[PATCH 7/7] devfreq: move statistics to separate struct

From: Kamil Konieczny
Date: Wed Nov 13 2019 - 04:14:09 EST


Count time and transitions between devfreq frequencies in separate struct
for improved code readability and maintenance.

Signed-off-by: Kamil Konieczny <k.konieczny@xxxxxxxxxxx>
---
drivers/devfreq/devfreq.c | 156 ++++++++++++++++-------------
drivers/devfreq/exynos-bus.c | 6 +-
drivers/devfreq/governor_passive.c | 26 +++--
include/linux/devfreq.h | 43 ++++----
4 files changed, 129 insertions(+), 102 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index d79412b0de59..d85867a91230 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -105,10 +105,11 @@ static unsigned long find_available_max_freq(struct devfreq *devfreq)
*/
static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq)
{
+ struct devfreq_stats *stats = devfreq->profile->stats;
int lev;

- for (lev = 0; lev < devfreq->profile->max_state; lev++)
- if (freq == devfreq->profile->freq_table[lev])
+ for (lev = 0; lev < stats->max_state; lev++)
+ if (freq == stats->freq_table[lev])
return lev;

return -EINVAL;
@@ -117,56 +118,64 @@ static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq)
static int set_freq_table(struct devfreq *devfreq)
{
struct devfreq_dev_profile *profile = devfreq->profile;
+ struct devfreq_stats *stats;
struct dev_pm_opp *opp;
unsigned long freq;
- int i, count;
+ int i, count, err = -ENOMEM;

/* Initialize the freq_table from OPP table */
count = dev_pm_opp_get_opp_count(devfreq->dev.parent);
if (count <= 0)
return -EINVAL;

- profile->max_state = count;
- profile->freq_table = devm_kcalloc(devfreq->dev.parent,
- count,
- sizeof(*profile->freq_table),
- GFP_KERNEL);
- if (!profile->freq_table) {
- profile->max_state = 0;
+ stats = devm_kzalloc(devfreq->dev.parent,
+ sizeof(struct devfreq_stats), GFP_KERNEL);
+ if (!stats)
return -ENOMEM;
- }

- for (i = 0, freq = 0; i < profile->max_state; i++, freq++) {
+ profile->stats = stats;
+ stats->max_state = count;
+ stats->freq_table = devm_kcalloc(devfreq->dev.parent,
+ count,
+ sizeof(*stats->freq_table),
+ GFP_KERNEL);
+ if (!stats->freq_table)
+ goto err_no_mem;
+
+ for (i = 0, freq = 0; i < count; i++, freq++) {
opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &freq);
if (IS_ERR(opp)) {
- devm_kfree(devfreq->dev.parent, profile->freq_table);
- profile->max_state = 0;
- return PTR_ERR(opp);
+ devm_kfree(devfreq->dev.parent, stats->freq_table);
+ stats->max_state = 0;
+ err = PTR_ERR(opp);
+ goto err_no_mem;
}
dev_pm_opp_put(opp);
- profile->freq_table[i] = freq;
+ stats->freq_table[i] = freq;
}

- profile->trans_table = devm_kzalloc(devfreq->dev.parent,
- array3_size(sizeof(unsigned int),
- count, count),
- GFP_KERNEL);
- if (!profile->trans_table)
+ stats->trans_table = devm_kzalloc(devfreq->dev.parent,
+ array3_size(sizeof(unsigned int),
+ count, count),
+ GFP_KERNEL);
+ if (!stats->trans_table)
goto err_no_mem;

- profile->time_in_state = devm_kcalloc(devfreq->dev.parent, count,
- sizeof(*profile->time_in_state),
- GFP_KERNEL);
- if (!profile->time_in_state)
+ stats->time_in_state = devm_kcalloc(devfreq->dev.parent, count,
+ sizeof(*stats->time_in_state),
+ GFP_KERNEL);
+ if (!stats->time_in_state)
goto err_no_mem;

- profile->last_time = get_jiffies_64();
- spin_lock_init(&profile->stats_lock);
+ stats->last_time = get_jiffies_64();
+ spin_lock_init(&stats->stats_lock);

return 0;
err_no_mem:
- profile->max_state = 0;
- return -ENOMEM;
+ stats->max_state = 0;
+ devm_kfree(devfreq->dev.parent, profile->stats);
+ profile->stats = NULL;
+ return err;
}

/**
@@ -176,7 +185,7 @@ static int set_freq_table(struct devfreq *devfreq)
*/
int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
{
- struct devfreq_dev_profile *profile = devfreq->profile;
+ struct devfreq_stats *stats = devfreq->profile->stats;
unsigned long long cur_time;
int lev, prev_lev, ret = 0;

