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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>
hifive-unleashed-5.1
Srinivas Pandruvada 2016-10-28 10:44:52 -07:00 committed by Rafael J. Wysocki
parent 33de45c133
commit a410c03d66
1 changed files with 22 additions and 0 deletions
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22
drivers/cpufreq/intel_pstate.c
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@ -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);
}