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.kumar@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 c6a14ba239a2..a6bdb55350f4 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1146,6 +1146,16 @@ 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; @@ -1187,6 +1197,10 @@ 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) { @@ -1300,9 +1314,7 @@ 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; @@ -1387,10 +1399,7 @@ 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 4e5c5dbfed7a..ba97912973c4 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 * @@ -298,6 +299,72 @@ 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 7ed93c310c08..08cf508948dd 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);