openwrt/target/linux/ipq806x/patches-5.15/111-v5.19-04-PM-devfreq-passive-Keep-cpufreq_policy-for-possible-.patch

From 26984d9d581e5049bd75091d2e789b9cc3ea12e0 Mon Sep 17 00:00:00 2001
From: Chanwoo Choi <cw00.choi@samsung.com>
Date: Wed, 27 Apr 2022 03:49:19 +0900
Subject: [PATCH 4/5] PM / devfreq: passive: Keep cpufreq_policy for possible
 cpus

The passive governor requires the cpu data to get the next target frequency
of devfreq device if depending on cpu. In order to reduce the unnecessary
memory data, keep cpufreq_policy data for possible cpus instead of NR_CPU.

Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Tested-by: Johnson Wang <johnson.wang@mediatek.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
---
 drivers/devfreq/governor.h         |  3 ++
 drivers/devfreq/governor_passive.c | 75 +++++++++++++++++++++++-------
 include/linux/devfreq.h            |  4 +-
 3 files changed, 64 insertions(+), 18 deletions(-)

--- a/drivers/devfreq/governor.h
+++ b/drivers/devfreq/governor.h
@@ -49,6 +49,7 @@
 
 /**
  * struct devfreq_cpu_data - Hold the per-cpu data
+ * @node:	list node
  * @dev:	reference to cpu device.
  * @first_cpu:	the cpumask of the first cpu of a policy.
  * @opp_table:	reference to cpu opp table.
@@ -60,6 +61,8 @@
  * This is auto-populated by the governor.
  */
 struct devfreq_cpu_data {
+	struct list_head node;
+
 	struct device *dev;
 	unsigned int first_cpu;
 
--- a/drivers/devfreq/governor_passive.c
+++ b/drivers/devfreq/governor_passive.c
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0-only
+	// SPDX-License-Identifier: GPL-2.0-only
 /*
  * linux/drivers/devfreq/governor_passive.c
  *
@@ -18,6 +18,22 @@
 
 #define HZ_PER_KHZ	1000
 
+static struct devfreq_cpu_data *
+get_parent_cpu_data(struct devfreq_passive_data *p_data,
+		    struct cpufreq_policy *policy)
+{
+	struct devfreq_cpu_data *parent_cpu_data;
+
+	if (!p_data || !policy)
+		return NULL;
+
+	list_for_each_entry(parent_cpu_data, &p_data->cpu_data_list, node)
+		if (parent_cpu_data->first_cpu == cpumask_first(policy->related_cpus))
+			return parent_cpu_data;
+
+	return NULL;
+}
+
 static unsigned long get_target_freq_by_required_opp(struct device *p_dev,
 						struct opp_table *p_opp_table,
 						struct opp_table *opp_table,
@@ -51,14 +67,24 @@ static int get_target_freq_with_cpufreq(
 	struct devfreq_passive_data *p_data =
 				(struct devfreq_passive_data *)devfreq->data;
 	struct devfreq_cpu_data *parent_cpu_data;
+	struct cpufreq_policy *policy;
 	unsigned long cpu, cpu_cur, cpu_min, cpu_max, cpu_percent;
 	unsigned long dev_min, dev_max;
 	unsigned long freq = 0;
+	int ret = 0;
 
 	for_each_online_cpu(cpu) {
-		parent_cpu_data = p_data->parent_cpu_data[cpu];
-		if (!parent_cpu_data || parent_cpu_data->first_cpu != cpu)
+		policy = cpufreq_cpu_get(cpu);
+		if (!policy) {
+			ret = -EINVAL;
+			continue;
+		}
+
+		parent_cpu_data = get_parent_cpu_data(p_data, policy);
+		if (!parent_cpu_data) {
+			cpufreq_cpu_put(policy);
 			continue;
+		}
 
 		/* Get target freq via required opps */
 		cpu_cur = parent_cpu_data->cur_freq * HZ_PER_KHZ;
@@ -67,6 +93,7 @@ static int get_target_freq_with_cpufreq(
 					devfreq->opp_table, &cpu_cur);
 		if (freq) {
 			*target_freq = max(freq, *target_freq);
+			cpufreq_cpu_put(policy);
 			continue;
 		}
 
@@ -81,9 +108,10 @@ static int get_target_freq_with_cpufreq(
 		freq = dev_min + mult_frac(dev_max - dev_min, cpu_percent, 100);
 
 		*target_freq = max(freq, *target_freq);
+		cpufreq_cpu_put(policy);
 	}
 
-	return 0;
+	return ret;
 }
 
 static int get_target_freq_with_devfreq(struct devfreq *devfreq,
@@ -168,12 +196,11 @@ static int cpufreq_passive_notifier_call
 	unsigned int cur_freq;
 	int ret;
 
