4 Copyright (c) 2008 - 2015, Intel Corporation. All rights reserved.<BR>
5 This program and the accompanying materials
6 are licensed and made available under the terms and conditions of the BSD License
7 which accompanies this distribution. The full text of the license may be found at
8 http://opensource.org/licenses/bsd-license.php
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
17 #include <Library/MtrrLib.h>
18 #include <Library/BaseLib.h>
19 #include <Library/CpuLib.h>
20 #include <Library/BaseMemoryLib.h>
21 #include <Library/DebugLib.h>
24 // Context to save and restore when MTRRs are programmed
28 BOOLEAN InterruptState
;
32 // This table defines the offset, base and length of the fixed MTRRs
34 CONST FIXED_MTRR mMtrrLibFixedMtrrTable
[] = {
36 MTRR_LIB_IA32_MTRR_FIX64K_00000
,
41 MTRR_LIB_IA32_MTRR_FIX16K_80000
,
46 MTRR_LIB_IA32_MTRR_FIX16K_A0000
,
51 MTRR_LIB_IA32_MTRR_FIX4K_C0000
,
56 MTRR_LIB_IA32_MTRR_FIX4K_C8000
,
61 MTRR_LIB_IA32_MTRR_FIX4K_D0000
,
66 MTRR_LIB_IA32_MTRR_FIX4K_D8000
,
71 MTRR_LIB_IA32_MTRR_FIX4K_E0000
,
76 MTRR_LIB_IA32_MTRR_FIX4K_E8000
,
81 MTRR_LIB_IA32_MTRR_FIX4K_F0000
,
86 MTRR_LIB_IA32_MTRR_FIX4K_F8000
,
93 // Lookup table used to print MTRRs
95 GLOBAL_REMOVE_IF_UNREFERENCED CONST CHAR8
*mMtrrMemoryCacheTypeShortName
[] = {
96 "UC", // CacheUncacheable
97 "WC", // CacheWriteCombining
100 "WT", // CacheWriteThrough
101 "WP", // CacheWriteProtected
102 "WB", // CacheWriteBack
107 Worker function returns the variable MTRR count for the CPU.
109 @return Variable MTRR count
113 GetVariableMtrrCountWorker (
117 UINT32 VariableMtrrCount
;
119 VariableMtrrCount
= (UINT32
)(AsmReadMsr64 (MTRR_LIB_IA32_MTRR_CAP
) & MTRR_LIB_IA32_MTRR_CAP_VCNT_MASK
);
120 ASSERT (VariableMtrrCount
<= MTRR_NUMBER_OF_VARIABLE_MTRR
);
121 return VariableMtrrCount
;
125 Returns the variable MTRR count for the CPU.
127 @return Variable MTRR count
132 GetVariableMtrrCount (
136 if (!IsMtrrSupported ()) {
139 return GetVariableMtrrCountWorker ();
143 Worker function returns the firmware usable variable MTRR count for the CPU.
145 @return Firmware usable variable MTRR count
149 GetFirmwareVariableMtrrCountWorker (
153 UINT32 VariableMtrrCount
;
154 UINT32 ReservedMtrrNumber
;
156 VariableMtrrCount
= GetVariableMtrrCountWorker ();
157 ReservedMtrrNumber
= PcdGet32 (PcdCpuNumberOfReservedVariableMtrrs
);
158 if (VariableMtrrCount
< ReservedMtrrNumber
) {
162 return VariableMtrrCount
- ReservedMtrrNumber
;
166 Returns the firmware usable variable MTRR count for the CPU.
168 @return Firmware usable variable MTRR count
173 GetFirmwareVariableMtrrCount (
177 if (!IsMtrrSupported ()) {
180 return GetFirmwareVariableMtrrCountWorker ();
184 Worker function returns the default MTRR cache type for the system.
186 @return The default MTRR cache type.
189 MTRR_MEMORY_CACHE_TYPE
190 MtrrGetDefaultMemoryTypeWorker (
194 return (MTRR_MEMORY_CACHE_TYPE
) (AsmReadMsr64 (MTRR_LIB_IA32_MTRR_DEF_TYPE
) & 0x7);
199 Returns the default MTRR cache type for the system.
201 @return The default MTRR cache type.
204 MTRR_MEMORY_CACHE_TYPE
206 MtrrGetDefaultMemoryType (
210 if (!IsMtrrSupported ()) {
211 return CacheUncacheable
;
213 return MtrrGetDefaultMemoryTypeWorker ();
217 Preparation before programming MTRR.
219 This function will do some preparation for programming MTRRs:
220 disable cache, invalid cache and disable MTRR caching functionality
222 @param[out] MtrrContext Pointer to context to save
227 OUT MTRR_CONTEXT
*MtrrContext
231 // Disable interrupts and save current interrupt state
233 MtrrContext
->InterruptState
= SaveAndDisableInterrupts();
236 // Enter no fill cache mode, CD=1(Bit30), NW=0 (Bit29)
241 // Save original CR4 value and clear PGE flag (Bit 7)
243 MtrrContext
->Cr4
= AsmReadCr4 ();
244 AsmWriteCr4 (MtrrContext
->Cr4
& (~BIT7
));
254 AsmMsrBitFieldWrite64 (MTRR_LIB_IA32_MTRR_DEF_TYPE
, 10, 11, 0);
258 Cleaning up after programming MTRRs.
260 This function will do some clean up after programming MTRRs:
261 Flush all TLBs, re-enable caching, restore CR4.
263 @param[in] MtrrContext Pointer to context to restore
267 PostMtrrChangeEnableCache (
268 IN MTRR_CONTEXT
*MtrrContext
277 // Enable Normal Mode caching CD=NW=0, CD(Bit30), NW(Bit29)
282 // Restore original CR4 value
284 AsmWriteCr4 (MtrrContext
->Cr4
);
287 // Restore original interrupt state
289 SetInterruptState (MtrrContext
->InterruptState
);
293 Cleaning up after programming MTRRs.
295 This function will do some clean up after programming MTRRs:
296 enable MTRR caching functionality, and enable cache
298 @param[in] MtrrContext Pointer to context to restore
303 IN MTRR_CONTEXT
*MtrrContext
309 AsmMsrBitFieldWrite64 (MTRR_LIB_IA32_MTRR_DEF_TYPE
, 10, 11, 3);
311 PostMtrrChangeEnableCache (MtrrContext
);
315 Worker function gets the content in fixed MTRRs
317 @param[out] FixedSettings A buffer to hold fixed MTRRs content.
