On 3/31/21 10:03 PM, andrew-sh.cheng wrote: > On Wed, 2021-03-31 at 17:35 +0900, Chanwoo Choi wrote: >> On 3/31/21 5:27 PM, Chanwoo Choi wrote: >>> Hi, >>> >>> On 3/31/21 5:03 PM, andrew-sh.cheng wrote: >>>> On Thu, 2021-03-25 at 17:14 +0900, Chanwoo Choi wrote: >>>>> Hi, >>>>> >>>>> You are missing to add these patches to linux-pm mailing list. >>>>> Need to send them to linu-pm ML. >>>>> >>>>> Also, before received this series, I tried to clean-up these patches >>>>> on testing branch[1]. So that I add my comment with my clean-up case. >>>>> [1] https://urldefense.com/v3/__https://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git/log/?h=devfreq-testing-passive-gov__;!!CTRNKA9wMg0ARbw!zIrzeDp9vPnm1_SDzVPuzqdHn3zWie9DnfBXaA-j9-CSrVc6aR9_rJQQiw81_CgAPh9XRRs$ >>>>> >>>>> And 'Saravana Kannan <skannan@xxxxxxxxxxxxxx>' is wrong email address. >>>>> Please update the email or drop this email. >>>> >>>> Hi Chanwoo, >>>> >>>> Thank you for the advices. >>>> I will resend patch v9 (add to linux-pm ML), remove this patch, and note >>>> that my patch set base on >>>> https://urldefense.com/v3/__https://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git/log/?h=devfreq-testing-passive-gov__;!!CTRNKA9wMg0ARbw!yUlsuxrL5PcbF7o6A9DlCfvoA6w8V8VXKjYIybYyiJg3D0HM-lI2xRuxLUV6b3UJ8WFhg_g$ >>> >>> I has not yet test this patch[1] on devfreq-testing-passive-gov branch. >>> So that if possible, I'd like you to test your patches with this patch[1] >>> and then if there is no problem, could you send the next patches with patch[1]? >>> >>> [1]https://urldefense.com/v3/__https://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git/commit/?h=devfreq-testing-passive-gov&id=39c80d11a8f42dd63ecea1e0df595a0ceb83b454__;!!CTRNKA9wMg0ARbw!yUlsuxrL5PcbF7o6A9DlCfvoA6w8V8VXKjYIybYyiJg3D0HM-lI2xRuxLUV6b3UJR2cQqZs$ >> >> >> Sorry for the confusion. I make the devfreq-testing-passive-gov[1] >> branch based on latest devfreq-next branch. >> [1] https://urldefense.com/v3/__https://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git/log/?h=devfreq-testing-passive-gov__;!!CTRNKA9wMg0ARbw!yUlsuxrL5PcbF7o6A9DlCfvoA6w8V8VXKjYIybYyiJg3D0HM-lI2xRuxLUV6b3UJ8WFhg_g$ >> >> First of all, if possible, I want to test them[1] with your patches in this series. >> And then if there are no any problem, please let me know. After confirmed from you, >> I'll send the patches of devfreq-testing-passive-gov[1] branch. >> How about that? >> > Hi Chanwoo~ > > We will use this on Google Chrome project. > Google Hsin-Yi has test your patch + my patch set v8 [2~8] > > make sure cci devfreqs runs with cpufreq. > suspend resume > speedometer2 benchmark > It is okay. > > Please send the patches of devfreq-testing-passive-gov[1] branch. > > I will send patch v9 base on yours latter. Thanks for your test. I'll send the patches today. > > >> >>> >>>> >>>> >>>>> >>>>> >>>>> On 3/23/21 8:33 PM, Andrew-sh.Cheng wrote: >>>>>> From: Saravana Kannan <skannan@xxxxxxxxxxxxxx> >>>>>> >>>>>> 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. >>>>>> >>>>>> Andrew-sh.Cheng change >>>>>> dev_pm_opp_xlate_opp to dev_pm_opp_xlate_required_opp devfreq->max_freq >>>>>> to devfreq->user_min_freq_req.data.freq.qos->min_freq.target_value >>>>>> after kernel-5.7 >>>>>> Don't return -EINVAL in devfreq_passive_event_handler() >>>>>> since it doesn't handle DEVFREQ_GOV_SUSPEND DEVFREQ_GOV_RESUME cases. >>>>>> >>>>>> Signed-off-by: Saravana Kannan <skannan@xxxxxxxxxxxxxx> >>>>>> [Sibi: Integrated cpu-freqmap governor into passive_governor] >>>>>> Signed-off-by: Sibi Sankar <sibis@xxxxxxxxxxxxxx> >>>>>> Signed-off-by: Andrew-sh.Cheng <andrew-sh.cheng@xxxxxxxxxxxx> >>>>>> --- >>>>>> drivers/devfreq/Kconfig | 2 + >>>>>> drivers/devfreq/governor_passive.c | 329 +++++++++++++++++++++++++++++++++++-- >>>>>> include/linux/devfreq.h | 29 +++- >>>>>> 3 files changed, 342 insertions(+), 18 deletions(-) >>>>>> >>>>>> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig >>>>>> index 00704efe6398..f56132b0ae64 100644 >>>>>> --- a/drivers/devfreq/Kconfig >>>>>> +++ b/drivers/devfreq/Kconfig >>>>>> @@ -73,6 +73,8 @@ config DEVFREQ_GOV_PASSIVE >>>>>> device. This governor does not change the frequency by itself >>>>>> through sysfs entries. The passive governor recommends that >>>>>> devfreq device uses the OPP table to get the frequency/voltage. >>>>>> + Alternatively the governor can also be chosen to scale based on >>>>>> + the online CPUs current frequency. >>>>>> >>>>>> comment "DEVFREQ Drivers" >>>>>> >>>>>> diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c >>>>>> index b094132bd20b..9cc57b083839 100644 >>>>>> --- a/drivers/devfreq/governor_passive.c >>>>>> +++ b/drivers/devfreq/governor_passive.c >>>>>> @@ -8,11 +8,103 @@ >>>>>> */ >>>>>> >>>>>> #include <linux/module.h> >>>>>> +#include <linux/cpu.h> >>>>>> +#include <linux/cpufreq.h> >>>>>> +#include <linux/cpumask.h> >>>>>> #include <linux/device.h> >>>>>> #include <linux/devfreq.h> >>>>>> +#include <linux/slab.h> >>>>>> #include "governor.h" >>>>>> >>>>>> -static int devfreq_passive_get_target_freq(struct devfreq *devfreq, >>>>>> +struct devfreq_cpu_state { >>>>>> + unsigned int curr_freq; >>>>>> + unsigned int min_freq; >>>>>> + unsigned int max_freq; >>>>>> + unsigned int first_cpu; >>>>>> + struct device *cpu_dev; >>>>>> + struct opp_table *opp_table; >>>>>> +}; >>>>> >>>>> As I knew, the previous version has the description of structure >>>>> as following: I wan to add the description like below. >>>>> >>>>> And if you have no any objection, I'd like you to order >>>>> the variables as following and use 'dev' instead of 'cpu_dev' >>>>> because this patch use the 'cpu_state->cpu_dev' at the multiple points. >>>>> I think that 'cpu_state->dev' is better than 'cpu_state->cpu_dev'. >>>>> Also, I prefer to use 'cur_freq' instead of 'curr_freq' >>>>> because devfreq subsystem uses 'cur_freq' for expressing the 'current frequency'. >>>>> >>>>> /** >>>>> * struct devfreq_cpu_state - 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_state { >>>>> struct device *dev; >>>>> unsigned int first_cpu; >>>>> >>>>> struct opp_table *opp_table; >>>>> unsigned