency before suspending the system, so provide a common infrastructure for them. Those platforms only need to point their ->suspend callback pointers to the generic routine. Tested-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [rjw: Changelog] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-06cpufreq: suspend governors on system suspend/hibernateViresh Kumar
This patch adds cpufreq suspend/resume calls to dpm_{suspend|resume}() for handling suspend/resume of cpufreq governors. Lan Tianyu (Intel) & Jinhyuk Choi (Broadcom) found an issue where the tunables configuration for clusters/sockets with non-boot CPUs was lost after system suspend/resume, as we were notifying governors with CPUFREQ_GOV_POLICY_EXIT on removal of the last CPU for that policy which caused the tunables memory to be freed. This is fixed by preventing any governor operations from being carried out between the device suspend and device resume stages of system suspend and resume, respectively. We could have added these callbacks at dpm_{suspend|resume}_noirq() level, but there is an additional problem that the majority of I/O devices is already suspended at that point and if cpufreq drivers want to change the frequency before suspending, then that not be possible on some platforms (which depend on peripherals like i2c, regulators, etc). Reported-and-tested-by: Lan Tianyu <tianyu.lan@intel.com> Reported-by: Jinhyuk Choi <jinchoi@broadcom.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [rjw: Changelog] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-01-17cpufreq: Add boost frequency support in coreLukasz Majewski
This commit adds boost frequency support in cpufreq core (Hardware & Software). Some SoCs (like Exynos4 - e.g. 4x12) allow setting frequency above its normal operation limits. Such mode shall be only used for a short time. Overclocking (boost) support is essentially provided by platform dependent cpufreq driver. This commit unifies support for SW and HW (Intel) overclocking solutions in the core cpufreq driver. Previously the "boost" sysfs attribute was defined in the ACPI processor driver code. By default boost is disabled. One global attribute is available at: /sys/devices/system/cpu/cpufreq/boost. It only shows up when cpufreq driver supports overclocking. Under the hood frequencies dedicated for boosting are marked with a special flag (CPUFREQ_BOOST_FREQ) at driver's frequency table. It is the user's concern to enable/disable overclocking with a proper call to sysfs. The cpufreq_boost_trigger_state() function is defined non static on purpose. It is used later with thermal subsystem to provide automatic enable/disable of the BOOST feature. Signed-off-by: Lukasz Majewski <l.majewski@samsung.com> Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-01-17cpufreq: introduce cpufreq_generic_get() routineViresh Kumar
CPUFreq drivers that use clock frameworks interface,i.e. clk_get_rate(), to get CPUs clk rate, have similar sort of code used in most of them. This patch adds a generic ->get() which will do the same thing for them. All those drivers are required to now is to set .get to cpufreq_generic_get() and set their clk pointer in policy->clk during ->init(). Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> Acked-by: Shawn Guo <shawn.guo@linaro.org> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Shawn Guo <shawn.guo@linaro.org> Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-01-17cpufreq: stats: handle cpufreq_unregister_driver() and suspend/resume properlyViresh Kumar
There are several problems with cpufreq stats in the way it handles cpufreq_unregister_driver() and suspend/resume.. - We must not lose data collected so far when suspend/resume happens and so stats directories must not be removed/allocated during these operations, which is done currently. - cpufreq_stat has registered notifiers with both cpufreq and hotplug. It adds sysfs stats directory with a cpufreq notifier: CPUFREQ_NOTIFY and removes this directory with a notifier from hotplug core. In case cpufreq_unregister_driver() is called (on rmmod cpufreq driver), stats directories per cpu aren't removed as CPUs are still online. The only call cpufreq_stats gets is cpufreq_stats_update_policy_cpu() for all CPUs except the last of each policy. And pointer to stat information is stored in the entry for last CPU in the per-cpu cpufreq_stats_table. But policy structure would be freed inside cpufreq core and so that will result in memory leak inside cpufreq stats (as we are never freeing memory for stats). Now if we again insert the module cpufreq_register_driver() will be called and we will again allocate stats data and put it on for first CPU of every policy. In case we only have a single