319 @retval The pointer of FixedSettings
323 MtrrGetFixedMtrrWorker (
324 OUT MTRR_FIXED_SETTINGS
*FixedSettings
329 for (Index
= 0; Index
< MTRR_NUMBER_OF_FIXED_MTRR
; Index
++) {
330 FixedSettings
->Mtrr
[Index
] =
331 AsmReadMsr64 (mMtrrLibFixedMtrrTable
[Index
].Msr
);
334 return FixedSettings
;
339 This function gets the content in fixed MTRRs
341 @param[out] FixedSettings A buffer to hold fixed MTRRs content.
343 @retval The pointer of FixedSettings
349 OUT MTRR_FIXED_SETTINGS
*FixedSettings
352 if (!IsMtrrSupported ()) {
353 return FixedSettings
;
356 return MtrrGetFixedMtrrWorker (FixedSettings
);
361 Worker function will get the raw value in variable MTRRs
363 @param[out] VariableSettings A buffer to hold variable MTRRs content.
365 @return The VariableSettings input pointer
368 MTRR_VARIABLE_SETTINGS
*
369 MtrrGetVariableMtrrWorker (
370 IN UINT32 VariableMtrrCount
,
371 OUT MTRR_VARIABLE_SETTINGS
*VariableSettings
376 ASSERT (VariableMtrrCount
<= MTRR_NUMBER_OF_VARIABLE_MTRR
);
378 for (Index
= 0; Index
< VariableMtrrCount
; Index
++) {
379 VariableSettings
->Mtrr
[Index
].Base
=
380 AsmReadMsr64 (MTRR_LIB_IA32_VARIABLE_MTRR_BASE
+ (Index
<< 1));
381 VariableSettings
->Mtrr
[Index
].Mask
=
382 AsmReadMsr64 (MTRR_LIB_IA32_VARIABLE_MTRR_BASE
+ (Index
<< 1) + 1);
385 return VariableSettings
;
389 This function will get the raw value in variable MTRRs
391 @param[out] VariableSettings A buffer to hold variable MTRRs content.
393 @return The VariableSettings input pointer
396 MTRR_VARIABLE_SETTINGS
*
398 MtrrGetVariableMtrr (
399 OUT MTRR_VARIABLE_SETTINGS
*VariableSettings
402 if (!IsMtrrSupported ()) {
403 return VariableSettings
;
406 return MtrrGetVariableMtrrWorker (
407 GetVariableMtrrCountWorker (),
413 Programs fixed MTRRs registers.
415 @param[in] MemoryCacheType The memory type to set.
416 @param[in, out] Base The base address of memory range.
417 @param[in, out] Length The length of memory range.
419 @retval RETURN_SUCCESS The cache type was updated successfully
420 @retval RETURN_UNSUPPORTED The requested range or cache type was invalid
426 IN UINT64 MemoryCacheType
,
428 IN OUT UINT64
*Length
441 for (MsrNum
= 0; MsrNum
< MTRR_NUMBER_OF_FIXED_MTRR
; MsrNum
++) {
442 if ((*Base
>= mMtrrLibFixedMtrrTable
[MsrNum
].BaseAddress
) &&
445 mMtrrLibFixedMtrrTable
[MsrNum
].BaseAddress
+
446 (8 * mMtrrLibFixedMtrrTable
[MsrNum
].Length
)
454 if (MsrNum
== MTRR_NUMBER_OF_FIXED_MTRR
) {
455 return RETURN_UNSUPPORTED
;
459 // We found the fixed MTRR to be programmed
461 for (ByteShift
= 0; ByteShift
< 8; ByteShift
++) {
464 mMtrrLibFixedMtrrTable
[MsrNum
].BaseAddress
+
465 (ByteShift
* mMtrrLibFixedMtrrTable
[MsrNum
].Length
)
472 if (ByteShift
== 8) {
473 return RETURN_UNSUPPORTED
;
478 ((ByteShift
< 8) && (*Length
>= mMtrrLibFixedMtrrTable
[MsrNum
].Length
));
481 OrMask
|= LShiftU64 ((UINT64
) MemoryCacheType
, (UINT32
) (ByteShift
* 8));
482 ClearMask
|= LShiftU64 ((UINT64
) 0xFF, (UINT32
) (ByteShift
* 8));
483 *Length
-= mMtrrLibFixedMtrrTable
[MsrNum
].Length
;
484 *Base
+= mMtrrLibFixedMtrrTable
[MsrNum
].Length
;
487 if (ByteShift
< 8 && (*Length
!= 0)) {
488 return RETURN_UNSUPPORTED
;
492 (AsmReadMsr64 (mMtrrLibFixedMtrrTable
[MsrNum
].Msr
) & ~ClearMask
) | OrMask
;
493 AsmWriteMsr64 (mMtrrLibFixedMtrrTable
[MsrNum
].Msr
, TempQword
);
494 return RETURN_SUCCESS
;
499 Worker function gets the attribute of variable MTRRs.
501 This function shadows the content of variable MTRRs into an
502 internal array: VariableMtrr.
504 @param[in] VariableSettings The variable MTRR values to shadow
505 @param[in] FirmwareVariableMtrrCount The number of variable MTRRs available to firmware
506 @param[in] MtrrValidBitsMask The mask for the valid bit of the MTRR
507 @param[in] MtrrValidAddressMask The valid address mask for MTRR
508 @param[out] VariableMtrr The array to shadow variable MTRRs content
510 @return The return value of this parameter indicates the
511 number of MTRRs which has been used.
515 MtrrGetMemoryAttributeInVariableMtrrWorker (
516 IN MTRR_VARIABLE_SETTINGS
*VariableSettings
,
517 IN UINTN FirmwareVariableMtrrCount
,
518 IN UINT64 MtrrValidBitsMask
,
519 IN UINT64 MtrrValidAddressMask
,
520 OUT VARIABLE_MTRR
*VariableMtrr
526 ZeroMem (VariableMtrr
, sizeof (VARIABLE_MTRR
) * MTRR_NUMBER_OF_VARIABLE_MTRR
);
527 for (Index
= 0, UsedMtrr
= 0; Index
< FirmwareVariableMtrrCount
; Index
++) {
528 if ((VariableSettings
->Mtrr
[Index
].Mask
& MTRR_LIB_CACHE_MTRR_ENABLED
) != 0) {
529 VariableMtrr
[Index
].Msr
= (UINT32
)Index
;
530 VariableMtrr
[Index
].BaseAddress
= (VariableSettings
->Mtrr
[Index
].Base
& MtrrValidAddressMask
);
531 VariableMtrr
[Index
].Length
= ((~(VariableSettings
->Mtrr
[Index
].Mask
& MtrrValidAddressMask
)) & MtrrValidBitsMask
) + 1;
532 VariableMtrr
[Index
].Type
= (VariableSettings
->Mtrr
[Index
].Base
& 0x0ff);
533 VariableMtrr
[Index
].Valid
= TRUE
;
534 VariableMtrr
[Index
].Used
= TRUE
;
543 Gets the attribute of variable MTRRs.
545 This function shadows the content of variable MTRRs into an
546 internal array: VariableMtrr.
