--- /dev/null
+From a03dacb0316f74400846aaf144d6c73f4217ca08 Mon Sep 17 00:00:00 2001
+From: Saravana Kannan <skannan@codeaurora.org>
+Date: Tue, 2 Mar 2021 15:58:21 +0900
+Subject: [PATCH 2/5] PM / devfreq: Add cpu based scaling support to passive
+ governor
+
+Many CPU architectures have caches that can scale independent of the
+CPUs. Frequency scaling of the caches is necessary to make sure that the
+cache is not a performance bottleneck that leads to poor performance and
+power. The same idea applies for RAM/DDR.
+
+To achieve this, this patch adds support for cpu based scaling to the
+passive governor. This is accomplished by taking the current frequency
+of each CPU frequency domain and then adjust the frequency of the cache
+(or any devfreq device) based on the frequency of the CPUs. It listens
+to CPU frequency transition notifiers to keep itself up to date on the
+current CPU frequency.
+
+To decide the frequency of the device, the governor does one of the
+following:
+* Derives the optimal devfreq device opp from required-opps property of
+ the parent cpu opp_table.
+
+* Scales the device frequency in proportion to the CPU frequency. So, if
+ the CPUs are running at their max frequency, the device runs at its
+ max frequency. If the CPUs are running at their min frequency, the
+ device runs at its min frequency. It is interpolated for frequencies
+ in between.
+
+Tested-by: Chen-Yu Tsai <wenst@chromium.org>
+Tested-by: Johnson Wang <johnson.wang@mediatek.com>
+Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
+[Sibi: Integrated cpu-freqmap governor into passive_governor]
+Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
+[Chanwoo: Fix conflict with latest code and cleanup code]
+Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
+---
+ drivers/devfreq/governor.h | 22 +++
+ drivers/devfreq/governor_passive.c | 298 +++++++++++++++++++++++++++--
+ include/linux/devfreq.h | 17 +-
+ 3 files changed, 323 insertions(+), 14 deletions(-)
+
+--- a/drivers/devfreq/governor.h
++++ b/drivers/devfreq/governor.h
+@@ -48,6 +48,28 @@
+ #define DEVFREQ_GOV_ATTR_TIMER BIT(1)
+
+ /**
++ * struct devfreq_cpu_data - Hold the per-cpu data
++ * @dev: reference to cpu device.
++ * @first_cpu: the cpumask of the first cpu of a policy.
++ * @opp_table: reference to cpu opp table.
++ * @cur_freq: the current frequency of the cpu.
++ * @min_freq: the min frequency of the cpu.
++ * @max_freq: the max frequency of the cpu.
++ *
++ * This structure stores the required cpu_data of a cpu.
++ * This is auto-populated by the governor.
++ */
++struct devfreq_cpu_data {
++ struct device *dev;
++ unsigned int first_cpu;
++
++ struct opp_table *opp_table;
++ unsigned int cur_freq;
++ unsigned int min_freq;
++ unsigned int max_freq;
++};
++
++/**
+ * struct devfreq_governor - Devfreq policy governor
+ * @node: list node - contains registered devfreq governors
+ * @name: Governor's name
+--- a/drivers/devfreq/governor_passive.c
++++ b/drivers/devfreq/governor_passive.c
+@@ -8,11 +8,85 @@
+ */
+
+ #include <linux/module.h>
++#include <linux/cpu.h>
++#include <linux/cpufreq.h>
++#include <linux/cpumask.h>
++#include <linux/slab.h>
+ #include <linux/device.h>
+ #include <linux/devfreq.h>
+ #include "governor.h"
+
+-static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
++#define HZ_PER_KHZ 1000
++
