cpufreq: Introducing CPUFREQ_RELATION_E

This newly introduced flag can be applied by a governor to a CPUFreq
relation, when looking for a frequency within the policy table. The
resolution would then only walk through efficient frequencies.

Even with the flag set, the policy max limit will still be honoured. If no
efficient frequencies can be found within the limits of the policy, an
inefficient one would be returned.

Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

6 files changed, 20 insertions, 8 deletions

diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
index 28467d83c745..3d514b82d055 100644
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -470,7 +470,8 @@ static unsigned int acpi_cpufreq_fast_switch(struct cpufreq_policy *policy,
 	if (policy->cached_target_freq == target_freq)
 		index = policy->cached_resolved_idx;
 	else
-		index = cpufreq_table_find_index_dl(policy, target_freq);
+		index = cpufreq_table_find_index_dl(policy, target_freq,
+						    false);
 
 	entry = &policy->freq_table[index];
 	next_freq = entry->frequency;
diff --git a/drivers/cpufreq/amd_freq_sensitivity.c b/drivers/cpufreq/amd_freq_sensitivity.c
index d0b10baf039a..6448e03bcf48 100644
--- a/drivers/cpufreq/amd_freq_sensitivity.c
+++ b/drivers/cpufreq/amd_freq_sensitivity.c
@@ -91,7 +91,8 @@ static unsigned int amd_powersave_bias_target(struct cpufreq_policy *policy,
 			unsigned int index;
 
 			index = cpufreq_table_find_index_h(policy,
-							   policy->cur - 1);
+							   policy->cur - 1,
+							   relation & CPUFREQ_RELATION_E);
 			freq_next = policy->freq_table[index].frequency;
 		}
 
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 284e940084c6..8069a7bac9ef 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -2260,8 +2260,16 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
 	    !(cpufreq_driver->flags & CPUFREQ_NEED_UPDATE_LIMITS))
 		return 0;
 
-	if (cpufreq_driver->target)
+	if (cpufreq_driver->target) {
+		/*
+		 * If the driver hasn't setup a single inefficient frequency,
+		 * it's unlikely it knows how to decode CPUFREQ_RELATION_E.
+		 */
+		if (!policy->efficiencies_available)
+			relation &= ~CPUFREQ_RELATION_E;
+
 		return cpufreq_driver->target(policy, target_freq, relation);
+	}
 
 	if (!cpufreq_driver->target_index)
 		return -EINVAL;
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index eb4320b619c9..f68cad9abd11 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -83,9 +83,11 @@ static unsigned int generic_powersave_bias_target(struct cpufreq_policy *policy,
 	freq_avg = freq_req - freq_reduc;
 
 	/* Find freq bounds for freq_avg in freq_table */
-	index = cpufreq_table_find_index_h(policy, freq_avg);
+	index = cpufreq_table_find_index_h(policy, freq_avg,
+					   relation & CPUFREQ_RELATION_E);
 	freq_lo = freq_table[index].frequency;
-	index = cpufreq_table_find_index_l(policy, freq_avg);
+	index = cpufreq_table_find_index_l(policy, freq_avg,
+					   relation & CPUFREQ_RELATION_E);
 	freq_hi = freq_table[index].frequency;
 
 	/* Find out how long we have to be in hi and lo freqs */
diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index 5a2cf5f91ccb..fddbd1ea1635 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -934,7 +934,7 @@ static void powernv_cpufreq_work_fn(struct work_struct *work)
 		policy = cpufreq_cpu_get(cpu);
 		if (!policy)
 			continue;
-		index = cpufreq_table_find_index_c(policy, policy->cur);
+		index = cpufreq_table_find_index_c(policy, policy->cur, false);
 		powernv_cpufreq_target_index(policy, index);
 		cpumask_andnot(&mask, &mask, policy->cpus);
 		cpufreq_cpu_put(policy);
@@ -1022,7 +1022,7 @@ static unsigned int powernv_fast_switch(struct cpufreq_policy *policy,
 	int index;
 	struct powernv_smp_call_data freq_data;
 
-	index = cpufreq_table_find_index_dl(policy, target_freq);
+	index = cpufreq_table_find_index_dl(policy, target_freq, false);
 	freq_data.pstate_id = powernv_freqs[index].driver_data;
 	freq_data.gpstate_id = powernv_freqs[index].driver_data;
 	set_pstate(&freq_data);
diff --git a/drivers/cpufreq/s5pv210-cpufreq.c b/drivers/cpufreq/s5pv210-cpufreq.c
index ad7d4f272ddc..76c888ed8d16 100644
--- a/drivers/cpufreq/s5pv210-cpufreq.c
+++ b/drivers/cpufreq/s5pv210-cpufreq.c
@@ -243,7 +243,7 @@ static int s5pv210_target(struct cpufreq_policy *policy, unsigned int index)
 	new_freq = s5pv210_freq_table[index].frequency;
 
 	/* Finding current running level index */
-	priv_index = cpufreq_table_find_index_h(policy, old_freq);
+	priv_index = cpufreq_table_find_index_h(policy, old_freq, false);
 
 	arm_volt = dvs_conf[index].arm_volt;
 	int_volt = dvs_conf[index].int_volt;