kernel/linux.git/drivers/devfreq/governor.h, branch v6.12.80

PM / devfreq: passive: Keep cpufreq_policy for possible cpus

2022-05-17T09:24:39+00:00

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 Tested-by: Johnson Wang Signed-off-by: Chanwoo Choi

PM / devfreq: Add cpu based scaling support to passive governor

2022-05-17T09:24:39+00:00

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 Tested-by: Johnson Wang Signed-off-by: Saravana Kannan [Sibi: Integrated cpu-freqmap governor into passive_governor] Signed-off-by: Sibi Sankar [Chanwoo: Fix conflict with latest code and cleanup code] Signed-off-by: Chanwoo Choi

PM / devfreq: Export devfreq_get_freq_range symbol within devfreq

2022-05-17T09:24:39+00:00

In order to get frequency range within devfreq governors, export devfreq_get_freq_range symbol within devfreq. Reviewed-by: Matthias Kaehlcke Tested-by: Chen-Yu Tsai Tested-by: Johnson Wang Signed-off-by: Chanwoo Choi

PM / devfreq: Add devm_devfreq_add_governor()

2021-10-05T04:24:38+00:00

Add resource-managed variant of devfreq_add_governor(). Signed-off-by: Dmitry Osipenko Acked-by: Chanwoo Choi Signed-off-by: Viresh Kumar

PM / devfreq: Remove the invalid description for get_target_freq

2021-04-08T04:14:51+00:00

First of all, no_central_polling was removed since commit 7e6fdd4bad03 ("PM / devfreq: Core updates to support devices which can idle") Secondly, get_target_freq() is not only called only with update_devfreq() notified by OPP now, but also min/max freq qos notifier. So remove this invalid description now to avoid confusing. Signed-off-by: Dong Aisheng Signed-off-by: Chanwoo Choi

PM / devfreq: Check get_dev_status in devfreq_update_stats

2021-04-08T04:14:51+00:00

Check .get_dev_status() in devfreq_update_stats in case it's abused when a device does not provide it. Signed-off-by: Dong Aisheng Signed-off-by: Chanwoo Choi

PM / devfreq: Correct spelling in a comment

2021-01-05T01:04:25+00:00

The device attribute exposed in sysfs is called 'polling_interval'. Align the comment. Signed-off-by: Lukasz Luba Signed-off-by: Chanwoo Choi

PM / devfreq: Remove redundant governor_name from struct devfreq

2020-10-26T02:50:51+00:00

The devfreq structure instance contains the governor_name and a governor instance. When need to show the governor name, better to use the name of devfreq_governor structure. So, governor_name variable in struct devfreq is a redundant and unneeded variable. Remove the redundant governor_name of struct devfreq and then use the name of devfreq_governor instance. Signed-off-by: Chanwoo Choi

PM / devfreq: Add governor attribute flag for specifc sysfs nodes

2020-10-26T02:46:54+00:00

DEVFREQ supports the default governors like performance, simple_ondemand and also allows the devfreq driver to add their own governor like tegra30-devfreq.c according to their requirement. In result, some sysfs attributes are useful or not useful. Prior to that the user can access all sysfs attributes regardless of the available attributes. So, clarify the access permission of sysfs attributes according to governor. When adding the devfreq governor, can specify the available attribute information by using DEVFREQ_GOV_ATTR_* constant variable. The user can read or write the sysfs attributes in accordance to the specified attributes. When adding the governor, can add the following attributes according to the governor feature. [Definition for speific sysfs attributes] - DEVFREQ_GOV_ATTR_POLLING_INTERVAL to update polling interval for timer. : /sys/class/devfreq/[devfreq dev name]/polling_interval - DEVFREQ_GOV_ATTR_TIMER to change the type of timer on either deferrable or dealyed timer. : /sys/class/devfreq/[devfreq dev name]/timer And all devfreq governors have to support the following common attributes. The common attributes are added to devfreq class by default. - governor - available_governors - available_frequencies - cur_freq - target_freq - min_freq - max_freq - trans_stat [Table of governor attribute flags for devfreq governors] ------------------------------------------------------------------------------ | simple | perfor | power | user | passive | tegra30 | ondemand | mance | save | space| | ------------------------------------------------------------------------------ governor | O | O | O | O | O | O available_governors | O | O | O | O | O | O available_frequencies | O | O | O | O | O | O cur_freq | O | O | O | O | O | O target_freq | O | O | O | O | O | O min_freq | O | O | O | O | O | O max_freq | O | O | O | O | O | O trans_stat | O | O | O | O | O | O -------------------------------------------------------- polling_interval | O | X | X | X | X | O timer | O | X | X | X | X | X ------------------------------------------------------------------------------ Reviewed-by: Dmitry Osipenko Tested-by: Dmitry Osipenko Signed-off-by: Chanwoo Choi

PM / devfreq: Add governor feature flag

2020-10-26T01:54:41+00:00

The devfreq governor is able to have the specific flag as follows in order to implement the specific feature. For example, devfreq allows user to change the governors on runtime via sysfs interface. But, if devfreq device uses 'passive' governor, don't allow user to change the governor. For this case, define the DEVFREQ_GOV_FLAG_IMMUTABLE and set it to flag of passive governor. [Definition for governor flag] - DEVFREQ_GOV_FLAG_IMMUTABLE : If immutable flag is set, governor is never changeable to other governors. - DEVFREQ_GOV_FLAG_IRQ_DRIVEN : Devfreq core won't schedule polling work for this governor if value is set. [Table of governor flag for devfreq governors] ------------------------------------------------------------------------------ | simple | perfor | power | user | passive | tegra30 | ondemand | mance | save | space| | ------------------------------------------------------------------------------ immutable | X | X | X | X | O | O interrupt_driven | X(polling)| X | X | X | X | O (irq) ------------------------------------------------------------------------------ Reviewed-by: Dmitry Osipenko Tested-by: Dmitry Osipenko Signed-off-by: Chanwoo Choi