On 12/14/2017 10:12 AM, Viresh Kumar wrote:
+ Gautham,
@Gautham: Can you please help reviewing this one ?
On 13-12-17, 13:49, Abhishek Goel wrote:
@@ -693,6 +746,8 @@ static int powernv_cpufreq_target_index(struct
cpufreq_policy *policy,
{
struct powernv_smp_call_data freq_data;
unsigned int cur_msec, gpstate_idx;
+ cpumask_t temp;
+ u32 cpu;
struct global_pstate_info *gpstates = policy->driver_data;
if (unlikely(rebooting) && new_index != get_nominal_index())
@@ -761,24 +816,48 @@ static int powernv_cpufreq_target_index(struct
cpufreq_policy *policy,
spin_unlock(&gpstates->gpstate_lock);
/*
- * Use smp_call_function to send IPI and execute the
- * mtspr on target CPU. We could do that without IPI
- * if current CPU is within policy->cpus (core)
+ * Use smp_call_function to send IPI and execute the mtspr on CPU.
+ * This needs to be done on every core of the policy
Why on each CPU ?
We need to do it in this way as the current implementation takes the max
of the PMSR of the cores. Thus, when the frequency is required to be
ramped up, it suffices to write to just the local PMSR, but when the
frequency is to be ramped down, if we don't send the IPI it breaks the
compatibility with P8.
*/
- smp_call_function_any(policy->cpus, set_pstate, &freq_data, 1);
+ cpumask_copy(&temp, policy->cpus);
+
+ while (!cpumask_empty(&temp)) {
+ cpu = cpumask_first(&temp);
+ smp_call_function_any(cpu_sibling_mask(cpu),
+ set_pstate, &freq_data, 1);
+ cpumask_andnot(&temp, &temp, cpu_sibling_mask(cpu));
+ }
+
return 0;
}
