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soc/intel/apollolake: enable MONITOR/MWAIT for GLK

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MONITOR/MWAIT had an irremediable hardware bug for Apollolake.
This has been fixed for GLK. Therefore, make MONITOR/MWAIT based
C-states the default for GLK and disable IO-Redirection based
C-states used for Apollolake.

Tested on GLK w/kernel 4.14.27 using turbostat to observe C-state
residencies with and without load.

Tested for S0ix entry and exit using:
"echo freeze > /sys/power/state" and "suspend_stress_test -c 500".

BUG=b:77639897

Change-Id: If648c25a9b26c04b278dce4af241d439790288ca
Signed-off-by: Cole Nelson <colex.nelson@intel.com>
Signed-off-by: Venkateswarlu Vinjamuri <venkateswarlu.v.vinjamuri@intel.com>
Reviewed-on: https://review.coreboot.org/19718
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
This commit is contained in:
Cole Nelson
2017-05-16 11:38:59 -07:00
committed by Aaron Durbin
parent b10e96f196
commit f357c2562a
2 changed files with 5 additions and 2 deletions
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2
src/soc/intel/apollolake/cpu.c
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@@ -45,6 +45,7 @@
#include <soc/pm.h>
static const struct reg_script core_msr_script[] = {
#if !IS_ENABLED(CONFIG_SOC_INTEL_GLK)
/* Enable C-state and IO/MWAIT redirect */
REG_MSR_WRITE(MSR_PMG_CST_CONFIG_CONTROL,
(PKG_C_STATE_LIMIT_C2_MASK | CORE_C_STATE_LIMIT_C10_MASK
@@ -56,6 +57,7 @@ static const struct reg_script core_msr_script[] = {
REG_MSR_RMW(MSR_POWER_CTL, ~0x2, 0),
/* Disable support for MONITOR and MWAIT instructions */
REG_MSR_RMW(MSR_IA32_MISC_ENABLES, ~MONITOR_MWAIT_DIS_MASK, 0),
#endif
/*
* Enable and Lock the Advanced Encryption Standard (AES-NI)
* feature register