int cur_freq; >>>>> unsigned int min_freq; >>>>> unsigned int max_freq; >>>>> }; >>>>> >>>>> >>>>>> + >>>>>> +static unsigned long xlate_cpufreq_to_devfreq(struct devfreq_passive_data *data, >>>>>> + unsigned int cpu) >>>>>> +{ >>>>>> + unsigned int cpu_min_freq, cpu_max_freq, cpu_curr_freq_khz, cpu_percent; >>>>>> + unsigned long dev_min_freq, dev_max_freq, dev_max_state; >>>>>> + >>>>>> + struct devfreq_cpu_state *cpu_state = data->cpu_state[cpu]; >>>>>> + struct devfreq *devfreq = (struct devfreq *)data->this; >>>>>> + unsigned long *dev_freq_table = devfreq->profile->freq_table; >>>>>> + struct dev_pm_opp *opp = NULL, *p_opp = NULL; >>>>>> + unsigned long cpu_curr_freq, freq; >>>>>> + >>>>>> + if (!cpu_state || cpu_state->first_cpu != cpu || >>>>>> + !cpu_state->opp_table || !devfreq->opp_table) >>>>>> + return 0; >>>>>> + >>>>>> + cpu_curr_freq = cpu_state->curr_freq * 1000; >>>>>> + p_opp = devfreq_recommended_opp(cpu_state->cpu_dev, &cpu_curr_freq, 0); >>>>>> + if (IS_ERR(p_opp)) >>>>>> + return 0; >>>>>> + >>>>>> + opp = dev_pm_opp_xlate_required_opp(cpu_state->opp_table, >>>>>> + devfreq->opp_table, p_opp); >>>>>> + dev_pm_opp_put(p_opp); >>>>>> + >>>>>> + if (!IS_ERR(opp)) { >>>>>> + freq = dev_pm_opp_get_freq(opp); >>>>>> + dev_pm_opp_put(opp); >>>>>> + goto out; >>>>>> + } >>>>>> + >>>>>> + /* Use Interpolation if required opps is not available */ >>>>>> + cpu_min_freq = cpu_state->min_freq; >>>>>> + cpu_max_freq = cpu_state->max_freq; >>>>>> + cpu_curr_freq_khz = cpu_state->curr_freq; >>>>>> + >>>>>> + if (dev_freq_table) { >>>>>> + /* Get minimum frequency according to sorting order */ >>>>>> + dev_max_state = dev_freq_table[devfreq->profile->max_state - 1]; >>>>>> + if (dev_freq_table[0] < dev_max_state) { >>>>>> + dev_min_freq = dev_freq_table[0]; >>>>>> + dev_max_freq = dev_max_state; >>>>>> + } else { >>>>>> + dev_min_freq = dev_max_state; >>>>>> + dev_max_freq = dev_freq_table[0]; >>>>>> + } >>>>>> + } else { >>>>>> + dev_min_freq = dev_pm_qos_read_value(devfreq->dev.parent, >>>>>> + DEV_PM_QOS_MIN_FREQUENCY); >>>>>> + dev_max_freq = dev_pm_qos_read_value(devfreq->dev.parent, >>>>>> + DEV_PM_QOS_MAX_FREQUENCY); >>>>>> + >>>>>> + if (dev_max_freq <= dev_min_freq) >>>>>> + return 0; >>>>>> + } >>>>>> + cpu_percent = ((cpu_curr_freq_khz - cpu_min_freq) * 100) / cpu_max_freq - cpu_min_freq; >>>>>> + freq = dev_min_freq + mult_frac(dev_max_freq - dev_min_freq, cpu_percent, 100); >>>>>> + >>>>>> +out: >>>>>> + return freq; >>>>>> +} >>>>>> + >>>>>> +static int get_target_freq_with_cpufreq(struct devfreq *devfreq, >>>>>> + unsigned long *freq) >>>>>> +{ >>>>>> + struct devfreq_passive_data *p_data = >>>>>> + (struct devfreq_passive_data *)devfreq->data; >>>>>> + unsigned int cpu; >>>>>> + unsigned long target_freq = 0; >>>>>> + >>>>>> + for_each_online_cpu(cpu) >>>>>> + target_freq = max(target_freq, >>>>>> + xlate_cpufreq_to_devfreq(p_data, cpu)); >>>>>> + >>>>>> + *freq = target_freq; >>>>>> + >>>>>> + return 0; >>>>>> +} >>>>> >>>>> As you knew, governor_passive.c was already used >>>>> both 