From 59d67246dbbe3f0fe29bc46c65f8ea4a6828cb2a Mon Sep 17 00:00:00 2001
From: Michael Kinney <michael.d.kinney@intel.com>
Date: Mon, 27 Apr 2015 19:47:26 +0000
Subject: [PATCH] MdePkg/BaseXApicLib: Support IA32 processors without
 MSR_IA32_APIC_BASE_ADDRESS

Use Family from CPUID 01 to detect support for the Local APIC Base Address MSR (MSR_IA32_APIC_BASE_ADDRESS).
If this MSR is not supported, then use Local APIC Base Address from the PCD PcdCpuLocalApicBaseAddress.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Michael Kinney <michael.d.kinney@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>



git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17216 6f19259b-4bc3-4df7-8a09-765794883524
---
 .../Library/BaseXApicLib/BaseXApicLib.c       | 66 ++++++++++++++++---
 .../Library/BaseXApicLib/BaseXApicLib.inf     |  6 +-
 2 files changed, 61 insertions(+), 11 deletions(-)

diff --git a/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c b/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c
index 6f8cd2eb9b..f219b07888 100644
--- a/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c
+++ b/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c
@@ -3,7 +3,7 @@
 
   This local APIC library instance supports xAPIC mode only.
 
-  Copyright (c) 2010 - 2014, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2010 - 2015, Intel Corporation. All rights reserved.<BR>
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
   which accompanies this distribution.  The full text of the license may be found at
@@ -21,11 +21,39 @@
 #include <Library/LocalApicLib.h>
 #include <Library/IoLib.h>
 #include <Library/TimerLib.h>
+#include <Library/PcdLib.h>
 
 //
 // Library internal functions
 //
 
+/**
+  Determine if the CPU supports the Local APIC Base Address MSR.
+
+  @retval TRUE  The CPU supports the Local APIC Base Address MSR.
+  @retval FALSE The CPU does not support the Local APIC Base Address MSR.
+
+**/
+BOOLEAN
+LocalApicBaseAddressMsrSupported (
+  VOID
+  )
+{
+  UINT32  RegEax;
+  UINTN   FamilyId;
+  
+  AsmCpuid (1, &RegEax, NULL, NULL, NULL);
+  FamilyId = BitFieldRead32 (RegEax, 8, 11);
+  if (FamilyId == 0x04 || FamilyId == 0x05) {
+    //
+    // CPUs with a FamilyId of 0x04 or 0x05 do not support the 
+    // Local APIC Base Address MSR
+    //
+    return FALSE;
+  }
+  return TRUE;
+}
+
 /**
   Retrieve the base address of local APIC.
 
@@ -38,8 +66,16 @@ GetLocalApicBaseAddress (
   VOID
   )
 {
-  MSR_IA32_APIC_BASE ApicBaseMsr;
-  
+  MSR_IA32_APIC_BASE  ApicBaseMsr;
+
+  if (!LocalApicBaseAddressMsrSupported ()) {
+    //
+    // If CPU does not support Local APIC Base Address MSR, then retrieve
+    // Local APIC Base Address from PCD
+    //
+    return PcdGet32 (PcdCpuLocalApicBaseAddress);
+  }
+
   ApicBaseMsr.Uint64 = AsmReadMsr64 (MSR_IA32_APIC_BASE_ADDRESS);
   
   return (UINTN)(LShiftU64 ((UINT64) ApicBaseMsr.Bits.ApicBaseHigh, 32)) +
@@ -60,10 +96,17 @@ SetLocalApicBaseAddress (
   IN UINTN                BaseAddress
   )
 {
-  MSR_IA32_APIC_BASE ApicBaseMsr;
+  MSR_IA32_APIC_BASE  ApicBaseMsr;
 
   ASSERT ((BaseAddress & (SIZE_4KB - 1)) == 0);
 
+  if (!LocalApicBaseAddressMsrSupported ()) {
+    //
+    // Ignore set request if the CPU does not support APIC Base Address MSR
+    //
+    return;
+  }
+
   ApicBaseMsr.Uint64 = AsmReadMsr64 (MSR_IA32_APIC_BASE_ADDRESS);
 
   ApicBaseMsr.Bits.ApicBaseLow  = (UINT32) (BaseAddress >> 12);
@@ -202,14 +245,19 @@ GetApicMode (
 {
   DEBUG_CODE (
     {
-      MSR_IA32_APIC_BASE ApicBaseMsr;
+      MSR_IA32_APIC_BASE  ApicBaseMsr;
 
-      ApicBaseMsr.Uint64 = AsmReadMsr64 (MSR_IA32_APIC_BASE_ADDRESS);
       //
-      // Local APIC should have been enabled
+      // Check to see if the CPU supports the APIC Base Address MSR 
       //
-      ASSERT (ApicBaseMsr.Bits.En != 0);
-      ASSERT (ApicBaseMsr.Bits.Extd == 0);
+      if (LocalApicBaseAddressMsrSupported ()) {
+        ApicBaseMsr.Uint64 = AsmReadMsr64 (MSR_IA32_APIC_BASE_ADDRESS);
+        //
+        // Local APIC should have been enabled
+        //
+        ASSERT (ApicBaseMsr.Bits.En != 0);
+        ASSERT (ApicBaseMsr.Bits.Extd == 0);
+      }
     }
   );
   return LOCAL_APIC_MODE_XAPIC;
diff --git a/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.inf b/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.inf
index 120e6e50e9..7dd2714af3 100644
--- a/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.inf
+++ b/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.inf
@@ -21,7 +21,7 @@
   MODULE_UNI_FILE                = BaseXApicLib.uni
   FILE_GUID                      = D87CA0A8-1AC2-439b-90F8-EF4A2AC88DAF
   MODULE_TYPE                    = BASE
-  VERSION_STRING                 = 1.0
+  VERSION_STRING                 = 1.1
   LIBRARY_CLASS                  = LocalApicLib 
 
 #
@@ -42,6 +42,8 @@
   DebugLib
   TimerLib
   IoLib
+  PcdLib
 
 [Pcd]
-  gUefiCpuPkgTokenSpaceGuid.PcdCpuInitIpiDelayInMicroSeconds   ## SOMETIMES_CONSUMES
+  gUefiCpuPkgTokenSpaceGuid.PcdCpuInitIpiDelayInMicroSeconds  ## SOMETIMES_CONSUMES
+  gUefiCpuPkgTokenSpaceGuid.PcdCpuLocalApicBaseAddress        ## SOMETIMES_CONSUMES
-- 
2.39.2