cpufreq: change '.set_boost' to act on one policy

Macro 'for_each_active_policy()' is defined internally. To avoid some
cpufreq driver needing this macro to iterate over all the policies in
'.set_boost' callback, we redefine '.set_boost' to act on only one
policy and pass the policy as an argument.

'cpufreq_boost_trigger_state()' iterates over all the policies to set
boost for the system.

This is preparation for adding SW BOOST support for CPPC.

To protect Boost enable/disable by sysfs from CPU online/offline,
add 'cpu_hotplug_lock' before calling '.set_boost' for each CPU.

Also move the lock from 'set_boost()' to 'store_cpb()' in
acpi_cpufreq.
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Suggested-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/acpi-cpufreq.c

@@ -126,12 +126,12 @@ static void boost_set_msr_each(void *p_en)
 	boost_set_msr(enable);
 }
 
-static int set_boost(int val)
+static int set_boost(struct cpufreq_policy *policy, int val)
 {
-	get_online_cpus();
-	on_each_cpu(boost_set_msr_each, (void *)(long)val, 1);
-	put_online_cpus();
-	pr_debug("Core Boosting %sabled.\n", val ? "en" : "dis");
+	on_each_cpu_mask(policy->cpus, boost_set_msr_each,
+			 (void *)(long)val, 1);
+	pr_debug("CPU %*pbl: Core Boosting %sabled.\n",
+		 cpumask_pr_args(policy->cpus), val ? "en" : "dis");
 
 	return 0;
 }
@@ -162,7 +162,9 @@ static ssize_t store_cpb(struct cpufreq_policy *policy, const char *buf,
 	if (ret || val > 1)
 		return -EINVAL;
 
-	set_boost(val);
+	get_online_cpus();
+	set_boost(policy, val);
+	put_online_cpus();
 
 	return count;
 }

drivers/cpufreq/cpufreq.c

@@ -2532,34 +2532,29 @@ EXPORT_SYMBOL_GPL(cpufreq_update_limits);
 /*********************************************************************
  *               BOOST						     *
  *********************************************************************/
-static int cpufreq_boost_set_sw(int state)
+static int cpufreq_boost_set_sw(struct cpufreq_policy *policy, int state)
 {
-	struct cpufreq_policy *policy;
-
-	for_each_active_policy(policy) {
-		int ret;
+	int ret;
 
-		if (!policy->freq_table)
-			return -ENXIO;
+	if (!policy->freq_table)
+		return -ENXIO;
 
-		ret = cpufreq_frequency_table_cpuinfo(policy,
-						      policy->freq_table);
-		if (ret) {
-			pr_err("%s: Policy frequency update failed\n",
-			       __func__);
-			return ret;
-		}
-
-		ret = freq_qos_update_request(policy->max_freq_req, policy->max);
-		if (ret < 0)
-			return ret;
+	ret = cpufreq_frequency_table_cpuinfo(policy, policy->freq_table);
+	if (ret) {
+		pr_err("%s: Policy frequency update failed\n", __func__);
+		return ret;
 	}
 
+	ret = freq_qos_update_request(policy->max_freq_req, policy->max);
+	if (ret < 0)
+		return ret;
+
 	return 0;
 }
 
 int cpufreq_boost_trigger_state(int state)
 {
+	struct cpufreq_policy *policy;
 	unsigned long flags;
 	int ret = 0;
 
@@ -2570,15 +2565,25 @@ int cpufreq_boost_trigger_state(int state)
 	cpufreq_driver->boost_enabled = state;
 	write_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
-	ret = cpufreq_driver->set_boost(state);
-	if (ret) {
-		write_lock_irqsave(&cpufreq_driver_lock, flags);
-		cpufreq_driver->boost_enabled = !state;
-		write_unlock_irqrestore(&cpufreq_driver_lock, flags);
-
-		pr_err("%s: Cannot %s BOOST\n",
-		       __func__, state ? "enable" : "disable");
+	get_online_cpus();
+	for_each_active_policy(policy) {
+		ret = cpufreq_driver->set_boost(policy, state);
+		if (ret)
+			goto err_reset_state;
 	}
+	put_online_cpus();
+
+	return 0;
+
+err_reset_state:
+	put_online_cpus();
+
+	write_lock_irqsave(&cpufreq_driver_lock, flags);
+	cpufreq_driver->boost_enabled = !state;
+	write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+	pr_err("%s: Cannot %s BOOST\n",
+	       __func__, state ? "enable" : "disable");
 
 	return ret;
 }

include/linux/cpufreq.h

@@ -367,7 +367,7 @@ struct cpufreq_driver {
 
 	/* platform specific boost support code */
 	bool		boost_enabled;
-	int		(*set_boost)(int state);
+	int		(*set_boost)(struct cpufreq_policy *policy, int state);
 };
 
 /* flags */