From f357c2562ac2b27f2520e8591a27001f39dc7e92 Mon Sep 17 00:00:00 2001 From: Cole Nelson Date: Tue, 16 May 2017 11:38:59 -0700 Subject: soc/intel/apollolake: enable MONITOR/MWAIT for GLK 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 Signed-off-by: Venkateswarlu Vinjamuri Reviewed-on: https://review.coreboot.org/19718 Reviewed-by: Aaron Durbin Tested-by: build bot (Jenkins) --- src/soc/intel/apollolake/chip.c | 5 +++-- src/soc/intel/apollolake/cpu.c | 2 ++ 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/src/soc/intel/apollolake/chip.c b/src/soc/intel/apollolake/chip.c index 1dd6daf16c..cac2c0061c 100644 --- a/src/soc/intel/apollolake/chip.c +++ b/src/soc/intel/apollolake/chip.c @@ -565,9 +565,10 @@ void platform_fsp_silicon_init_params_cb(FSPS_UPD *silupd) silconfig->LPSS_S0ixEnable = cfg->lpss_s0ix_enable; /* Disable monitor mwait since it is broken due to a hardware bug - * without a fix + * without a fix. Specific to Apollolake. */ - silconfig->MonitorMwaitEnable = 0; + if (!IS_ENABLED(CONFIG_SOC_INTEL_GLK)) + silconfig->MonitorMwaitEnable = 0; silconfig->SkipMpInit = 1; diff --git a/src/soc/intel/apollolake/cpu.c b/src/soc/intel/apollolake/cpu.c index d093acc06a..172a2b9708 100644 --- a/src/soc/intel/apollolake/cpu.c +++ b/src/soc/intel/apollolake/cpu.c @@ -45,6 +45,7 @@ #include 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 -- cgit v1.2.3