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://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git/log/?h=devfreq-testing-passive-gov > > 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://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git/commit/?h=devfreq-testing-passive-gov&id=39c80d11a8f42dd63ecea1e0df595a0ceb83b454 Sorry for the confusion. I make the devfreq-testing-passive-gov[1] branch based on latest devfreq-next branch. [1] https://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git/log/?h=devfreq-testing-passive-gov 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? > >> >> >>> >>> >>> 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