'dev_pm_opp_xlate_required_opp' and 'devfreq_recommended_opp' >>>>> to get the target from OPP. So, I wan to make the common function >>>>> like 'get_taget_freq_by_required_opp' as following: >>>>> If define 'get_taget_freq_by_required_opp' as following, >>>>> it will be used for get_target_freq_with_devfreq(). >>>>> After finisied the review of this patch, I'll send the patch[2]. >>>>> [2] https://urldefense.com/v3/__https://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git/commit/?h=devfreq-testing-passive-gov&id=101c5a087586ab2b5cf3370166a7e39227ca83cf__;!!CTRNKA9wMg0ARbw!zIrzeDp9vPnm1_SDzVPuzqdHn3zWie9DnfBXaA-j9-CSrVc6aR9_rJQQiw81_CgA6mp3Yqo$ >>>>> >>>>> For example but this code is not tested, >>>>> static unsigned long get_taget_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; >>>>> >>>>> 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; >>>>> >>>>> freq = dev_pm_opp_get_freq(opp); >>>>> dev_pm_opp_put(opp); >>>>> >>>>> return 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 *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) { >>>>> cpu_data = p_data->cpu_data[cpu]; >>>>> if (!cpu_data || cpu_data->first_cpu != cpu) >>>>> continue; >>>>> >>>>> /* Get target freq via required opps */ >>>>> cpu_cur = cpu_data->cur_freq * HZ_PER_KHZ; >>>>> freq = get_taget_freq_by_required_opp(cpu_data->dev, >>>>> 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 = cpu_data->min_freq; >>>>> cpu_max = cpu_data->max_freq; >>>>> cpu_cur = 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 >>>>>> @@ -23,14 +115,6 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq, >>>>>> int i, count; >>>>>> >>>>>> /* >>>>>> - * 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); >>>>>> - >>>>>> - /* >>>>>> * If the parent and passive devfreq device uses the OPP table, >>>>>> * get the next frequency by using the OPP table. >>>>>> */ >>>>>> @@ -98,6 +182,37 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq, >>>>>> 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 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 devfreq_passive_notifier_call(struct notifier_block *nb, >>>>>> unsigned long event, void *ptr) >>>>>> { >>>>>> @@ -130,16 +245,200 @@ static int devfreq_passive_notifier_call(struct notifier_block *nb, >>>>>> return NOTIFY_DONE; >>>>>> } >>>>>> >>>>>> +static int cpufreq_passive_notifier_call(struct notifier_block *nb, >>>>>> + unsigned long event, void *ptr) >>>>>> +{ >>>>>> + struct devfreq_passive_data *data = >>>>>> + container_of(nb, struct devfreq_passive_data, nb); >>>>>> + struct devfreq *devfreq = (struct devfreq *)data->this; >>>>>> + struct devfreq_cpu_state *cpu_state; >>>>>> + struct cpufreq_freqs *cpu_freq = ptr; >>>>> >>>>> Use 'freqs' variable name. I prefer to use the same variable name >>>>> for both devfreq_freqs and cpufreq_freqs instance. >>>>> >>>>>> + unsigned int curr_freq; >>>>> >>>>> As I commented above, better to use 'cur_frq' instead of 'curr_freq' >>>>> if there is no any special reason. >>>>> >>>>>> + int ret; >>>>>> + >>>>>> + if (event != CPUFREQ_POSTCHANGE || !cpu_freq || >>>>>> + !data->cpu_state[cpu_freq->policy->cpu]) >>>>>> + return 0; >>>>>> + >>>>>> + cpu_state = data->cpu_state[cpu_freq->policy->cpu]; >>>>>> + if (cpu_state->curr_freq == cpu_freq->new) >>>>>> + return 0; >>>>>> + >>>>>> + /* Backup current freq and pre-update cpu state freq*/ >>>>> >>>>> I think that this commnet is not critial. So, please drop this comment. >>>>> >>>>>> + curr_freq = cpu_state->curr_freq; >>>>>> + cpu_state->curr_freq = cpu_freq->new; >>>>>> + >>>>>> + mutex_lock(&devfreq->lock); >>>>>> + ret = update_devfreq(devfreq); >>>>> >>>>> I recommend to use 'devfreq_update_target' instead of 'update_devfreq' >>>>> as following: >>>>> devfreq_update_target(devfreq, freqs->new); >>>>> >>>>>> + mutex_unlock(&devfreq->lock); >>>>>> + if (ret) { >>>>>> + cpu_state->curr_freq = curr_freq; >>>>>> + dev_err(&devfreq->dev, "Couldn't update the frequency.\n"); >>>>>> + return ret; >>>>>> + } >>>>>> + >>>>>> + return 0; >>>>>> +} >>>>>> + >>>>>> +static int cpufreq_passive_register(struct devfreq_passive_data **p_data) >>>>> >>>>> In order to keep the consistent style of function name, >>>>> please change the name as following because devfreq defines >>>>> the function name as 'devfreq_regiter_notifier' >>>>> - cpufreq_passive_register -> cpufreq_passive_register_notifier >>>>> >>>>>> +{ >>>>>> + struct devfreq_passive_data *data = *p_data; >>>>>> + struct devfreq *devfreq = (struct devfreq *)data->this; >>>>>> + struct device *dev = devfreq->dev.parent; >>>>>> + struct opp_table *opp_table = NULL; >>>>>> + struct devfreq_cpu_state *cpu_state; >>>>>> + struct cpufreq_policy *policy; >>>>>> + struct device *cpu_dev; >>>>>> + unsigned int cpu; >>>>>> + int ret; >>>>>> + >>>>>> + get_online_cpus(); >>>>>> + >>>>>> + data->nb.notifier_call = cpufreq_passive_notifier_call; >>>>>> + ret = cpufreq_register_notifier(&data->nb, >>>>>> + CPUFREQ_TRANSITION_NOTIFIER); >>>>>> + if (ret) { >>>>>> + dev_err(dev, "Couldn't register cpufreq notifier.\n"); >>>>>> + data->nb.notifier_call = NULL; >>>>>> + goto out; >>>>>> + } >>>>>> + >>>>>> + /* Populate devfreq_cpu_state */ >>>>> >>>>> Don't need this comment. Please drop it. >>>>> >>>>>> + for_each_online_cpu(cpu) { >>>>>> + if (data->cpu_state[cpu]) >>>>>> + continue; >>>>>> + >>>>>> + policy = cpufreq_cpu_get(cpu); >>>>>> + if (!policy) { >>>>>> + ret = -EINVAL; >>>>>> + goto out; >>>>>> + } else if (PTR_ERR(policy) == -EPROBE_DEFER) { >>>>>> + ret = -EPROBE_DEFER; >>>>>> + goto out; >>>>>> + } else if (IS_ERR(policy)) { >>>>>> + ret = PTR_ERR(policy); >>>>>> + dev_err(dev, "Couldn't get the cpufreq_poliy.\n"); >>>>>> + goto out; >>>>>> + } >>>>> >>>>> Use dev_err_probe() funciotn to handle hte EPROBE_DEFER. >>>>> It make code more simple. >>>>> >>>>>> + >>>>>> + cpu_state = kzalloc(sizeof(*cpu_state), GFP_KERNEL); >>>>>> + if (!cpu_state) { >>>>>> + ret = -ENOMEM; >>>>>> + goto out; >>>>>> + } >>>>>> + >>>>>> + cpu_dev = get_cpu_device(cpu); >>>>>> + if (!cpu_dev) { >>>>>> + dev_err(dev, "Couldn't get cpu device.