548 @param[in] MtrrValidBitsMask The mask for the valid bit of the MTRR
549 @param[in] MtrrValidAddressMask The valid address mask for MTRR
550 @param[out] VariableMtrr The array to shadow variable MTRRs content
552 @return The return value of this paramter indicates the
553 number of MTRRs which has been used.
558 MtrrGetMemoryAttributeInVariableMtrr (
559 IN UINT64 MtrrValidBitsMask
,
560 IN UINT64 MtrrValidAddressMask
,
561 OUT VARIABLE_MTRR
*VariableMtrr
564 MTRR_VARIABLE_SETTINGS VariableSettings
;
566 if (!IsMtrrSupported ()) {
570 MtrrGetVariableMtrrWorker (
571 GetVariableMtrrCountWorker (),
575 return MtrrGetMemoryAttributeInVariableMtrrWorker (
577 GetFirmwareVariableMtrrCountWorker (),
579 MtrrValidAddressMask
,
586 Checks overlap between given memory range and MTRRs.
588 @param[in] FirmwareVariableMtrrCount The number of variable MTRRs available
590 @param[in] Start The start address of memory range.
591 @param[in] End The end address of memory range.
592 @param[in] VariableMtrr The array to shadow variable MTRRs content
594 @retval TRUE Overlap exists.
595 @retval FALSE No overlap.
599 CheckMemoryAttributeOverlap (
600 IN UINTN FirmwareVariableMtrrCount
,
601 IN PHYSICAL_ADDRESS Start
,
602 IN PHYSICAL_ADDRESS End
,
603 IN VARIABLE_MTRR
*VariableMtrr
608 for (Index
= 0; Index
< FirmwareVariableMtrrCount
; Index
++) {
610 VariableMtrr
[Index
].Valid
&&
612 (Start
> (VariableMtrr
[Index
].BaseAddress
+
613 VariableMtrr
[Index
].Length
- 1)
615 (End
< VariableMtrr
[Index
].BaseAddress
)
627 Marks a variable MTRR as non-valid.
629 @param[in] Index The index of the array VariableMtrr to be invalidated
630 @param[in] VariableMtrr The array to shadow variable MTRRs content
631 @param[out] UsedMtrr The number of MTRRs which has already been used
635 InvalidateShadowMtrr (
637 IN VARIABLE_MTRR
*VariableMtrr
,
641 VariableMtrr
[Index
].Valid
= FALSE
;
642 *UsedMtrr
= *UsedMtrr
- 1;
647 Combines memory attributes.
649 If overlap exists between given memory range and MTRRs, try to combine them.
651 @param[in] FirmwareVariableMtrrCount The number of variable MTRRs
652 available to firmware.
653 @param[in] Attributes The memory type to set.
654 @param[in, out] Base The base address of memory range.
655 @param[in, out] Length The length of memory range.
656 @param[in] VariableMtrr The array to shadow variable MTRRs content
657 @param[in, out] UsedMtrr The number of MTRRs which has already been used
658 @param[out] OverwriteExistingMtrr Returns whether an existing MTRR was used
660 @retval EFI_SUCCESS Memory region successfully combined.
661 @retval EFI_ACCESS_DENIED Memory region cannot be combined.
665 CombineMemoryAttribute (
666 IN UINT32 FirmwareVariableMtrrCount
,
667 IN UINT64 Attributes
,
669 IN OUT UINT64
*Length
,
670 IN VARIABLE_MTRR
*VariableMtrr
,
671 IN OUT UINT32
*UsedMtrr
,
672 OUT BOOLEAN
*OverwriteExistingMtrr
680 BOOLEAN CoveredByExistingMtrr
;
682 *OverwriteExistingMtrr
= FALSE
;
683 CoveredByExistingMtrr
= FALSE
;
684 EndAddress
= *Base
+*Length
- 1;
686 for (Index
= 0; Index
< FirmwareVariableMtrrCount
; Index
++) {
688 MtrrEnd
= VariableMtrr
[Index
].BaseAddress
+ VariableMtrr
[Index
].Length
- 1;
690 !VariableMtrr
[Index
].Valid
||
693 (EndAddress
< VariableMtrr
[Index
].BaseAddress
)
700 // Combine same attribute MTRR range
702 if (Attributes
== VariableMtrr
[Index
].Type
) {
704 // if the MTRR range contain the request range, set a flag, then continue to
705 // invalidate any MTRR of the same request range with higher priority cache type.
707 if (VariableMtrr
[Index
].BaseAddress
<= *Base
&& MtrrEnd
>= EndAddress
) {
708 CoveredByExistingMtrr
= TRUE
;
712 // invalid this MTRR, and program the combine range
715 (*Base
) < VariableMtrr
[Index
].BaseAddress
?
717 VariableMtrr
[Index
].BaseAddress
;
718 CombineEnd
= EndAddress
> MtrrEnd
? EndAddress
: MtrrEnd
;
721 // Record the MTRR usage status in VariableMtrr array.
723 InvalidateShadowMtrr (Index
, VariableMtrr
, UsedMtrr
);
724 *Base
= CombineStart
;
725 *Length
= CombineEnd
- CombineStart
+ 1;
726 EndAddress
= CombineEnd
;
727 *OverwriteExistingMtrr
= TRUE
;
731 // The cache type is different, but the range is convered by one MTRR
733 if (VariableMtrr
[Index
].BaseAddress
== *Base
&& MtrrEnd
== EndAddress
) {
734 InvalidateShadowMtrr (Index
, VariableMtrr
, UsedMtrr
);
740 if ((Attributes
== MTRR_CACHE_WRITE_THROUGH
&&
741 VariableMtrr
[Index
].Type
== MTRR_CACHE_WRITE_BACK
) ||
742 (Attributes
== MTRR_CACHE_WRITE_BACK
&&
743 VariableMtrr
[Index
].Type
== MTRR_CACHE_WRITE_THROUGH
) ||
744 (Attributes
== MTRR_CACHE_UNCACHEABLE
) ||
745 (VariableMtrr
[Index
].Type
== MTRR_CACHE_UNCACHEABLE
)
747 *OverwriteExistingMtrr
= TRUE
;
751 // Other type memory overlap is invalid
753 return RETURN_ACCESS_DENIED
;
756 if (CoveredByExistingMtrr
) {
760 return RETURN_SUCCESS
;
765 Calculates the maximum value which is a power of 2, but less the MemoryLength.
767 @param[in] MemoryLength The number to pass in.
