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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-12-09 09:31:24 +0100 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-12-09 09:31:24 +0100 |
commit | e8ad8d5108e0304532fc800433714ed664ecf71d (patch) | |
tree | a74b9e5196e4c460a8d5ddc130011d84e9d9bae4 | |
parent | Linux 5.5-rc1 (diff) | |
parent | PM / devfreq: Use PM QoS for sysfs min/max_freq (diff) | |
download | linux-e8ad8d5108e0304532fc800433714ed664ecf71d.tar.xz linux-e8ad8d5108e0304532fc800433714ed664ecf71d.zip |
Merge tag 'devfreq-fixes-for-5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux
Pull devfreq updates for 5.5-rc1 from Chanwoo Choi:
"Update devfreq core:
- Add PM QoS support for devfreq device with following QoS type.
External user of devfreq device can request the minimum and
maximum frequency according to their multiple requirements.
: DEV_PM_QOS_MIN_FREQUENCY is used for requesting the minimum
device frequency.
: DEV_PM_QOS_MAX_FREQUENCY is used for requesting the maximum
device frequency.
- Use PM QoS interface when entering the min/max_freq via sysfs
interface.
- Add get_freq_range() helper function in order to get the final
min/max frequency among the multiple requirements of min/max
frequency.
- Fix a function return value and modify code for more correct
exception handling if errors happen."
* tag 'devfreq-fixes-for-5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux:
PM / devfreq: Use PM QoS for sysfs min/max_freq
PM / devfreq: Add PM QoS support
PM / devfreq: Don't fail devfreq_dev_release if not in list
PM / devfreq: Introduce get_freq_range helper
PM / devfreq: Set scaling_max_freq to max on OPP notifier error
PM / devfreq: Fix devfreq_notifier_call returning errno
-rw-r--r-- | drivers/devfreq/devfreq.c | 273 | ||||
-rw-r--r-- | include/linux/devfreq.h | 14 |
2 files changed, 212 insertions, 75 deletions
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 425149e8bab0..57f6944d65a6 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -24,11 +24,14 @@ #include <linux/printk.h> #include <linux/hrtimer.h> #include <linux/of.h> +#include <linux/pm_qos.h> #include "governor.h" #define CREATE_TRACE_POINTS #include <trace/events/devfreq.h> +#define HZ_PER_KHZ 1000 + static struct class *devfreq_class; /* @@ -99,6 +102,54 @@ static unsigned long find_available_max_freq(struct devfreq *devfreq) } /** + * get_freq_range() - Get the current freq range + * @devfreq: the devfreq instance + * @min_freq: the min frequency + * @max_freq: the max frequency + * + * This takes into consideration all constraints. + */ +static void get_freq_range(struct devfreq *devfreq, + unsigned long *min_freq, + unsigned long *max_freq) +{ + unsigned long *freq_table = devfreq->profile->freq_table; + s32 qos_min_freq, qos_max_freq; + + lockdep_assert_held(&devfreq->lock); + + /* + * Initialize minimum/maximum frequency from freq table. + * The devfreq drivers can initialize this in either ascending or + * descending order and devfreq core supports both. + */ + if (freq_table[0] < freq_table[devfreq->profile->max_state - 1]) { + *min_freq = freq_table[0]; + *max_freq = freq_table[devfreq->profile->max_state - 1]; + } else { + *min_freq = freq_table[devfreq->profile->max_state - 1]; + *max_freq = freq_table[0]; + } + + /* Apply constraints from PM QoS */ + qos_min_freq = dev_pm_qos_read_value(devfreq->dev.parent, + DEV_PM_QOS_MIN_FREQUENCY); + qos_max_freq = dev_pm_qos_read_value(devfreq->dev.parent, + DEV_PM_QOS_MAX_FREQUENCY); + *min_freq = max(*min_freq, (unsigned long)HZ_PER_KHZ * qos_min_freq); + if (qos_max_freq != PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE) + *max_freq = min(*max_freq, + (unsigned