New patch to review for coreboot: soc/intel/apollolake: Disable Monitor and Mwait feature
Venkateswarlu V Vinjamuri (venkateswarlu.v.vinjamuri@intel.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/17200
-gerrit
commit ae45eea0e40a6eda9646eb9703fc2c0a780bff65 Author: Venkateswarlu Vinjamuri venkateswarlu.v.vinjamuri@intel.com Date: Mon Oct 31 17:03:55 2016 -0700
soc/intel/apollolake: Disable Monitor and Mwait feature
Disable Monitor/Mwait as part of SkipMpInit enablement.
BUG=chrome-os-partner:56922 BRANCH=None
Change-Id: I12cd4280de62e0a639b43538171660ee4c0a0265 Signed-off-by: Venkateswarlu Vinjamuri venkateswarlu.v.vinjamuri@intel.com --- src/soc/intel/apollolake/cpu.c | 13 +++++++++++++ src/soc/intel/apollolake/include/soc/cpu.h | 8 ++++++++ 2 files changed, 21 insertions(+)
diff --git a/src/soc/intel/apollolake/cpu.c b/src/soc/intel/apollolake/cpu.c index bd5cff5..07d38f2 100644 --- a/src/soc/intel/apollolake/cpu.c +++ b/src/soc/intel/apollolake/cpu.c @@ -43,10 +43,23 @@ static const struct reg_script core_msr_script[] = { REG_SCRIPT_END };
+static void configure_features(void) +{ + msr_t msr; + + /* Disable support for MONITOR and MWAIT instructions */ + msr = rdmsr(MSR_IA32_MISC_ENABLES); + msr.lo &= ~MONITOR_MWAIT_DIS_MASK; + wrmsr(MSR_IA32_MISC_ENABLES, msr); +} + static void soc_core_init(device_t cpu) { /* Set core MSRs */ reg_script_run(core_msr_script); + + /* Set and lock feature MSR's */ + configure_features(); }
static struct device_operations cpu_dev_ops = { diff --git a/src/soc/intel/apollolake/include/soc/cpu.h b/src/soc/intel/apollolake/include/soc/cpu.h index e94972d..c2e02be 100644 --- a/src/soc/intel/apollolake/include/soc/cpu.h +++ b/src/soc/intel/apollolake/include/soc/cpu.h @@ -28,6 +28,14 @@ void apollolake_init_cpus(struct device *dev); #define CPUID_APOLLOLAKE_A0 0x506c8 #define CPUID_APOLLOLAKE_B0 0x506c9
+/* Miscellaneous features for core and package */ +#ifndef MSR_IA32_MISC_ENABLES +#define MSR_IA32_MISC_ENABLES 0x1a0 +#endif + +/* Disable the Monitor Mwait FSM feature */ +#define MONITOR_MWAIT_DIS_MASK 0x40000 + #define MSR_PLATFORM_INFO 0xce #define MSR_POWER_MISC 0x120 #define MSR_CORE_THREAD_COUNT 0x35
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Venkateswarlu V Vinjamuri