769 @return The maximum value which is align to power of 2 and less the MemoryLength
774 IN UINT64 MemoryLength
779 if (RShiftU64 (MemoryLength
, 32) != 0) {
781 (UINT64
) GetPowerOfTwo32 (
782 (UINT32
) RShiftU64 (MemoryLength
, 32)
787 Result
= (UINT64
) GetPowerOfTwo32 ((UINT32
) MemoryLength
);
795 Determines the MTRR numbers used to program a memory range.
797 This function first checks the alignment of the base address.
798 If the alignment of the base address <= Length, cover the memory range
799 (BaseAddress, alignment) by a MTRR, then BaseAddress += alignment and
800 Length -= alignment. Repeat the step until alignment > Length.
802 Then this function determines which direction of programming the variable
803 MTRRs for the remaining length will use fewer MTRRs.
805 @param[in] BaseAddress Length of Memory to program MTRR
806 @param[in] Length Length of Memory to program MTRR
807 @param[in] MtrrNumber Pointer to the number of necessary MTRRs
809 @retval TRUE Positive direction is better.
810 FALSE Negative direction is better.
814 GetMtrrNumberAndDirection (
815 IN UINT64 BaseAddress
,
827 if (BaseAddress
!= 0) {
830 // Calculate the alignment of the base address.
832 Alignment
= LShiftU64 (1, (UINTN
)LowBitSet64 (BaseAddress
));
834 if (Alignment
> Length
) {
839 BaseAddress
+= Alignment
;
853 TempQword
-= Power2MaxMemory (TempQword
);
855 } while (TempQword
!= 0);
857 TempQword
= Power2MaxMemory (LShiftU64 (Length
, 1)) - Length
;
860 TempQword
-= Power2MaxMemory (TempQword
);
862 } while (TempQword
!= 0);
864 if (Positive
<= Subtractive
) {
865 *MtrrNumber
+= Positive
;
868 *MtrrNumber
+= Subtractive
;
874 Invalid variable MTRRs according to the value in the shadow array.
876 This function programs MTRRs according to the values specified
879 @param[in] VariableMtrrCount Number of variable MTRRs
880 @param[in, out] VariableMtrr Shadow of variable MTRR contents
885 IN UINTN VariableMtrrCount
,
886 IN OUT VARIABLE_MTRR
*VariableMtrr
890 MTRR_CONTEXT MtrrContext
;
892 PreMtrrChange (&MtrrContext
);
894 while (Index
< VariableMtrrCount
) {
895 if (!VariableMtrr
[Index
].Valid
&& VariableMtrr
[Index
].Used
) {
896 AsmWriteMsr64 (VariableMtrr
[Index
].Msr
, 0);
897 AsmWriteMsr64 (VariableMtrr
[Index
].Msr
+ 1, 0);
898 VariableMtrr
[Index
].Used
= FALSE
;
902 PostMtrrChange (&MtrrContext
);
907 Programs variable MTRRs
909 This function programs variable MTRRs
911 @param[in] MtrrNumber Index of MTRR to program.
912 @param[in] BaseAddress Base address of memory region.
913 @param[in] Length Length of memory region.
914 @param[in] MemoryCacheType Memory type to set.
915 @param[in] MtrrValidAddressMask The valid address mask for MTRR
919 ProgramVariableMtrr (
921 IN PHYSICAL_ADDRESS BaseAddress
,
923 IN UINT64 MemoryCacheType
,
924 IN UINT64 MtrrValidAddressMask
928 MTRR_CONTEXT MtrrContext
;
930 PreMtrrChange (&MtrrContext
);
933 // MTRR Physical Base
935 TempQword
= (BaseAddress
& MtrrValidAddressMask
) | MemoryCacheType
;
936 AsmWriteMsr64 ((UINT32
) MtrrNumber
, TempQword
);
939 // MTRR Physical Mask
941 TempQword
= ~(Length
- 1);
943 (UINT32
) (MtrrNumber
+ 1),
944 (TempQword
& MtrrValidAddressMask
) | MTRR_LIB_CACHE_MTRR_ENABLED
947 PostMtrrChange (&MtrrContext
);
952 Converts the Memory attribute value to MTRR_MEMORY_CACHE_TYPE.
954 @param[in] MtrrType MTRR memory type
956 @return The enum item in MTRR_MEMORY_CACHE_TYPE
959 MTRR_MEMORY_CACHE_TYPE
960 GetMemoryCacheTypeFromMtrrType (
965 case MTRR_CACHE_UNCACHEABLE
:
966 return CacheUncacheable
;
967 case MTRR_CACHE_WRITE_COMBINING
:
968 return CacheWriteCombining
;
969 case MTRR_CACHE_WRITE_THROUGH
:
970 return CacheWriteThrough
;
971 case MTRR_CACHE_WRITE_PROTECTED
:
972 return CacheWriteProtected
;
973 case MTRR_CACHE_WRITE_BACK
:
974 return CacheWriteBack
;
977 // MtrrType is MTRR_CACHE_INVALID_TYPE, that means
978 // no MTRR covers the range
980 return MtrrGetDefaultMemoryType ();
985 Initializes the valid bits mask and valid address mask for MTRRs.
987 This function initializes the valid bits mask and valid address mask for MTRRs.
989 @param[out] MtrrValidBitsMask The mask for the valid bit of the MTRR
990 @param[out] MtrrValidAddressMask The valid address mask for the MTRR
994 MtrrLibInitializeMtrrMask (
995 OUT UINT64
*MtrrValidBitsMask
,
996 OUT UINT64
*MtrrValidAddressMask
1000 UINT8 PhysicalAddressBits
;
1002 AsmCpuid (0x80000000, &RegEax
, NULL
, NULL
, NULL
);
1004 if (RegEax
>= 0x80000008) {
1005 AsmCpuid (0x80000008, &RegEax
, NULL
, NULL
, NULL
);
1007 PhysicalAddressBits
= (UINT8
) RegEax
;
1009 *MtrrValidBitsMask
= LShiftU64 (1, PhysicalAddressBits
) - 1;
1010 *MtrrValidAddressMask
= *MtrrValidBitsMask
& 0xfffffffffffff000ULL
;
1012 *MtrrValidBitsMask
= MTRR_LIB_MSR_VALID_MASK
;
1013 *MtrrValidAddressMask
= MTRR_LIB_CACHE_VALID_ADDRESS
;