CPU per policy, we will return with a error from cpufreq_stats_create_table() due to this code: if (per_cpu(cpufreq_stats_table, cpu)) return -EBUSY; And so probably cpufreq stats directory would not show up anymore (as it was added inside last policies->kobj which doesn't exist anymore). I haven't tested it, though. Also the values in stats files wouldn't be refreshed as we are using the earlier stats structure. - CPUFREQ_NOTIFY is called from cpufreq_set_policy() which is called for scenarios where we don't really want cpufreq_stat_notifier_policy() to get called. For example whenever we are changing anything related to a policy: min/max/current freq, etc. cpufreq_set_policy() is called and so cpufreq stats is notified. Where we don't do any useful stuff other than simply returning with -EBUSY from cpufreq_stats_create_table(). And so this isn't the right notifier that cpufreq stats.. Due to all above reasons this patch does following changes: - Add new notifiers CPUFREQ_CREATE_POLICY and CPUFREQ_REMOVE_POLICY, which are only called when policy is created/destroyed. They aren't called for suspend/resume paths.. - Use these notifiers in cpufreq_stat_notifier_policy() to create/destory stats sysfs entries. And so cpufreq_unregister_driver() or suspend/resume shouldn't be a problem for cpufreq_stats. - Return early from cpufreq_stat_cpu_callback() for suspend/resume sequence, so that we don't free stats structure. 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>
2014-01-06cpufreq: Make sure CPU is running on a freq from freq-tableViresh Kumar
Sometimes boot loaders set CPU frequency to a value outside of frequency table present with cpufreq core. In such cases CPU might be unstable if it has to run on that frequency for long duration of time and so its better to set it to a frequency which is specified in freq-table. This also makes cpufreq stats inconsistent as cpufreq-stats would fail to register because current frequency of CPU isn't found in freq-table. Because we don't want this change to affect boot process badly, we go for the next freq which is >= policy->cur ('cur' must be set by now, otherwise we will end up setting freq to lowest of the table as 'cur' is initialized to zero). In case current frequency doesn't match any frequency from freq-table, we throw warnings to user, so that user can get this fixed in their bootloaders or freq-tables. Reported-by: Carlos Hernandez <ceh@ti.com> Reported-and-tested-by: Nishanth Menon <nm@ti.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-01-06cpufreq: Mark ARM drivers with CPUFREQ_NEED_INITIAL_FREQ_CHECK flagViresh Kumar
Sometimes boot loaders set CPU frequency to a value outside of frequency table present with cpufreq core. In such cases CPU might be unstable if it has to run on that frequency for long duration of time and so its better to set it to a frequency which is specified in frequency table. On some systems we can't really say what frequency we're running at the moment and so for these we shouldn't check if we are running at a frequency present in frequency table. And so we really can't force this for all the cpufreq drivers. Hence we are created another flag here: CPUFREQ_NEED_INITIAL_FREQ_CHECK that will be marked by platforms which want to go for this check at boot time. Initially this is done for all ARM platforms but others may follow if required. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-01-06cpufreq: Introduce cpufreq_notify_post_transition()Viresh Kumar
This introduces a new routine cpufreq_notify_post_transition() which can be used to send POSTCHANGE notification for new freq with or without both {PRE|POST}CHANGE notifications for last freq. This is useful at multiple places, especially for sending transition failure notifications. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-12-08Revert "cpufreq: suspend governors on system suspend/hibernate"Rafael J. Wysocki
Commit 5a87182aa21d (cpufreq: suspend governors on system suspend/hibernate) causes hibernation problems to happen on Bjørn Mork's and Paul Bolle's systems, so revert it. Fixes: 5a87182aa21d (cpufreq: suspend governors on system suspend/hibernate) Reported-by: Bjørn Mork <bjorn@mork.no> Reported-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-12-06Merge branches 'pm-cpuidle' and 'pm-cpufreq'Rafael J. Wysocki
* pm-cpuidle: cpuidle: Check for dev before deregistering it. intel_idle: Fixed C6 state on Avoton/Rangeley processors * pm-cpufreq: cpufreq: fix garbage kobjects on errors during suspend/resume cpufreq: suspend governors on system suspend/hibernate
2013-11-28cpufreq: suspend governors on system suspend/hibernateViresh Kumar
