[coreboot-gerrit] Patch set updated for coreboot: intel/skylake: add function is_secondary_thread()
Robbie Zhang (robbie.zhang@intel.com)
gerrit at coreboot.org
Wed Feb 15 20:55:06 CET 2017
Robbie Zhang (robbie.zhang at intel.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/18366
-gerrit
commit 87d6fa08af73d2b9c5cf940b2baba4896d62362c
Author: Robbie Zhang <robbie.zhang at intel.com>
Date: Tue Feb 14 15:12:17 2017 -0800
intel/skylake: add function is_secondary_thread()
There are MSRs that are programmable per-core not per-thread, so add
a function to check whether current executing CPU is a primary core
or a "hyperthreaded"/secondary core. For instance when trying to
program Core PRMRR MSRs(per-core) with mp_init, cpu exception is thrown
from the secondary thread. This function was used to avoid that.
Potentially this function can be put to common code or arch/x86 or cpu/x86.
BUG=chrome-os-partner:62438
BRANCH=NONE
TEST=Tested on Eve, verified core PRMRR MSRs get programmed only on primary
thread avoiding exeception.
Change-Id: Ic9648351fadf912164a39206788859baf3e5c173
Signed-off-by: Robbie Zhang <robbie.zhang at intel.com>
---
src/soc/intel/skylake/cpu.c | 11 +++++++++++
src/soc/intel/skylake/include/soc/cpu.h | 1 +
2 files changed, 12 insertions(+)
diff --git a/src/soc/intel/skylake/cpu.c b/src/soc/intel/skylake/cpu.c
index fd726c8..4784889 100644
--- a/src/soc/intel/skylake/cpu.c
+++ b/src/soc/intel/skylake/cpu.c
@@ -431,6 +431,17 @@ static int adjust_apic_id(int index, int apic_id)
return index;
}
+/* Check whether the current CPU is the sibling hyperthread. */
+int is_secondary_thread(void)
+{
+ int apic_id;
+ apic_id = lapicid();
+
+ if (!ht_disabled && (apic_id & 1))
+ return 1;
+ return 0;
+}
+
static void per_cpu_smm_trigger(void)
{
/* Relocate the SMM handler. */
diff --git a/src/soc/intel/skylake/include/soc/cpu.h b/src/soc/intel/skylake/include/soc/cpu.h
index ecb9833..bf720e6 100644
--- a/src/soc/intel/skylake/include/soc/cpu.h
+++ b/src/soc/intel/skylake/include/soc/cpu.h
@@ -63,5 +63,6 @@ int cpu_config_tdp_levels(void);
u32 cpu_family_model(void);
u32 cpu_stepping(void);
int cpu_is_ult(void);
+int is_secondary_thread(void);
#endif
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