UefiCpuPkg/CpuFeature: Introduce First to indicate 1st unit.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1584

The flow of CPU feature initialization logic is:
1. BSP calls GetConfigDataFunc() for each thread/AP;
2. Each thread/AP calls SupportFunc() to detect its own capability;
3. BSP calls InitializeFunc() for each thread/AP.

There is a design gap in step #3. For a package scope feature that only
requires one thread of each package does the initialization operation,
what InitializeFunc() currently does is to do the initialization
operation only CPU physical location Core# is 0.
But in certain platform, Core#0 might be disabled in hardware level
which results the certain package scope feature isn't initialized at
all.

The patch adds a new field First to indicate the CPU's location in
its parent scope.
First.Package is set for all APs/threads under first package;
First.Core is set for all APs/threads under first core of each
package;
First.Thread is set for the AP/thread of each core.

Signed-off-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>

1 files changed, 36 insertions, 0 deletions

diff --git a/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h b/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h
index be14a92b35..27bd2f6b48 100644
--- a/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h
+++ b/UefiCpuPkg/Include/Library/RegisterCpuFeaturesLib.h
@@ -79,6 +79,37 @@
 /// @}

 

 ///

+/// The bit field to indicate whether the processor is the first in its parent scope.

+///

+typedef struct {

+  //

+  // Set to 1 when current processor is the first thread in the core it resides in.

+  //

+  UINT32 Thread   : 1;

+  //

+  // Set to 1 when current processor is a thread of the first core in the module it resides in.

+  //

+  UINT32 Core     : 1;

+  //

+  // Set to 1 when current processor is a thread of the first module in the tile it resides in.

+  //

+  UINT32 Module   : 1;

+  //

+  // Set to 1 when current processor is a thread of the first tile in the die it resides in.

+  //

+  UINT32 Tile     : 1;

+  //

+  // Set to 1 when current processor is a thread of the first die in the package it resides in.

+  //

+  UINT32 Die      : 1;

+  //

+  // Set to 1 when current processor is a thread of the first package in the system.

+  //

+  UINT32 Package  : 1;

+  UINT32 Reserved : 26;

+} REGISTER_CPU_FEATURE_FIRST_PROCESSOR;

+

+///

 /// CPU Information passed into the SupportFunc and InitializeFunc of the

 /// RegisterCpuFeature() library function.  This structure contains information

 /// that is commonly used during CPU feature detection and initialization.

@@ -88,6 +119,11 @@ typedef struct {
   /// The package that the CPU resides

   ///

   EFI_PROCESSOR_INFORMATION            ProcessorInfo;

+

+  ///

+  /// The bit flag indicating whether the CPU is the first Thread/Core/Module/Tile/Die/Package in its parent scope.

+  ///

+  REGISTER_CPU_FEATURE_FIRST_PROCESSOR First;

   ///

   /// The Display Family of the CPU computed from CPUID leaf CPUID_VERSION_INFO

   ///