From: Jan Kiszka <jan.kiszka@siemens.com>
Date: Fri, 8 Jul 2016 18:42:04 +0000 (+0200)
Subject: intel_pstate: Fix MSR_CONFIG_TDP_x addressing in core_get_max_pstate()
X-Git-Tag: firefly_0821_release~176^2~4^2~31^2~417
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=695c69bf304d7874e0b918684818711f0d7830f9;p=firefly-linux-kernel-4.4.55.git

intel_pstate: Fix MSR_CONFIG_TDP_x addressing in core_get_max_pstate()

commit 5fc8f707a2aa40c767c3a338738b9b6fcd151ac1 upstream.

If MSR_CONFIG_TDP_CONTROL is locked, we currently try to address some
MSR 0x80000648 or so. Mask out the relevant level bits 0 and 1.

Found while running over the Jailhouse hypervisor which became upset
about this strange MSR index.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index f53b02a6bc05..6e80e4298274 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -662,7 +662,7 @@ static int core_get_max_pstate(void)
 			if (err)
 				goto skip_tar;
 
-			tdp_msr = MSR_CONFIG_TDP_NOMINAL + tdp_ctrl;
+			tdp_msr = MSR_CONFIG_TDP_NOMINAL + (tdp_ctrl & 0x3);
 			err = rdmsrl_safe(tdp_msr, &tdp_ratio);
 			if (err)
 				goto skip_tar;