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2016-03-09cpufreq: governor: Clean up load-related computationsRafael J. Wysocki
Clean up some load-related computations in dbs_check_cpu() and cpufreq_governor_start() to get rid of unnecessary operations and type casts and make the code easier to read. No functional changes. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09cpufreq: governor: Fix nice contribution computation in dbs_check_cpu()Rafael J. Wysocki
The contribution of the CPU nice time to the idle time in dbs_check_cpu() is computed in a bogus way, as the code may subtract current and previous nice values for different CPUs. That doesn't matter for cases when cpufreq policies are not shared, but may lead to problems otherwise. Fix the computation and simplify it to avoid taking unnecessary steps. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09cpufreq: governor: Avoid atomic operations in hot pathsRafael J. Wysocki
Rework the handling of work items by dbs_update_util_handler() and dbs_work_handler() so the former (which is executed in scheduler paths) only uses atomic operations when absolutely necessary. That is, when the policy is shared and dbs_update_util_handler() has already decided that this is the time to queue up a work item. In particular, this avoids the atomic ops entirely on platforms where policy objects are never shared. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09cpufreq: governor: Simplify gov_cancel_work() slightlyRafael J. Wysocki
The atomic work counter incrementation in gov_cancel_work() is not necessary any more, because work items won't be queued up after gov_clear_update_util() anyway, so drop it along with the comment about how it may be missed by the gov_clear_update_util(). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09cpufreq: governor: Avoid irq_work_queue_on() crash on non-SMP ARMRafael J. Wysocki
As it turns out, irq_work_queue_on() will crash if invoked on non-SMP ARM platforms, but in fact it is not necessary to use that function in the cpufreq governor code (as it doesn't matter to that code which CPU will handle the irq_work), so change it to always use irq_work_queue(). Fixes: 8fb47ff100af (cpufreq: governor: Replace timers with utilization update callbacks) Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net> Reported-and-tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09cpufreq: ondemand: Rearrange od_dbs_timer() to avoid updating delayViresh Kumar
Avoid extra checks in od_dbs_timer() by rearranging updates to the local delay variable in it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09cpufreq: conservative: Update sample_delay_ns immediatelyViresh Kumar
The ondemand governor already updates sample_delay_ns immediately on updates to the sampling rate, but conservative doesn't do that. It was left out earlier as the code was really too complex to get that done easily. Things are sorted out very well now, however, and the conservative governor can be modified to follow ondemand in that respect. Moreover, since the code needed to implement that in the conservative governor would be identical to the corresponding ondemand governor's code, make that code common and change both governors to use it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09cpufreq: governor: No need to manage state machine nowViresh Kumar
The cpufreq core now guarantees that policy->rwsem won't be dropped while running the ->governor callback for the CPUFREQ_GOV_POLICY_EXIT event and will be held acquired until the complete sequence of governor state changes has finished. This allows governor state machine checks to be dropped from multiple functions in cpufreq_governor.c. This also means that policy_dbs->policy can be initialized upfront, so the entire initialization of struct policy_dbs can be carried out in one place. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09cpufreq: Remove cpufreq_governor_lockViresh Kumar
We used to drop policy->rwsem just before calling __cpufreq_governor() in some cases earlier and so it was possible that __cpufreq_governor() ran concurrently via separate threads for the same policy. In order to guarantee valid state transitions for governors, 'governor_enabled' was required to be protected using some locking and cpufreq_governor_lock was added for that. But now __cpufreq_governor() is always called under policy->rwsem, and 'governor_enabled' is protected against races even without cpufreq_governor_lock. Get rid of the extra lock now. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw : Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09cpufreq: Call __cpufreq_governor() with policy->rwsem heldViresh Kumar
