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Commit a410c03d authored by Srinivas Pandruvada's avatar Srinivas Pandruvada Committed by Rafael J. Wysocki
Browse files

cpufreq: intel_pstate: protect limits variable 



The limits variable gets modified from intel_pstate sysfs and also gets
modified from cpufreq sysfs. So protect with a mutex to keep data
integrity, when they are getting modified from multiple threads.

Signed-off-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 33de45c1

drivers/cpufreq/intel_pstate.c

+22 −0
Original line number Diff line number Diff line
@@ -373,6 +373,8 @@ static struct perf_limits *limits = &performance_limits; 
static struct perf_limits *limits = &powersave_limits;

#endif



static DEFINE_MUTEX(intel_pstate_limits_lock);



#ifdef CONFIG_ACPI



static bool intel_pstate_get_ppc_enable_status(void)
@@ -730,14 +732,19 @@ static ssize_t store_no_turbo(struct kobject *a, struct attribute *b, 
	if (ret != 1)

		return -EINVAL;



	mutex_lock(&intel_pstate_limits_lock);



	update_turbo_state();

	if (limits->turbo_disabled) {

		pr_warn("Turbo disabled by BIOS or unavailable on processor\n");

		mutex_unlock(&intel_pstate_limits_lock);

		return -EPERM;

	}



	limits->no_turbo = clamp_t(int, input, 0, 1);



	mutex_unlock(&intel_pstate_limits_lock);



	if (hwp_active)

		intel_pstate_hwp_set_online_cpus();
@@ -754,6 +761,8 @@ static ssize_t store_max_perf_pct(struct kobject *a, struct attribute *b, 
	if (ret != 1)

		return -EINVAL;



	mutex_lock(&intel_pstate_limits_lock);



	limits->max_sysfs_pct = clamp_t(int, input, 0 , 100);

	limits->max_perf_pct = min(limits->max_policy_pct,

				   limits->max_sysfs_pct);
@@ -763,6 +772,8 @@ static ssize_t store_max_perf_pct(struct kobject *a, struct attribute *b, 
				   limits->max_perf_pct);

	limits->max_perf = div_fp(limits->max_perf_pct, 100);



	mutex_unlock(&intel_pstate_limits_lock);



	if (hwp_active)

		intel_pstate_hwp_set_online_cpus();

	return count;
@@ -778,6 +789,8 @@ static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b, 
	if (ret != 1)

		return -EINVAL;



	mutex_lock(&intel_pstate_limits_lock);



	limits->min_sysfs_pct = clamp_t(int, input, 0 , 100);

	limits->min_perf_pct = max(limits->min_policy_pct,

				   limits->min_sysfs_pct);
@@ -787,6 +800,8 @@ static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b, 
				   limits->min_perf_pct);

	limits->min_perf = div_fp(limits->min_perf_pct, 100);



	mutex_unlock(&intel_pstate_limits_lock);



	if (hwp_active)

		intel_pstate_hwp_set_online_cpus();

	return count;
@@ -1528,6 +1543,7 @@ static void intel_pstate_clear_update_util_hook(unsigned int cpu) 


static void intel_pstate_set_performance_limits(struct perf_limits *limits)

{

	mutex_lock(&intel_pstate_limits_lock);

	limits->no_turbo = 0;

	limits->turbo_disabled = 0;

	limits->max_perf_pct = 100;
@@ -1538,11 +1554,15 @@ static void intel_pstate_set_performance_limits(struct perf_limits *limits) 
	limits->max_sysfs_pct = 100;

	limits->min_policy_pct = 0;

	limits->min_sysfs_pct = 0;

	mutex_unlock(&intel_pstate_limits_lock);

}



static void intel_pstate_update_perf_limits(struct cpufreq_policy *policy,

					    struct perf_limits *limits)

{



	mutex_lock(&intel_pstate_limits_lock);



	limits->max_policy_pct = DIV_ROUND_UP(policy->max * 100,

					      policy->cpuinfo.max_freq);

	limits->max_policy_pct = clamp_t(int, limits->max_policy_pct, 0, 100);
@@ -1572,6 +1592,8 @@ static void intel_pstate_update_perf_limits(struct cpufreq_policy *policy, 
	limits->max_perf = div_fp(limits->max_perf_pct, 100);

	limits->max_perf = round_up(limits->max_perf, FRAC_BITS);



	mutex_unlock(&intel_pstate_limits_lock);



	pr_debug("cpu:%d max_perf_pct:%d min_perf_pct:%d\n", policy->cpu,

		 limits->max_perf_pct, limits->min_perf_pct);

}