On Thu, Jan 17, 2019 at 05:46:32PM -0800, Matthias Kaehlcke wrote: > On Fri, Jan 11, 2019 at 02:48:35PM +0530, Viresh Kumar wrote: > > 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. > > nit: 'for now'? > > > Signed-off-by: Viresh Kumar <[email protected]> > > --- > > 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; > > + } > > nit: for if/else constructs with a typical and an 'exception' case > IMO it is usually more readable when the normal case is handled in the > 'if' branch (first) and the exception in 'else'.
Forgot to add this: Reviewed-by: Matthias Kaehlcke <[email protected]>