The cpufreq core code is not consistent with respect to invoking __cpufreq_governor() under policy->rwsem. Changing all code to always hold policy->rwsem around __cpufreq_governor() invocations will allow us to remove cpufreq_governor_lock that is used today because we can't guarantee that __cpufreq_governor() isn't executed twice in parallel for the same policy. We should also ensure that policy->rwsem is held across governor state changes. For example, while adding a CPU to the policy in the CPU online path, we need to stop the governor, change policy->cpus, start the governor and then refresh its limits. The complete sequence must be guaranteed to complete without interruptions by concurrent governor state updates. That can be achieved by holding policy->rwsem around those sequences of operations. Also note that after this patch cpufreq_driver->stop_cpu() and ->exit() will get called under policy->rwsem which wasn't the case earlier. That shouldn't have any side effects, though. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09cpufreq: Merge cpufreq_offline_prepare/finish routinesViresh Kumar
Commit 1aee40ac9c86 (cpufreq: Invoke __cpufreq_remove_dev_finish() after releasing cpu_hotplug.lock) split the cpufreq's CPU offline routine in two pieces, one of them to be run with CPU offline/online locked and the other to be called later. The reason for that split was a possible deadlock scenario involving cpufreq sysfs attributes and CPU offline. However, the handling of CPU offline in cpufreq has changed since then. Policy sysfs attributes are never removed during CPU offline, so there's no need to worry about accessing them during CPU offline, because that can't lead to any deadlocks now. Governor sysfs attributes are still removed in __cpufreq_governor(_EXIT), but there is a new kobject type for them now and its show/store callbacks don't lock CPU offline/online (they don't need to do that). This means that the CPU offline code in cpufreq doesn't need to be split any more, so combine cpufreq_offline_prepare() with cpufreq_offline_finish(). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Changelog ] Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09cpufreq: governor: Create and traverse list of policy_dbs to avoid deadlockViresh Kumar
The dbs_data_mutex lock is currently used in two places. First, cpufreq_governor_dbs() uses it to guarantee mutual exclusion between invocations of governor operations from the core. Second, it is used by ondemand governor's update_sampling_rate() to ensure the stability of data structures walked by it. The second usage is quite problematic, because update_sampling_rate() is called from a governor sysfs attribute's ->store callback and that leads to a deadlock scenario involving cpufreq_governor_exit() which runs under dbs_data_mutex. Thus it is better to rework the code so update_sampling_rate() doesn't need to acquire dbs_data_mutex. To that end, rework update_sampling_rate() to walk a list of policy_dbs objects supported by the dbs_data one it has been called for (instead of walking cpu_dbs_info object for all CPUs). The list manipulation is protected with dbs_data->mutex which also is held around the execution of update_sampling_rate(), it is not necessary to hold dbs_data_mutex in that function any more. Reported-by: Juri Lelli <juri.lelli@arm.com> Reported-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09Revert "cpufreq: Drop rwsem lock around CPUFREQ_GOV_POLICY_EXIT"Viresh Kumar
Earlier, when the struct freq-attr was used to represent governor attributes, the standard cpufreq show/store sysfs attribute callbacks were applied to the governor tunable attributes and they always acquire the policy->rwsem lock before carrying out the operation. That could have resulted in an ABBA deadlock if governor tunable attributes are removed under policy->rwsem while one of them is being accessed concurrently (if sysfs attributes removal wins the race, it will wait for the access to complete with policy->rwsem held while the attribute callback will block on policy->rwsem indefinitely). We attempted to address this issue by dropping policy->rwsem around governor tunable attributes removal (that is, around invocations of the ->governor callback with the event arg equal to CPUFREQ_GOV_POLICY_EXIT) in cpufreq_set_policy(), but that opened up race conditions that had not been possible with policy->rwsem held all the time. The previous commit, "cpufreq: governor: New sysfs show/store callbacks for governor tunables", fixed the original ABBA deadlock by adding new governor specific show/store callbacks. We don't have to drop rwsem around invocations of governor event CPUFREQ_GOV_POLICY_EXIT anymore, and original fix can be reverted now. Fixes: 955ef4833574 (cpufreq: Drop rwsem lock around CPUFREQ_GOV_POLICY_EXIT) Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reported-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09cpufreq: governor: Drop unused macros for creating governor tunable attributesViresh Kumar
The previous commit introduced a new set of macros for creating sysfs attributes that represent governor tunables and the old macros used for this purpose are not needed any more, so drop them. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09cpufreq: governor: New sysfs show/store callbacks for governor tunablesViresh Kumar