1019 Determines the real attribute of a memory range.
1021 This function is to arbitrate the real attribute of the memory when
1022 there are 2 MTRRs covers the same memory range. For further details,
1023 please refer the IA32 Software Developer's Manual, Volume 3,
1026 @param[in] MtrrType1 The first kind of Memory type
1027 @param[in] MtrrType2 The second kind of memory type
1032 IN UINT64 MtrrType1
,
1038 MtrrType
= MTRR_CACHE_INVALID_TYPE
;
1039 switch (MtrrType1
) {
1040 case MTRR_CACHE_UNCACHEABLE
:
1041 MtrrType
= MTRR_CACHE_UNCACHEABLE
;
1043 case MTRR_CACHE_WRITE_COMBINING
:
1045 MtrrType2
==MTRR_CACHE_WRITE_COMBINING
||
1046 MtrrType2
==MTRR_CACHE_UNCACHEABLE
1048 MtrrType
= MtrrType2
;
1051 case MTRR_CACHE_WRITE_THROUGH
:
1053 MtrrType2
==MTRR_CACHE_WRITE_THROUGH
||
1054 MtrrType2
==MTRR_CACHE_WRITE_BACK
1056 MtrrType
= MTRR_CACHE_WRITE_THROUGH
;
1057 } else if(MtrrType2
==MTRR_CACHE_UNCACHEABLE
) {
1058 MtrrType
= MTRR_CACHE_UNCACHEABLE
;
1061 case MTRR_CACHE_WRITE_PROTECTED
:
1062 if (MtrrType2
== MTRR_CACHE_WRITE_PROTECTED
||
1063 MtrrType2
== MTRR_CACHE_UNCACHEABLE
) {
1064 MtrrType
= MtrrType2
;
1067 case MTRR_CACHE_WRITE_BACK
:
1069 MtrrType2
== MTRR_CACHE_UNCACHEABLE
||
1070 MtrrType2
==MTRR_CACHE_WRITE_THROUGH
||
1071 MtrrType2
== MTRR_CACHE_WRITE_BACK
1073 MtrrType
= MtrrType2
;
1076 case MTRR_CACHE_INVALID_TYPE
:
1077 MtrrType
= MtrrType2
;
1083 if (MtrrType2
== MTRR_CACHE_INVALID_TYPE
) {
1084 MtrrType
= MtrrType1
;
1092 This function will get the memory cache type of the specific address.
1094 This function is mainly for debug purpose.
1096 @param[in] Address The specific address
1098 @return Memory cache type of the specific address
1101 MTRR_MEMORY_CACHE_TYPE
1103 MtrrGetMemoryAttribute (
1104 IN PHYSICAL_ADDRESS Address
1111 UINT64 TempMtrrType
;
1112 MTRR_MEMORY_CACHE_TYPE CacheType
;
1113 VARIABLE_MTRR VariableMtrr
[MTRR_NUMBER_OF_VARIABLE_MTRR
];
1114 UINT64 MtrrValidBitsMask
;
1115 UINT64 MtrrValidAddressMask
;
1116 UINTN VariableMtrrCount
;
1117 MTRR_VARIABLE_SETTINGS VariableSettings
;
1119 if (!IsMtrrSupported ()) {
1120 return CacheUncacheable
;
1124 // Check if MTRR is enabled, if not, return UC as attribute
1126 TempQword
= AsmReadMsr64 (MTRR_LIB_IA32_MTRR_DEF_TYPE
);
1127 MtrrType
= MTRR_CACHE_INVALID_TYPE
;
1129 if ((TempQword
& MTRR_LIB_CACHE_MTRR_ENABLED
) == 0) {
1130 return CacheUncacheable
;
1134 // If address is less than 1M, then try to go through the fixed MTRR
1136 if (Address
< BASE_1MB
) {
1137 if ((TempQword
& MTRR_LIB_CACHE_FIXED_MTRR_ENABLED
) != 0) {
1139 // Go through the fixed MTRR
1141 for (Index
= 0; Index
< MTRR_NUMBER_OF_FIXED_MTRR
; Index
++) {
1142 if (Address
>= mMtrrLibFixedMtrrTable
[Index
].BaseAddress
&&
1144 mMtrrLibFixedMtrrTable
[Index
].BaseAddress
+
1145 (mMtrrLibFixedMtrrTable
[Index
].Length
* 8)
1149 ((UINTN
)Address
- mMtrrLibFixedMtrrTable
[Index
].BaseAddress
) /
1150 mMtrrLibFixedMtrrTable
[Index
].Length
;
1151 TempQword
= AsmReadMsr64 (mMtrrLibFixedMtrrTable
[Index
].Msr
);
1152 MtrrType
= RShiftU64 (TempQword
, SubIndex
* 8) & 0xFF;
1153 return GetMemoryCacheTypeFromMtrrType (MtrrType
);
1158 MtrrLibInitializeMtrrMask(&MtrrValidBitsMask
, &MtrrValidAddressMask
);
1160 MtrrGetVariableMtrrWorker (
1161 GetVariableMtrrCountWorker (),
1165 MtrrGetMemoryAttributeInVariableMtrrWorker (
1167 GetFirmwareVariableMtrrCountWorker (),
1169 MtrrValidAddressMask
,
1174 // Go through the variable MTRR
1176 VariableMtrrCount
= GetVariableMtrrCountWorker ();
1177 ASSERT (VariableMtrrCount
<= MTRR_NUMBER_OF_VARIABLE_MTRR
);
1179 for (Index
= 0; Index
< VariableMtrrCount
; Index
++) {
1180 if (VariableMtrr
[Index
].Valid
) {
1181 if (Address
>= VariableMtrr
[Index
].BaseAddress
&&
1182 Address
< VariableMtrr
[Index
].BaseAddress
+VariableMtrr
[Index
].Length
) {
1183 TempMtrrType
= VariableMtrr
[Index
].Type
;
1184 MtrrType
= MtrrPrecedence (MtrrType
, TempMtrrType
);
1188 CacheType
= GetMemoryCacheTypeFromMtrrType (MtrrType
);
