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authorChen Yu <yu.c.chen@intel.com>2015-09-09 10:27:31 (GMT)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-09-09 20:55:23 (GMT)
commit43717aadd2bc87fb10fbf1cd815c1cbae9bb95b3 (patch)
treea525f784c4a857f55c09d6dc8eee594ea042cffb /drivers/cpufreq/intel_pstate.c
parent953ba9ff77f3d08635712eaeffb218d46889b58a (diff)
downloadlinux-43717aadd2bc87fb10fbf1cd815c1cbae9bb95b3.tar.xz
intel_pstate: Fix user input of min/max to legal policy region
In current code, max_perf_pct might be smaller than min_perf_pct by improper user input: $ grep . /sys/devices/system/cpu/intel_pstate/m*_perf_pct /sys/devices/system/cpu/intel_pstate/max_perf_pct:100 /sys/devices/system/cpu/intel_pstate/min_perf_pct:100 $ echo 80 > /sys/devices/system/cpu/intel_pstate/max_perf_pct $ grep . /sys/devices/system/cpu/intel_pstate/m*_perf_pct /sys/devices/system/cpu/intel_pstate/max_perf_pct:80 /sys/devices/system/cpu/intel_pstate/min_perf_pct:100 Fix this problem by 2 steps: 1. Normalize the user input to [min_policy, max_policy]. 2. Make sure max_perf_pct>=min_perf_pct, suggested by Seiichi Ikarashi. Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Kristen Carlson Accardi <kristen@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq/intel_pstate.c')
-rw-r--r--drivers/cpufreq/intel_pstate.c17
1 files changed, 14 insertions, 3 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 31d0548..63075cc 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -423,6 +423,8 @@ static ssize_t store_max_perf_pct(struct kobject *a, struct attribute *b,
limits.max_sysfs_pct = clamp_t(int, input, 0 , 100);
limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct);
+ limits.max_perf_pct = max(limits.min_policy_pct, limits.max_perf_pct);
+ limits.max_perf_pct = max(limits.min_perf_pct, limits.max_perf_pct);
limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
if (hwp_active)
@@ -442,6 +444,8 @@ static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b,
limits.min_sysfs_pct = clamp_t(int, input, 0 , 100);
limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct);
+ limits.min_perf_pct = min(limits.max_policy_pct, limits.min_perf_pct);
+ limits.min_perf_pct = min(limits.max_perf_pct, limits.min_perf_pct);
limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
if (hwp_active)
@@ -989,12 +993,19 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
limits.min_policy_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
limits.min_policy_pct = clamp_t(int, limits.min_policy_pct, 0 , 100);
- limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct);
- limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
-
limits.max_policy_pct = (policy->max * 100) / policy->cpuinfo.max_freq;
limits.max_policy_pct = clamp_t(int, limits.max_policy_pct, 0 , 100);
+
+ /* Normalize user input to [min_policy_pct, max_policy_pct] */
+ limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct);
+ limits.min_perf_pct = min(limits.max_policy_pct, limits.min_perf_pct);
limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct);
+ limits.max_perf_pct = max(limits.min_policy_pct, limits.max_perf_pct);
+
+ /* Make sure min_perf_pct <= max_perf_pct */
+ limits.min_perf_pct = min(limits.max_perf_pct, limits.min_perf_pct);
+
+ limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100));
if (hwp_active)