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

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
Rafael J. Wysocki
2 parents 867a420b22 419e172145
Showing 5 changed files Side-by-side Diff
Documentation/ABI/testing/sysfs-devices-system-cpu
drivers/cpufreq/acpi-cpufreq.c
drivers/cpufreq/cpufreq.c
drivers/cpufreq/cpufreq_governor.c
include/linux/cpufreq.h
@@ -144,6 +144,21 @@
 		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
@@ -70,6 +70,7 @@
 	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 @@
 						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 @@
 	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 @@
  
 	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 @@
 	    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 @@
 	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 @@
 	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 @@
 		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 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,
 };
@@ -312,6 +312,12 @@
 	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 @@
 		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 @@
 	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 @@
 	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_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_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 @@
  
 	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)
@@ -366,6 +366,7 @@
  
 		mutex_lock(&dbs_data->mutex);
 		mutex_destroy(&cpu_cdbs->timer_mutex);
+		cpu_cdbs->cur_policy = NULL;
  
 		mutex_unlock(&dbs_data->mutex);
  
@@ -119,6 +119,7 @@
  
 	struct kobject		kobj;
 	struct completion	kobj_unregister;
+	bool			transition_ongoing; /* Tracks transition status */
 };
  
 #define CPUFREQ_ADJUST			(0)
@@ -438,5 +439,8 @@
 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 */
...	...	@@ -144,6 +144,21 @@
144	144	to learn how to control the knobs.
145	145
146	146
	147	+What: /sys/devices/system/cpu/cpu#/cpufreq/freqdomain_cpus
	148	+Date: June 2013
	149	+Contact: cpufreq@vger.kernel.org
	150	+Description: Discover CPUs in the same CPU frequency coordination domain
	151	+
	152	+ freqdomain_cpus is the list of CPUs (online+offline) that share
	153	+ the same clock/freq domain (possibly at the hardware level).
	154	+ That information may be hidden from the cpufreq core and the
	155	+ value of related_cpus may be different from freqdomain_cpus. This
	156	+ attribute is useful for user space DVFS controllers to get better
	157	+ power/performance results for platforms using acpi-cpufreq.
	158	+
	159	+ This file is only present if the acpi-cpufreq driver is in use.
	160	+
	161	+
147	162	What: /sys/devices/system/cpu/cpu*/cache/index3/cache_disable_{0,1}
148	163	Date: August 2008
149	164	KernelVersion: 2.6.27
...	...	@@ -70,6 +70,7 @@
70	70	struct cpufreq_frequency_table *freq_table;
71	71	unsigned int resume;
72	72	unsigned int cpu_feature;
	73	+ cpumask_var_t freqdomain_cpus;
73	74	};
74	75
75	76	static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data);
...	...	@@ -176,6 +177,15 @@
176	177	show_global_boost,
177	178	store_global_boost);
178	179
	180	+static ssize_t show_freqdomain_cpus(struct cpufreq_policy policy, char buf)
	181	+{
	182	+ struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
	183	+
	184	+ return cpufreq_show_cpus(data->freqdomain_cpus, buf);
	185	+}
	186	+
	187	+cpufreq_freq_attr_ro(freqdomain_cpus);
	188	+
179	189	#ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
180	190	static ssize_t store_cpb(struct cpufreq_policy policy, const char buf,
181	191	size_t count)
...	...	@@ -704,6 +714,11 @@
704	714	if (!data)
705	715	return -ENOMEM;
706	716
	717	+ if (!zalloc_cpumask_var(&data->freqdomain_cpus, GFP_KERNEL)) {
	718	+ result = -ENOMEM;
	719	+ goto err_free;
	720	+ }
	721	+
707	722	data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
708	723	per_cpu(acfreq_data, cpu) = data;
709	724
...	...	@@ -712,7 +727,7 @@
712	727
713	728	result = acpi_processor_register_performance(data->acpi_data, cpu);
714	729	if (result)
715		- goto err_free;
	730	+ goto err_free_mask;
716	731
717	732	perf = data->acpi_data;
718	733	policy->shared_type = perf->shared_type;
...	...	@@ -725,6 +740,7 @@
725	740	policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