-	if (event != CPUFREQ_POSTCHANGE || !freqs ||
-		!p_data->parent_cpu_data[freqs->policy->cpu])
+	if (event != CPUFREQ_POSTCHANGE || !freqs)
 		return 0;
 
-	parent_cpu_data = p_data->parent_cpu_data[freqs->policy->cpu];
-	if (parent_cpu_data->cur_freq == freqs->new)
+	parent_cpu_data = get_parent_cpu_data(p_data, freqs->policy);
+	if (!parent_cpu_data || parent_cpu_data->cur_freq == freqs->new)
 		return 0;
 
 	cur_freq = parent_cpu_data->cur_freq;
@@ -196,7 +223,7 @@ static int cpufreq_passive_unregister_no
 	struct devfreq_passive_data *p_data
 			= (struct devfreq_passive_data *)devfreq->data;
 	struct devfreq_cpu_data *parent_cpu_data;
-	int cpu, ret;
+	int cpu, ret = 0;
 
 	if (p_data->nb.notifier_call) {
 		ret = cpufreq_unregister_notifier(&p_data->nb,
@@ -206,16 +233,26 @@ static int cpufreq_passive_unregister_no
 	}
 
 	for_each_possible_cpu(cpu) {
-		parent_cpu_data = p_data->parent_cpu_data[cpu];
-		if (!parent_cpu_data)
+		struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+		if (!policy) {
+			ret = -EINVAL;
+			continue;
+		}
+
+		parent_cpu_data = get_parent_cpu_data(p_data, policy);
+		if (!parent_cpu_data) {
+			cpufreq_cpu_put(policy);
 			continue;
+		}
 
+		list_del(&parent_cpu_data->node);
 		if (parent_cpu_data->opp_table)
 			dev_pm_opp_put_opp_table(parent_cpu_data->opp_table);
 		kfree(parent_cpu_data);
+		cpufreq_cpu_put(policy);
 	}
 
-	return 0;
+	return ret;
 }
 
 static int cpufreq_passive_register_notifier(struct devfreq *devfreq)
@@ -230,6 +267,9 @@ static int cpufreq_passive_register_noti
 	unsigned int cpu;
 	int ret;
 
+	p_data->cpu_data_list
+		= (struct list_head)LIST_HEAD_INIT(p_data->cpu_data_list);
+
 	p_data->nb.notifier_call = cpufreq_passive_notifier_call;
 	ret = cpufreq_register_notifier(&p_data->nb, CPUFREQ_TRANSITION_NOTIFIER);
 	if (ret) {
@@ -239,15 +279,18 @@ static int cpufreq_passive_register_noti
 	}
 
 	for_each_possible_cpu(cpu) {
-		if (p_data->parent_cpu_data[cpu])
-			continue;
-
 		policy = cpufreq_cpu_get(cpu);
 		if (!policy) {
 			ret = -EPROBE_DEFER;
 			goto err;
 		}
 
+		parent_cpu_data = get_parent_cpu_data(p_data, policy);
+		if (parent_cpu_data) {
+			cpufreq_cpu_put(policy);
+			continue;
+		}
+
 		parent_cpu_data = kzalloc(sizeof(*parent_cpu_data),
 						GFP_KERNEL);
 		if (!parent_cpu_data) {
@@ -276,7 +319,7 @@ static int cpufreq_passive_register_noti
 		parent_cpu_data->min_freq = policy->cpuinfo.min_freq;
 		parent_cpu_data->max_freq = policy->cpuinfo.max_freq;
 
-		p_data->parent_cpu_data[cpu] = parent_cpu_data;
+		list_add_tail(&parent_cpu_data->node, &p_data->cpu_data_list);
 		cpufreq_cpu_put(policy);
 	}
 
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -310,7 +310,7 @@ enum devfreq_parent_dev_type {
  * @this:		the devfreq instance of own device.
  * @nb:			the notifier block for DEVFREQ_TRANSITION_NOTIFIER or
  *			CPUFREQ_TRANSITION_NOTIFIER list.
- * @parent_cpu_data:	the state min/max/current frequency of all online cpu's.
+ * @cpu_data_list:	the list of cpu frequency data for all cpufreq_policy.
  *
  * The devfreq_passive_data have to set the devfreq instance of parent
  * device with governors except for the passive governor. But, don't need to
@@ -330,7 +330,7 @@ struct devfreq_passive_data {
 	/* For passive governor's internal use. Don't need to set them */
 	struct devfreq *this;
 	struct notifier_block nb;
-	struct devfreq_cpu_data *parent_cpu_data[NR_CPUS];
+	struct list_head cpu_data_list;
 };
 #endif