[PATCH V2 2/6] cpufreq: Remove cpufreq_frequency_get_table()
From: Viresh Kumar
Date: Thu Jun 02 2016 - 10:05:52 EST
Most of the callers of cpufreq_frequency_get_table() already have the
pointer to a valid 'policy' structure and they don't really need to go
through the per-cpu variable first and then a check to validate the
frequency, in order to find the freq-table for the policy.
Directly use the policy->freq_table field instead for them.
Only one user of that API is left after above changes, cpu_cooling.c and
it accesses the freq_table in a racy way as the policy can get freed in
between.
Fix it by using cpufreq_cpu_get() properly.
Since there are no more users of cpufreq_frequency_get_table() left, get
rid of it.
Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
drivers/cpufreq/cpufreq.c | 38 +++++++++++++----------------------
drivers/cpufreq/cpufreq_ondemand.c | 2 +-
drivers/cpufreq/cpufreq_stats.c | 3 +--
drivers/cpufreq/freq_table.c | 9 +++------
drivers/cpufreq/ppc_cbe_cpufreq_pmi.c | 3 +--
drivers/thermal/cpu_cooling.c | 22 +++++++++++++++-----
include/linux/cpufreq.h | 2 --
7 files changed, 37 insertions(+), 42 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index fbc97b1fa371..1833eda1f9d4 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -126,15 +126,6 @@ struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy)
}
EXPORT_SYMBOL_GPL(get_governor_parent_kobj);
-struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
-{
- struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);
-
- return policy && !policy_is_inactive(policy) ?
- policy->freq_table : NULL;
-}
-EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table);
-
static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
{
u64 idle_time;
@@ -1950,7 +1941,7 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
if (!cpufreq_driver->target_index)
return -EINVAL;
- freq_table = cpufreq_frequency_get_table(policy->cpu);
+ freq_table = policy->freq_table;
if (unlikely(!freq_table)) {
pr_err("%s: Unable to find freq_table\n", __func__);
return -EINVAL;
@@ -2345,26 +2336,25 @@ static struct notifier_block __refdata cpufreq_cpu_notifier = {
*********************************************************************/
static int cpufreq_boost_set_sw(int state)
{
- struct cpufreq_frequency_table *freq_table;
struct cpufreq_policy *policy;
int ret = -EINVAL;
for_each_active_policy(policy) {
- freq_table = cpufreq_frequency_get_table(policy->cpu);
- if (freq_table) {
- ret = cpufreq_frequency_table_cpuinfo(policy,
- freq_table);
- if (ret) {
- pr_err("%s: Policy frequency update failed\n",
- __func__);
- break;
- }
+ if (!policy->freq_table)
+ continue;
- down_write(&policy->rwsem);
- policy->user_policy.max = policy->max;
- cpufreq_governor_limits(policy);
- up_write(&policy->rwsem);
+ ret = cpufreq_frequency_table_cpuinfo(policy,
+ policy->freq_table);
+ if (ret) {
+ pr_err("%s: Policy frequency update failed\n",
+ __func__);
+ break;
}
+
+ down_write(&policy->rwsem);
+ policy->user_policy.max = policy->max;
+ cpufreq_governor_limits(policy);
+ up_write(&policy->rwsem);
}
return ret;
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index c84fc2240d49..4d2fe2710c5d 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -113,7 +113,7 @@ static void ondemand_powersave_bias_init(struct cpufreq_policy *policy)
{
struct od_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data);
- dbs_info->freq_table = cpufreq_frequency_get_table(policy->cpu);
+ dbs_info->freq_table = policy->freq_table;
dbs_info->freq_lo = 0;
}
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index c6e7f81a0397..06d3abdffd3a 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -157,11 +157,10 @@ void cpufreq_stats_create_table(struct cpufreq_policy *policy)
unsigned int i = 0, count = 0, ret = -ENOMEM;
struct cpufreq_stats *stats;
unsigned int alloc_size;
- unsigned int cpu = policy->cpu;
struct cpufreq_frequency_table *pos, *table;
/* We need cpufreq table for creating stats table */
- table = cpufreq_frequency_get_table(cpu);
+ table = policy->freq_table;
if (unlikely(!table))
return;