726	741	cpumask_copy(policy->cpus, perf->shared_cpu_map);
727	742	}
	743	+ cpumask_copy(data->freqdomain_cpus, perf->shared_cpu_map);
728	744
729	745	#ifdef CONFIG_SMP
730	746	dmi_check_system(sw_any_bug_dmi_table);
...	...	@@ -736,6 +752,7 @@
736	752	if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) {
737	753	cpumask_clear(policy->cpus);
738	754	cpumask_set_cpu(cpu, policy->cpus);
	755	+ cpumask_copy(data->freqdomain_cpus, cpu_sibling_mask(cpu));
739	756	policy->shared_type = CPUFREQ_SHARED_TYPE_HW;
740	757	pr_info_once(PFX "overriding BIOS provided _PSD data\n");
741	758	}
...	...	@@ -870,6 +887,8 @@
870	887	kfree(data->freq_table);
871	888	err_unreg:
872	889	acpi_processor_unregister_performance(perf, cpu);
	890	+err_free_mask:
	891	+ free_cpumask_var(data->freqdomain_cpus);
873	892	err_free:
874	893	kfree(data);
875	894	per_cpu(acfreq_data, cpu) = NULL;
...	...	@@ -888,6 +907,7 @@
888	907	per_cpu(acfreq_data, policy->cpu) = NULL;
889	908	acpi_processor_unregister_performance(data->acpi_data,
890	909	policy->cpu);
	910	+ free_cpumask_var(data->freqdomain_cpus);
891	911	kfree(data->freq_table);
892	912	kfree(data);
893	913	}
...	...	@@ -908,6 +928,7 @@
908	928
909	929	static struct freq_attr *acpi_cpufreq_attr[] = {
910	930	&cpufreq_freq_attr_scaling_available_freqs,
	931	+ &freqdomain_cpus,
911	932	NULL, /* this is a placeholder for cpb, do not remove */
912	933	NULL,
913	934	};
...	...	@@ -312,6 +312,12 @@
312	312	switch (state) {
313	313
314	314	case CPUFREQ_PRECHANGE:
	315	+ if (WARN(policy->transition_ongoing,
	316	+ "In middle of another frequency transition\n"))
	317	+ return;
	318	+
	319	+ policy->transition_ongoing = true;
	320	+
315	321	/* detect if the driver reported a value as "old frequency"
316	322	* which is not equal to what the cpufreq core thinks is
317	323	* "old frequency".
...	...	@@ -331,6 +337,12 @@
331	337	break;
332	338
333	339	case CPUFREQ_POSTCHANGE:
	340	+ if (WARN(!policy->transition_ongoing,
	341	+ "No frequency transition in progress\n"))
	342	+ return;
	343	+
	344	+ policy->transition_ongoing = false;
	345	+
334	346	adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
335	347	pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new,
336	348	(unsigned long)freqs->cpu);
...	...	@@ -573,7 +585,7 @@
573	585	return i;
574	586	}
575	587
576		-static ssize_t show_cpus(const struct cpumask mask, char buf)
	588	+ssize_t cpufreq_show_cpus(const struct cpumask mask, char buf)
577	589	{
578	590	ssize_t i = 0;
579	591	unsigned int cpu;
...	...	@@ -588,6 +600,7 @@
588	600	i += sprintf(&buf[i], "\n");
589	601	return i;
590	602	}
	603	+EXPORT_SYMBOL_GPL(cpufreq_show_cpus);
591	604
592	605	/**
593	606	* show_related_cpus - show the CPUs affected by each transition even if
...	...	@@ -595,7 +608,7 @@
595	608	*/
596	609	static ssize_t show_related_cpus(struct cpufreq_policy policy, char buf)
597	610	{
598		- return show_cpus(policy->related_cpus, buf);
	611	+ return cpufreq_show_cpus(policy->related_cpus, buf);
599	612	}
600	613
601	614	/**
...	...	@@ -603,7 +616,7 @@
603	616	*/
604	617	static ssize_t show_affected_cpus(struct cpufreq_policy policy, char buf)
605	618	{
606		- return show_cpus(policy->cpus, buf);
	619	+ return cpufreq_show_cpus(policy->cpus, buf);
607	620	}
608	621
609	622	static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy,
...	...	@@ -1539,6 +1552,8 @@
1539	1552
1540	1553	if (cpufreq_disabled())
1541	1554	return -ENODEV;
	1555	+ if (policy->transition_ongoing)
	1556	+ return -EBUSY;
1542	1557
1543	1558	/* Make sure that target_freq is within supported range */
1544	1559	if (target_freq > policy->max)
...	...	@@ -366,6 +366,7 @@
366	366
367	367	mutex_lock(&dbs_data->mutex);
368	368	mutex_destroy(&cpu_cdbs->timer_mutex);
	369	+ cpu_cdbs->cur_policy = NULL;
369	370
370	371	mutex_unlock(&dbs_data->mutex);
371	372
...	...	@@ -119,6 +119,7 @@
119	119
120	120	struct kobject kobj;
121	121	struct completion kobj_unregister;
	122	+ bool transition_ongoing; /* Tracks transition status */
122	123	};
123	124
124	125	#define CPUFREQ_ADJUST (0)
...	...	@@ -438,5 +439,8 @@
438	439	void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
439	440
440	441	void cpufreq_frequency_table_put_attr(unsigned int cpu);
	442	+
	443	+ssize_t cpufreq_show_cpus(const struct cpumask mask, char buf);
	444	+
441	445	#endif /* _LINUX_CPUFREQ_H */