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path: root/drivers/cpufreq/arm_big_little.c
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2014-03-19cpufreq: arm_big_little: set 'physical_cluster' for each CPUviresh kumar
We have a per-CPU variable for managing which cluster a CPU belongs to. Currently, physical_cluster is set for policy->cpu only which leads to the following on some SoC's: - There are two clusters: - Cluster 0 has four ARM Cortex A7 CPUs (slower ones): 0,1,2,3 - Cluster 1 has four ARM Cortex A15 CPUs (faster ones): 4,5,6,7 - CPUs are booted in order 0,1..7 and so initially policy->cpu for A7 cluster would be 0 and for A15 cluster would be 4. - Now CPU4 (i.e. A15_0) is hotplugged out and so policy->cpu for A15 cluster becomes 5 (i.e. A15_1). - But physical cluster is only set for CPU0 and CPU4 in ARM big LITTLE driver and isn't updated. - Now freq change request comes for A15 cluster and we would try to update freq of physical_cluster of CPU5, i.e. A15_1. And it is currently set to zero (default value of uninitialized global variables). - And so we actually try to change freq of A7 cluster instead of A15. - This also results in kernel crash as sometimes we might request freq above A7's limit and CPU may behave badly.. Fix this by initializing physical_cluster for all CPUs of a policy. Based on previous work by Xin Wang. 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>
2014-01-06cpufreq: 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>
2013-10-31cpufreq: move freq change notifications to cpufreq coreViresh Kumar
Most of the drivers do following in their ->target_index() routines: struct cpufreq_freqs freqs; freqs.old = old freq... freqs.new = new freq... cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); /* Change rate here */ cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); This is replicated over all cpufreq drivers today and there doesn't exists a good enough reason why this shouldn't be moved to cpufreq core instead. There are few special cases though, like exynos5440, which doesn't do everything on the call to ->target_index() routine and call some kind of bottom halves for doing this work, work/tasklet/etc.. They may continue doing notification from their own code as flag: CPUFREQ_ASYNC_NOTIFICATION is already set for them. All drivers are also modified in this patch to avoid breaking 'git bisect', as double notification would happen otherwise. 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: Stephen Warren <swarren@nvidia.com> Tested-by: Andrew Lunn <andrew@lunn.ch> Tested-by: Nicolas Pitre <nicolas.pitre@linaro.org> Reviewed-by: Lan Tianyu <tianyu.lan@intel.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-31cpufreq: arm_big_little: reconfigure switcher behavior at run timeNicolas Pitre
The b.L switcher can be turned on/off at run time. It is therefore necessary to change the cpufreq driver behavior accordingly. The driver must be unregistered/registered with the cpufreq core to reconfigure freq tables for the virtual or actual CPUs. This is accomplished via the b.L switcher notifier callback. Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-31cpufreq: arm_big_little: add in-kernel switching (IKS) supportViresh Kumar
This patch adds IKS (In Kernel Switcher) support to cpufreq driver. This creates a combined freq table for A7-A15 CPU pairs. A7 frequencies are virtualized and scaled down to half the actual frequencies to approximate a linear scale across the combined A7+A15 range. When the requested frequency change crosses the A7-A15 boundary a cluster switch is invoked. Based on earlier work from Sudeep KarkadaNagesha. Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Nicolas Pitre <nico@linaro.org> 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>
2013-10-25Merge back earlier 'pm-cpufreq' material.Rafael J. Wysocki
Conflicts: drivers/cpufreq/omap-cpufreq.c
2013-10-25PM / OPP: rename header to linux/pm_opp.hNishanth Menon
Since Operating Performance Points (OPP) functions are specific to device specific power management, be specific and rename opp.h to pm_opp.h Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-25PM / OPP: rename functions to dev_pm_opp*Nishanth Menon
Since Operating Performance Points (OPP) functions are specific to device specific power management, be specific and rename opp_* accessors in OPP library with dev_pm_opp_* equivalent. Affected functions are: opp_get_voltage opp_get_freq opp_get_opp_count opp_find_freq_exact opp_find_freq_floor opp_find_freq_ceil opp_add opp_enable opp_disable opp_get_notifier opp_init_cpufreq_table opp_free_cpufreq_table Reported-by: Randy Dunlap <rdunlap@infradead.org> 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>
2013-10-16cpufreq: arm-big-little: use clk_get instead of clk_get_sysSudeep KarkadaNagesha
Currently clk_get_sys is used with cpu-cluster.<n> as the device id which is incorrect. It should be connection/consumer ID instead. It is possible to specify input clock in the cpu device node along with the optional clock-name. clk_get_sys can't handle that. This patch replaces clk_get_sys with clk_get to extend support for clocks specified in the device tree cpu node. Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-16cpufreq: arm_big_little: don't initialize part of policy is set by coreViresh Kumar
Many common initializations of struct policy are moved to core now and hence this driver doesn't need to do it. This patch removes such code. Most recent of those changes is to call ->get() in the core after calling ->init(). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-16cpufreq: arm_big_little: Use generic cpufreq 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 uses these generic routines in the arm_big_little driver. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> 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>
2013-09-30cpufreq: arm_big_little: call cpufreq_frequency_table_put_attr()Viresh Kumar
Drivers which have an exit path must call cpufreq_frequency_table_put_attr() if they have called cpufreq_frequency_table_get_attr() in their init path. This driver was missing this part and is fixed with this patch. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-30cpufreq: arm_big_little: use cpufreq_table_validate_and_show()Viresh Kumar
Lets use cpufreq_table_validate_and_show() instead of calling cpufreq_frequency_table_cpuinfo() and cpufreq_frequency_table_get_attr(). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-06-24cpufreq: arm-big-little: call CPUFREQ_POSTCHANGE notfier in error casesViresh Kumar
PRECHANGE and POSTCHANGE notifiers must be called in groups, i.e either both should be called or both shouldn't be. In case we have started PRECHANGE notifier and found an error, we must call POSTCHANGE notifier with freqs.new = freqs.old to guarantee that sequence of calling notifiers is complete. This patch fixes it. This also removes code setting policy->cur as this is also done by POSTCHANGE notifier. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2013-05-12cpufreq: ARM big LITTLE: Improve print messageViresh Kumar
The message printed at the end of driver->init() doesn't include the "cpufreq" string at all and so is difficult to find in dmesg. Add function name to that message to clearly state where the message is coming from. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12cpufreq: ARM big LITTLE: Move cpu_to_cluster() to arm_big_little.hViresh Kumar
The cpu_to_cluster() function may be used by glue drivers, so it's better to keep it in arm_big_little.h. [rjw: Changelog] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-22cpufreq: ARM big LITTLE: Adapt to latest cpufreq updatesViresh Kumar
This driver isn't updated to work with latest cpufreq core updates that happened recently. Fix them. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-02cpufreq: ARM big LITTLE: Add generic cpufreq driver and its DT glueViresh Kumar
big LITTLE is ARM's new Architecture focussing power/performance needs of modern world. More information about big LITTLE can be found here: http://www.arm.com/products/processors/technologies/biglittleprocessing.php http://lwn.net/Articles/481055/ In order to keep cpufreq support for all big LITTLE platforms simple/generic, this patch tries to add a generic cpufreq driver layer for all big LITTLE platforms. The driver is divided into two parts: - Core driver: Generic and shared across all big LITTLE SoC's - Glue drivers: Per platform drivers providing ops to the core driver This patch adds in a generic glue driver which would extract information from Device Tree. Future SoC's can either reuse the DT glue or write their own depending on the need. Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>