UefiCpuPkg/MpInitLib: add struct MP_HAND_OFF_CONFIG

Move the WaitLoopExecutionMode and StartupSignalValue fields to a
separate HOB with the new struct.

WaitLoopExecutionMode and StartupSignalValue are independent of
processor index ranges; they are global to MpInitLib (i.e., the entire
system). Therefore they shouldn't be repeated in every MpHandOff GUID
HOB.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-Id: <20240228114855.1615788-1-kraxel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Oliver Steffen <osteffen@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
[lersek@redhat.com: turn the "Cc:" message headers from Gerd's on-list
 posting into "Cc:" tags in the commit message, in order to pacify
 "PatchCheck.py"]

UefiCpuPkg/Library/MpInitLib/MpHandOff.h

@@ -15,7 +15,13 @@
     0x11e2bd88, 0xed38, 0x4abd, {0xa3, 0x99, 0x21, 0xf2, 0x5f, 0xd0, 0x7a, 0x60 } \
   }
 
+#define MP_HANDOFF_CONFIG_GUID \
+  { \
+    0xdabbd793, 0x7b46, 0x4144, {0x8a, 0xd4, 0x10, 0x1c, 0x7c, 0x08, 0xeb, 0xfa } \
+  }
+
 extern EFI_GUID  mMpHandOffGuid;
+extern EFI_GUID  mMpHandOffConfigGuid;
 
 //
 // The information required to transfer from the PEI phase to the
@@ -43,8 +49,11 @@ typedef struct {
   //
   UINT32                ProcessorIndex;
   UINT32                CpuCount;
-  UINT32                WaitLoopExecutionMode;
-  UINT32                StartupSignalValue;
   PROCESSOR_HAND_OFF    Info[];
 } MP_HAND_OFF;
+
+typedef struct {
+  UINT32    WaitLoopExecutionMode;
+  UINT32    StartupSignalValue;
+} MP_HAND_OFF_CONFIG;
 #endif

UefiCpuPkg/Library/MpInitLib/MpLib.c

@@ -15,6 +15,7 @@
 
 EFI_GUID  mCpuInitMpLibHobGuid = CPU_INIT_MP_LIB_HOB_GUID;
 EFI_GUID  mMpHandOffGuid       = MP_HANDOFF_GUID;
+EFI_GUID  mMpHandOffConfigGuid = MP_HANDOFF_CONFIG_GUID;
 
 /**
   Save the volatile registers required to be restored following INIT IPI.
@@ -1935,10 +1936,12 @@ GetBspNumber (
   This procedure allows the AP to switch to another section of
   memory and continue its loop there.
 
+  @param[in] MpHandOffConfig  Pointer to MP hand-off config HOB body.
   @param[in] FirstMpHandOff   Pointer to first MP hand-off HOB body.
 **/
 VOID
 SwitchApContext (
+  IN CONST MP_HAND_OFF_CONFIG  *MpHandOffConfig,
   IN CONST MP_HAND_OFF         *FirstMpHandOff
   )
 {
@@ -1955,7 +1958,7 @@ SwitchApContext (
     for (Index = 0; Index < MpHandOff->CpuCount; Index++) {
       if (MpHandOff->ProcessorIndex + Index != BspNumber) {
         *(UINTN *)(UINTN)MpHandOff->Info[Index].StartupProcedureAddress = (UINTN)SwitchContextPerAp;
-        *(UINT32 *)(UINTN)MpHandOff->Info[Index].StartupSignalAddress   = MpHandOff->StartupSignalValue;
+        *(UINT32 *)(UINTN)MpHandOff->Info[Index].StartupSignalAddress   = MpHandOffConfig->StartupSignalValue;
       }
     }
   }
@@ -1975,6 +1978,26 @@ SwitchApContext (
   }
 }
 
+/**
+  Get pointer to MP_HAND_OFF_CONFIG GUIDed HOB body.
+
+  @return  The pointer to MP_HAND_OFF_CONFIG structure.
+**/
+MP_HAND_OFF_CONFIG *
+GetMpHandOffConfigHob (
+  VOID
+  )
+{
+  EFI_HOB_GUID_TYPE  *GuidHob;
+
+  GuidHob = GetFirstGuidHob (&mMpHandOffConfigGuid);
+  if (GuidHob == NULL) {
+    return NULL;
+  }
+
+  return (MP_HAND_OFF_CONFIG *)GET_GUID_HOB_DATA (GuidHob);
+}
+
 /**
   Get pointer to next MP_HAND_OFF GUIDed HOB body.
 