1196 This function prints all MTRRs for debugging.
1200 MtrrDebugPrintAllMtrrs (
1205 MTRR_SETTINGS MtrrSettings
;
1208 UINTN VariableMtrrCount
;
1216 UINT64 NoRangeLimit
;
1219 UINTN PreviousMemoryType
;
1222 if (!IsMtrrSupported ()) {
1226 DEBUG((DEBUG_CACHE
, "MTRR Settings\n"));
1227 DEBUG((DEBUG_CACHE
, "=============\n"));
1229 MtrrGetAllMtrrs (&MtrrSettings
);
1230 DEBUG((DEBUG_CACHE
, "MTRR Default Type: %016lx\n", MtrrSettings
.MtrrDefType
));
1231 for (Index
= 0; Index
< MTRR_NUMBER_OF_FIXED_MTRR
; Index
++) {
1232 DEBUG((DEBUG_CACHE
, "Fixed MTRR[%02d] : %016lx\n", Index
, MtrrSettings
.Fixed
.Mtrr
[Index
]));
1235 VariableMtrrCount
= GetVariableMtrrCount ();
1236 for (Index
= 0; Index
< VariableMtrrCount
; Index
++) {
1237 DEBUG((DEBUG_CACHE
, "Variable MTRR[%02d]: Base=%016lx Mask=%016lx\n",
1239 MtrrSettings
.Variables
.Mtrr
[Index
].Base
,
1240 MtrrSettings
.Variables
.Mtrr
[Index
].Mask
1243 DEBUG((DEBUG_CACHE
, "\n"));
1244 DEBUG((DEBUG_CACHE
, "MTRR Ranges\n"));
1245 DEBUG((DEBUG_CACHE
, "====================================\n"));
1248 PreviousMemoryType
= MTRR_CACHE_INVALID_TYPE
;
1249 for (Index
= 0; Index
< MTRR_NUMBER_OF_FIXED_MTRR
; Index
++) {
1250 Base
= mMtrrLibFixedMtrrTable
[Index
].BaseAddress
;
1251 for (Index1
= 0; Index1
< 8; Index1
++) {
1252 MemoryType
= (UINTN
)(RShiftU64 (MtrrSettings
.Fixed
.Mtrr
[Index
], Index1
* 8) & 0xff);
1253 if (MemoryType
> CacheWriteBack
) {
1254 MemoryType
= MTRR_CACHE_INVALID_TYPE
;
1256 if (MemoryType
!= PreviousMemoryType
) {
1257 if (PreviousMemoryType
!= MTRR_CACHE_INVALID_TYPE
) {
1258 DEBUG((DEBUG_CACHE
, "%016lx\n", Base
- 1));
1260 PreviousMemoryType
= MemoryType
;
1261 DEBUG((DEBUG_CACHE
, "%a:%016lx-", mMtrrMemoryCacheTypeShortName
[MemoryType
], Base
));
1263 Base
+= mMtrrLibFixedMtrrTable
[Index
].Length
;
1266 DEBUG((DEBUG_CACHE
, "%016lx\n", Base
- 1));
1268 VariableMtrrCount
= GetVariableMtrrCount ();
1271 AsmCpuid (0x80000000, &RegEax
, NULL
, NULL
, NULL
);
1272 if (RegEax
>= 0x80000008) {
1273 AsmCpuid (0x80000008, &RegEax
, NULL
, NULL
, NULL
);
1274 Limit
= LShiftU64 (1, RegEax
& 0xff) - 1;
1277 PreviousMemoryType
= MTRR_CACHE_INVALID_TYPE
;
1279 MemoryType
= MtrrGetMemoryAttribute (Base
);
1280 if (MemoryType
> CacheWriteBack
) {
1281 MemoryType
= MTRR_CACHE_INVALID_TYPE
;
1284 if (MemoryType
!= PreviousMemoryType
) {
1285 if (PreviousMemoryType
!= MTRR_CACHE_INVALID_TYPE
) {
1286 DEBUG((DEBUG_CACHE
, "%016lx\n", Base
- 1));
1288 PreviousMemoryType
= MemoryType
;
1289 DEBUG((DEBUG_CACHE
, "%a:%016lx-", mMtrrMemoryCacheTypeShortName
[MemoryType
], Base
));
1292 RangeBase
= BASE_1MB
;
1293 NoRangeBase
= BASE_1MB
;
1295 NoRangeLimit
= Limit
;
1297 for (Index
= 0, Found
= FALSE
; Index
< VariableMtrrCount
; Index
++) {
1298 if ((MtrrSettings
.Variables
.Mtrr
[Index
].Mask
& BIT11
) == 0) {
1300 // If mask is not valid, then do not display range
1304 MtrrBase
= (MtrrSettings
.Variables
.Mtrr
[Index
].Base
& (~(SIZE_4KB
- 1)));
1305 MtrrLimit
= MtrrBase
+ ((~(MtrrSettings
.Variables
.Mtrr
[Index
].Mask
& (~(SIZE_4KB
- 1)))) & Limit
);
1307 if (Base
>= MtrrBase
&& Base
< MtrrLimit
) {
1311 if (Base
>= MtrrBase
&& MtrrBase
> RangeBase
) {
1312 RangeBase
= MtrrBase
;
1314 if (Base
> MtrrLimit
&& MtrrLimit
> RangeBase
) {
1315 RangeBase
= MtrrLimit
+ 1;
1317 if (Base
< MtrrBase
&& MtrrBase
< RangeLimit
) {
1318 RangeLimit
= MtrrBase
- 1;
1320 if (Base
< MtrrLimit
&& MtrrLimit
<= RangeLimit
) {
1321 RangeLimit
= MtrrLimit
;
1324 if (Base
> MtrrLimit
&& NoRangeBase
< MtrrLimit
) {
1325 NoRangeBase
= MtrrLimit
+ 1;
1327 if (Base
< MtrrBase
&& NoRangeLimit
> MtrrBase
) {
1328 NoRangeLimit
= MtrrBase
- 1;
1333 Base
= RangeLimit
+ 1;
1335 Base
= NoRangeLimit
+ 1;
1337 } while (Base
< Limit
);
1338 DEBUG((DEBUG_CACHE
, "%016lx\n\n", Base
- 1));
1342 This function attempts to set the attributes for a memory range.
1344 @param[in] BaseAddress The physical address that is the start
1345 address of a memory region.
1346 @param[in] Length The size in bytes of the memory region.
1347 @param[in] Attribute The bit mask of attributes to set for the
1350 @retval RETURN_SUCCESS The attributes were set for the memory
1352 @retval RETURN_INVALID_PARAMETER Length is zero.
1353 @retval RETURN_UNSUPPORTED The processor does not support one or
1354 more bytes of the memory resource range
1355 specified by BaseAddress and Length.