This patch adds cpufreq suspend/resume calls to dpm_{suspend|resume}_noirq() for handling suspend/resume of cpufreq governors. Lan Tianyu (Intel) & Jinhyuk Choi (Broadcom) found anr issue where tunables configuration for clusters/sockets with non-boot CPUs was getting lost after suspend/resume, as we were notifying governors with CPUFREQ_GOV_POLICY_EXIT on removal of the last cpu for that policy and so deallocating memory for tunables. This is fixed by this patch as we don't allow any operation on governors after device suspend and before device resume now. Reported-and-tested-by: Lan Tianyu <tianyu.lan@intel.com> Reported-by: Jinhyuk Choi <jinchoi@broadcom.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [rjw: Changelog, minor cleanups] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-11-15Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linuxLinus Torvalds
Pull drm updates from Dave Airlie: "This is a combo of -next and some -fixes that came in in the intervening time. Highlights: New drivers: ARM Armada driver for Marvell Armada 510 SOCs Intel: Broadwell initial support under a default off switch, Stereo/3D HDMI mode support Valleyview improvements Displayport improvements Haswell fixes initial mipi dsi panel support CRC support for debugging build with CONFIG_FB=n Radeon: enable DPM on a number of GPUs by default secondary GPU powerdown support enable HDMI audio by default Hawaii support Nouveau: dynamic pm code infrastructure reworked, does nothing major yet GK208 modesetting support MSI fixes, on by default again PMPEG improvements pageflipping fixes GMA500: minnowboard SDVO support VMware: misc fixes MSM: prime, plane and rendernodes support Tegra: rearchitected to put the drm driver into the drm subsystem. HDMI and gr2d support for tegra 114 SoC QXL: oops fix, and multi-head fixes DRM core: sysfs lifetime fixes client capability ioctl further cleanups to device midlayer more vblank timestamp fixes" * 'drm-next' of git://people.freedesktop.org/~airlied/linux: (789 commits) drm/nouveau: do not map evicted vram buffers in nouveau_bo_vma_add drm/nvc0-/gr: shift wrapping bug in nvc0_grctx_generate_r406800 drm/nouveau/pwr: fix missing mutex unlock in a failure path drm/nv40/therm: fix slowing down fan when pstate undefined drm/nv11-: synchronise flips to vblank, unless async flip requested drm/nvc0-: remove nasty fifo swmthd hack for flip completion method drm/nv10-: we no longer need to create nvsw object on user channels drm/nouveau: always queue flips relative to kernel channel activity drm/nouveau: there is no need to reserve/fence the new fb when flipping drm/nouveau: when bailing out of a pushbuf ioctl, do not remove previous fence drm/nouveau: allow nouveau_fence_ref() to be a noop drm/nvc8/mc: msi rearm is via the nvc0 method drm/ttm: Fix vma page_prot bit manipulation drm/vmwgfx: Fix a couple of compile / sparse warnings and errors drm/vmwgfx: Resource evict fixes drm/edid: compare actual vrefresh for all modes for quirks drm: shmob_drm: Convert to clk_prepare/unprepare drm/nouveau: fix 32-bit build drm/i915/opregion: fix build error on CONFIG_ACPI=n Revert "drm/radeon/audio: don't set speaker allocation on DCE4+" ...
2013-10-31cpufreq: distinguish drivers that do asynchronous notificationsViresh Kumar
There are few special cases like exynos5440 which doesn't send POSTCHANGE notification from their ->target() routine and call some kind of bottom halves for doing this work, work/tasklet/etc.. From which they finally send POSTCHANGE notification. Its better if we distinguish them from other cpufreq drivers in some way so that core can handle them specially. So this patch introduces another flag: CPUFREQ_ASYNC_NOTIFICATION, which will be set by such drivers. This also changes exynos5440-cpufreq.c and powernow-k8 in order to set this flag. Acked-by: Amit Daniel Kachhap <amit.daniel@samsung.com> Acked-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-25cpufreq: create per policy rwsem instead of per CPU cpu_policy_rwsemviresh kumar
We have per-CPU cpu_policy_rwsem for cpufreq core, but we never use all of them. We always use rwsem of policy->cpu and so we can actually make this rwsem per policy instead. This patch does this change. With this change other tricky situations are also avoided now, like which lock to take while we are changing policy->cpu, etc. Suggested-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Tested-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-25cpufreq: Implement light weight ->target_index() routineViresh Kumar