@@ -2022,6 +2045,7 @@ MpInitLibInitialize (
   VOID
   )
 {
+  MP_HAND_OFF_CONFIG       *MpHandOffConfig;
   MP_HAND_OFF              *FirstMpHandOff;
   MP_HAND_OFF              *MpHandOff;
   CPU_INFO_IN_HOB          *CpuInfoInHob;
@@ -2239,13 +2263,24 @@ MpInitLibInitialize (
       }
     }
 
+    MpHandOffConfig = GetMpHandOffConfigHob ();
+    if (MpHandOffConfig == NULL) {
+      DEBUG ((
+        DEBUG_ERROR,
+        "%a: at least one MpHandOff HOB, but no MpHandOffConfig HOB\n",
+        __func__
+        ));
+      ASSERT (MpHandOffConfig != NULL);
+      CpuDeadLoop ();
+    }
+
     DEBUG ((
       DEBUG_INFO,
       "FirstMpHandOff->WaitLoopExecutionMode: %04d, sizeof (VOID *): %04d\n",
-      FirstMpHandOff->WaitLoopExecutionMode,
+      MpHandOffConfig->WaitLoopExecutionMode,
       sizeof (VOID *)
       ));
-    if (FirstMpHandOff->WaitLoopExecutionMode == sizeof (VOID *)) {
+    if (MpHandOffConfig->WaitLoopExecutionMode == sizeof (VOID *)) {
       ASSERT (CpuMpData->ApLoopMode != ApInHltLoop);
 
       CpuMpData->FinishedCount                        = 0;
@@ -2261,7 +2296,7 @@ MpInitLibInitialize (
       // enables the APs to switch to a different memory section and continue their
       // looping process there.
       //
-      SwitchApContext (FirstMpHandOff);
+      SwitchApContext (MpHandOffConfig, FirstMpHandOff);
       //
       // Wait for all APs finished initialization
       //

UefiCpuPkg/Library/MpInitLib/MpLib.h

@@ -482,6 +482,7 @@ GetWakeupBuffer (
 **/
 VOID
 SwitchApContext (
+  IN CONST MP_HAND_OFF_CONFIG  *MpHandOffConfig,
   IN CONST MP_HAND_OFF         *FirstMpHandOff
   );
 

UefiCpuPkg/Library/MpInitLib/PeiMpLib.c

@@ -133,6 +133,7 @@ SaveCpuMpData (
   UINT32              HobBase;
   CPU_INFO_IN_HOB     *CpuInfoInHob;
   MP_HAND_OFF         *MpHandOff;
+  MP_HAND_OFF_CONFIG  MpHandOffConfig;
   UINTN               MpHandOffSize;
 
   MaxCpusPerHob = (0xFFF8 - sizeof (EFI_HOB_GUID_TYPE) - sizeof (MP_HAND_OFF)) / sizeof (PROCESSOR_HAND_OFF);
@@ -155,11 +156,6 @@ SaveCpuMpData (
 
       MpHandOff->ProcessorIndex = HobBase;
       MpHandOff->CpuCount       = CpusInHob;
-
-      if (CpuMpData->ApLoopMode != ApInHltLoop) {
-        MpHandOff->StartupSignalValue    = MP_HAND_OFF_SIGNAL;
-        MpHandOff->WaitLoopExecutionMode = sizeof (VOID *);
-      }
     }
 
     MpHandOff->Info[Index-HobBase].ApicId = CpuInfoInHob[Index].ApicId;
@@ -170,6 +166,18 @@ SaveCpuMpData (
     }
   }
 
+  ZeroMem (&MpHandOffConfig, sizeof (MpHandOffConfig));
+  if (CpuMpData->ApLoopMode != ApInHltLoop) {
+    MpHandOffConfig.StartupSignalValue    = MP_HAND_OFF_SIGNAL;
+    MpHandOffConfig.WaitLoopExecutionMode = sizeof (VOID *);
+  }
+
+  BuildGuidDataHob (
+    &mMpHandOffConfigGuid,
+    (VOID *)&MpHandOffConfig,
+    sizeof (MpHandOffConfig)
+    );
+
   //
   // Build location of CPU MP DATA buffer in HOB
   //