Add Checking for MTRR existence.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@10223 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 88 insertions, 1 deletions

diff --git a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
index 4e6878f282..dab0535fe9 100644
--- a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
+++ b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
@@ -93,6 +93,10 @@ GetVariableMtrrCount (
   VOID

   )

 {

+  if (!IsMtrrSupported ()) {

+    return 0;

+  }

+

   return (UINT32)(AsmReadMsr64 (MTRR_LIB_IA32_MTRR_CAP) & MTRR_LIB_IA32_MTRR_CAP_VCNT_MASK);

 }

 

@@ -107,7 +111,14 @@ GetFirmwareVariableMtrrCount (
   VOID

   )

 {

-  return GetVariableMtrrCount () - RESERVED_FIRMWARE_VARIABLE_MTRR_NUMBER;

+  UINT32  VariableMtrrCount;

+

+  VariableMtrrCount = GetVariableMtrrCount ();

+  if (VariableMtrrCount < RESERVED_FIRMWARE_VARIABLE_MTRR_NUMBER) {

+    return 0;

+  }

+

+  return VariableMtrrCount - RESERVED_FIRMWARE_VARIABLE_MTRR_NUMBER;

 }

 

 /**

@@ -319,6 +330,10 @@ MtrrGetMemoryAttributeInVariableMtrr (
   UINT32  FirmwareVariableMtrrCount;

   UINT32  VariableMtrrEnd;

 

+  if (!IsMtrrSupported ()) {

+    return 0;

+  }

+

   FirmwareVariableMtrrCount = GetFirmwareVariableMtrrCount ();

   VariableMtrrEnd = MTRR_LIB_IA32_VARIABLE_MTRR_BASE + (2 * GetVariableMtrrCount ()) - 1;

 

@@ -870,6 +885,10 @@ MtrrSetMemoryAttribute (
   UINT32                    FirmwareVariableMtrrCount;

   UINT32                    VariableMtrrEnd;

 

+  if (!IsMtrrSupported ()) {

+    return RETURN_UNSUPPORTED;

+  }

+

   FirmwareVariableMtrrCount = GetFirmwareVariableMtrrCount ();

   VariableMtrrEnd = MTRR_LIB_IA32_VARIABLE_MTRR_BASE + (2 * GetVariableMtrrCount ()) - 1;

 

@@ -1110,6 +1129,10 @@ MtrrGetMemoryAttribute (
   UINT64                  MtrrValidAddressMask;

   UINTN                   VariableMtrrCount;

 

+  if (!IsMtrrSupported ()) {

+    return CacheUncacheable;

+  }

+

   //

   // Check if MTRR is enabled, if not, return UC as attribute

   //

@@ -1190,6 +1213,10 @@ MtrrGetVariableMtrr (
   UINT32  Index;

   UINT32  VariableMtrrCount;

 

+  if (!IsMtrrSupported ()) {

+    return VariableSettings;

+  }

+

   VariableMtrrCount = GetVariableMtrrCount ();

   ASSERT (VariableMtrrCount <= MTRR_NUMBER_OF_VARIABLE_MTRR);

 

@@ -1250,6 +1277,10 @@ MtrrSetVariableMtrr (
 {

   UINTN  Cr4;

 

+  if (!IsMtrrSupported ()) {

+    return VariableSettings;

+  }

+

   Cr4 = PreMtrrChange ();

   MtrrSetVariableMtrrWorker (VariableSettings);

   PostMtrrChange (Cr4);

@@ -1273,6 +1304,10 @@ MtrrGetFixedMtrr (
 {

   UINT32  Index;

 

+  if (!IsMtrrSupported ()) {

+    return FixedSettings;

+  }

+

   for (Index = 0; Index < MTRR_NUMBER_OF_FIXED_MTRR; Index++) {

       FixedSettings->Mtrr[Index] =

         AsmReadMsr64 (MtrrLibFixedMtrrTable[Index].Msr);

@@ -1319,6 +1354,10 @@ MtrrSetFixedMtrr (
 {

   UINTN  Cr4;

 

+  if (!IsMtrrSupported ()) {

+    return FixedSettings;

+  }

+

   Cr4 = PreMtrrChange ();

   MtrrSetFixedMtrrWorker (FixedSettings);

   PostMtrrChange (Cr4);

@@ -1341,6 +1380,10 @@ MtrrGetAllMtrrs (
   OUT MTRR_SETTINGS                *MtrrSetting

   )

 {

+  if (!IsMtrrSupported ()) {

+    return MtrrSetting;

+  }

+

   //

   // Get fixed MTRRs

   //

@@ -1376,6 +1419,10 @@ MtrrSetAllMtrrs (
 {

   UINTN  Cr4;

 

+  if (!IsMtrrSupported ()) {

+    return MtrrSetting;

+  }

+

   Cr4 = PreMtrrChange ();

 

   //

@@ -1412,6 +1459,10 @@ MtrrDebugPrintAllMtrrs (
       UINTN          Index;

       UINTN          VariableMtrrCount;

 

+      if (!IsMtrrSupported ()) {

+        return;

+      }

+

       MtrrGetAllMtrrs (&MtrrSettings);

       DEBUG((EFI_D_ERROR, "DefaultType = %016lx\n", MtrrSettings.MtrrDefType));

       for (Index = 0; Index < MTRR_NUMBER_OF_FIXED_MTRR; Index++) {

@@ -1435,3 +1486,39 @@ MtrrDebugPrintAllMtrrs (
   );

 }

 

+/**

+  Checks if MTRR is supported.

+

+  @retval TRUE  MTRR is supported.

+  @retval FALSE MTRR is not supported.

+

+**/

+BOOLEAN

+EFIAPI

+IsMtrrSupported (

+  VOID

+  )

+{

+  UINT32  RegEdx;

+  UINT64  MtrrCap;

+

+  //

+  // Check CPUID(1).EDX[12] for MTRR capability

+  //

+  AsmCpuid (1, NULL, NULL, NULL, &RegEdx);

+  if (BitFieldRead32 (RegEdx, 12, 12) == 0) {

+    return FALSE;

+  }

+

+  //

+  // Check IA32_MTRRCAP.[0..7] for number of variable MTRRs and IA32_MTRRCAP[8] for

+  // fixed MTRRs existence. If number of variable MTRRs is zero, or fixed MTRRs do not

+  // exist, return false.

+  //

+  MtrrCap = AsmReadMsr64 (MTRR_LIB_IA32_MTRR_CAP);

+  if  ((BitFieldRead64 (MtrrCap, 0, 7) == 0) || (BitFieldRead64 (MtrrCap, 8, 8) == 0)) {

+    return FALSE;

+  }

+

+  return TRUE;

+}