Currently, the prototype of cpufreq_drivers target routines is: int target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation); And most of the drivers call cpufreq_frequency_table_target() to get a valid index of their frequency table which is closest to the target_freq. And they don't use target_freq and relation after that. So, it makes sense to just do this work in cpufreq core before calling cpufreq_frequency_table_target() and simply pass index instead. But this can be done only with drivers which expose their frequency table with cpufreq core. For others we need to stick with the old prototype of target() until those drivers are converted to expose frequency tables. This patch implements the new light weight prototype for target_index() routine. It looks like this: int target_index(struct cpufreq_policy *policy, unsigned int index); CPUFreq core will call cpufreq_frequency_table_target() before calling this routine and pass index to it. Because CPUFreq core now requires to call routines present in freq_table.c CONFIG_CPU_FREQ_TABLE must be enabled all the time. This also marks target() interface as deprecated. So, that new drivers avoid using it. And Documentation is updated accordingly. It also converts existing .target() to newly defined light weight .target_index() routine for many driver. Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Russell King <linux@arm.linux.org.uk> Acked-by: David S. Miller <davem@davemloft.net> Tested-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>
2013-10-18cpufreq: Add dummy cpufreq_cpu_get/put for CONFIG_CPU_FREQ=nDaniel Vetter
The drm/i915 driver wants to adjust it's own power policies using the cpu policies as a guideline (we can implicitly boost the cpus through the gpus on some platforms). To avoid a dreaded select (since a depends will leave users wondering where where their driver has gone too) add dummy functions. Reported-by: kbuild test robot <fengguang.wu@intel.com> Cc: kbuild test robot <fengguang.wu@intel.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: cpufreq@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2013-10-16cpufreq: create cpufreq_generic_init() routineViresh Kumar
Many CPUFreq drivers for SMP system (where all cores share same clock lines), do similar stuff in their ->init() part. This patch creates a generic routine in cpufreq core which can be used by these so that we can remove some redundant code. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-16cpufreq: define generic .attr, .exit() and .verify() routinesViresh Kumar
Most of the CPUFreq drivers do similar things in .exit() and .verify() routines and .attr. So its better if we have generic routines for them which can be used by cpufreq drivers then. This patch introduces generic .attr, .exit() and .verify() cpufreq drivers. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-16cpufreq: add new routine cpufreq_verify_within_cpu_limits()Viresh Kumar
Most of the users of cpufreq_verify_within_limits() calls it for limiting with min/max from policy->cpuinfo. We can make that code simple by introducing another routine which will do this for them automatically. This patch adds another routine cpufreq_verify_within_cpu_limits() and updates others to use it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-16cpufreq: use cpufreq_driver->flags to mark CPUFREQ_HAVE_GOVERNOR_PER_POLICYViresh Kumar
Use cpufreq_driver->flags to mark CPUFREQ_HAVE_GOVERNOR_PER_POLICY instead of a separate field within cpufreq_driver. This will save some bytes of memory. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-16cpufreq: rewrite cpufreq_driver->flags using shift operatorViresh Kumar
Currently cpufreq_driver's flags are defined directly using 0x1, 0x2, 0x4, 0x8, etc.. As the list grows it becomes less readable.. Use bitwise shift operator << to generate these numbers for respective positions. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-30cpufreq: Add new helper cpufreq_table_validate_and_show()Viresh Kumar
Almost every cpufreq driver is required to validate its frequency table with: cpufreq_frequency_table_cpuinfo() and then expose it to cpufreq core with: cpufreq_frequency_table_get_attr(). This patch creates another helper routine cpufreq_table_validate_and_show() that will do both these steps in a single call and will return 0 for success, error otherwise. This also fixes potential bugs in cpufreq drivers where people have called cpufreq_frequency_table_get_attr() before calling cpufreq_frequency_table_cpuinfo(), as the later may fail. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-10Revert "cpufreq: make sure frequency transitions are serialized"Rafael J. Wysocki
