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path: root/drivers/cpufreq/powernv-cpufreq.c
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2014-08-05powerpc/cpufreq: Add pr_warn() on OPAL firmware failuresVaidyanathan Srinivasan
Cpufreq depends on platform firmware to implement PStates. In case of platform firmware failure, cpufreq should not panic host kernel with BUG_ON(). Less severe pr_warn() will suffice. Add firmware_has_feature(FW_FEATURE_OPALv3) check to skip probing for device-tree on non-powernv platforms. Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Acked-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> CC: <stable@vger.kernel.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-05-16cpufreq: powernv: make local function staticBrian Norris
powernv_cpufreq_get() is only referenced in this file. Signed-off-by: Brian Norris <computersforpeace@gmail.com> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> on V2. Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-21cpufreq, powernv: Fix build failure on UPSrivatsa S. Bhat
Paul Gortmaker reported the following build failure of the powernv cpufreq driver on UP configs: drivers/cpufreq/powernv-cpufreq.c:241:2: error: implicit declaration of function 'cpu_sibling_mask' [-Werror=implicit-function-declaration] cc1: some warnings being treated as errors make[3]: *** [drivers/cpufreq/powernv-cpufreq.o] Error 1 make[2]: *** [drivers/cpufreq] Error 2 make[1]: *** [drivers] Error 2 make: *** [sub-make] Error 2 The trouble here is that cpu_sibling_mask is defined only in <asm/smp.h>, and <linux/smp.h> includes <asm/smp.h> only in SMP builds. So fix this build failure by explicitly including <asm/smp.h> in the driver, so that we get the definition of cpu_sibling_mask even in UP configurations. Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com> 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>
2014-04-07cpufreq: powernv: Use cpufreq_frequency_table.driver_data to store pstate idsGautham R. Shenoy
The .driver_data field in the cpufreq_frequency_table was supposed to be private to the drivers. However at some later point, it was being used to indicate if the particular frequency in the table is the BOOST_FREQUENCY. After patches [1] and [2], the .driver_data is once again private to the driver. Thus we can safely use cpufreq_frequency_table.driver_data to store pstate_ids instead of having to maintain a separate array powernv_pstate_ids[] for this purpose. [1]: Subject: cpufreq: don't print value of .driver_data from core From : Viresh Kumar <viresh.kumar@ linaro.org> url : http://marc.info/?l=linux-pm&m=139601421504709&w=2 [2]: Subject: cpufreq: create another field .flags in cpufreq_frequency_table From : Viresh Kumar <viresh.kumar@linaro.org> url : http://marc.info/?l=linux-pm&m=139601416804702&w=2 Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-07cpufreq: powernv: cpufreq driver for powernv platformVaidyanathan Srinivasan
Backend driver to dynamically set voltage and frequency on IBM POWER non-virtualized platforms. Power management SPRs are used to set the required PState. This driver works in conjunction with cpufreq governors like 'ondemand' to provide a demand based frequency and voltage setting on IBM POWER non-virtualized platforms. PState table is obtained from OPAL v3 firmware through device tree. powernv_cpufreq back-end driver would parse the relevant device-tree nodes and initialise the cpufreq subsystem on powernv platform. The code was originally written by svaidy@linux.vnet.ibm.com. Over time it was modified to accomodate bug-fixes as well as updates to the the cpu-freq core. Relevant portions of the change logs corresponding to those modifications are noted below: * The policy->cpus needs to be populated in a hotplug-invariant manner instead of using cpu_sibling_mask() which varies with cpu-hotplug. This is because the cpufreq core code copies this content into policy->related_cpus mask which should not vary on cpu-hotplug. [Authored by srivatsa.bhat@linux.vnet.ibm.com] * Create a helper routine that can return the cpu-frequency for the corresponding pstate_id. Also, cache the values of the pstate_max, pstate_min and pstate_nominal and nr_pstates in a static structure so that they can be reused in the future to perform any validations. [Authored by ego@linux.vnet.ibm.com] * Create a driver attribute named cpuinfo_nominal_freq which creates a sysfs read-only file named cpuinfo_nominal_freq. Export the frequency corresponding to the nominal_pstate through this interface. Nominal frequency is the highest non-turbo frequency for the platform. This is generally used for setting governor policies from user space for optimal energy efficiency. [Authored by ego@linux.vnet.ibm.com] * Implement a powernv_cpufreq_get(unsigned int cpu) method which will return the current operating frequency. Export this via the sysfs interface cpuinfo_cur_freq by setting powernv_cpufreq_driver.get to powernv_cpufreq_get(). [Authored by ego@linux.vnet.ibm.com] [Change log updated by ego@linux.vnet.ibm.com] Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>