long)HZ_PER_KHZ * qos_max_freq); + + /* Apply constraints from OPP interface */ + *min_freq = max(*min_freq, devfreq->scaling_min_freq); + *max_freq = min(*max_freq, devfreq->scaling_max_freq); + + if (*min_freq > *max_freq) + *min_freq = *max_freq; +} + +/** * devfreq_get_freq_level() - Lookup freq_table for the frequency * @devfreq: the devfreq instance * @freq: the target frequency @@ -351,16 +402,7 @@ int update_devfreq(struct devfreq *devfreq) err = devfreq->governor->get_target_freq(devfreq, &freq); if (err) return err; - - /* - * Adjust the frequency with user freq, QoS and available freq. - * - * List from the highest priority - * max_freq - * min_freq - */ - max_freq = min(devfreq->scaling_max_freq, devfreq->max_freq); - min_freq = max(devfreq->scaling_min_freq, devfreq->min_freq); + get_freq_range(devfreq, &min_freq, &max_freq); if (freq < min_freq) { freq = min_freq; @@ -568,26 +610,69 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type, void *devp) { struct devfreq *devfreq = container_of(nb, struct devfreq, nb); - int ret; + int err = -EINVAL; mutex_lock(&devfreq->lock); devfreq->scaling_min_freq = find_available_min_freq(devfreq); - if (!devfreq->scaling_min_freq) { - mutex_unlock(&devfreq->lock); - return -EINVAL; - } + if (!devfreq->scaling_min_freq) + goto out; devfreq->scaling_max_freq = find_available_max_freq(devfreq); if (!devfreq->scaling_max_freq) { - mutex_unlock(&devfreq->lock); - return -EINVAL; + devfreq->scaling_max_freq = ULONG_MAX; + goto out; } - ret = update_devfreq(devfreq); + err = update_devfreq(devfreq); + +out: mutex_unlock(&devfreq->lock); + if (err) + dev_err(devfreq->dev.parent, + "failed to update frequency from OPP notifier (%d)\n", + err); - return ret; + return NOTIFY_OK; +} + +/** + * qos_notifier_call() - Common handler for QoS constraints. + * @devfreq: the devfreq instance. + */ +static int qos_notifier_call(struct devfreq *devfreq) +{ + int err; + + mutex_lock(&devfreq->lock); + err = update_devfreq(devfreq); + mutex_unlock(&devfreq->lock); + if (err) + dev_err(devfreq->dev.parent, + "failed to update frequency from PM QoS (%d)\n", + err); + + return NOTIFY_OK; +} + +/** + * qos_min_notifier_call() - Callback for QoS min_freq changes. + * @nb: Should be devfreq->nb_min + */ +static int qos_min_notifier_call(struct notifier_block *nb, + unsigned long val, void *ptr) +{ + return qos_notifier_call(container_of(nb, struct devfreq, nb_min)); +} + +/** + * qos_max_notifier_call() - Callback for QoS max_freq changes. + * @nb: Should be devfreq->nb_max + */ +static int qos_max_notifier_call(struct notifier_block *nb, + unsigned long val, void *ptr) +{ + return qos_notifier_call(container_of(nb, struct devfreq, nb_max)); } /** @@ -599,16 +684,36 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type, static void devfreq_dev_release(struct device *dev) { struct devfreq *devfreq = to_devfreq(dev); + int err; mutex_lock(&devfreq_list_lock); - if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) { - mutex_unlock(&devfreq_list_lock); - dev_warn(&devfreq->dev, "releasing devfreq which doesn't exist\n"); - return; - } list_del(&devfreq->node); mutex_unlock(&devfreq_list_lock); + err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_max, + DEV_PM_QOS_MAX_FREQUENCY); + if (err && err != -ENOENT) + dev_warn(dev->parent, + "Failed to remove max_freq notifier: %d\n", err); + err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_min, + DEV_PM_QOS_MIN_FREQUENCY); + if (err && err != -ENOENT) + dev_warn(dev->parent, + "Failed to remove min_freq notifier: %d\n", err); + + if (dev_pm_qos_request_active(&devfreq->user_max_freq_req)) { + err = dev_pm_qos_remove_request(&devfreq->user_max_freq_req); + if (err) + dev_warn(dev->parent, + "Failed to remove max_freq request: %d\n", err); + } + if (dev_pm_qos_request_active(&devfreq->user_min_freq_req)) { + err = dev_pm_qos_remove_request(&devfreq->user_min_freq_req); + if (err) + dev_warn(dev->parent, + "Failed to remove min_freq request: %d\n", err); + } + if (devfreq->profile->exit) devfreq->profile->exit(devfreq->dev.parent); @@ -660,6 +765,7 @@ struct devfreq *devfreq_add_device(struct device *dev, devfreq->dev.parent = dev; devfreq->dev.class = devfreq_class; devfreq->dev.release = devfreq_dev_release; + INIT_LIST_HEAD(&devfreq->node); devfreq->profile = profile; strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN); devfreq->previous_freq = profile->initial_freq; @@ -681,7 +787,6 @@ struct devfreq *devfreq_add_device(struct device *dev, err = -EINVAL; goto err_dev; } - devfreq->min_freq = devfreq->scaling_min_freq; devfreq->scaling_max_freq = find_available_max_freq(devfreq); if (!devfreq->scaling_max_freq) { @@ -689,7 +794,6 @@ struct devfreq *devfreq_add_device(struct device *dev, err = -EINVAL; goto err_dev; } - devfreq->max_freq = devfreq->scaling_max_freq; devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev); atomic_set(&devfreq->suspend_count, 0); @@ -730,6 +834,28 @@ struct devfreq *devfreq_add_device(struct device *dev, mutex_unlock(&devfreq->lock); + err = dev_pm_qos_add_request(dev, &devfreq->user_min_freq_req, + DEV_PM_QOS_MIN_FREQUENCY, 0); + if (err < 0) + goto err_devfreq; + err = dev_pm_qos_add_request(dev, &devfreq->user_max_freq_req, + DEV_PM_QOS_MAX_FREQUENCY, + PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE); + if (err < 0) + goto err_devfreq; + + devfreq->nb_min.notifier_call = qos_min_notifier_call; + err = dev_pm_qos_add_notifier(devfreq->dev.parent, &devfreq->nb_min, + DEV_PM_QOS_MIN_FREQUENCY); + if (err) + goto err_devfreq; + + devfreq->nb_max.notifier_call = qos_max_notifier_call; + err = dev_pm_qos_add_notifier(devfreq->dev.parent, &devfreq->nb_max, + DEV_PM_QOS_MAX_FREQUENCY); + if (err) + goto err_devfreq; + mutex_lock(&devfreq_list_lock); governor = try_then_request_governor(devfreq->governor_name); @@ -1303,41 +1429,37 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr, unsigned long value; int ret; + /* + * Protect against theoretical sysfs writes between + * device_add and dev_pm_qos_add_request + */ + if (!dev_pm_qos_request_active(&df->user_min_freq_req)) + return -EAGAIN; + ret = sscanf(buf, "%lu", &value); if (ret != 1) return -EINVAL; - mutex_lock(&df->lock); - - if (value) { - if (value > df->max_freq) { - ret = -EINVAL; - goto unlock; - } - } else { - unsigned long *freq_table = df->profile->freq_table; - - /* Get minimum frequency according to sorting order */ - if (freq_table[0] < freq_table[df->profile->max_state - 1]) - value = freq_table[0]; - else - value = freq_table[df->profile->max_state - 1]; - } + /* Round down to kHz for PM QoS */ + ret = dev_pm_qos_update_request(&df->user_min_freq_req, + value / HZ_PER_KHZ); + if (ret < 0) + return ret; - df->min_freq = value; - update_devfreq(df); - ret = count; -unlock: - mutex_unlock(&df->lock); - return ret; + return count; } static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr, char *buf) { struct devfreq *df = to_devfreq(dev); + unsigned long min_freq, max_freq; - return sprintf(buf, "%lu\n", max(df->scaling_min_freq, df->min_freq)); + mutex_lock(&df->lock); + get_freq_range(df, &min_freq, &max_freq); + mutex_unlock(&df->lock); + + return sprintf(buf, "%lu\n", min_freq); } static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, @@ -1347,33 +1469,37 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, unsigned long value; int ret; + /* + * Protect