cpufreq: arm_big_little: add in-kernel switching (IKS) support (e79a23c5) · Commits · 戴 / test

drivers/cpufreq/arm_big_little.c

+337 −26

Original line number	Diff line number	Diff line
		@@ -24,27 +24,165 @@
		#include <linux/cpufreq.h>
		#include <linux/cpumask.h>
		#include <linux/export.h>
		#include <linux/mutex.h>
		#include <linux/of_platform.h>
		#include <linux/pm_opp.h>
		#include <linux/slab.h>
		#include <linux/topology.h>
		#include <linux/types.h>
		#include <asm/bL_switcher.h>

		#include "arm_big_little.h"

		/* Currently we support only two clusters */
		#define A15_CLUSTER 0
		#define A7_CLUSTER 1
		#define MAX_CLUSTERS 2

		#ifdef CONFIG_BL_SWITCHER
		#define is_bL_switching_enabled() true
		#else
		#define is_bL_switching_enabled() false
		#endif

		#define ACTUAL_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq << 1 : freq)
		#define VIRT_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq >> 1 : freq)

		static struct cpufreq_arm_bL_ops *arm_bL_ops;
		static struct clk *clk[MAX_CLUSTERS];
		static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS];
		static atomic_t cluster_usage[MAX_CLUSTERS] = {ATOMIC_INIT(0), ATOMIC_INIT(0)};
		static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1];
		static atomic_t cluster_usage[MAX_CLUSTERS + 1];

		static unsigned int clk_big_min; /* (Big) clock frequencies */
		static unsigned int clk_little_max; /* Maximum clock frequency (Little) */

		static DEFINE_PER_CPU(unsigned int, physical_cluster);
		static DEFINE_PER_CPU(unsigned int, cpu_last_req_freq);

		static struct mutex cluster_lock[MAX_CLUSTERS];

		static unsigned int bL_cpufreq_get(unsigned int cpu)
		static inline int raw_cpu_to_cluster(int cpu)
		{
		u32 cur_cluster = cpu_to_cluster(cpu);
		return topology_physical_package_id(cpu);
		}

		return clk_get_rate(clk[cur_cluster]) / 1000;
		static inline int cpu_to_cluster(int cpu)
		{
		return is_bL_switching_enabled() ?
		MAX_CLUSTERS : raw_cpu_to_cluster(cpu);
		}

		static unsigned int find_cluster_maxfreq(int cluster)
		{
		int j;
		u32 max_freq = 0, cpu_freq;

		for_each_online_cpu(j) {
		cpu_freq = per_cpu(cpu_last_req_freq, j);

		if ((cluster == per_cpu(physical_cluster, j)) &&
		(max_freq < cpu_freq))
		max_freq = cpu_freq;
		}

		pr_debug("%s: cluster: %d, max freq: %d\n", __func__, cluster,
		max_freq);

		return max_freq;
		}

		static unsigned int clk_get_cpu_rate(unsigned int cpu)
		{
		u32 cur_cluster = per_cpu(physical_cluster, cpu);
		u32 rate = clk_get_rate(clk[cur_cluster]) / 1000;

		/* For switcher we use virtual A7 clock rates */
		if (is_bL_switching_enabled())
		rate = VIRT_FREQ(cur_cluster, rate);

		pr_debug("%s: cpu: %d, cluster: %d, freq: %u\n", __func__, cpu,
		cur_cluster, rate);

		return rate;
		}

		static unsigned int bL_cpufreq_get_rate(unsigned int cpu)
		{
		if (is_bL_switching_enabled()) {
		pr_debug("%s: freq: %d\n", __func__, per_cpu(cpu_last_req_freq,
		cpu));

		return per_cpu(cpu_last_req_freq, cpu);
		} else {
		return clk_get_cpu_rate(cpu);
		}
		}

		static unsigned int
		bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
		{
		u32 new_rate, prev_rate;
		int ret;
		bool bLs = is_bL_switching_enabled();

		mutex_lock(&cluster_lock[new_cluster]);

		if (bLs) {
		prev_rate = per_cpu(cpu_last_req_freq, cpu);
		per_cpu(cpu_last_req_freq, cpu) = rate;
		per_cpu(physical_cluster, cpu) = new_cluster;

		new_rate = find_cluster_maxfreq(new_cluster);
		new_rate = ACTUAL_FREQ(new_cluster, new_rate);
		} else {
		new_rate = rate;
		}

		pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d, freq: %d\n",
		__func__, cpu, old_cluster, new_cluster, new_rate);

		ret = clk_set_rate(clk[new_cluster], new_rate * 1000);
		if (WARN_ON(ret)) {
		pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret,
		new_cluster);
		if (bLs) {
		per_cpu(cpu_last_req_freq, cpu) = prev_rate;
		per_cpu(physical_cluster, cpu) = old_cluster;
		}

		mutex_unlock(&cluster_lock[new_cluster]);

		return ret;
		}

		mutex_unlock(&cluster_lock[new_cluster]);

		/* Recalc freq for old cluster when switching clusters */
		if (old_cluster != new_cluster) {
		pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d\n",
		__func__, cpu, old_cluster, new_cluster);