1356 @retval RETURN_UNSUPPORTED The bit mask of attributes is not support
1357 for the memory resource range specified
1358 by BaseAddress and Length.
1359 @retval RETURN_ACCESS_DENIED The attributes for the memory resource
1360 range specified by BaseAddress and Length
1362 @retval RETURN_OUT_OF_RESOURCES There are not enough system resources to
1363 modify the attributes of the memory
1369 MtrrSetMemoryAttribute (
1370 IN PHYSICAL_ADDRESS BaseAddress
,
1372 IN MTRR_MEMORY_CACHE_TYPE Attribute
1376 RETURN_STATUS Status
;
1383 VARIABLE_MTRR VariableMtrr
[MTRR_NUMBER_OF_VARIABLE_MTRR
];
1385 UINT64 MtrrValidBitsMask
;
1386 UINT64 MtrrValidAddressMask
;
1387 BOOLEAN OverwriteExistingMtrr
;
1388 UINT32 FirmwareVariableMtrrCount
;
1389 UINT32 VariableMtrrEnd
;
1390 MTRR_CONTEXT MtrrContext
;
1391 UINT32 VariableMtrrCount
;
1392 MTRR_VARIABLE_SETTINGS OriginalVariableSettings
;
1393 MTRR_VARIABLE_SETTINGS WorkingVariableSettings
;
1394 MTRR_VARIABLE_SETTINGS
*VariableSettings
;
1396 DEBUG((DEBUG_CACHE
, "MtrrSetMemoryAttribute() %a:%016lx-%016lx\n", mMtrrMemoryCacheTypeShortName
[Attribute
], BaseAddress
, Length
));
1398 if (!IsMtrrSupported ()) {
1399 Status
= RETURN_UNSUPPORTED
;
1403 FirmwareVariableMtrrCount
= GetFirmwareVariableMtrrCountWorker ();
1404 VariableMtrrEnd
= MTRR_LIB_IA32_VARIABLE_MTRR_BASE
+ (2 * GetVariableMtrrCount ()) - 1;
1406 MtrrLibInitializeMtrrMask(&MtrrValidBitsMask
, &MtrrValidAddressMask
);
1409 MemoryType
= (UINT64
)Attribute
;
1410 OverwriteExistingMtrr
= FALSE
;
1413 // Check for an invalid parameter
1416 Status
= RETURN_INVALID_PARAMETER
;
1421 (BaseAddress
& ~MtrrValidAddressMask
) != 0 ||
1422 (Length
& ~MtrrValidAddressMask
) != 0
1424 Status
= RETURN_UNSUPPORTED
;
1429 // Check if Fixed MTRR
1431 Status
= RETURN_SUCCESS
;
1432 while ((BaseAddress
< BASE_1MB
) && (Length
> 0) && Status
== RETURN_SUCCESS
) {
1433 PreMtrrChange (&MtrrContext
);
1434 Status
= ProgramFixedMtrr (MemoryType
, &BaseAddress
, &Length
);
1435 PostMtrrChange (&MtrrContext
);
1436 if (RETURN_ERROR (Status
)) {
1443 // A Length of 0 can only make sense for fixed MTTR ranges.
1444 // Since we just handled the fixed MTRRs, we can skip the
1445 // variable MTRR section.
1451 // Since memory ranges below 1MB will be overridden by the fixed MTRRs,
1452 // we can set the base to 0 to save variable MTRRs.
1454 if (BaseAddress
== BASE_1MB
) {
1460 // Read all variable MTRRs
1462 VariableMtrrCount
= GetVariableMtrrCountWorker ();
1463 MtrrGetVariableMtrrWorker (VariableMtrrCount
, &OriginalVariableSettings
);
1464 CopyMem (&WorkingVariableSettings
, &OriginalVariableSettings
, sizeof (WorkingVariableSettings
));
1465 VariableSettings
= &WorkingVariableSettings
;
1468 // Check for overlap
1470 UsedMtrr
= MtrrGetMemoryAttributeInVariableMtrrWorker (
1472 FirmwareVariableMtrrCount
,
1474 MtrrValidAddressMask
,
1477 OverLap
= CheckMemoryAttributeOverlap (
1478 FirmwareVariableMtrrCount
,
1480 BaseAddress
+ Length
- 1,
1485 Status
= CombineMemoryAttribute (
1486 FirmwareVariableMtrrCount
,
1492 &OverwriteExistingMtrr
1494 if (RETURN_ERROR (Status
)) {
1500 // Combined successfully, invalidate the now-unused MTRRs
1502 InvalidateMtrr(VariableMtrrCount
, VariableMtrr
);
1503 Status
= RETURN_SUCCESS
;
1509 // The memory type is the same with the type specified by
1510 // MTRR_LIB_IA32_MTRR_DEF_TYPE.
1512 if ((!OverwriteExistingMtrr
) && (Attribute
== MtrrGetDefaultMemoryType ())) {
1514 // Invalidate the now-unused MTRRs
1516 InvalidateMtrr(VariableMtrrCount
, VariableMtrr
);
1520 Positive
= GetMtrrNumberAndDirection (BaseAddress
, Length
, &MtrrNumber
);
1522 if ((UsedMtrr
+ MtrrNumber
) > FirmwareVariableMtrrCount
) {
1523 Status
= RETURN_OUT_OF_RESOURCES
;
1528 // Invalidate the now-unused MTRRs
1530 InvalidateMtrr(VariableMtrrCount
, VariableMtrr
);
1533 // Find first unused MTRR
1535 for (MsrNum
= MTRR_LIB_IA32_VARIABLE_MTRR_BASE
;
1536 MsrNum
< VariableMtrrEnd
;
1539 if ((AsmReadMsr64 (MsrNum
+ 1) & MTRR_LIB_CACHE_MTRR_ENABLED
) == 0) {
1544 if (BaseAddress
!= 0) {
1547 // Calculate the alignment of the base address.