The ondemand and conservative governors use the global-attr or freq-attr structures to represent sysfs attributes corresponding to their tunables (which of them is actually used depends on whether or not different policy objects can use the same governor with different tunables at the same time and, consequently, on where those attributes are located in sysfs). Unfortunately, in the freq-attr case, the standard cpufreq show/store sysfs attribute callbacks are applied to the governor tunable attributes and they always acquire the policy->rwsem lock before carrying out the operation. That may lead to an ABBA deadlock if governor tunable attributes are removed under policy->rwsem while one of them is being accessed concurrently (if sysfs attributes removal wins the race, it will wait for the access to complete with policy->rwsem held while the attribute callback will block on policy->rwsem indefinitely). We attempted to address this issue by dropping policy->rwsem around governor tunable attributes removal (that is, around invocations of the ->governor callback with the event arg equal to CPUFREQ_GOV_POLICY_EXIT) in cpufreq_set_policy(), but that opened up race conditions that had not been possible with policy->rwsem held all the time. Therefore policy->rwsem cannot be dropped in cpufreq_set_policy() at any point, but the deadlock situation described above must be avoided too. To that end, use the observation that in principle governor tunables may be represented by the same data type regardless of whether the governor is system-wide or per-policy and introduce a new structure, struct governor_attr, for representing them and new corresponding macros for creating show/store sysfs callbacks for them. Also make their parent kobject use a new kobject type whose default show/store callbacks are not related to the standard core cpufreq ones in any way (and they don't acquire policy->rwsem in particular). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw: Subject & changelog + rebase ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09cpufreq: governor: Move common tunables to 'struct dbs_data'Viresh Kumar
There are a few common tunables shared between the ondemand and conservative governors. Move them to struct dbs_data to simplify code. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09cpufreq: governor: Create generic macro for common tunablesViresh Kumar
Some tunables are present in governor-specific structures, whereas one (min_sampling_rate) is located directly in struct dbs_data. There is a special macro for creating its sysfs attribute and the show/store callbacks, but since more tunables are going to be moved to struct dbs_data, a new generic macro for such cases will be useful, so add it and use it for min_sampling_rate. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Juri Lelli <juri.lelli@arm.com> Tested-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-09cpufreq: governor: Drop pointless goto from cpufreq_governor_init()Rafael J. Wysocki
It is silly to jump around "return 0", so don't do that. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09cpufreq: governor: Rename skip_work to work_countRafael J. Wysocki
The skip_work field in struct policy_dbs_info technically is a counter, so give it a new name to reflect that. No functional changes. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09cpufreq: governor: Symmetrize cpu_dbs_info initialization and cleanupRafael J. Wysocki
Make the initialization of struct cpu_dbs_info objects in alloc_policy_dbs_info() and the code that cleans them up in free_policy_dbs_info() more symmetrical. In particular, set/clear the update_util.func field in those functions along with the policy_dbs field. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09cpufreq: governor: Rearrange governor data structuresRafael J. Wysocki
The struct policy_dbs_info objects representing per-policy governor data are not accessible directly from the corresponding policy objects. To access them, one has to get a pointer to the struct cpu_dbs_info of policy->cpu and use the policy_dbs field of that which isn't really straightforward. To address that rearrange the governor data structures so the governor_data pointer in struct cpufreq_policy will point to struct policy_dbs_info (instead of struct dbs_data) and that will contain a pointer to struct dbs_data. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09cpufreq: governor: Simplify cpufreq_governor_limits()Rafael J. Wysocki
Use the observation that cpufreq_governor_limits() doesn't have to get to the policy object it wants to manipulate by walking the reference chain cdbs->policy_dbs->policy, as the final pointer is actually equal to its argument, and make it access the policy object directy via its argument. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09cpufreq: governor: Drop cpu argument from dbs_check_cpu()Rafael J. Wysocki
Since policy->cpu is always passed as the second argument to dbs_check_cpu(), it is not really necessary to pass it, because the function can obtain that value via its first argument just fine. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09cpufreq: governor: Rename cpu_common_dbs_info to policy_dbs_infoRafael J. Wysocki