++static unsigned long get_target_freq_by_required_opp(struct device *p_dev,
++ struct opp_table *p_opp_table,
++ struct opp_table *opp_table,
++ unsigned long *freq)
++{
++ struct dev_pm_opp *opp = NULL, *p_opp = NULL;
++ unsigned long target_freq;
++
++ if (!p_dev || !p_opp_table || !opp_table || !freq)
++ return 0;
++
++ p_opp = devfreq_recommended_opp(p_dev, freq, 0);
++ if (IS_ERR(p_opp))
++ return 0;
++
++ opp = dev_pm_opp_xlate_required_opp(p_opp_table, opp_table, p_opp);
++ dev_pm_opp_put(p_opp);
++
++ if (IS_ERR(opp))
++ return 0;
++
++ target_freq = dev_pm_opp_get_freq(opp);
++ dev_pm_opp_put(opp);
++
++ return target_freq;
++}
++
++static int get_target_freq_with_cpufreq(struct devfreq *devfreq,
++ unsigned long *target_freq)
++{
++ struct devfreq_passive_data *p_data =
++ (struct devfreq_passive_data *)devfreq->data;
++ struct devfreq_cpu_data *parent_cpu_data;
++ unsigned long cpu, cpu_cur, cpu_min, cpu_max, cpu_percent;
++ unsigned long dev_min, dev_max;
++ unsigned long freq = 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)
++ continue;
++
++ /* Get target freq via required opps */
++ cpu_cur = parent_cpu_data->cur_freq * HZ_PER_KHZ;
++ freq = get_target_freq_by_required_opp(parent_cpu_data->dev,
++ parent_cpu_data->opp_table,
++ devfreq->opp_table, &cpu_cur);
++ if (freq) {
++ *target_freq = max(freq, *target_freq);
++ continue;
++ }
++
++ /* Use interpolation if required opps is not available */
++ devfreq_get_freq_range(devfreq, &dev_min, &dev_max);
++
++ cpu_min = parent_cpu_data->min_freq;
++ cpu_max = parent_cpu_data->max_freq;
++ cpu_cur = parent_cpu_data->cur_freq;
++
++ cpu_percent = ((cpu_cur - cpu_min) * 100) / (cpu_max - cpu_min);
++ freq = dev_min + mult_frac(dev_max - dev_min, cpu_percent, 100);
++
++ *target_freq = max(freq, *target_freq);
++ }
++
++ return 0;
++}
++
++static int get_target_freq_with_devfreq(struct devfreq *devfreq,
+ unsigned long *freq)
+ {
+ struct devfreq_passive_data *p_data
+@@ -99,6 +173,181 @@ no_required_opp:
+ return 0;
+ }
+
++static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
++ unsigned long *freq)
++{
++ struct devfreq_passive_data *p_data =
++ (struct devfreq_passive_data *)devfreq->data;
++ int ret;
++
++ if (!p_data)
++ return -EINVAL;
++
++ /*
++ * If the devfreq device with passive governor has the specific method
++ * to determine the next frequency, should use the get_target_freq()
++ * of struct devfreq_passive_data.
++ */
++ if (p_data->get_target_freq)
++ return p_data->get_target_freq(devfreq, freq);
++
++ switch (p_data->parent_type) {
++ case DEVFREQ_PARENT_DEV:
++ ret = get_target_freq_with_devfreq(devfreq, freq);
++ break;
++ case CPUFREQ_PARENT_DEV:
++ ret = get_target_freq_with_cpufreq(devfreq, freq);
++ break;
++ default:
++ ret = -EINVAL;
++ dev_err(&devfreq->dev, "Invalid parent type\n");
++ break;
++ }
++
++ return ret;
++}
++
++static int cpufreq_passive_notifier_call(struct notifier_block *nb,
++ unsigned long event, void *ptr)
++{
++ struct devfreq_passive_data *p_data =
++ container_of(nb, struct devfreq_passive_data, nb);
++ struct devfreq *devfreq = (struct devfreq *)p_data->this;
++ struct devfreq_cpu_data *parent_cpu_data;
++ struct cpufreq_freqs *freqs = ptr;
++ unsigned int cur_freq;
++ int ret;
++
++ if (event != CPUFREQ_POSTCHANGE || !freqs ||
++ !p_data->parent_cpu_data[freqs->policy->cpu])
++ return 0;
++
