UefiCpuPkg/MtrrLib: Reduce hardware init when program fixed MTRRs

When MtrrSetMemoryAttribute() programs fixed MTRRs, it may disable/enable cache
and disable/enable MTRRs several times. This updating tries to do operation in
local variable and does the hardware initialization one time only.

Cc: Feng Tian <feng.tian@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Michael Kinney <michael.d.kinney@intel.com>
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19157 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 70 insertions, 20 deletions

diff --git a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
index 697dc43..322f47b 100644
--- a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
+++ b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
@@ -415,6 +415,9 @@ MtrrGetVariableMtrr (
   @param[in]      MemoryCacheType  The memory type to set.

   @param[in, out] Base             The base address of memory range.

   @param[in, out] Length           The length of memory range.

+  @param[out]     ReturnMsrNum     The index of the fixed MTRR MSR to program.

+  @param[out]     ReturnClearMask  The bits to clear in the fixed MTRR MSR.

+  @param[out]     ReturnOrMask     The bits to set in the fixed MTRR MSR.

 

   @retval RETURN_SUCCESS      The cache type was updated successfully

   @retval RETURN_UNSUPPORTED  The requested range or cache type was invalid

@@ -423,9 +426,12 @@ MtrrGetVariableMtrr (
 **/

 RETURN_STATUS

 ProgramFixedMtrr (

-  IN     UINT64     MemoryCacheType,

-  IN OUT UINT64     *Base,

-  IN OUT UINT64     *Length

+  IN     UINT64               MemoryCacheType,

+  IN OUT UINT64               *Base,

+  IN OUT UINT64               *Length,

+  OUT    UINT32               *ReturnMsrNum,

+  OUT    UINT64               *ReturnClearMask,

+  OUT    UINT64               *ReturnOrMask

   )

 {

   UINT32  MsrNum;

@@ -488,9 +494,10 @@ ProgramFixedMtrr (
     return RETURN_UNSUPPORTED;

   }

 

-  TempQword =

-    (AsmReadMsr64 (mMtrrLibFixedMtrrTable[MsrNum].Msr) & ~ClearMask) | OrMask;

-  AsmWriteMsr64 (mMtrrLibFixedMtrrTable[MsrNum].Msr, TempQword);

+  *ReturnMsrNum    = MsrNum;

+  *ReturnClearMask = ClearMask;

+  *ReturnOrMask    = OrMask;

+

   return RETURN_SUCCESS;

 }

 

@@ -1388,12 +1395,25 @@ MtrrSetMemoryAttribute (
   UINT32                    FirmwareVariableMtrrCount;

   UINT32                    VariableMtrrEnd;

   MTRR_CONTEXT              MtrrContext;

+  BOOLEAN                   MtrrContextValid;

+  BOOLEAN                   FixedSettingsValid[MTRR_NUMBER_OF_FIXED_MTRR];

+  BOOLEAN                   FixedSettingsModified[MTRR_NUMBER_OF_FIXED_MTRR];

+  MTRR_FIXED_SETTINGS       WorkingFixedSettings;

   UINT32                    VariableMtrrCount;

   MTRR_VARIABLE_SETTINGS    OriginalVariableSettings;

   MTRR_VARIABLE_SETTINGS    WorkingVariableSettings;

+  UINT32                    Index;

+  UINT64                    ClearMask;

+  UINT64                    OrMask;

+  UINT64                    NewValue;

   MTRR_VARIABLE_SETTINGS    *VariableSettings;

 

   DEBUG((DEBUG_CACHE, "MtrrSetMemoryAttribute() %a:%016lx-%016lx\n", mMtrrMemoryCacheTypeShortName[Attribute], BaseAddress, Length));

+  MtrrContextValid = FALSE;

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

+    FixedSettingsValid[Index]    = FALSE;

+    FixedSettingsModified[Index] = FALSE;

+  }

 

   if (!IsMtrrSupported ()) {

     Status = RETURN_UNSUPPORTED;

@@ -1429,22 +1449,31 @@ MtrrSetMemoryAttribute (
   // Check if Fixed MTRR

   //

   Status = RETURN_SUCCESS;

-  while ((BaseAddress < BASE_1MB) && (Length > 0) && Status == RETURN_SUCCESS) {

-    PreMtrrChange (&MtrrContext);

-    Status = ProgramFixedMtrr (MemoryType, &BaseAddress, &Length);

-    PostMtrrChange (&MtrrContext);

-    if (RETURN_ERROR (Status)) {

-      goto Done;

+  if (BaseAddress < BASE_1MB) {

+    while ((BaseAddress < BASE_1MB) && (Length > 0) && Status == RETURN_SUCCESS) {

+      Status = ProgramFixedMtrr (MemoryType, &BaseAddress, &Length, &MsrNum, &ClearMask, &OrMask);

+      if (RETURN_ERROR (Status)) {

+        goto Done;

+      }

+      if (!FixedSettingsValid[MsrNum]) {

+        WorkingFixedSettings.Mtrr[MsrNum] = AsmReadMsr64 (mMtrrLibFixedMtrrTable[MsrNum].Msr);

+        FixedSettingsValid[MsrNum] = TRUE;

+      }

+      NewValue = (WorkingFixedSettings.Mtrr[MsrNum] & ~ClearMask) | OrMask;

+      if (WorkingFixedSettings.Mtrr[MsrNum] != NewValue) {

+        WorkingFixedSettings.Mtrr[MsrNum] = NewValue;

+        FixedSettingsModified[MsrNum] = TRUE;

+      }

     }

-  }

 

-  if (Length == 0) {

-    //

-    // A Length of 0 can only make sense for fixed MTTR ranges.

-    // Since we just handled the fixed MTRRs, we can skip the

-    // variable MTRR section.

-    //

-    goto Done;

+    if (Length == 0) {

+      //

+      // A Length of 0 can only make sense for fixed MTTR ranges.

+      // Since we just handled the fixed MTRRs, we can skip the

+      // variable MTRR section.

+      //

+      goto Done;

+    }

   }

 

   //

@@ -1634,6 +1663,27 @@ MtrrSetMemoryAttribute (
   } while (TempQword > 0);

 

 Done:

+

+  //

+  // Write fixed MTRRs that have been modified

+  //

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

+    if (FixedSettingsModified[Index]) {

+      if (!MtrrContextValid) {

+        PreMtrrChange (&MtrrContext);

+        MtrrContextValid = TRUE;

+      }

+      AsmWriteMsr64 (

+        mMtrrLibFixedMtrrTable[Index].Msr,

+        WorkingFixedSettings.Mtrr[Index]

+        );

+    }

+  }

+

+  if (MtrrContextValid) {

+    PostMtrrChange (&MtrrContext);

+  }

+

   DEBUG((DEBUG_CACHE, "  Status = %r\n", Status));

   if (!RETURN_ERROR (Status)) {

     MtrrDebugPrintAllMtrrs ();