Merge branch 'pm-cpufreq'

* pm-cpufreq:
  cpufreq: don't leave stale policy pointer in cdbs->cur_policy
  acpi-cpufreq: Add new sysfs attribute freqdomain_cpus
  cpufreq: make sure frequency transitions are serialized

Documentation/ABI/testing/sysfs-devices-system-cpu

@@ -144,6 +144,21 @@ Description:	Discover and change clock speed of CPUs
 		to learn how to control the knobs.
 
 
+What:		/sys/devices/system/cpu/cpu#/cpufreq/freqdomain_cpus
+Date:		June 2013
+Contact:	cpufreq@vger.kernel.org
+Description:	Discover CPUs in the same CPU frequency coordination domain
+
+		freqdomain_cpus is the list of CPUs (online+offline) that share
+		the same clock/freq domain (possibly at the hardware level).
+		That information may be hidden from the cpufreq core and the
+		value of related_cpus may be different from freqdomain_cpus. This
+		attribute is useful for user space DVFS controllers to get better
+		power/performance results for platforms using acpi-cpufreq.
+
+		This file is only present if the acpi-cpufreq driver is in use.
+
+
 What:		/sys/devices/system/cpu/cpu*/cache/index3/cache_disable_{0,1}
 Date:		August 2008
 KernelVersion:	2.6.27

drivers/cpufreq/acpi-cpufreq.c

@@ -70,6 +70,7 @@ struct acpi_cpufreq_data {
 	struct cpufreq_frequency_table *freq_table;
 	unsigned int resume;
 	unsigned int cpu_feature;
+	cpumask_var_t freqdomain_cpus;
 };
 
 static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data);
@@ -176,6 +177,15 @@ static struct global_attr global_boost = __ATTR(boost, 0644,
 						show_global_boost,
 						store_global_boost);
 
+static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
+{
+	struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
+
+	return cpufreq_show_cpus(data->freqdomain_cpus, buf);
+}
+
+cpufreq_freq_attr_ro(freqdomain_cpus);
+
 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
 static ssize_t store_cpb(struct cpufreq_policy *policy, const char *buf,
 			 size_t count)
@@ -704,6 +714,11 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 	if (!data)
 		return -ENOMEM;
 
+	if (!zalloc_cpumask_var(&data->freqdomain_cpus, GFP_KERNEL)) {
+		result = -ENOMEM;
+		goto err_free;
+	}
+
 	data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
 	per_cpu(acfreq_data, cpu) = data;
 
@@ -712,7 +727,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 
 	result = acpi_processor_register_performance(data->acpi_data, cpu);
 	if (result)
-		goto err_free;
+		goto err_free_mask;
 
 	perf = data->acpi_data;
 	policy->shared_type = perf->shared_type;
@@ -725,6 +740,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 	    policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
 		cpumask_copy(policy->cpus, perf->shared_cpu_map);
 	}
+	cpumask_copy(data->freqdomain_cpus, perf->shared_cpu_map);
 
 #ifdef CONFIG_SMP
 	dmi_check_system(sw_any_bug_dmi_table);
@@ -736,6 +752,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 	if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) {
 		cpumask_clear(policy->cpus);
 		cpumask_set_cpu(cpu, policy->cpus);
+		cpumask_copy(data->freqdomain_cpus, cpu_sibling_mask(cpu));
 		policy->shared_type = CPUFREQ_SHARED_TYPE_HW;
 		pr_info_once(PFX "overriding BIOS provided _PSD data\n");
 	}
@@ -870,6 +887,8 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 	kfree(data->freq_table);
 err_unreg:
 	acpi_processor_unregister_performance(perf, cpu);
+err_free_mask:
+	free_cpumask_var(data->freqdomain_cpus);
 err_free:
 	kfree(data);
 	per_cpu(acfreq_data, cpu) = NULL;
@@ -888,6 +907,7 @@ static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 		per_cpu(acfreq_data, policy->cpu) = NULL;
 		acpi_processor_unregister_performance(data->acpi_data,
 						      policy->cpu);
+		free_cpumask_var(data->freqdomain_cpus);
 		kfree(data->freq_table);
 		kfree(data);
 	}
@@ -908,6 +928,7 @@ static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
 
 static struct freq_attr *acpi_cpufreq_attr[] = {
 	&cpufreq_freq_attr_scaling_available_freqs,
+	&freqdomain_cpus,
 	NULL,	/* this is a placeholder for cpb, do not remove */
 	NULL,
 };

drivers/cpufreq/cpufreq.c

@@ -312,6 +312,12 @@ static void __cpufreq_notify_transition(struct cpufreq_policy *policy,
 	switch (state) {
 
 	case CPUFREQ_PRECHANGE:
+		if (WARN(policy->transition_ongoing,
+				"In middle of another frequency transition\n"))
+			return;
+
+		policy->transition_ongoing = true;
+
 		/* detect if the driver reported a value as "old frequency"
 		 * which is not equal to what the cpufreq core thinks is
 		 * "old frequency".
@@ -331,6 +337,12 @@ static void __cpufreq_notify_transition(struct cpufreq_policy *policy,
 		break;
 
 	case CPUFREQ_POSTCHANGE:
+		if (WARN(!policy->transition_ongoing,
+				"No frequency transition in progress\n"))
+			return;
+
+		policy->transition_ongoing = false;
+
 		adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
 		pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new,
 			(unsigned long)freqs->cpu);
@@ -573,7 +585,7 @@ static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
 	return i;
 }
 
-static ssize_t show_cpus(const struct cpumask *mask, char *buf)
+ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf)
 {
 	ssize_t i = 0;
 	unsigned int cpu;
@@ -588,6 +600,7 @@ static ssize_t show_cpus(const struct cpumask *mask, char *buf)
 	i += sprintf(&buf[i], "\n");
 	return i;
 }
+EXPORT_SYMBOL_GPL(cpufreq_show_cpus);
 
 /**
  * show_related_cpus - show the CPUs affected by each transition even if
@@ -595,7 +608,7 @@ static ssize_t show_cpus(const struct cpumask *mask, char *buf)
  */
 static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
 {
-	return show_cpus(policy->related_cpus, buf);
+	return cpufreq_show_cpus(policy->related_cpus, buf);
 }
 
 /**
@@ -603,7 +616,7 @@ static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf)
  */
 static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf)
 {
-	return show_cpus(policy->cpus, buf);
+	return cpufreq_show_cpus(policy->cpus, buf);
 }
 
 static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
@@ -1539,6 +1552,8 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
 
 	if (cpufreq_disabled())
 		return -ENODEV;
+	if (policy->transition_ongoing)
+		return -EBUSY;
 
 	/* Make sure that target_freq is within supported range */
 	if (target_freq > policy->max)

drivers/cpufreq/cpufreq_governor.c

@@ -366,6 +366,7 @@ int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 
 		mutex_lock(&dbs_data->mutex);
 		mutex_destroy(&cpu_cdbs->timer_mutex);
+		cpu_cdbs->cur_policy = NULL;
 
 		mutex_unlock(&dbs_data->mutex);
 

include/linux/cpufreq.h

@@ -119,6 +119,7 @@ struct cpufreq_policy {
 
 	struct kobject		kobj;
 	struct completion	kobj_unregister;
+	bool			transition_ongoing; /* Tracks transition status */
 };
 
 #define CPUFREQ_ADJUST			(0)
@@ -438,4 +439,7 @@ void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
 
 void cpufreq_frequency_table_put_attr(unsigned int cpu);
+
+ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);
+
 #endif /* _LINUX_CPUFREQ_H */