		/* Switch cluster */
		bL_switch_request(cpu, new_cluster);

		mutex_lock(&cluster_lock[old_cluster]);

		/* Set freq of old cluster if there are cpus left on it */
		new_rate = find_cluster_maxfreq(old_cluster);
		new_rate = ACTUAL_FREQ(old_cluster, new_rate);

		if (new_rate) {
		pr_debug("%s: Updating rate of old cluster: %d, to freq: %d\n",
		__func__, old_cluster, new_rate);

		if (clk_set_rate(clk[old_cluster], new_rate * 1000))
		pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n",
		__func__, ret, old_cluster);
		}
		mutex_unlock(&cluster_lock[old_cluster]);
		}

		return 0;
		}

		/* Set clock frequency */
		@@ -52,63 +190,164 @@ static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
		unsigned int index)
		{
		struct cpufreq_freqs freqs;
		u32 cpu = policy->cpu, cur_cluster;
		u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
		int ret = 0;

		cur_cluster = cpu_to_cluster(policy->cpu);
		cur_cluster = cpu_to_cluster(cpu);
		new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);

		freqs.old = bL_cpufreq_get(policy->cpu);
		freqs.old = bL_cpufreq_get_rate(cpu);
		freqs.new = freq_table[cur_cluster][index].frequency;

		pr_debug("%s: cpu: %d, cluster: %d, oldfreq: %d, target freq: %d, new freq: %d\n",
		__func__, cpu, cur_cluster, freqs.old, freqs.new,
		freqs.new);

		if (is_bL_switching_enabled()) {
		if ((actual_cluster == A15_CLUSTER) &&
		(freqs.new < clk_big_min)) {
		new_cluster = A7_CLUSTER;
		} else if ((actual_cluster == A7_CLUSTER) &&
		(freqs.new > clk_little_max)) {
		new_cluster = A15_CLUSTER;
		}
		}

		cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);

		ret = clk_set_rate(clk[cur_cluster], freqs.new * 1000);
		if (ret) {
		pr_err("clk_set_rate failed: %d\n", ret);
		ret = bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs.new);
		if (ret)
		freqs.new = freqs.old;
		}

		cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);

		return ret;
		}

		static void put_cluster_clk_and_freq_table(struct device *cpu_dev)
		static inline u32 get_table_count(struct cpufreq_frequency_table *table)
		{
		u32 cluster = cpu_to_cluster(cpu_dev->id);
		int count;

		for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
		;

		return count;
		}

		/* get the minimum frequency in the cpufreq_frequency_table */
		static inline u32 get_table_min(struct cpufreq_frequency_table *table)
		{
		int i;
		uint32_t min_freq = ~0;
		for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++)
		if (table[i].frequency < min_freq)
		min_freq = table[i].frequency;
		return min_freq;
		}

		/* get the maximum frequency in the cpufreq_frequency_table */
		static inline u32 get_table_max(struct cpufreq_frequency_table *table)
		{
		int i;
		uint32_t max_freq = 0;
		for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++)
		if (table[i].frequency > max_freq)
		max_freq = table[i].frequency;
		return max_freq;
		}

		static int merge_cluster_tables(void)
		{
		int i, j, k = 0, count = 1;
		struct cpufreq_frequency_table *table;

		for (i = 0; i < MAX_CLUSTERS; i++)
		count += get_table_count(freq_table[i]);

		table = kzalloc(sizeof(table) count, GFP_KERNEL);
		if (!table)
		return -ENOMEM;

		freq_table[MAX_CLUSTERS] = table;

		/* Add in reverse order to get freqs in increasing order */
		for (i = MAX_CLUSTERS - 1; i >= 0; i--) {
		for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
		j++) {
		table[k].frequency = VIRT_FREQ(i,
		freq_table[i][j].frequency);
		pr_debug("%s: index: %d, freq: %d\n", __func__, k,
		table[k].frequency);
		k++;
		}
		}

		table[k].driver_data = k;
		table[k].frequency = CPUFREQ_TABLE_END;

		pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);

		return 0;
		}

		static void _put_cluster_clk_and_freq_table(struct device *cpu_dev)
		{
		u32 cluster = raw_cpu_to_cluster(cpu_dev->id);

		if (!freq_table[cluster])
		return;

		if (!atomic_dec_return(&cluster_usage[cluster])) {
		clk_put(clk[cluster]);
		dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
		dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
		}
		}

		static int get_cluster_clk_and_freq_table(struct device *cpu_dev)
		static void put_cluster_clk_and_freq_table(struct device *cpu_dev)
		{
		u32 cluster = cpu_to_cluster(cpu_dev->id);
		int i;

		if (atomic_dec_return(&cluster_usage[cluster]))
		return;

		if (cluster < MAX_CLUSTERS)
		return _put_cluster_clk_and_freq_table(cpu_dev);

		for_each_present_cpu(i) {
		struct device *cdev = get_cpu_device(i);
		if (!cdev) {
		pr_err("%s: failed to get cpu%d device\n", __func__, i);
		return;
		}