\n"); >>>>>> + ret = -ENODEV; >>>>>> + goto out; >>>>>> + } >>>>>> + >>>>>> + opp_table = dev_pm_opp_get_opp_table(cpu_dev); >>>>>> + if (IS_ERR(devfreq->opp_table)) { >>>>>> + ret = PTR_ERR(opp_table); >>>>>> + goto out; >>>>>> + } >>>>>> + >>>>>> + cpu_state->cpu_dev = cpu_dev; >>>>>> + cpu_state->opp_table = opp_table; >>>>>> + cpu_state->first_cpu = cpumask_first(policy->related_cpus); >>>>>> + cpu_state->curr_freq = policy->cur; >>>>>> + cpu_state->min_freq = policy->cpuinfo.min_freq; >>>>>> + cpu_state->max_freq = policy->cpuinfo.max_freq; >>>>>> + data->cpu_state[cpu] = cpu_state; >>>>>> + >>>>>> + cpufreq_cpu_put(policy); >>>>>> + } >>>>>> + >>>>>> +out: >>>>>> + put_online_cpus(); >>>>>> + if (ret) >>>>>> + return ret; >>>>>> + >>>>>> + /* Update devfreq */ >>>>>> + mutex_lock(&devfreq->lock); >>>>>> + ret = update_devfreq(devfreq); >>>>> >>>>>> + mutex_unlock(&devfreq->lock); >>>>>> + if (ret) >>>>>> + dev_err(dev, "Couldn't update the frequency.\n"); >>>>>> + >>>>>> + return ret; >>>>>> +} >>>>>> + >>>>>> +static int cpufreq_passive_unregister(struct devfreq_passive_data **p_data) >>>>> >>>>> As I commented above, please change the name as following: >>>>> - cpufreq_passive_unregister -> cpufreq_passive_unregister_notifier >>>>> >>>>>> +{ >>>>>> + struct devfreq_passive_data *data = *p_data; >>>>>> + struct devfreq_cpu_state *cpu_state; >>>>>> + int cpu; >>>>>> + >>>>>> + if (data->nb.notifier_call) >>>>>> + cpufreq_unregister_notifier(&data->nb, >>>>>> + CPUFREQ_TRANSITION_NOTIFIER); >>>>>> + >>>>>> + for_each_possible_cpu(cpu) { >>>>>> + cpu_state = data->cpu_state[cpu]; >>>>>> + if (cpu_state) { >>>>>> + if (cpu_state->opp_table) >>>>>> + dev_pm_opp_put_opp_table(cpu_state->opp_table); >>>>>> + kfree(cpu_state); >>>>>> + cpu_state = NULL; >>>>>> + } >>>>>> + } >>>>>> + >>>>>> + return 0; >>>>>> +} >>>>>> + >>>>>> +int register_parent_dev_notifier(struct devfreq_passive_data **p_data) >>>>>> +{ >>>>>> + struct notifier_block *nb = &(*p_data)->nb; >>>>>> + int ret = 0; >>>>>> + >>>>>> + switch ((*p_data)->parent_type) { >>>>>> + case DEVFREQ_PARENT_DEV: >>>>>> + nb->notifier_call = devfreq_passive_notifier_call; >>>>>> + ret = devfreq_register_notifier((struct devfreq *)(*p_data)->parent, nb, >>>>>> + DEVFREQ_TRANSITION_NOTIFIER); >>>>>> + break; >>>>>> + case CPUFREQ_PARENT_DEV: >>>>>> + ret = cpufreq_passive_register(p_data); >>>>>> + break; >>>>>> + default: >>>>>> + ret = -EINVAL; >>>>>> + break; >>>>>> + } >>>>>> + return ret; >>>>>> +} >>>>>> + >>>>>> +int unregister_parent_dev_notifier(struct devfreq_passive_data **p_data) >>>>>> +{ >>>>>> + int ret = 0; >>>>>> + >>>>>> + switch ((*p_data)->parent_type) { >>>>>> + case DEVFREQ_PARENT_DEV: >>>>>> + WARN_ON(devfreq_unregister_notifier((struct devfreq *)(*p_data)->parent, >>>>>> + &(*p_data)->nb, >>>>>> + DEVFREQ_TRANSITION_NOTIFIER)); >>>>>> + break; >>>>>> + case CPUFREQ_PARENT_DEV: >>>>>> + cpufreq_passive_unregister(p_data); >>>>>> + break; >>>>>> + default: >>>>>> + ret = -EINVAL; >>>>>> + break; >>>>>> + } >>>>>> + return ret; >>>>>> +} >>>>> >>>>> I think that you don't need to define