The struct cpu_common_dbs_info structure represents the per-policy part of the governor data (for the ondemand and conservative governors), but its name doesn't reflect its purpose. Rename it to struct policy_dbs_info and rename variables related to it accordingly. No functional changes. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09cpufreq: governor: Drop the gov pointer from struct dbs_dataRafael J. Wysocki
Since it is possible to obtain a pointer to struct dbs_governor from a pointer to the struct governor embedded in it with the help of container_of(), the additional gov pointer in struct dbs_data isn't really necessary. Drop that pointer and make the code using it reach the dbs_governor object via policy->governor. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09cpufreq: governor: Rework cpufreq_governor_dbs()Rafael J. Wysocki
Since it is possible to obtain a pointer to struct dbs_governor from a pointer to the struct governor embedded in it via container_of(), the second argument of cpufreq_governor_init() is not necessary. Accordingly, cpufreq_governor_dbs() doesn't need its second argument either and the ->governor callbacks for both the ondemand and conservative governors may be set to cpufreq_governor_dbs() directly. Make that happen. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Saravana Kannan <skannan@codeaurora.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09cpufreq: governor: Rename some data types and variablesRafael J. Wysocki
The ondemand and conservative governors are represented by struct common_dbs_data whose name doesn't reflect the purpose it is used for, so rename it to struct dbs_governor and rename variables of that type accordingly. No functional changes. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09cpufreq: governor: Put governor structure into common_dbs_dataRafael J. Wysocki
For the ondemand and conservative governors (generally, governors that use the common code in cpufreq_governor.c), there are two static data structures representing the governor, the struct governor structure (the interface to the cpufreq core) and the struct common_dbs_data one (the interface to the cpufreq_governor.c code). There's no fundamental reason why those two structures have to be separate. Moreover, if the struct governor one is included into struct common_dbs_data, it will be possible to reach the latter from the policy via its policy->governor pointer, so it won't be necessary to pass a separate pointer to it around. For this reason, embed struct governor in struct common_dbs_data. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Saravana Kannan <skannan@codeaurora.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09cpufreq: governor: Avoid passing dbs_data pointers around unnecessarilyRafael J. Wysocki
Do not pass struct dbs_data pointers to the family of functions implementing governor operations in cpufreq_governor.c as they can take that pointer from policy->governor by themselves. The cpufreq_governor_init() case is slightly more complicated, since policy->governor may be NULL when it is invoked, but then it can reach the pointer in question via its cdata argument just fine. While at it, rework cpufreq_governor_dbs() to avoid a pointless policy_governor check in the CPUFREQ_GOV_POLICY_INIT case. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09cpufreq: governor: Use common mutex for dbs_data protectionRafael J. Wysocki
Every governor relying on the common code in cpufreq_governor.c has to provide its own mutex in struct common_dbs_data. However, there actually is no need to have a separate mutex per governor for this purpose, they may be using the same global mutex just fine. Accordingly, introduce a single common mutex for that and drop the mutex field from struct common_dbs_data. That at least will ensure that the mutex is always present and initialized regardless of what the particular governors do. Another benefit is that the common code does not need a pointer to a governor-related structure to get to the mutex which sometimes helps. Finally, it makes the code generally easier to follow. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Saravana Kannan <skannan@codeaurora.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-03-09cpufreq: governor: Replace timers with utilization update callbacksRafael J. Wysocki
Instead of using a per-CPU deferrable timer for queuing up governor work items, register a utilization update callback that will be invoked from the scheduler on utilization changes. The sampling rate is still the same as what was used for the deferrable timers and the added irq_work overhead should be offset by the eliminated timers overhead, so in theory the functional impact of this patch should not be significant. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
2016-03-09cpufreq: intel_pstate: Replace timers with utilization update callbacksRafael J. Wysocki
