The drivers aren't required to provide a sorted frequency table today,
and its not optimal to work on an unsorted freq table.
To simplify and improve code performance, create a frequency table
within core and keep it sorted in ascending order.
Note that this should eventually replace policy->freq_table itself,
which isn't done currently as few drivers will break due to that.
Signed-off-by: Viresh Kumar <viresh.ku...@linaro.org>
---
drivers/cpufreq/cpufreq.c | 23 ++++++++++-----
drivers/cpufreq/freq_table.c | 67 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/cpufreq.h | 3 ++
3 files changed, 86 insertions(+), 7 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 07c933c6c29a..799e03daa4a3 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1137,6 +1137,16 @@ static void cpufreq_policy_free(struct cpufreq_policy
*policy, bool notify)
kfree(policy);
}
+static void cpufreq_policy_exit(struct cpufreq_policy *policy)
+{
+ if (!cpufreq_driver->exit)
+ return;
+
+ cpufreq_driver->exit(policy);
+ free_sorted_freq_table(policy);
+ policy->freq_table = NULL;
+}
+
static int cpufreq_online(unsigned int cpu)
{
struct cpufreq_policy *policy;
@@ -1178,6 +1188,10 @@ static int cpufreq_online(unsigned int cpu)
goto out_free_policy;
}
+ ret = create_sorted_freq_table(policy);
+ if (ret)
+ goto out_exit_policy;
+
down_write(&policy->rwsem);
if (new_policy) {
@@ -1291,9 +1305,7 @@ static int cpufreq_online(unsigned int cpu)
out_exit_policy:
up_write(&policy->rwsem);
-
- if (cpufreq_driver->exit)
- cpufreq_driver->exit(policy);
+ cpufreq_policy_exit(policy);
out_free_policy:
cpufreq_policy_free(policy, !new_policy);
return ret;
@@ -1378,10 +1390,7 @@ static void cpufreq_offline(unsigned int cpu)
* since this is a core component, and is essential for the
* subsequent light-weight ->init() to succeed.
*/
- if (cpufreq_driver->exit) {
- cpufreq_driver->exit(policy);
- policy->freq_table = NULL;
- }
+ cpufreq_policy_exit(policy);
unlock:
up_write(&policy->rwsem);
diff --git a/drivers/cpufreq/freq_table.c b/drivers/cpufreq/freq_table.c
index eac8bcbdaad1..d536136c8e1f 100644
--- a/drivers/cpufreq/freq_table.c
+++ b/drivers/cpufreq/freq_table.c
@@ -13,6 +13,7 @@
#include <linux/cpufreq.h>
#include <linux/module.h>
+#include <linux/slab.h>
/*********************************************************************
* FREQUENCY TABLE HELPERS *
@@ -297,6 +298,72 @@ struct freq_attr *cpufreq_generic_attr[] = {
};
EXPORT_SYMBOL_GPL(cpufreq_generic_attr);
+static int next_larger(struct cpufreq_policy *policy, unsigned int freq,
+ struct cpufreq_frequency_table *table)
+{
+ struct cpufreq_frequency_table *pos;
+ unsigned int next_freq = ~0;
+ int index = -EINVAL;
+
+ cpufreq_for_each_valid_entry(pos, table) {
+ if (pos->frequency <= freq)
+ continue;
+
+ if (next_freq > pos->frequency) {
+ next_freq = pos->frequency;
+ index = pos - table;
+ }
+ }
+
+ return index;
+}
+
+void free_sorted_freq_table(struct cpufreq_policy *policy)
+{
+ kfree(policy->sorted_freq_table);
+ policy->sorted_freq_table = NULL;
+}
+
+int create_sorted_freq_table(struct cpufreq_policy *policy)
+{
+ struct cpufreq_frequency_table *pos, *new_table;
+ unsigned int freq, index, i, count = 0;
+ struct cpufreq_frequency_table *table = policy->freq_table;
+
+ if (!table)
+ return 0;
+
+ cpufreq_for_each_valid_entry(pos, table)
+ count++;
+
+ /* Extra entry for CPUFREQ_TABLE_END */
+ count++;
+
+ new_table = kmalloc_array(count, sizeof(*new_table), GFP_KERNEL);
+ if (!new_table)
+ return -ENOMEM;
+
+ for (i = 0, freq = 0; i < count - 1; i++) {
+ index = next_larger(policy, freq, table);
+ if (index == -EINVAL)
+ break;
+
+ /*
+ * driver_data of the sorted table points to the index of the
+ * unsorted table.
+ */
+ new_table[i].driver_data = index;
+ new_table[i].frequency = table[index].frequency;
+
+ freq = table[index].frequency;
+ }
+
+ new_table[i].frequency = CPUFREQ_TABLE_END;
+ policy->sorted_freq_table = new_table;
+
+ return 0;
+}
+
int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
struct cpufreq_frequency_table *table)
{
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index c378776628b4..5e23eed2252c 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -87,6 +87,7 @@ struct cpufreq_policy {
struct cpufreq_user_policy user_policy;
struct cpufreq_frequency_table *freq_table;
+ struct cpufreq_frequency_table *sorted_freq_table;
struct list_head policy_list;
struct kobject kobj;
@@ -592,6 +593,8 @@ static inline void dev_pm_opp_free_cpufreq_table(struct
device *dev,
int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
struct cpufreq_frequency_table *table);
+int create_sorted_freq_table(struct cpufreq_policy *policy);
+void free_sorted_freq_table(struct cpufreq_policy *policy);
int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
struct cpufreq_frequency_table *table);
--
2.7.1.410.g6faf27b
