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authorSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>2016-10-28 10:44:52 -0700
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-11-01 06:10:54 +0100
commita410c03d668122923ab9b17c0c5728b520edddb4 (patch)
tree1a7efd942884c001df55c5652ef09f56197ae20e /drivers/cpufreq
parent33de45c133b40a129a880c175af4c2bb39dafc88 (diff)
downloadlinux-a410c03d668122923ab9b17c0c5728b520edddb4.tar.bz2
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: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/intel_pstate.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 8e7390bb2175..0837175395b9 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -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);
}