register_parent_dev_notifier >>>>> and unregister_parent_dev_notifier as the separate functions. >>>>> >>>>> Instead of the separate functions, just add the code >>>>> into devfreq_passive_event_handler. >>>>> >>>>> >>>>>> + >>>>>> 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; >>>>>> struct devfreq *parent = (struct devfreq *)p_data->parent; >>>>>> - struct notifier_block *nb = &p_data->nb; >>>>>> int ret = 0; >>>>>> >>>>>> - if (!parent) >>>>>> + if (p_data->parent_type == DEVFREQ_PARENT_DEV && !parent) >>>>>> return -EPROBE_DEFER; >>>>>> >>>>>> switch (event) { >>>>>> @@ -147,13 +446,11 @@ static int devfreq_passive_event_handler(struct devfreq *devfreq, >>>>>> if (!p_data->this) >>>>>> p_data->this = devfreq; >>>>>> >>>>>> - nb->notifier_call = devfreq_passive_notifier_call; >>>>>> - ret = devfreq_register_notifier(parent, nb, >>>>>> - DEVFREQ_TRANSITION_NOTIFIER); >>>>>> + ret = register_parent_dev_notifier(&p_data); >>>>>> break; >>>>>> + >>>>>> case DEVFREQ_GOV_STOP: >>>>>> - WARN_ON(devfreq_unregister_notifier(parent, nb, >>>>>> - DEVFREQ_TRANSITION_NOTIFIER)); >>>>>> + ret = unregister_parent_dev_notifier(&p_data); >>>>>> break; >>>>>> default: >>>>>> break; >>>>>> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h >>>>>> index 26ea0850be9b..e0093b7c805c 100644 >>>>>> --- a/include/linux/devfreq.h >>>>>> +++ b/include/linux/devfreq.h >>>>>> @@ -280,6 +280,25 @@ struct devfreq_simple_ondemand_data { >>>>>> >>>>>> #if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) >>>>>> /** >>>>>> + * struct devfreq_cpu_state - holds the per-cpu state >>>>>> + * @freq: the current frequency of the cpu. >>>>>> + * @min_freq: the min frequency of the cpu. >>>>>> + * @max_freq: the max frequency of the cpu. >>>>>> + * @first_cpu: the cpumask of the first cpu of a policy. >>>>>> + * @dev: reference to cpu device. >>>>>> + * @opp_table: reference to cpu opp table. >>>>>> + * >>>>>> + * This structure stores the required cpu_state of a cpu. >>>>>> + * This is auto-populated by the governor. >>>>>> + */ >>>>>> +struct devfreq_cpu_state; >>>>>> + >>>>>> +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 >>>>>> * @parent: the devfreq instance of parent device. >>>>>> @@ -290,13 +309,15 @@ 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. >>>>>> + * @parent_type: parent type of the device >>>>>> * @this: the devfreq instance of own device. >>>>>> * @nb: the notifier block for DEVFREQ_TRANSITION_NOTIFIER list >>>>>> + * @cpu_state: 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 >>>>>> - * initialize the 'this' and 'nb' field because the devfreq core will handle >>>>>> - * them. >>>>>> + * initialize the 'this', 'nb' and 'cpu_state' field because the devfreq core >>>>>> + * will handle them. >>>>>> */ >>>>>> struct devfreq_passive_data { >>>>>> /* Should set the devfreq instance of parent device */ >>>>>> @@ -305,9 +326,13 @@ 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_state *cpu_state[NR_CPUS]; >>>>>> }; >>>>>> #endif >>>>>> >>>>>> >>>>> >>>> >>> >>> >> >> > -- Best Regards, Chanwoo Choi Samsung Electronics
