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PM / devfreq: Rework freq_table to be local to devfreq struct 

On a devfreq PROBE_DEFER, the freq_table in the driver profile struct,
is never reset and may be leaved in an undefined state.

This comes from the fact that we store the freq_table in the driver
profile struct that is commonly defined as static and not reset on
PROBE_DEFER.
We currently skip the reinit of the freq_table if we found
it's already defined since a driver may declare his own freq_table.

This logic is flawed in the case devfreq core generate a freq_table, set
it in the profile struct and then PROBE_DEFER, freeing the freq_table.
In this case devfreq will found a NOT NULL freq_table that has been
freed, skip the freq_table generation and probe the driver based on the
wrong table.

To fix this and correctly handle PROBE_DEFER, use a local freq_table and
max_state in the devfreq struct and never modify the freq_table present
in the profile struct if it does provide it.

Fixes: 0ec09ac2ce ("PM / devfreq: Set the freq_table of devfreq device")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
This commit is contained in:
Christian Marangi 2022-06-20 00:03:51 +02:00 committed by Chanwoo Choi
parent f44b799603
commit b5d281f6c1
3 changed files with 46 additions and 44 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

71
drivers/devfreq/devfreq.c
View File

@ -123,7 +123,7 @@ void devfreq_get_freq_range(struct devfreq *devfreq,
unsigned long *min_freq,
unsigned long *max_freq)
{
unsigned long *freq_table = devfreq->profile->freq_table;
unsigned long *freq_table = devfreq->freq_table;
s32 qos_min_freq, qos_max_freq;
lockdep_assert_held(&devfreq->lock);
@ -133,11 +133,11 @@ void devfreq_get_freq_range(struct devfreq *devfreq,
* 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]) {
if (freq_table[0] < freq_table[devfreq->max_state - 1]) {
*min_freq = freq_table[0];
*max_freq = freq_table[devfreq->profile->max_state - 1];
*max_freq = freq_table[devfreq->max_state - 1];
} else {
*min_freq = freq_table[devfreq->profile->max_state - 1];
*min_freq = freq_table[devfreq->max_state - 1];
*max_freq = freq_table[0];
}
@ -169,8 +169,8 @@ static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq)
{
int lev;
for (lev = 0; lev < devfreq->profile->max_state; lev++)
if (freq == devfreq->profile->freq_table[lev])
for (lev = 0; lev < devfreq->max_state; lev++)
if (freq == devfreq->freq_table[lev])
return lev;
return -EINVAL;
@ -178,7 +178,6 @@ 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 dev_pm_opp *opp;
unsigned long freq;
int i, count;
@ -188,25 +187,22 @@ static int set_freq_table(struct devfreq *devfreq)
if (count <= 0)
return -EINVAL;
profile->max_state = count;
profile->freq_table = devm_kcalloc(devfreq->dev.parent,
profile->max_state,
sizeof(*profile->freq_table),
GFP_KERNEL);
if (!profile->freq_table) {
profile->max_state = 0;
devfreq->max_state = count;
devfreq->freq_table = devm_kcalloc(devfreq->dev.parent,
devfreq->max_state,
sizeof(*devfreq->freq_table),
GFP_KERNEL);
if (!devfreq->freq_table)
return -ENOMEM;
}
for (i = 0, freq = 0; i < profile->max_state; i++, freq++) {
for (i = 0, freq = 0; i < devfreq->max_state; 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;
devm_kfree(devfreq->dev.parent, devfreq->freq_table);
return PTR_ERR(opp);
}
dev_pm_opp_put(opp);
profile->freq_table[i] = freq;
devfreq->freq_table[i] = freq;
}
return 0;
@ -246,7 +242,7 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
if (lev != prev_lev) {
devfreq->stats.trans_table[
(prev_lev * devfreq->profile->max_state) + lev]++;
(prev_lev * devfreq->max_state) + lev]++;
devfreq->stats.total_trans++;
}
@ -835,6 +831,9 @@ struct devfreq *devfreq_add_device(struct device *dev,
if (err < 0)
goto err_dev;
mutex_lock(&devfreq->lock);
} else {
devfreq->freq_table = devfreq->profile->freq_table;
devfreq->max_state = devfreq->profile->max_state;
}
devfreq->scaling_min_freq = find_available_min_freq(devfreq);
@ -870,8 +869,8 @@ struct devfreq *devfreq_add_device(struct device *dev,
devfreq->stats.trans_table = devm_kzalloc(&devfreq->dev,
array3_size(sizeof(unsigned int),
devfreq->profile->max_state,
devfreq->profile->max_state),
devfreq->max_state,
devfreq->max_state),
GFP_KERNEL);
if (!devfreq->stats.trans_table) {
mutex_unlock(&devfreq->lock);
@ -880,7 +879,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
}
devfreq->stats.time_in_state = devm_kcalloc(&devfreq->dev,
devfreq->profile->max_state,
devfreq->max_state,
sizeof(*devfreq->stats.time_in_state),
GFP_KERNEL);
if (!devfreq->stats.time_in_state) {
@ -1666,9 +1665,9 @@ static ssize_t available_frequencies_show(struct device *d,
mutex_lock(&df->lock);
for (i = 0; i < df->profile->max_state; i++)
for (i = 0; i < df->max_state; i++)
count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
"%lu ", df->profile->freq_table[i]);
"%lu ", df->freq_table[i]);
mutex_unlock(&df->lock);
/* Truncate the trailing space */
@ -1691,7 +1690,7 @@ static ssize_t trans_stat_show(struct device *dev,
if (!df->profile)
return -EINVAL;
max_state = df->profile->max_state;
max_state = df->max_state;
if (max_state == 0)
return sprintf(buf, "Not Supported.\n");
@ -1708,19 +1707,17 @@ static ssize_t trans_stat_show(struct device *dev,
len += sprintf(buf + len, " :");
for (i = 0; i < max_state; i++)
len += sprintf(buf + len, "%10lu",
df->profile->freq_table[i]);
df->freq_table[i]);
len += sprintf(buf + len, " time(ms)\n");
for (i = 0; i < max_state; i++) {
if (df->profile->freq_table[i]
== df->previous_freq) {
if (df->freq_table[i] == df->previous_freq)
len += sprintf(buf + len, "*");
} else {
else
len += sprintf(buf + len, " ");
}
len += sprintf(buf + len, "%10lu:",
df->profile->freq_table[i]);
len += sprintf(buf + len, "%10lu:", df->freq_table[i]);
for (j = 0; j < max_state; j++)
len += sprintf(buf + len, "%10u",
df->stats.trans_table[(i * max_state) + j]);
@ -1744,7 +1741,7 @@ static ssize_t trans_stat_store(struct device *dev,
if (!df->profile)
return -EINVAL;
if (df->profile->max_state == 0)
if (df->max_state == 0)
return count;
err = kstrtoint(buf, 10, &value);
@ -1752,11 +1749,11 @@ static ssize_t trans_stat_store(struct device *dev,
return -EINVAL;
mutex_lock(&df->lock);
memset(df->stats.time_in_state, 0, (df->profile->max_state *
memset(df->stats.time_in_state, 0, (df->max_state *
sizeof(*df->stats.time_in_state)));
memset(df->stats.trans_table, 0, array3_size(sizeof(unsigned int),
df->profile->max_state,
df->profile->max_state));
df->max_state,
df->max_state));
df->stats.total_trans = 0;
df->stats.last_update = get_jiffies_64();
mutex_unlock(&df->lock);