Commit 7c30ed5 (cpufreq: make sure frequency transitions are serialized) attempted to serialize frequency transitions by adding checks to the CPUFREQ_PRECHANGE and CPUFREQ_POSTCHANGE notifications. However, it assumed that the notifications will always originate from the driver's .target() callback, but they also can be triggered by cpufreq_out_of_sync() and that leads to warnings like this on some systems: WARNING: CPU: 0 PID: 14543 at drivers/cpufreq/cpufreq.c:317 __cpufreq_notify_transition+0x238/0x260() In middle of another frequency transition accompanied by a call trace similar to this one: [<ffffffff81720daa>] dump_stack+0x46/0x58 [<ffffffff8106534c>] warn_slowpath_common+0x8c/0xc0 [<ffffffff815b8560>] ? acpi_cpufreq_target+0x320/0x320 [<ffffffff81065436>] warn_slowpath_fmt+0x46/0x50 [<ffffffff815b1ec8>] __cpufreq_notify_transition+0x238/0x260 [<ffffffff815b33be>] cpufreq_notify_transition+0x3e/0x70 [<ffffffff815b345d>] cpufreq_out_of_sync+0x6d/0xb0 [<ffffffff815b370c>] cpufreq_update_policy+0x10c/0x160 [<ffffffff815b3760>] ? cpufreq_update_policy+0x160/0x160 [<ffffffff81413813>] cpufreq_set_cur_state+0x8c/0xb5 [<ffffffff814138df>] processor_set_cur_state+0xa3/0xcf [<ffffffff8158e13c>] thermal_cdev_update+0x9c/0xb0 [<ffffffff8159046a>] step_wise_throttle+0x5a/0x90 [<ffffffff8158e21f>] handle_thermal_trip+0x4f/0x140 [<ffffffff8158e377>] thermal_zone_device_update+0x57/0xa0 [<ffffffff81415b36>] acpi_thermal_check+0x2e/0x30 [<ffffffff81415ca0>] acpi_thermal_notify+0x40/0xdc [<ffffffff813e7dbd>] acpi_device_notify+0x19/0x1b [<ffffffff813f8241>] acpi_ev_notify_dispatch+0x41/0x5c [<ffffffff813e3fbe>] acpi_os_execute_deferred+0x25/0x32 [<ffffffff81081060>] process_one_work+0x170/0x4a0 [<ffffffff81082121>] worker_thread+0x121/0x390 [<ffffffff81082000>] ? manage_workers.isra.20+0x170/0x170 [<ffffffff81088fe0>] kthread+0xc0/0xd0 [<ffffffff81088f20>] ? flush_kthread_worker+0xb0/0xb0 [<ffffffff8173582c>] ret_from_fork+0x7c/0xb0 [<ffffffff81088f20>] ? flush_kthread_worker+0xb0/0xb0 For this reason, revert commit 7c30ed5 along with the fix 266c13d (cpufreq: Fix serialization of frequency transitions) on top of it and we will revisit the serialization problem later. Reported-by: Alessandro Bono <alessandro.bono@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-10cpufreq: Remove temporary fix for race between CPU hotplug and sysfs-writesSrivatsa S. Bhat
Commit "cpufreq: serialize calls to __cpufreq_governor()" had been a temporary and partial solution to the race condition between writing to a cpufreq sysfs file and taking a CPU offline. Now that we have a proper and complete solution to that problem, remove the temporary fix. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-10cpufreq: serialize calls to __cpufreq_governor()Viresh Kumar
We can't take a big lock around __cpufreq_governor() as this causes recursive locking for some cases. But calls to this routine must be serialized for every policy. Otherwise we can see some unpredictable events. For example, consider following scenario: __cpufreq_remove_dev() __cpufreq_governor(policy, CPUFREQ_GOV_STOP); policy->governor->governor(policy, CPUFREQ_GOV_STOP); cpufreq_governor_dbs() case CPUFREQ_GOV_STOP: mutex_destroy(&cpu_cdbs->timer_mutex) cpu_cdbs->cur_policy = NULL; <PREEMPT> store() __cpufreq_set_policy() __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); policy->governor->governor(policy, CPUFREQ_GOV_LIMITS); case CPUFREQ_GOV_LIMITS: mutex_lock(&cpu_cdbs->timer_mutex); <-- Warning (destroyed mutex) if (policy->max < cpu_cdbs->cur_policy->cur) <- cur_policy == NULL And so store() will eventually result in a crash if cur_policy is NULL at this point. Introduce an additional variable which would guarantee serialization here. Reported-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-10cpufreq: Drop the owner field from struct cpufreq_driverViresh Kumar
We don't need to set .owner = THIS_MODULE any more in cpufreq drivers as this field isn't used any more by the cpufreq core. This patch removes it and updates all dependent drivers accordingly. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-10cpufreq: Store cpufreq policies in a listLukasz Majewski
Policies available in the cpufreq framework are now linked together. They are accessible via cpufreq_policy_list defined in the cpufreq core. [rjw: Fix from Yinghai Lu folded in] Signed-off-by: Lukasz Majewski <l.majewski@samsung.com> Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-07cpufreq: Give consistent names to cpufreq_policy objectsViresh Kumar
They are called policy, cur_policy, new_policy, data, etc. Just call them policy wherever possible. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-07cpufreq: Re-arrange declarations in cpufreq.hViresh Kumar
They are pretty much mixed up. Although generic headers are present, definitions/declarations are present outside of them too ... This patch just moves stuff up and down to make it look better and consistent. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>