++ parent_cpu_data = p_data->parent_cpu_data[freqs->policy->cpu];
++ if (parent_cpu_data->cur_freq == freqs->new)
++ return 0;
++
++ cur_freq = parent_cpu_data->cur_freq;
++ parent_cpu_data->cur_freq = freqs->new;
++
++ mutex_lock(&devfreq->lock);
++ ret = devfreq_update_target(devfreq, freqs->new);
++ mutex_unlock(&devfreq->lock);
++ if (ret) {
++ parent_cpu_data->cur_freq = cur_freq;
++ dev_err(&devfreq->dev, "failed to update the frequency.\n");
++ return ret;
++ }
++
++ return 0;
++}
++
++static int cpufreq_passive_unregister_notifier(struct devfreq *devfreq)
++{
++ struct devfreq_passive_data *p_data
++ = (struct devfreq_passive_data *)devfreq->data;
++ struct devfreq_cpu_data *parent_cpu_data;
++ int cpu, ret;
++
++ if (p_data->nb.notifier_call) {
++ ret = cpufreq_unregister_notifier(&p_data->nb,
++ CPUFREQ_TRANSITION_NOTIFIER);
++ if (ret < 0)
++ return ret;
++ }
++
++ for_each_possible_cpu(cpu) {
++ parent_cpu_data = p_data->parent_cpu_data[cpu];
++ if (!parent_cpu_data)
++ continue;
++
++ if (parent_cpu_data->opp_table)
++ dev_pm_opp_put_opp_table(parent_cpu_data->opp_table);
++ kfree(parent_cpu_data);
++ }
++
++ return 0;
++}
++
++static int cpufreq_passive_register_notifier(struct devfreq *devfreq)
++{
++ struct devfreq_passive_data *p_data
++ = (struct devfreq_passive_data *)devfreq->data;
++ struct device *dev = devfreq->dev.parent;
++ struct opp_table *opp_table = NULL;
++ struct devfreq_cpu_data *parent_cpu_data;
++ struct cpufreq_policy *policy;
++ struct device *cpu_dev;
++ unsigned int cpu;
++ int ret;
++
++ p_data->nb.notifier_call = cpufreq_passive_notifier_call;
++ ret = cpufreq_register_notifier(&p_data->nb, CPUFREQ_TRANSITION_NOTIFIER);
++ if (ret) {
++ dev_err(dev, "failed to register cpufreq notifier\n");
++ p_data->nb.notifier_call = NULL;
++ goto err;
++ }
++
++ 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 = kzalloc(sizeof(*parent_cpu_data),
++ GFP_KERNEL);
++ if (!parent_cpu_data) {
++ ret = -ENOMEM;
++ goto err_put_policy;
++ }
++
++ cpu_dev = get_cpu_device(cpu);
++ if (!cpu_dev) {
++ dev_err(dev, "failed to get cpu device\n");
++ ret = -ENODEV;
++ goto err_free_cpu_data;
++ }
++
++ opp_table = dev_pm_opp_get_opp_table(cpu_dev);
++ if (IS_ERR(opp_table)) {
++ dev_err(dev, "failed to get opp_table of cpu%d\n", cpu);
++ ret = PTR_ERR(opp_table);
++ goto err_free_cpu_data;
++ }
++
++ parent_cpu_data->dev = cpu_dev;
++ parent_cpu_data->opp_table = opp_table;
++ parent_cpu_data->first_cpu = cpumask_first(policy->related_cpus);
++ parent_cpu_data->cur_freq = policy->cur;
++ 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;
++ cpufreq_cpu_put(policy);
++ }
++
++ mutex_lock(&devfreq->lock);
++ ret = devfreq_update_target(devfreq, 0L);
++ mutex_unlock(&devfreq->lock);
++ if (ret)
++ dev_err(dev, "failed to update the frequency\n");
++
++ return ret;
++
++err_free_cpu_data:
++ kfree(parent_cpu_data);
++err_put_policy:
++ cpufreq_cpu_put(policy);
++err:
++ WARN_ON(cpufreq_passive_unregister_notifier(devfreq));
++
++ return ret;
++}
++
+ static int devfreq_passive_notifier_call(struct notifier_block *nb,
+ unsigned long event, void *ptr)
+ {
+@@ -131,30 +380,55 @@ static int devfreq_passive_notifier_call
+ return NOTIFY_DONE;
+ }
+
+-static int devfreq_passive_event_handler(struct devfreq *devfreq,
+- unsigned int event, void *data)
++static int devfreq_passive_unregister_notifier(struct devfreq *devfreq)
