cpufreq: remove cpufreq_policy_cpu per-cpu variable

cpufreq_policy_cpu per-cpu variables are used for storing the ID of
the CPU that manages the given CPU's policy.  However, we also store
a policy pointer for each cpu in cpufreq_cpu_data, so the
cpufreq_policy_cpu information is simply redundant.

It is better to use cpufreq_cpu_data to retrieve a policy and get
policy->cpu from there, so make that happen everywhere and drop the
cpufreq_policy_cpu per-cpu variables which aren't necessary any more.

[rjw: Changelog]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index b03a851..0586bd2 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -64,15 +64,14 @@ static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor);
  * - Lock should not be held across
  *     __cpufreq_governor(data, CPUFREQ_GOV_STOP);
  */
-static DEFINE_PER_CPU(int, cpufreq_policy_cpu);
 static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem);
 
 #define lock_policy_rwsem(mode, cpu)                                   \
 static int lock_policy_rwsem_##mode(int cpu)                           \
 {                                                                      \
-       int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu);              \
-       BUG_ON(policy_cpu == -1);                                       \
-       down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu));            \
+       struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); \
+       BUG_ON(!policy);                                                \
+       down_##mode(&per_cpu(cpu_policy_rwsem, policy->cpu));           \
                                                                        \
        return 0;                                                       \
 }
@@ -83,9 +82,9 @@ lock_policy_rwsem(write, cpu);
 #define unlock_policy_rwsem(mode, cpu)                                 \
 static void unlock_policy_rwsem_##mode(int cpu)                                \
 {                                                                      \
-       int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu);              \
-       BUG_ON(policy_cpu == -1);                                       \
-       up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu));              \
+       struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); \
+       BUG_ON(!policy);                                                \
+       up_##mode(&per_cpu(cpu_policy_rwsem, policy->cpu));             \
 }
 
 unlock_policy_rwsem(read, cpu);
@@ -887,7 +886,6 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy,
        write_lock_irqsave(&cpufreq_driver_lock, flags);
 
        cpumask_set_cpu(cpu, policy->cpus);
-       per_cpu(cpufreq_policy_cpu, cpu) = policy->cpu;
        per_cpu(cpufreq_cpu_data, cpu) = policy;
        write_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
@@ -1013,9 +1011,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
        policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
        cpumask_copy(policy->cpus, cpumask_of(cpu));
 
-       /* Initially set CPU itself as the policy_cpu */
-       per_cpu(cpufreq_policy_cpu, cpu) = cpu;
-
        init_completion(&policy->kobj_unregister);
        INIT_WORK(&policy->update, handle_update);
 
@@ -1053,10 +1048,8 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
 #endif
 
        write_lock_irqsave(&cpufreq_driver_lock, flags);
-       for_each_cpu(j, policy->cpus) {
+       for_each_cpu(j, policy->cpus)
                per_cpu(cpufreq_cpu_data, j) = policy;
-               per_cpu(cpufreq_policy_cpu, j) = policy->cpu;
-       }
        write_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
        if (!frozen) {
@@ -1080,15 +1073,11 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
 
 err_out_unregister:
        write_lock_irqsave(&cpufreq_driver_lock, flags);
-       for_each_cpu(j, policy->cpus) {
+       for_each_cpu(j, policy->cpus)
                per_cpu(cpufreq_cpu_data, j) = NULL;
-               if (j != cpu)
-                       per_cpu(cpufreq_policy_cpu, j) = -1;
-       }
        write_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
 err_set_policy_cpu:
-       per_cpu(cpufreq_policy_cpu, cpu) = -1;
        cpufreq_policy_free(policy);
 nomem_out:
        up_read(&cpufreq_rwsem);
@@ -1112,14 +1101,9 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
 
 static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
 {
-       int j;
-
        policy->last_cpu = policy->cpu;
        policy->cpu = cpu;
 
-       for_each_cpu(j, policy->cpus)
-               per_cpu(cpufreq_policy_cpu, j) = cpu;
-
 #ifdef CONFIG_CPU_FREQ_TABLE
        cpufreq_frequency_table_update_policy_cpu(policy);
 #endif
@@ -1131,7 +1115,6 @@ static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy,
                                           unsigned int old_cpu, bool frozen)
 {
        struct device *cpu_dev;
-       unsigned long flags;
        int ret;
 
        /* first sibling now owns the new sysfs dir */
@@ -1148,11 +1131,6 @@ static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *policy,
 
                WARN_ON(lock_policy_rwsem_write(old_cpu));
                cpumask_set_cpu(old_cpu, policy->cpus);
-
-               write_lock_irqsave(&cpufreq_driver_lock, flags);
-               per_cpu(cpufreq_cpu_data, old_cpu) = policy;
-               write_unlock_irqrestore(&cpufreq_driver_lock, flags);
-
                unlock_policy_rwsem_write(old_cpu);
 
                ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj,
@@ -1186,7 +1164,6 @@ static int __cpufreq_remove_dev(struct device *dev,
        write_lock_irqsave(&cpufreq_driver_lock, flags);
 
        policy = per_cpu(cpufreq_cpu_data, cpu);
-       per_cpu(cpufreq_cpu_data, cpu) = NULL;
 
        /* Save the policy somewhere when doing a light-weight tear-down */
        if (frozen)
@@ -1292,7 +1269,7 @@ static int __cpufreq_remove_dev(struct device *dev,
                }
        }
 
-       per_cpu(cpufreq_policy_cpu, cpu) = -1;
+       per_cpu(cpufreq_cpu_data, cpu) = NULL;
        return 0;
 }
 
@@ -2148,10 +2125,8 @@ static int __init cpufreq_core_init(void)
        if (cpufreq_disabled())
                return -ENODEV;
 
-       for_each_possible_cpu(cpu) {
-               per_cpu(cpufreq_policy_cpu, cpu) = -1;
+       for_each_possible_cpu(cpu)
                init_rwsem(&per_cpu(cpu_policy_rwsem, cpu));
-       }
 
        cpufreq_global_kobject = kobject_create();
        BUG_ON(!cpufreq_global_kobject);