Instead of using a per-CPU deferrable timer for utilization sampling and P-states adjustments, register a utilization update callback that will be invoked from the scheduler on utilization changes. The sampling rate is still the same as what was used for the deferrable timers, so the functional impact of this patch should not be significant. Based on an earlier patch from Srinivas Pandruvada. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
2016-03-09cpufreq: Add mechanism for registering utilization update callbacksRafael J. Wysocki
Introduce a mechanism by which parts of the cpufreq subsystem ("setpolicy" drivers or the core) can register callbacks to be executed from cpufreq_update_util() which is invoked by the scheduler's update_load_avg() on CPU utilization changes. This allows the "setpolicy" drivers to dispense with their timers and do all of the computations they need and frequency/voltage adjustments in the update_load_avg() code path, among other things. The update_load_avg() changes were suggested by Peter Zijlstra. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@kernel.org>
2016-03-03cpufreq: acpi-cpufreq: Make read and write operations more efficientRafael J. Wysocki
Setting a new CPU frequency and reading the current request value in the ACPI cpufreq driver involves each at least two switch instructions (there's more if the policy is shared). One of them is present in drv_read/write() that prepares a command structure and the other happens in subsequent do_drv_read/write() when that structure is interpreted. However, all of those switches may be avoided by using function pointers. To that end, add two function pointers to struct acpi_cpufreq_data to represent read and write operations on the frequency register and set them up during policy intitialization to point to the pair of routines suitable for the given processor (Intel/AMD MSR access or I/O port access). Then, use those pointers in do_drv_read/write() and modify drv_read/write() to prepare the command structure for them without any checks. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-01cpufreq: mediatek: allow building as a moduleArnd Bergmann
The MT8173 cpufreq driver can currently only be built-in, but it has a Kconfig dependency on the thermal core. THERMAL can be a loadable module, which in turn makes this driver impossible to build. It is nicer to make the cpufreq driver a module as well, so this patch turns the option in to a 'tristate' and adapts the dependency accordingly. The driver has no module_exit() function, so it will continue to not support unloading, but it can be built as a module and loaded at runtime now. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 5269e7067cd6 (cpufreq: Add ARM_MT8173_CPUFREQ dependency on THERMAL) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-01cpufreq: qoriq: allow building as module with THERMAL=mArnd Bergmann
My previous patch to avoid link errors with the qoriq cpufreq driver disallowed all of the broken cases, but also prevented the driver from being built when CONFIG_THERMAL is a module. This changes the dependency to allow the cpufreq driver to also be a module in this case, just not built-in. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 8ae1702a0df5 (cpufreq: qoriq: Register cooling device based on device tree) Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-03-01Merge tag 'pxa-for-4.6' of https://github.com/rjarzmik/linux into next/socArnd Bergmann
Merge "pxa changes for v4.6 cycle" from Robert Jarzmik: This is a minor cycle with : - cleanup fixes from Arnd, mainly build oriented and sparse type ones - dma fixes for requestors above 32 (impacting mainly camera driver) - some minor cleanup on pxa3xx device-tree side * tag 'pxa-for-4.6' of https://github.com/rjarzmik/linux: dmaengine: pxa_dma: fix the maximum requestor line ARM: pxa: add the number of DMA requestor lines dmaengine: mmp-pdma: add number of requestors dma: mmp_pdma: Add the #dma-requests DT property documentation ARM: pxa: pxa3xx device-tree support cleanup ARM: pxa: don't select RFKILL if CONFIG_NET is disabled ARM: pxa: fix building without IWMMXT ARM: pxa: move extern declarations to pm.h ARM: pxa: always select one of the two CPU types ARM: pxa: don't select GPIO_SYSFS for MIOA701 ARM: pxa: mark unused eseries code as __maybe_unused ARM: pxa: mark spitz_card_pwr_ctrl as __maybe_unused ARM: pxa: define clock registers as __iomem
2016-02-26cpufreq: powernv: Fix bugs in powernv_cpufreq_{init/exit}Shilpasri G Bhat
Unregister the notifiers if cpufreq_driver_register() fails in powernv_cpufreq_init(). Re-arrange the unregistration and cleanup routines in powernv_cpufreq_exit() to free all the resources after the driver has unregistered. Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-26cpufreq: intel_pstate: disable HWP notificationsSrinivas Pandruvada
Disable HWP Interrupt notification before enabling HWP. Since we don't have HWP interrupt handling for possible performance interrupts, there is not much use of enabling HWP interrupts. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-26cpufreq: intel_pstate: Enable HWP by defaultSrinivas Pandruvada
