Messages in this thread Patch in this message | | | From | Viresh Kumar <> | Subject | [PATCH 2/3] cpufreq: Implement freq-constraint callback | Date | Fri, 11 Jan 2019 14:48:35 +0530 |
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This implements the frequency constraint callback and registers it with the freq-constraint framework whenever a policy is created. On policy removal the callback is unregistered.
The constraints are also taken into consideration in cpufreq_set_policy().
No constraints are added until now though.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- drivers/cpufreq/Kconfig | 1 + drivers/cpufreq/cpufreq.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 45 insertions(+)
diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig index 608af20a3494..2c2842cf2734 100644 --- a/drivers/cpufreq/Kconfig +++ b/drivers/cpufreq/Kconfig @@ -2,6 +2,7 @@ menu "CPU Frequency scaling" config CPU_FREQ bool "CPU Frequency scaling" + select DEVICE_FREQ_CONSTRAINT select SRCU help CPU Frequency scaling allows you to change the clock speed of diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index a8fa684f5f90..63028612d011 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -21,6 +21,7 @@ #include <linux/cpufreq.h> #include <linux/delay.h> #include <linux/device.h> +#include <linux/freq_constraint.h> #include <linux/init.h> #include <linux/kernel_stat.h> #include <linux/module.h> @@ -1163,6 +1164,7 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy) per_cpu(cpufreq_cpu_data, cpu) = NULL; write_unlock_irqrestore(&cpufreq_driver_lock, flags); + freq_constraint_remove_cpumask_callback(policy->related_cpus); cpufreq_policy_put_kobj(policy); free_cpumask_var(policy->real_cpus); free_cpumask_var(policy->related_cpus); @@ -1170,6 +1172,24 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy) kfree(policy); } +static void freq_constraint_callback(void *param) +{ + struct cpufreq_policy *policy = param; + struct cpufreq_policy new_policy = *policy; + + new_policy.min = policy->user_policy.min; + new_policy.max = policy->user_policy.max; + + down_write(&policy->rwsem); + if (policy_is_inactive(policy)) + goto unlock; + + cpufreq_set_policy(policy, &new_policy); + +unlock: + up_write(&policy->rwsem); +} + static int cpufreq_online(unsigned int cpu) { struct cpufreq_policy *policy; @@ -1236,6 +1256,14 @@ static int cpufreq_online(unsigned int cpu) per_cpu(cpufreq_cpu_data, j) = policy; add_cpu_dev_symlink(policy, j); } + + ret = freq_constraint_set_cpumask_callback(policy->related_cpus, + freq_constraint_callback, policy); + if (ret) { + pr_err("Failed to set freq-constraints: %d (%*pbl)\n", + ret, cpumask_pr_args(policy->cpus)); + goto out_destroy_policy; + } } else { policy->min = policy->user_policy.min; policy->max = policy->user_policy.max; @@ -2198,6 +2226,8 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, struct cpufreq_policy *new_policy) { struct cpufreq_governor *old_gov; + struct device *cpu_dev = get_cpu_device(policy->cpu); + unsigned long fc_min, fc_max; int ret; pr_debug("setting new policy for CPU %u: %u - %u kHz\n", @@ -2217,6 +2247,20 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, if (ret) return ret; + ret = freq_constraints_get(cpu_dev, &fc_min, &fc_max); + if (ret) { + dev_err(cpu_dev, "cpufreq: Failed to get freq-constraints\n"); + } else { + if (fc_min > new_policy->min) + new_policy->min = fc_min; + if (fc_max < new_policy->max) + new_policy->max = fc_max; + } + + /* + * The notifier-chain shall be removed once all the users of + * CPUFREQ_ADJUST are moved to use the freq-constraints. + */ /* adjust if necessary - all reasons */ blocking_notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_ADJUST, new_policy); -- 2.7.4
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