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path: root/drivers/devfreq/devfreq.c
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Diffstat (limited to 'drivers/devfreq/devfreq.c')
-rw-r--r--drivers/devfreq/devfreq.c273
1 files changed, 202 insertions, 71 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);