If the processor supports HWP, enable it by default without checking for the cpu model. This will allow to enable HWP in all supported processors without driver change. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-26cpufreq: acpi-cpufreq: Drop pointless label from acpi_cpufreq_target()Rafael J. Wysocki
The "out" label at the final return statement in acpi_cpufreq_target() is totally pointless, so drop them and modify the code to return the right values immediately instead of jumping to it. No functional changes. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-26cpufreq: Rearrange __cpufreq_driver_target()Rafael J. Wysocki
Drop a pointless label at a return statement from __cpufreq_driver_target() and rearrange that function to reduce the indentation level. No intentional functional changes. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-24Merge tag 'samsung-drivers-4.6' of ↵Olof Johansson
git://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux into next/drivers Exynos-specific driver changes for v4.6: 1. Minor cleanup in s5pv210-cpufreq driver. * tag 'samsung-drivers-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux: cpufreq: s5pv210: remove superfluous CONFIG_PM ifdefs Signed-off-by: Olof Johansson <olof@lixom.net>
2016-02-23intel_pstate: Update frequencies of policy->cpus only from ->set_policy()Viresh Kumar
The intel-pstate driver is using intel_pstate_hwp_set() from two separate paths, i.e. ->set_policy() callback and sysfs update path for the files present in /sys/devices/system/cpu/intel_pstate/ directory. While an update to the sysfs path applies to all the CPUs being managed by the driver (which essentially means all the online CPUs), the update via the ->set_policy() callback applies to a smaller group of CPUs managed by the policy for which ->set_policy() is called. And so, intel_pstate_hwp_set() should update frequencies of only the CPUs that are part of policy->cpus mask, while it is called from ->set_policy() callback. In order to do that, add a parameter (cpumask) to intel_pstate_hwp_set() and apply the frequency changes only to the concerned CPUs. For ->set_policy() path, we are only concerned about policy->cpus, and so policy->rwsem lock taken by the core prior to calling ->set_policy() is enough to take care of any races. The larger lock acquired by get_online_cpus() is required only for the updates to sysfs files. Add another routine, intel_pstate_hwp_set_online_cpus(), and call it from the sysfs update paths. This also fixes a lockdep reported recently, where policy->rwsem and get_online_cpus() could have been acquired in any order causing an ABBA deadlock. The sequence of events leading to that was: intel_pstate_init(...) ...cpufreq_online(...) down_write(&policy->rwsem); // Locks policy->rwsem ... cpufreq_init_policy(policy); ...intel_pstate_hwp_set(); get_online_cpus(); // Temporarily locks cpu_hotplug.lock ... up_write(&policy->rwsem); pm_suspend(...) ...disable_nonboot_cpus() _cpu_down() cpu_hotplug_begin(); // Locks cpu_hotplug.lock __cpu_notify(CPU_DOWN_PREPARE, ...); ...cpufreq_offline_prepare(); down_write(&policy->rwsem); // Locks policy->rwsem Reported-and-tested-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-22cpufreq: simplify for_each_suitable_policy() macroEric Biggers
Signed-off-by: Eric Biggers <ebiggers3@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-22cpufreq: fix comment about return value of cpufreq_register_driver()Eric Biggers
The comment has been incorrect since commit 4dea5806d332 ("cpufreq: return EEXIST instead of EBUSY for second registering"). Signed-off-by: Eric Biggers <ebiggers3@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-12cpufreq: Drop unnecessary checks from show() and store()Rafael J. Wysocki
The show() and store() routines in the cpufreq core don't need to check if the struct freq_attr they want to use really provides the callbacks they need as expected (if that's not the case, it means a bug in the code anyway), so change them to avoid doing that. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-02-11cpufreq: dt: No need to allocate resources anymoreViresh Kumar
OPP layer manages it now and cpufreq-dt driver doesn't need it. But, we still need to check for availability of resources for deferred probing. 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>
2016-02-11cpufreq: dt: No need to fetch voltage-toleranceViresh Kumar
Its already done by core and we don't need to get it anymore. And so, we don't need to get of node in cpufreq_init() anymore, move that to find_supply_name() instead. 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>
2016-02-11cpufreq: dt: Use dev_pm_opp_set_rate() to switch frequencyViresh Kumar
OPP core supports frequency/voltage changes based on the target frequency now, use that instead of open coding the same in cpufreq-dt driver. 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>