		_put_cluster_clk_and_freq_table(cdev);
		}

		/* free virtual table */
		kfree(freq_table[cluster]);
		}

		static int _get_cluster_clk_and_freq_table(struct device *cpu_dev)
		{
		u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
		char name[14] = "cpu-cluster.";
		int ret;

		if (atomic_inc_return(&cluster_usage[cluster]) != 1)
		if (freq_table[cluster])
		return 0;

		ret = arm_bL_ops->init_opp_table(cpu_dev);
		if (ret) {
		dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
		__func__, cpu_dev->id, ret);
		goto atomic_dec;
		goto out;
		}

		ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
		if (ret) {
		dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
		__func__, cpu_dev->id, ret);
		goto atomic_dec;
		goto out;
		}

		name[12] = cluster + '0';
		@@ -125,13 +364,72 @@ static int get_cluster_clk_and_freq_table(struct device *cpu_dev)
		ret = PTR_ERR(clk[cluster]);
		dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);

		atomic_dec:
		atomic_dec(&cluster_usage[cluster]);
		out:
		dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
		cluster);
		return ret;
		}

		static int get_cluster_clk_and_freq_table(struct device *cpu_dev)
		{
		u32 cluster = cpu_to_cluster(cpu_dev->id);
		int i, ret;

		if (atomic_inc_return(&cluster_usage[cluster]) != 1)
		return 0;

		if (cluster < MAX_CLUSTERS) {
		ret = _get_cluster_clk_and_freq_table(cpu_dev);
		if (ret)
		atomic_dec(&cluster_usage[cluster]);
		return ret;
		}

		/*
		* Get data for all clusters and fill virtual cluster with a merge of
		* both
		*/
		for_each_present_cpu(i) {
		struct device *cdev = get_cpu_device(i);
		if (!cdev) {
		pr_err("%s: failed to get cpu%d device\n", __func__, i);
		return -ENODEV;
		}

		ret = _get_cluster_clk_and_freq_table(cdev);
		if (ret)
		goto put_clusters;
		}

		ret = merge_cluster_tables();
		if (ret)
		goto put_clusters;

		/* Assuming 2 cluster, set clk_big_min and clk_little_max */
		clk_big_min = get_table_min(freq_table[0]);
		clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));

		pr_debug("%s: cluster: %d, clk_big_min: %d, clk_little_max: %d\n",
		__func__, cluster, clk_big_min, clk_little_max);

		return 0;

		put_clusters:
		for_each_present_cpu(i) {
		struct device *cdev = get_cpu_device(i);
		if (!cdev) {
		pr_err("%s: failed to get cpu%d device\n", __func__, i);
		return -ENODEV;
		}

		_put_cluster_clk_and_freq_table(cdev);
		}

		atomic_dec(&cluster_usage[cluster]);

		return ret;
		}

		/* Per-CPU initialization */
		static int bL_cpufreq_init(struct cpufreq_policy *policy)
		{
		@@ -158,13 +456,23 @@ static int bL_cpufreq_init(struct cpufreq_policy *policy)
		return ret;
		}

		if (cur_cluster < MAX_CLUSTERS) {
		cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));

		per_cpu(physical_cluster, policy->cpu) = cur_cluster;
		} else {
		/* Assumption: during init, we are always running on A15 */
		per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
		}

		if (arm_bL_ops->get_transition_latency)
		policy->cpuinfo.transition_latency =
		arm_bL_ops->get_transition_latency(cpu_dev);
		else
		policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;

		cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
		if (is_bL_switching_enabled())
		per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu);

		dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
		return 0;
		@@ -194,7 +502,7 @@ static struct cpufreq_driver bL_cpufreq_driver = {
		CPUFREQ_HAVE_GOVERNOR_PER_POLICY,
		.verify = cpufreq_generic_frequency_table_verify,
		.target_index = bL_cpufreq_set_target,
		.get = bL_cpufreq_get,
		.get = bL_cpufreq_get_rate,
		.init = bL_cpufreq_init,
		.exit = bL_cpufreq_exit,
		.attr = cpufreq_generic_attr,
		@@ -202,7 +510,7 @@ static struct cpufreq_driver bL_cpufreq_driver = {

		int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
		{
		int ret;
		int ret, i;

		if (arm_bL_ops) {
		pr_debug("%s: Already registered: %s, exiting\n", __func__,
		@@ -217,6 +525,9 @@ int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)

		arm_bL_ops = ops;

		for (i = 0; i < MAX_CLUSTERS; i++)
		mutex_init(&cluster_lock[i]);

		ret = cpufreq_register_driver(&bL_cpufreq_driver);
		if (ret) {
		pr_info("%s: Failed registering platform driver: %s, err: %d\n",

drivers/cpufreq/arm_big_little.h

+0 −5

Original line number	Diff line number	Diff line
		@@ -34,11 +34,6 @@ struct cpufreq_arm_bL_ops {
		int (init_opp_table)(struct device cpu_dev);
		};

		static inline int cpu_to_cluster(int cpu)
		{
		return topology_physical_package_id(cpu);
		}

		int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops);
		void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops);

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