| Message ID | 730613d6f7182c6a6784fd509d6324f28be2cac3.1568764439.git.leonard.crestez@nxp.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | PM / devfreq: Add dev_pm_qos support | expand |
Hi Leonard, On Wed, Sep 18, 2019 at 03:18:24AM +0300, Leonard Crestez wrote: > Moving handling of min/max freq to a single function and call it from > update_devfreq and for printing min/max freq values in sysfs. > > This changes the behavior of out-of-range min_freq/max_freq: clamping > is now done at evaluation time. This means that if an out-of-range > constraint is imposed by sysfs and it later becomes valid then it will > be enforced. > > Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> > --- > drivers/devfreq/devfreq.c | 111 +++++++++++++++++++++----------------- > 1 file changed, 63 insertions(+), 48 deletions(-) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index 860cbbab476c..51a4179e2c69 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -24,10 +24,12 @@ > #include <linux/printk.h> > #include <linux/hrtimer.h> > #include <linux/of.h> > #include "governor.h" > > +#define HZ_PER_KHZ 1000 > + > #define CREATE_TRACE_POINTS > #include <trace/events/devfreq.h> > > static struct class *devfreq_class; > > @@ -96,10 +98,50 @@ static unsigned long find_available_max_freq(struct devfreq *devfreq) > dev_pm_opp_put(opp); > > return max_freq; > } > > +/** > + * 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 devfreq_get_freq_range(struct devfreq *devfreq, > + unsigned long *min_freq, > + unsigned long *max_freq) > +{ > + unsigned long *freq_table = devfreq->profile->freq_table; > + > + lockdep_assert_held(&devfreq->lock); > + > + /* Init min/max frequency from freq table */ > + 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]; > + } > + > + /* constraints from sysfs: */ > + *min_freq = max(*min_freq, devfreq->min_freq); > + *max_freq = min(*max_freq, devfreq->max_freq); > + > + /* constraints from opp interface: */ nit: OPP > + *min_freq = max(*min_freq, devfreq->scaling_min_freq); > + /* scaling_max_freq can be zero on error */ > + if (devfreq->scaling_max_freq) > + *max_freq = min(*max_freq, devfreq->scaling_max_freq); > + > + /* max_freq takes precedence over min_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 > */ > @@ -349,21 +391,13 @@ int update_devfreq(struct devfreq *devfreq) > > /* Reevaluate the proper frequency */ > err = devfreq->governor->get_target_freq(devfreq, &freq); > if (err) > return err; > + devfreq_get_freq_range(devfreq, &min_freq, &max_freq); > > - /* > - * 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); > - > + /* max freq takes priority over min freq */ > if (freq < min_freq) { > freq = min_freq; > flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */ > } > if (freq > max_freq) { > @@ -1293,40 +1327,28 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr, > 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]; > - } > - > 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); > + devfreq_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, > const char *buf, size_t count) > { > @@ -1338,40 +1360,33 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, > 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; > - > - /* 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]; > - } > + /* Interpret zero as "don't care" */ > + if (!value) > + value = ULONG_MAX; > > df->max_freq = value; > update_devfreq(df); > - ret = count; > -unlock: > mutex_unlock(&df->lock); > - return ret; > + > + return count; > } > static DEVICE_ATTR_RW(min_freq); > > 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); > + devfreq_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); > > static ssize_t available_frequencies_show(struct device *d, > struct device_attribute *attr, Nice, having the constraint evaluation in a single function makes it easier to follow the code. Clamping userspace constraints at runtime makes sense. Reviewed-by: Matthias Kaehlcke <mka@chromium.org> I plan to take a look at the rest of the series, but probably won't find time for all of it before next week.
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 860cbbab476c..51a4179e2c69 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -24,10 +24,12 @@ #include <linux/printk.h> #include <linux/hrtimer.h> #include <linux/of.h> #include "governor.h" +#define HZ_PER_KHZ 1000 + #define CREATE_TRACE_POINTS #include <trace/events/devfreq.h> static struct class *devfreq_class; @@ -96,10 +98,50 @@ static unsigned long find_available_max_freq(struct devfreq *devfreq) dev_pm_opp_put(opp); return max_freq; } +/** + * 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 devfreq_get_freq_range(struct devfreq *devfreq, + unsigned long *min_freq, + unsigned long *max_freq) +{ + unsigned long *freq_table = devfreq->profile->freq_table; + + lockdep_assert_held(&devfreq->lock); + + /* Init min/max frequency from freq table */ + 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]; + } + + /* constraints from sysfs: */ + *min_freq = max(*min_freq, devfreq->min_freq); + *max_freq = min(*max_freq, devfreq->max_freq); + + /* constraints from opp interface: */ + *min_freq = max(*min_freq, devfreq->scaling_min_freq); + /* scaling_max_freq can be zero on error */ + if (devfreq->scaling_max_freq) + *max_freq = min(*max_freq, devfreq->scaling_max_freq); + + /* max_freq takes precedence over min_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 */ @@ -349,21 +391,13 @@ int update_devfreq(struct devfreq *devfreq) /* Reevaluate the proper frequency */ err = devfreq->governor->get_target_freq(devfreq, &freq); if (err) return err; + devfreq_get_freq_range(devfreq, &min_freq, &max_freq); - /* - * 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); - + /* max freq takes priority over min freq */ if (freq < min_freq) { freq = min_freq; flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */ } if (freq > max_freq) { @@ -1293,40 +1327,28 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr, 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]; - } - 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); + devfreq_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, const char *buf, size_t count) { @@ -1338,40 +1360,33 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, 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; - - /* 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]; - } + /* Interpret zero as "don't care" */ + if (!value) + value = ULONG_MAX; df->max_freq = value; update_devfreq(df); - ret = count; -unlock: mutex_unlock(&df->lock); - return ret; + + return count; } static DEVICE_ATTR_RW(min_freq); 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); + devfreq_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); static ssize_t available_frequencies_show(struct device *d, struct device_attribute *attr,
Moving handling of min/max freq to a single function and call it from update_devfreq and for printing min/max freq values in sysfs. This changes the behavior of out-of-range min_freq/max_freq: clamping is now done at evaluation time. This means that if an out-of-range constraint is imposed by sysfs and it later becomes valid then it will be enforced. Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> --- drivers/devfreq/devfreq.c | 111 +++++++++++++++++++++----------------- 1 file changed, 63 insertions(+), 48 deletions(-)