policy->cpus is cleared unconditionally now on hotplug-out of a CPU and it can be checked to know if a policy is active or inactive. Create helper routines to iterate over all active/inactive policies, based on policy->cpus field.
Replace all instances of for_each_policy() with for_each_active_policy() to make them iterate only for active policies. (We haven't made changes yet to keep inactive policies in the same list, but that will be followed in a later patch).
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/cpufreq/cpufreq.c | 81 +++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 72 insertions(+), 9 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 6ed87d02d293..d3f9ce3b94d3 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -32,11 +32,74 @@ #include <trace/events/power.h>
/* Macros to iterate over lists */ -/* Iterate over online CPUs policies */ static LIST_HEAD(cpufreq_policy_list); +static inline bool policy_is_inactive(struct cpufreq_policy *policy) +{ + return cpumask_empty(policy->cpus); +} + +/* + * Finds Next Acive/Inactive policy + * + * policy: Previous policy. + * active: Looking for active policy (true) or Inactive policy (false). + */ +static struct cpufreq_policy *next_policy(struct cpufreq_policy *policy, + bool active) +{ + while (1) { + if (likely(policy)) + policy = list_next_entry(policy, policy_list); + else + policy = list_first_entry(&cpufreq_policy_list, + typeof(*policy), policy_list); + + /* No more policies */ + if (&policy->policy_list == &cpufreq_policy_list) + return policy; + + /* + * Table to explains logic behind following expression: + * + * Active policy_is_inactive Result + * (policy or next) + * + * 0 0 next + * 0 1 policy + * 1 0 policy + * 1 1 next + */ + if (active ^ policy_is_inactive(policy)) + return policy; + }; +} + +/* + * Iterate over online CPUs policies + * + * Explanation: + * - expr1: marks __temp NULL and gets the first __active policy. + * - expr2: checks if list is finished, if yes then it sets __policy to the last + * __active policy and returns 0 to end the loop. + * - expr3: preserves last __active policy and gets the next one. + */ +#define __for_each_active_policy(__policy, __temp, __active) \ + for (__temp = NULL, __policy = next_policy(NULL, __active); \ + &__policy->policy_list != &cpufreq_policy_list || \ + ((__policy = __temp) && 0); \ + __temp = __policy, __policy = next_policy(__policy, __active)) + #define for_each_policy(__policy) \ list_for_each_entry(__policy, &cpufreq_policy_list, policy_list)
+/* + * Routines to iterate over active or inactive policies + * __policy: next active/inactive policy will be returned in this. + * __temp: for internal purpose, not to be used by caller. + */ +#define for_each_active_policy(__policy, __temp) __for_each_active_policy(__policy, __temp, true) +#define for_each_inactive_policy(__policy, __temp) __for_each_active_policy(__policy, __temp, false) + /* Iterate over governors */ static LIST_HEAD(cpufreq_governor_list); #define for_each_governor(__governor) \ @@ -1142,7 +1205,7 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) { unsigned int j, cpu = dev->id; int ret = -ENOMEM; - struct cpufreq_policy *policy; + struct cpufreq_policy *policy, *tpolicy; unsigned long flags; bool recover_policy = cpufreq_suspended;
@@ -1156,7 +1219,7 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
/* Check if this cpu already has a policy to manage it */ read_lock_irqsave(&cpufreq_driver_lock, flags); - for_each_policy(policy) { + for_each_active_policy(policy, tpolicy) { if (cpumask_test_cpu(cpu, policy->related_cpus)) { read_unlock_irqrestore(&cpufreq_driver_lock, flags); ret = cpufreq_add_policy_cpu(policy, cpu, dev); @@ -1664,7 +1727,7 @@ EXPORT_SYMBOL(cpufreq_generic_suspend); */ void cpufreq_suspend(void) { - struct cpufreq_policy *policy; + struct cpufreq_policy *policy, *tpolicy;
if (!cpufreq_driver) return; @@ -1674,7 +1737,7 @@ void cpufreq_suspend(void)
pr_debug("%s: Suspending Governors\n", __func__);
- for_each_policy(policy) { + for_each_active_policy(policy, tpolicy) { if (__cpufreq_governor(policy, CPUFREQ_GOV_STOP)) pr_err("%s: Failed to stop governor for policy: %p\n", __func__, policy); @@ -1696,7 +1759,7 @@ void cpufreq_suspend(void) */ void cpufreq_resume(void) { - struct cpufreq_policy *policy; + struct cpufreq_policy *policy, *tpolicy;
if (!cpufreq_driver) return; @@ -1708,7 +1771,7 @@ void cpufreq_resume(void)
pr_debug("%s: Resuming Governors\n", __func__);
- for_each_policy(policy) { + for_each_active_policy(policy, tpolicy) { if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) pr_err("%s: Failed to resume driver: %p\n", __func__, policy); @@ -2348,10 +2411,10 @@ 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; + struct cpufreq_policy *policy, *tpolicy; int ret = -EINVAL;
- for_each_policy(policy) { + for_each_active_policy(policy, tpolicy) { freq_table = cpufreq_frequency_get_table(policy->cpu); if (freq_table) { ret = cpufreq_frequency_table_cpuinfo(policy,