@@ -184,22 +193,21 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)

/* Immediately exit if previous_freq is not initialized yet. */
if (!devfreq->previous_freq) {
- spin_lock(&profile->stats_lock);
- profile->last_time = cur_time;
- spin_unlock(&profile->stats_lock);
+ spin_lock(&stats->stats_lock);
+ stats->last_time = cur_time;
+ spin_unlock(&stats->stats_lock);
return 0;
}

prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq);

- spin_lock(&profile->stats_lock);
+ spin_lock(&stats->stats_lock);
if (prev_lev < 0) {
ret = prev_lev;
goto out;
}

- profile->time_in_state[prev_lev] +=
- cur_time - profile->last_time;
+ stats->time_in_state[prev_lev] += cur_time - stats->last_time;
lev = devfreq_get_freq_level(devfreq, freq);
if (lev < 0) {
ret = lev;
@@ -207,14 +215,14 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
}

if (lev != prev_lev) {
- profile->trans_table[(prev_lev *
- profile->max_state) + lev]++;
- profile->total_trans++;
+ stats->trans_table[(prev_lev *
+ stats->max_state) + lev]++;
+ stats->total_trans++;
}

out:
- profile->last_time = cur_time;
- spin_unlock(&profile->stats_lock);
+ stats->last_time = cur_time;
+ spin_unlock(&stats->stats_lock);
return ret;
}
EXPORT_SYMBOL(devfreq_update_status);
@@ -504,9 +512,9 @@ void devfreq_monitor_resume(struct devfreq *devfreq)
queue_delayed_work(devfreq_wq, &devfreq->work,
msecs_to_jiffies(profile->polling_ms));

- spin_lock(&profile->stats_lock);
- profile->last_time = get_jiffies_64();
- spin_unlock(&profile->stats_lock);
+ spin_lock(&profile->stats->stats_lock);
+ profile->stats->last_time = get_jiffies_64();
+ spin_unlock(&profile->stats->stats_lock);
devfreq->stop_polling = false;

if (profile->get_cur_freq &&
@@ -677,7 +685,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
devfreq->data = data;
devfreq->nb.notifier_call = devfreq_notifier_call;

- if (!profile->max_state && !profile->freq_table) {
+ if (!profile->stats) {
mutex_unlock(&devfreq->lock);
err = set_freq_table(devfreq);
if (err < 0)
@@ -1282,6 +1290,7 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct devfreq *df = to_devfreq(dev);
+ struct devfreq_stats *stats = df->profile->stats;
unsigned long value;
int ret;

@@ -1297,13 +1306,13 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
goto unlock;
}
} else {
- unsigned long *freq_table = df->profile->freq_table;
+ unsigned long *freq_table = stats->freq_table;

/* Get minimum frequency according to sorting order */
- if (freq_table[0] < freq_table[df->profile->max_state - 1])
+ if (freq_table[0] < freq_table[stats->max_state - 1])
value = freq_table[0];
else
- value = freq_table[df->profile->max_state - 1];
+ value = freq_table[stats->max_state - 1];
}

df->min_freq = value;
@@ -1326,6 +1335,7 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct devfreq *df = to_devfreq(dev);
+ struct devfreq_stats *stats = df->profile->stats;
unsigned long value;
int ret;

@@ -1341,11 +1351,11 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
goto unlock;
}
} else {
- unsigned long *freq_table = df->profile->freq_table;
+ unsigned long *freq_table = stats->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];
+ if (freq_table[0] < freq_table[stats->max_state - 1])
+ value = freq_table[stats->max_state - 1];
else
value = freq_table[0];
}
@@ -1373,14 +1383,15 @@ static ssize_t available_frequencies_show(struct device *d,
char *buf)
{
struct devfreq *df = to_devfreq(d);
+ struct devfreq_stats *stats = df->profile->stats;
ssize_t count = 0;
int i;

mutex_lock(&df->lock);

- for (i = 0; i < df->profile->max_state; i++)
+ for (i = 0; i < stats->max_state; i++)
count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
- "%lu ", df->profile->freq_table[i]);
+ "%lu ", stats->freq_table[i]);

mutex_unlock(&df->lock);
/* Truncate the trailing space */
@@ -1398,9 +1409,10 @@ static ssize_t trans_stat_show(struct device *dev,
{
struct devfreq *devfreq = to_devfreq(dev);
struct devfreq_dev_profile *profile = devfreq->profile;
+ struct devfreq_stats *stats = profile->stats;
+ unsigned int max_state = stats->max_state;
ssize_t len;
int i, j;
- unsigned int max_state = profile->max_state;

if (!devfreq->stop_polling &&
devfreq_update_status(devfreq, devfreq->previous_freq))
@@ -1411,45 +1423,45 @@ static ssize_t trans_stat_show(struct device *dev,
len = sprintf(buf, " From : To\n");
len += sprintf(buf + len, " :");

