cpufreq: intel_pstate: Check cpuid for MSR_HWP_INTERRUPT

The MSR MSR_HWP_INTERRUPT is valid only when CPUID.06H:EAX[8] = 1, so
check for feature before accessing this MSR.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 9c8a78f9ddce623b45bd84581ce50e931e1a94b4..d8028def199dc373cb73f9d6bc5904e88da96228 100644 (file)
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -806,7 +806,8 @@ static void __init intel_pstate_sysfs_expose_params(void)
 static void intel_pstate_hwp_enable(struct cpudata *cpudata)
 {
        /* First disable HWP notification interrupt as we don't process them */
-       wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_INTERRUPT, 0x00);
+       if (static_cpu_has(X86_FEATURE_HWP_NOTIFY))
+               wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_INTERRUPT, 0x00);
 
        wrmsrl_on_cpu(cpudata->cpu, MSR_PM_ENABLE, 0x1);
 }