++{
++ struct devfreq_passive_data *p_data
++ = (struct devfreq_passive_data *)devfreq->data;
++ struct devfreq *parent = (struct devfreq *)p_data->parent;
++ struct notifier_block *nb = &p_data->nb;
++
++ return devfreq_unregister_notifier(parent, nb, DEVFREQ_TRANSITION_NOTIFIER);
++}
++
++static int devfreq_passive_register_notifier(struct devfreq *devfreq)
+ {
+ struct devfreq_passive_data *p_data
+ = (struct devfreq_passive_data *)devfreq->data;
+ struct devfreq *parent = (struct devfreq *)p_data->parent;
+ struct notifier_block *nb = &p_data->nb;
+- int ret = 0;
+
+ if (!parent)
+ return -EPROBE_DEFER;
+
++ nb->notifier_call = devfreq_passive_notifier_call;
++ return devfreq_register_notifier(parent, nb, DEVFREQ_TRANSITION_NOTIFIER);
++}
++
++static int devfreq_passive_event_handler(struct devfreq *devfreq,
++ unsigned int event, void *data)
++{
++ struct devfreq_passive_data *p_data
++ = (struct devfreq_passive_data *)devfreq->data;
++ int ret = -EINVAL;
++
++ if (!p_data)
++ return -EINVAL;
++
++ if (!p_data->this)
++ p_data->this = devfreq;
++
+ switch (event) {
+ case DEVFREQ_GOV_START:
+- if (!p_data->this)
+- p_data->this = devfreq;
+-
+- nb->notifier_call = devfreq_passive_notifier_call;
+- ret = devfreq_register_notifier(parent, nb,
+- DEVFREQ_TRANSITION_NOTIFIER);
++ if (p_data->parent_type == DEVFREQ_PARENT_DEV)
++ ret = devfreq_passive_register_notifier(devfreq);
++ else if (p_data->parent_type == CPUFREQ_PARENT_DEV)
++ ret = cpufreq_passive_register_notifier(devfreq);
+ break;
+ case DEVFREQ_GOV_STOP:
+- WARN_ON(devfreq_unregister_notifier(parent, nb,
+- DEVFREQ_TRANSITION_NOTIFIER));
++ if (p_data->parent_type == DEVFREQ_PARENT_DEV)
++ WARN_ON(devfreq_passive_unregister_notifier(devfreq));
++ else if (p_data->parent_type == CPUFREQ_PARENT_DEV)
++ WARN_ON(cpufreq_passive_unregister_notifier(devfreq));
+ break;
+ default:
+ break;
+--- a/include/linux/devfreq.h
++++ b/include/linux/devfreq.h
+@@ -38,6 +38,7 @@ enum devfreq_timer {
+
+ struct devfreq;
+ struct devfreq_governor;
++struct devfreq_cpu_data;
+ struct thermal_cooling_device;
+
+ /**
+@@ -289,6 +290,11 @@ struct devfreq_simple_ondemand_data {
+ #endif
+
+ #if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
++enum devfreq_parent_dev_type {
++ DEVFREQ_PARENT_DEV,
++ CPUFREQ_PARENT_DEV,
++};
++
+ /**
+ * struct devfreq_passive_data - ``void *data`` fed to struct devfreq
+ * and devfreq_add_device
+@@ -300,8 +306,11 @@ struct devfreq_simple_ondemand_data {
+ * using governors except for passive governor.
+ * If the devfreq device has the specific method to decide
+ * the next frequency, should use this callback.
+- * @this: the devfreq instance of own device.
+- * @nb: the notifier block for DEVFREQ_TRANSITION_NOTIFIER list
++ * @parent_type: the parent type of the device.
++ * @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.
+ *
+ * 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
+@@ -315,9 +324,13 @@ struct devfreq_passive_data {
+ /* Optional callback to decide the next frequency of passvice device */
+ int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
+
++ /* Should set the type of parent device */
++ enum devfreq_parent_dev_type parent_type;
++
+ /* 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];
+ };
+ #endif
+
projects / openwrt / staging / ldir.git / blobdiff