14
drivers/devfreq/governor_passive.c
View File

@ -144,18 +144,18 @@ static int get_target_freq_with_devfreq(struct devfreq *devfreq,
goto out;
/* Use interpolation if required opps is not available */
for (i = 0; i < parent_devfreq->profile->max_state; i++)
if (parent_devfreq->profile->freq_table[i] == *freq)
for (i = 0; i < parent_devfreq->max_state; i++)
if (parent_devfreq->freq_table[i] == *freq)
break;
if (i == parent_devfreq->profile->max_state)
if (i == parent_devfreq->max_state)
return -EINVAL;
if (i < devfreq->profile->max_state) {
child_freq = devfreq->profile->freq_table[i];
if (i < devfreq->max_state) {
child_freq = devfreq->freq_table[i];
} else {
count = devfreq->profile->max_state;
child_freq = devfreq->profile->freq_table[count - 1];
count = devfreq->max_state;
child_freq = devfreq->freq_table[count - 1];
}
out:

5
include/linux/devfreq.h
View File

@ -148,6 +148,8 @@ struct devfreq_stats {
* reevaluate operable frequencies. Devfreq users may use
* devfreq.nb to the corresponding register notifier call chain.
* @work: delayed work for load monitoring.
* @freq_table: current frequency table used by the devfreq driver.
* @max_state: count of entry present in the frequency table.
* @previous_freq: previously configured frequency value.
* @last_status: devfreq user device info, performance statistics
* @data: Private data of the governor. The devfreq framework does not
@ -185,6 +187,9 @@ struct devfreq {
struct notifier_block nb;
struct delayed_work work;
unsigned long *freq_table;
unsigned int max_state;
unsigned long previous_freq;
struct devfreq_dev_status last_status;