- spin_lock(&profile->stats_lock);
+ spin_lock(&stats->stats_lock);
for (i = 0; i < max_state; i++)
len += sprintf(buf + len, "%10lu",
- profile->freq_table[i]);
+ stats->freq_table[i]);

len += sprintf(buf + len, " time(ms)\n");

for (i = 0; i < max_state; i++) {
- if (profile->freq_table[i] == devfreq->previous_freq)
+ if (stats->freq_table[i] == devfreq->previous_freq)
len += sprintf(buf + len, "*");
else
len += sprintf(buf + len, " ");

len += sprintf(buf + len, "%10lu:",
- profile->freq_table[i]);
+ stats->freq_table[i]);
for (j = 0; j < max_state; j++)
len += sprintf(buf + len, "%10u",
- profile->trans_table[(i * max_state) + j]);
+ stats->trans_table[(i * max_state) + j]);
len += sprintf(buf + len, "%10llu\n", (u64)
- jiffies64_to_msecs(profile->time_in_state[i]));
+ jiffies64_to_msecs(stats->time_in_state[i]));
}

len += sprintf(buf + len, "Total transition : %u\n",
- profile->total_trans);
- spin_unlock(&profile->stats_lock);
+ stats->total_trans);
+ spin_unlock(&stats->stats_lock);
return len;
}
static DEVICE_ATTR_RO(trans_stat);

-static void defvreq_stats_clear_table(struct devfreq_dev_profile *profile)
+static void defvreq_stats_clear_table(struct devfreq_stats *stats)
{
- unsigned int count = profile->max_state;
-
- spin_lock(&profile->stats_lock);
- memset(profile->time_in_state, 0, count * sizeof(u64));
- memset(profile->trans_table, 0, count * count * sizeof(int));
- profile->last_time = get_jiffies_64();
- profile->total_trans = 0;
- spin_unlock(&profile->stats_lock);
+ unsigned int count = stats->max_state;
+
+ spin_lock(&stats->stats_lock);
+ memset(stats->time_in_state, 0, count * sizeof(u64));
+ memset(stats->trans_table, 0, count * count * sizeof(int));
+ stats->last_time = get_jiffies_64();
+ stats->total_trans = 0;
+ spin_unlock(&stats->stats_lock);
}

static ssize_t trans_reset_store(struct device *dev,
@@ -1459,7 +1471,7 @@ static ssize_t trans_reset_store(struct device *dev,
{
struct devfreq *devfreq = to_devfreq(dev);

- defvreq_stats_clear_table(devfreq->profile);
+ defvreq_stats_clear_table(devfreq->profile->stats);

return count;
}
diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
index d9f377912c10..b212aae2bb3e 100644
--- a/drivers/devfreq/exynos-bus.c
+++ b/drivers/devfreq/exynos-bus.c
@@ -496,9 +496,9 @@ static int exynos_bus_probe(struct platform_device *pdev)
}

out:
- max_state = bus->devfreq->profile->max_state;
- min_freq = (bus->devfreq->profile->freq_table[0] / 1000);
- max_freq = (bus->devfreq->profile->freq_table[max_state - 1] / 1000);
+ max_state = profile->stats->max_state;
+ min_freq = (profile->stats->freq_table[0] / 1000);
+ max_freq = (profile->stats->freq_table[max_state - 1] / 1000);
pr_info("exynos-bus: new bus device registered: %s (%6ld KHz ~ %6ld KHz)\n",
dev_name(dev), min_freq, max_freq);

diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
index 58308948b863..b2d87a88335c 100644
--- a/drivers/devfreq/governor_passive.c
+++ b/drivers/devfreq/governor_passive.c
@@ -18,6 +18,8 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
struct devfreq_passive_data *p_data
= (struct devfreq_passive_data *)devfreq->data;
struct devfreq *parent_devfreq = (struct devfreq *)p_data->parent;
+ struct devfreq_stats *parent_stats = parent_devfreq->profile->stats;
+ struct devfreq_stats *stats;
unsigned long child_freq = ULONG_MAX;
struct dev_pm_opp *opp;
int i, count, ret = 0;
@@ -47,10 +49,14 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
* device. And then the index is used for getting the suitable
* new frequency for passive devfreq device.
*/
- if (!devfreq->profile || !devfreq->profile->freq_table
- || devfreq->profile->max_state <= 0)
+ if (!devfreq->profile || !devfreq->profile->stats ||
+ devfreq->profile->stats->max_state <= 0 ||
+ !parent_devfreq->profile || !parent_devfreq->profile->stats ||
+ parent_devfreq->profile->stats->max_state <= 0)
return -EINVAL;