1549 Alignment
= LShiftU64 (1, (UINTN
)LowBitSet64 (BaseAddress
));
1551 if (Alignment
> Length
) {
1558 for (; MsrNum
< VariableMtrrEnd
; MsrNum
+= 2) {
1559 if ((AsmReadMsr64 (MsrNum
+ 1) & MTRR_LIB_CACHE_MTRR_ENABLED
) == 0) {
1564 ProgramVariableMtrr (
1569 MtrrValidAddressMask
1571 BaseAddress
+= Alignment
;
1572 Length
-= Alignment
;
1583 Length
= Power2MaxMemory (LShiftU64 (TempQword
, 1));
1588 for (; MsrNum
< VariableMtrrEnd
; MsrNum
+= 2) {
1589 if ((AsmReadMsr64 (MsrNum
+ 1) & MTRR_LIB_CACHE_MTRR_ENABLED
) == 0) {
1594 ProgramVariableMtrr (
1599 MtrrValidAddressMask
1601 BaseAddress
+= Length
;
1602 TempQword
= Length
- TempQword
;
1603 MemoryType
= MTRR_CACHE_UNCACHEABLE
;
1610 for (; MsrNum
< VariableMtrrEnd
; MsrNum
+= 2) {
1611 if ((AsmReadMsr64 (MsrNum
+ 1) & MTRR_LIB_CACHE_MTRR_ENABLED
) == 0) {
1616 Length
= Power2MaxMemory (TempQword
);
1618 BaseAddress
-= Length
;
1621 ProgramVariableMtrr (
1626 MtrrValidAddressMask
1630 BaseAddress
+= Length
;
1632 TempQword
-= Length
;
1634 } while (TempQword
> 0);
1637 DEBUG((DEBUG_CACHE
, " Status = %r\n", Status
));
1638 if (!RETURN_ERROR (Status
)) {
1639 MtrrDebugPrintAllMtrrs ();
1645 Worker function setting variable MTRRs
1647 @param[in] VariableSettings A buffer to hold variable MTRRs content.
1651 MtrrSetVariableMtrrWorker (
1652 IN MTRR_VARIABLE_SETTINGS
*VariableSettings
1656 UINT32 VariableMtrrCount
;
1658 VariableMtrrCount
= GetVariableMtrrCountWorker ();
1659 ASSERT (VariableMtrrCount
<= MTRR_NUMBER_OF_VARIABLE_MTRR
);
1661 for (Index
= 0; Index
< VariableMtrrCount
; Index
++) {
1663 MTRR_LIB_IA32_VARIABLE_MTRR_BASE
+ (Index
<< 1),
1664 VariableSettings
->Mtrr
[Index
].Base
1667 MTRR_LIB_IA32_VARIABLE_MTRR_BASE
+ (Index
<< 1) + 1,
1668 VariableSettings
->Mtrr
[Index
].Mask
1675 This function sets variable MTRRs
1677 @param[in] VariableSettings A buffer to hold variable MTRRs content.
1679 @return The pointer of VariableSettings
1682 MTRR_VARIABLE_SETTINGS
*
1684 MtrrSetVariableMtrr (
1685 IN MTRR_VARIABLE_SETTINGS
*VariableSettings
1688 MTRR_CONTEXT MtrrContext
;
1690 if (!IsMtrrSupported ()) {
1691 return VariableSettings
;
1694 PreMtrrChange (&MtrrContext
);
1695 MtrrSetVariableMtrrWorker (VariableSettings
);
1696 PostMtrrChange (&MtrrContext
);
1697 return VariableSettings
;
1701 Worker function setting fixed MTRRs
1703 @param[in] FixedSettings A buffer to hold fixed MTRRs content.
1707 MtrrSetFixedMtrrWorker (
1708 IN MTRR_FIXED_SETTINGS
*FixedSettings
1713 for (Index
= 0; Index
< MTRR_NUMBER_OF_FIXED_MTRR
; Index
++) {
1715 mMtrrLibFixedMtrrTable
[Index
].Msr
,
1716 FixedSettings
->Mtrr
[Index
]
1723 This function sets fixed MTRRs
1725 @param[in] FixedSettings A buffer to hold fixed MTRRs content.
1727 @retval The pointer of FixedSettings
1730 MTRR_FIXED_SETTINGS
*
1733 IN MTRR_FIXED_SETTINGS
*FixedSettings
1736 MTRR_CONTEXT MtrrContext
;
1738 if (!IsMtrrSupported ()) {
1739 return FixedSettings
;
1742 PreMtrrChange (&MtrrContext
);
1743 MtrrSetFixedMtrrWorker (FixedSettings
);
1744 PostMtrrChange (&MtrrContext
);
1746 return FixedSettings
;
1751 This function gets the content in all MTRRs (variable and fixed)
1753 @param[out] MtrrSetting A buffer to hold all MTRRs content.
1755 @retval the pointer of MtrrSetting
1761 OUT MTRR_SETTINGS
*MtrrSetting
1764 if (!IsMtrrSupported ()) {
1771 MtrrGetFixedMtrrWorker (&MtrrSetting
->Fixed
);
1774 // Get variable MTRRs
1776 MtrrGetVariableMtrrWorker (
1777 GetVariableMtrrCountWorker (),
1778 &MtrrSetting
->Variables
1782 // Get MTRR_DEF_TYPE value
1784 MtrrSetting
->MtrrDefType
= AsmReadMsr64 (MTRR_LIB_IA32_MTRR_DEF_TYPE
);
1791 This function sets all MTRRs (variable and fixed)
1793 @param[in] MtrrSetting A buffer holding all MTRRs content.
1795 @retval The pointer of MtrrSetting
1801 IN MTRR_SETTINGS
*MtrrSetting
1804 MTRR_CONTEXT MtrrContext
;
1806 if (!IsMtrrSupported ()) {
1810 PreMtrrChange (&MtrrContext
);
1815 MtrrSetFixedMtrrWorker (&MtrrSetting
->Fixed
);
1818 // Set variable MTRRs
1820 MtrrSetVariableMtrrWorker (&MtrrSetting
->Variables
);
1823 // Set MTRR_DEF_TYPE value
1825 AsmWriteMsr64 (MTRR_LIB_IA32_MTRR_DEF_TYPE
, MtrrSetting
->MtrrDefType
);
1827 PostMtrrChangeEnableCache (&MtrrContext
);
1833 Checks if MTRR is supported.
1835 @retval TRUE MTRR is supported.
1836 @retval FALSE MTRR is not supported.
1849 // Check CPUID(1).EDX[12] for MTRR capability
1851 AsmCpuid (1, NULL
, NULL
, NULL
, &RegEdx
);
1852 if (BitFieldRead32 (RegEdx
, 12, 12) == 0) {
1857 // Check IA32_MTRRCAP.[0..7] for number of variable MTRRs and IA32_MTRRCAP[8] for
1858 // fixed MTRRs existence. If number of variable MTRRs is zero, or fixed MTRRs do not
1859 // exist, return false.
1861 MtrrCap
= AsmReadMsr64 (MTRR_LIB_IA32_MTRR_CAP
);
1862 if ((BitFieldRead64 (MtrrCap
, 0, 7) == 0) || (BitFieldRead64 (MtrrCap
, 8, 8) == 0)) {