[coreboot-gerrit] Patch set updated for coreboot: soc/intel/apollolake: Disable Monitor and Mwait feature

Venkateswarlu V Vinjamuri (venkateswarlu.v.vinjamuri@intel.com) gerrit at coreboot.org
Tue Nov 1 20:18:21 CET 2016


Venkateswarlu V Vinjamuri (venkateswarlu.v.vinjamuri at intel.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/17200

-gerrit

commit a03e060cab4446b90fc3f1991b422c2f936b60c0
Author: Venkateswarlu Vinjamuri <venkateswarlu.v.vinjamuri at intel.com>
Date:   Mon Oct 31 17:03:55 2016 -0700

    soc/intel/apollolake: Disable Monitor and Mwait feature
    
    Monitor/Mwait is broken on APL. So, it needs to be disabled.
    
    BUG=chrome-os-partner:56922
    BRANCH=None
    
    Change-Id: I12cd4280de62e0a639b43538171660ee4c0a0265
    Signed-off-by: Venkateswarlu Vinjamuri <venkateswarlu.v.vinjamuri at intel.com>
---
 src/soc/intel/apollolake/cpu.c             | 3 +++
 src/soc/intel/apollolake/include/soc/cpu.h | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/src/soc/intel/apollolake/cpu.c b/src/soc/intel/apollolake/cpu.c
index bd5cff5..6b5dee2 100644
--- a/src/soc/intel/apollolake/cpu.c
+++ b/src/soc/intel/apollolake/cpu.c
@@ -29,6 +29,7 @@
 #include <soc/cpu.h>
 #include <soc/iomap.h>
 #include <soc/smm.h>
+#include <cpu/intel/turbo.h>
 
 static const struct reg_script core_msr_script[] = {
 	/* Enable C-state and IO/MWAIT redirect */
@@ -40,6 +41,8 @@ static const struct reg_script core_msr_script[] = {
 		(ACPI_PMIO_CST_REG | (PMG_IO_BASE_CST_RNG_BLK_SIZE << 16))),
 	/* Disable C1E */
 	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),
 	REG_SCRIPT_END
 };
 
diff --git a/src/soc/intel/apollolake/include/soc/cpu.h b/src/soc/intel/apollolake/include/soc/cpu.h
index e94972d..2ecab7f 100644
--- a/src/soc/intel/apollolake/include/soc/cpu.h
+++ b/src/soc/intel/apollolake/include/soc/cpu.h
@@ -62,6 +62,8 @@ void apollolake_init_cpus(struct device *dev);
 #define IO_MWAIT_REDIRECT_MASK	0x400
 /* Set MSR_PMG_CST_CONFIG_CONTROL[15] to lock CST_CFG [0-15] bits */
 #define CST_CFG_LOCK_MASK	0x8000
+/* Disable the Monitor Mwait FSM feature */
+#define MONITOR_MWAIT_DIS_MASK	0x40000
 
 #define MSR_PMG_CST_CONFIG_CONTROL	0xe2
 #define MSR_PMG_IO_CAPTURE_BASE	0xe4



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