against theoretical sysfs writes between + * device_add and dev_pm_qos_add_request + */ + if (!dev_pm_qos_request_active(&df->user_max_freq_req)) + return -EINVAL; + ret = sscanf(buf, "%lu", &value); if (ret != 1) return -EINVAL; - mutex_lock(&df->lock); - - if (value) { - if (value < df->min_freq) { - ret = -EINVAL; - goto unlock; - } - } else { - unsigned long *freq_table = df->profile->freq_table; + /* + * PM QoS frequencies are in kHz so we need to convert. Convert by + * rounding upwards so that the acceptable interval never shrinks. + * + * For example if the user writes "666666666" to sysfs this value will + * be converted to 666667 kHz and back to 666667000 Hz before an OPP + * lookup, this ensures that an OPP of 666666666Hz is still accepted. + * + * A value of zero means "no limit". + */ + if (value) + value = DIV_ROUND_UP(value, HZ_PER_KHZ); + else + value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE; - /* Get maximum frequency according to sorting order */ - if (freq_table[0] < freq_table[df->profile->max_state - 1]) - value = freq_table[df->profile->max_state - 1]; - else - value = freq_table[0]; - } + ret = dev_pm_qos_update_request(&df->user_max_freq_req, value); + if (ret < 0) + return ret; - df->max_freq = value; - update_devfreq(df); - ret = count; -unlock: - mutex_unlock(&df->lock); - return ret; + return count; } static DEVICE_ATTR_RW(min_freq); @@ -1381,8 +1507,13 @@ static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr, char *buf) { struct devfreq *df = to_devfreq(dev); + unsigned long min_freq, max_freq; + + mutex_lock(&df->lock); + get_freq_range(df, &min_freq, &max_freq); + mutex_unlock(&df->lock); - return sprintf(buf, "%lu\n", min(df->scaling_max_freq, df->max_freq)); + return sprintf(buf, "%lu\n", max_freq); } static DEVICE_ATTR_RW(max_freq); diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index 2bae9ed3c783..fb376b5b7281 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -13,6 +13,7 @@ #include <linux/device.h> #include <linux/notifier.h> #include <linux/pm_opp.h> +#include <linux/pm_qos.h> #define DEVFREQ_NAME_LEN 16 @@ -123,8 +124,8 @@ struct devfreq_dev_profile { * @previous_freq: previously configured frequency value. * @data: Private data of the governor. The devfreq framework does not * touch this. - * @min_freq: Limit minimum frequency requested by user (0: none) - * @max_freq: Limit maximum frequency requested by user (0: none) + * @user_min_freq_req: PM QoS minimum frequency request from user (via sysfs) + * @user_max_freq_req: PM QoS maximum frequency request from user (via sysfs) * @scaling_min_freq: Limit minimum frequency requested by OPP interface * @scaling_max_freq: Limit maximum frequency requested by OPP interface * @stop_polling: devfreq polling status of a device. @@ -136,6 +137,8 @@ struct devfreq_dev_profile { * @time_in_state: Statistics of devfreq states * @last_stat_updated: The last time stat updated * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier + * @nb_min: Notifier block for DEV_PM_QOS_MIN_FREQUENCY + * @nb_max: Notifier block for DEV_PM_QOS_MAX_FREQUENCY * * This structure stores the devfreq information for a give device. * @@ -161,8 +164,8 @@ struct devfreq { void *data; /* private data for governors */ - unsigned long min_freq; - unsigned long max_freq; + struct dev_pm_qos_request user_min_freq_req; + struct dev_pm_qos_request user_max_freq_req; unsigned long scaling_min_freq; unsigned long scaling_max_freq; bool stop_polling; @@ -178,6 +181,9 @@ struct devfreq { unsigned long last_stat_updated; struct srcu_notifier_head transition_notifier_list; + + struct notifier_block nb_min; + struct notifier_block nb_max; }; struct devfreq_freqs { |