+ stats = devfreq->profile->stats;
+ parent_stats = parent_devfreq->profile->stats;
/*
* The passive governor have to get the correct frequency from OPP
* list of parent device. Because in this case, *freq is temporary
@@ -68,21 +74,21 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
* Get the OPP table's index of decided freqeuncy by governor
* of parent device.
*/
- for (i = 0; i < parent_devfreq->profile->max_state; i++)
- if (parent_devfreq->profile->freq_table[i] == *freq)
+ for (i = 0; i < parent_stats->max_state; i++)
+ if (parent_stats->freq_table[i] == *freq)
break;

- if (i == parent_devfreq->profile->max_state) {
+ if (i == parent_stats->max_state) {
ret = -EINVAL;
goto out;
}

/* Get the suitable frequency by using index of parent device. */
- if (i < devfreq->profile->max_state) {
- child_freq = devfreq->profile->freq_table[i];
+ if (i < stats->max_state) {
+ child_freq = stats->freq_table[i];
} else {
- count = devfreq->profile->max_state;
- child_freq = devfreq->profile->freq_table[count - 1];
+ count = stats->max_state;
+ child_freq = stats->freq_table[count - 1];
}

/* Return the suitable frequency for passive device. */
@@ -109,7 +115,7 @@ static int update_devfreq_passive(struct devfreq *devfreq, unsigned long freq)
if (ret < 0)
goto out;

- if (devfreq->profile->freq_table
+ if (devfreq->profile->stats
&& (devfreq_update_status(devfreq, freq)))
dev_err(&devfreq->dev,
"Couldn't update frequency transition information.\n");
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 4ceb2a517a9c..8459af1a1583 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -64,6 +64,30 @@ struct devfreq_dev_status {
*/
#define DEVFREQ_FLAG_LEAST_UPPER_BOUND 0x1

+/**
+ * struct devfreq_stats - Devfreq's transitions stats counters
+ * @freq_table: Optional list of frequencies to support statistics
+ * and freq_table must be generated in ascending order.
+ * @max_state: The size of freq_table.
+ * @total_trans: Number of devfreq transitions
+ * @trans_table: Statistics of devfreq transitions
+ * @time_in_state: Statistics of devfreq states
+ * @last_time: The last time stats were updated
+ * @stats_lock: Lock protecting trans_table, time_in_state,
+ * last_time and total_trans used for statistics
+ */
+struct devfreq_stats {
+ unsigned long *freq_table;
+ unsigned int max_state;
+
+ /* information for device frequency transition */
+ unsigned int total_trans;
+ unsigned int *trans_table;
+ u64 *time_in_state;
+ unsigned long long last_time;
+ spinlock_t stats_lock;
+};
+
/**
* struct devfreq_dev_profile - Devfreq's user device profile
* @initial_freq: The operating frequency when devfreq_add_device() is
@@ -88,15 +112,7 @@ struct devfreq_dev_status {
* from devfreq_remove_device() call. If the user
* has registered devfreq->nb at a notifier-head,
* this is the time to unregister it.
- * @freq_table: Optional list of frequencies to support statistics
- * and freq_table must be generated in ascending order.
- * @max_state: The size of freq_table.
- * @total_trans: Number of devfreq transitions
- * @trans_table: Statistics of devfreq transitions
- * @time_in_state: Statistics of devfreq states
- * @last_time: The last time stats were updated
- * @stats_lock: Lock protecting trans_table, time_in_state,
- * last_time and total_trans used for statistics
+ * @stats: Statistics of devfreq states and state transitions
*/
struct devfreq_dev_profile {
unsigned long initial_freq;
@@ -108,14 +124,7 @@ struct devfreq_dev_profile {
int (*get_cur_freq)(struct device *dev, unsigned long *freq);
void (*exit)(struct device *dev);

- unsigned long *freq_table;
- unsigned int max_state;
- /* information for device frequency transition */
- unsigned int total_trans;
- unsigned int *trans_table;
- u64 *time_in_state;
- unsigned long long last_time;
- spinlock_t stats_lock;
+ struct devfreq_stats *stats;
};

/**
--
2.24.0