diff --git a/drivers/cpufreq/freq_table.c b/drivers/cpufreq/freq_table.c
index 4e5c5dbfed7a..f52b5473b1f4 100644
--- a/drivers/cpufreq/freq_table.c
+++ b/drivers/cpufreq/freq_table.c
@@ -106,12 +106,10 @@ EXPORT_SYMBOL_GPL(cpufreq_frequency_table_verify);
*/
int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy)
{
- struct cpufreq_frequency_table *table =
- cpufreq_frequency_get_table(policy->cpu);
- if (!table)
+ if (!policy->freq_table)
return -ENODEV;
- return cpufreq_frequency_table_verify(policy, table);
+ return cpufreq_frequency_table_verify(policy, policy->freq_table);
}
EXPORT_SYMBOL_GPL(cpufreq_generic_frequency_table_verify);
@@ -210,9 +208,8 @@ EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target);
int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
unsigned int freq)
{
- struct cpufreq_frequency_table *pos, *table;
+ struct cpufreq_frequency_table *pos, *table = policy->freq_table;
- table = cpufreq_frequency_get_table(policy->cpu);
if (unlikely(!table)) {
pr_debug("%s: Unable to find frequency table\n", __func__);
return -ENOENT;
diff --git a/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c b/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c
index 7c4cd5c634f2..dc112481a408 100644
--- a/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c
+++ b/drivers/cpufreq/ppc_cbe_cpufreq_pmi.c
@@ -94,7 +94,7 @@ static int pmi_notifier(struct notifier_block *nb,
unsigned long event, void *data)
{
struct cpufreq_policy *policy = data;
- struct cpufreq_frequency_table *cbe_freqs;
+ struct cpufreq_frequency_table *cbe_freqs = policy->freq_table;
u8 node;
/* Should this really be called for CPUFREQ_ADJUST and CPUFREQ_NOTIFY
@@ -103,7 +103,6 @@ static int pmi_notifier(struct notifier_block *nb,
if (event == CPUFREQ_START)
return 0;
- cbe_freqs = cpufreq_frequency_get_table(policy->cpu);
node = cbe_cpu_to_node(policy->cpu);
pr_debug("got notified, event=%lu, node=%u\n", event, node);
diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
index 6ceac4f2d4b2..63f760869651 100644
--- a/drivers/thermal/cpu_cooling.c
+++ b/drivers/thermal/cpu_cooling.c
@@ -787,6 +787,7 @@ __cpufreq_cooling_register(struct device_node *np,
const struct cpumask *clip_cpus, u32 capacitance,
get_static_t plat_static_func)
{
+ struct cpufreq_policy *policy;
struct thermal_cooling_device *cool_dev;
struct cpufreq_cooling_device *cpufreq_dev;
char dev_name[THERMAL_NAME_LENGTH];
@@ -794,15 +795,24 @@ __cpufreq_cooling_register(struct device_node *np,
unsigned int freq, i, num_cpus;
int ret;
- table = cpufreq_frequency_get_table(cpumask_first(clip_cpus));
+ policy = cpufreq_cpu_get(cpumask_first(clip_cpus));
+ if (!policy) {
+ pr_debug("%s: CPUFreq policy not found\n", __func__);
+ return ERR_PTR(-EPROBE_DEFER);
+ }
+
+ table = policy->freq_table;
if (!table) {
pr_debug("%s: CPUFreq table not found\n", __func__);
- return ERR_PTR(-EPROBE_DEFER);
+ cool_dev = ERR_PTR(-ENODEV);
+ goto put_policy;
}
cpufreq_dev = kzalloc(sizeof(*cpufreq_dev), GFP_KERNEL);
- if (!cpufreq_dev)
- return ERR_PTR(-ENOMEM);
+ if (!cpufreq_dev) {
+ cool_dev = ERR_PTR(-ENOMEM);
+ goto put_policy;
+ }
num_cpus = cpumask_weight(clip_cpus);
cpufreq_dev->time_in_idle = kcalloc(num_cpus,
@@ -892,7 +902,7 @@ __cpufreq_cooling_register(struct device_node *np,
CPUFREQ_POLICY_NOTIFIER);
mutex_unlock(&cooling_cpufreq_lock);
- return cool_dev;
+ goto put_policy;
remove_idr:
release_idr(&cpufreq_idr, cpufreq_dev->id);
@@ -906,6 +916,8 @@ __cpufreq_cooling_register(struct device_node *np,
kfree(cpufreq_dev->time_in_idle);
free_cdev:
kfree(cpufreq_dev);
+put_policy:
+ cpufreq_cpu_put(policy);
return cool_dev;
}
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 7ed93c310c08..1342cbc0f25e 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -632,8 +632,6 @@ static inline bool policy_has_boost_freq(struct cpufreq_policy *policy)
return false;
}
#endif
-/* the following funtion is for cpufreq core use only */
-struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
/* the following are really really optional */
extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
--
2.7.1.410.g6faf27b