Firstly, get ApLoopMode from PcdCpuApLoopMode. If MonitorMwait feature is not
supported, update ApLoopMode to ApHltLoop. If MonitorMwait feature is supported,
get MointorFilter size by CPUID.[EAX=05H]:EBX.BIT0-15.
Cc: Michael Kinney <michael.d.kin...@intel.com>
Cc: Feng Tian <feng.t...@intel.com>
Cc: Giri P Mudusuru <giri.p.mudus...@intel.com>
Cc: Laszlo Ersek <ler...@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff....@intel.com>
---
UefiCpuPkg/Library/MpInitLib/MpLib.c | 63 ++++++++++++++++++++++++++++++++++++
UefiCpuPkg/Library/MpInitLib/MpLib.h | 6 ++++
2 files changed, 69 insertions(+)
diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c
b/UefiCpuPkg/Library/MpInitLib/MpLib.c
index 506e839..8ee8360 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
@@ -16,6 +16,65 @@
/**
+ Detect whether Mwait-monitor feature is supported.
+
+ @retval TRUE Mwait-monitor feature is supported.
+ @retval FALSE Mwait-monitor feature is not supported.
+**/
+BOOLEAN
+IsMwaitSupport (
+ VOID
+ )
+{
+ CPUID_VERSION_INFO_ECX VersionInfoEcx;
+
+ AsmCpuid (CPUID_VERSION_INFO, NULL, NULL, &VersionInfoEcx.Uint32, NULL);
+ return (VersionInfoEcx.Bits.MONITOR == 1) ? TRUE : FALSE;
+}
+
+/**
+ Get AP loop mode.
+
+ @param[out] MonitorFilterSize Returns the largest monitor-line size in
bytes.
+
+ @return The AP loop mode.
+**/
+UINT8
+GetApLoopMode (
+ OUT UINT32 *MonitorFilterSize
+ )
+{
+ UINT8 ApLoopMode;
+ CPUID_MONITOR_MWAIT_EBX MonitorMwaitEbx;
+
+ ASSERT (MonitorFilterSize != NULL);
+
+ ApLoopMode = PcdGet8 (PcdCpuApLoopMode);
+ ASSERT (ApLoopMode >= ApInHltLoop && ApLoopMode <= ApInRunLoop);
+ if (ApLoopMode == ApInMwaitLoop) {
+ if (!IsMwaitSupport ()) {
+ //
+ // If processor does not support MONITOR/MWAIT feature,
+ // force AP in Hlt-loop mode
+ //
+ ApLoopMode = ApInHltLoop;
+ }
+ }
+
+ if (ApLoopMode != ApInMwaitLoop) {
+ *MonitorFilterSize = sizeof (UINT32);
+ } else {
+ //
+ // CPUID.[EAX=05H]:EBX.BIT0-15: Largest monitor-line size in bytes
+ // CPUID.[EAX=05H].EDX: C-states supported using MWAIT
+ //
+ AsmCpuid (CPUID_MONITOR_MWAIT, NULL, &MonitorMwaitEbx.Uint32, NULL, NULL);
+ *MonitorFilterSize = MonitorMwaitEbx.Bits.LargestMonitorLineSize;
+ }
+
+ return ApLoopMode;
+}
+/**
MP Initialize Library initialization.
This service will allocate AP reset vector and wakeup all APs to do APs
@@ -35,10 +94,14 @@ MpInitLibInitialize (
)
{
MP_ASSEMBLY_ADDRESS_MAP AddressMap;
+ UINT32 MonitorFilterSize;
+ UINT8 ApLoopMode;
UINTN ApResetVectorSize;
AsmGetAddressMap (&AddressMap);
ApResetVectorSize = AddressMap.RendezvousFunnelSize + sizeof
(MP_CPU_EXCHANGE_INFO);
+ ApLoopMode = GetApLoopMode (&MonitorFilterSize);
+
return EFI_SUCCESS;
}
diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.h
b/UefiCpuPkg/Library/MpInitLib/MpLib.h
index 84f5821..8b51571 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.h
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.h
@@ -35,6 +35,12 @@
#include <Library/MtrrLib.h>
#include <Library/HobLib.h>
+typedef enum {
+ ApInHltLoop = 1,
+ ApInMwaitLoop = 2,
+ ApInRunLoop = 3
+} AP_LOOP_MODE;
+
//
// AP reset code information
//
--
2.7.4.windows.1
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