[edk2-devel] [PATCH v4] IntelFsp2Pkg: LoadMicrocodeDefault() causing unnecessary delay.
Chiu, Chasel
chasel.chiu at intel.com
Mon Apr 3 18:34:05 UTC 2023
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4391
FSP should support the scenario that CPU microcode already loaded
before calling LoadMicrocodeDefault(), in this case it should return
directly without spending more time.
Also the LoadMicrocodeDefault() should only attempt to load one version
of the microcode for current CPU and return directly without parsing
rest of the microcode in FV.
This patch also removed unnecessary LoadCheck code after supporting
CPU microcode already loaded scenario.
Cc: Nate DeSimone <nathaniel.l.desimone at intel.com>
Cc: Star Zeng <star.zeng at intel.com>
Cc: Ray Ni <ray.ni at intel.com>
Signed-off-by: Chasel Chiu <chasel.chiu at intel.com>
Reviewed-by: Ted Kuo <ted.kuo at intel.com>
---
IntelFsp2Pkg/FspSecCore/Ia32/FspApiEntryT.nasm | 46 ++++++++++++++++++++++++----------------------
IntelFsp2Pkg/FspSecCore/X64/FspApiEntryT.nasm | 45 ++++++++++++++++++++++++---------------------
2 files changed, 48 insertions(+), 43 deletions(-)
diff --git a/IntelFsp2Pkg/FspSecCore/Ia32/FspApiEntryT.nasm b/IntelFsp2Pkg/FspSecCore/Ia32/FspApiEntryT.nasm
index 2cff8b3643..900126b93b 100644
--- a/IntelFsp2Pkg/FspSecCore/Ia32/FspApiEntryT.nasm
+++ b/IntelFsp2Pkg/FspSecCore/Ia32/FspApiEntryT.nasm
@@ -245,6 +245,22 @@ ASM_PFX(LoadMicrocodeDefault):
cmp esp, 0
jz ParamError
+ ;
+ ; If microcode already loaded before this function, exit this function with SUCCESS.
+ ;
+ mov ecx, MSR_IA32_BIOS_SIGN_ID
+ xor eax, eax ; Clear EAX
+ xor edx, edx ; Clear EDX
+ wrmsr ; Load 0 to MSR at 8Bh
+
+ mov eax, 1
+ cpuid
+ mov ecx, MSR_IA32_BIOS_SIGN_ID
+ rdmsr ; Get current microcode signature
+ xor eax, eax
+ test edx, edx
+ jnz Exit2
+
; skip loading Microcode if the MicrocodeCodeSize is zero
; and report error if size is less than 2k
; first check UPD header revision
@@ -330,7 +346,7 @@ CheckMainHeader:
cmp ebx, dword [esi + MicrocodeHdr.MicrocodeHdrProcessor]
jne LoadMicrocodeDefault1
test edx, dword [esi + MicrocodeHdr.MicrocodeHdrFlags ]
- jnz LoadCheck ; Jif signature and platform ID match
+ jnz LoadMicrocode ; Jif signature and platform ID match
LoadMicrocodeDefault1:
; Check if extended header exists
@@ -363,7 +379,7 @@ CheckExtSig:
cmp dword [edi + ExtSig.ExtSigProcessor], ebx
jne LoadMicrocodeDefault2
test dword [edi + ExtSig.ExtSigFlags], edx
- jnz LoadCheck ; Jif signature and platform ID match
+ jnz LoadMicrocode ; Jif signature and platform ID match
LoadMicrocodeDefault2:
; Check if any more extended signatures exist
add edi, ExtSig.size
@@ -435,23 +451,7 @@ LoadMicrocodeDefault4:
; Is valid Microcode start point ?
cmp dword [esi + MicrocodeHdr.MicrocodeHdrVersion], 0ffffffffh
jz Done
-
-LoadCheck:
- ; Get the revision of the current microcode update loaded
- mov ecx, MSR_IA32_BIOS_SIGN_ID
- xor eax, eax ; Clear EAX
- xor edx, edx ; Clear EDX
- wrmsr ; Load 0 to MSR at 8Bh
-
- mov eax, 1
- cpuid
- mov ecx, MSR_IA32_BIOS_SIGN_ID
- rdmsr ; Get current microcode signature
-
- ; Verify this microcode update is not already loaded
- cmp dword [esi + MicrocodeHdr.MicrocodeHdrRevision], edx
- je Continue
-
+ jmp CheckMainHeader
LoadMicrocode:
; EAX contains the linear address of the start of the Update Data
; EDX contains zero
@@ -465,10 +465,12 @@ LoadMicrocode:
mov eax, 1
cpuid
-Continue:
- jmp NextMicrocode
-
Done:
+ mov ecx, MSR_IA32_BIOS_SIGN_ID
+ xor eax, eax ; Clear EAX
+ xor edx, edx ; Clear EDX
+ wrmsr ; Load 0 to MSR at 8Bh
+
mov eax, 1
cpuid
mov ecx, MSR_IA32_BIOS_SIGN_ID
diff --git a/IntelFsp2Pkg/FspSecCore/X64/FspApiEntryT.nasm b/IntelFsp2Pkg/FspSecCore/X64/FspApiEntryT.nasm
index b32fa32a89..698bb063a7 100644
--- a/IntelFsp2Pkg/FspSecCore/X64/FspApiEntryT.nasm
+++ b/IntelFsp2Pkg/FspSecCore/X64/FspApiEntryT.nasm
@@ -141,6 +141,22 @@ ASM_PFX(LoadMicrocodeDefault):
jz ParamError
mov rsp, rcx
+ ;
+ ; If microcode already loaded before this function, exit this function with SUCCESS.
+ ;
+ mov ecx, MSR_IA32_BIOS_SIGN_ID
+ xor eax, eax ; Clear EAX
+ xor edx, edx ; Clear EDX
+ wrmsr ; Load 0 to MSR at 8Bh
+
+ mov eax, 1
+ cpuid
+ mov ecx, MSR_IA32_BIOS_SIGN_ID
+ rdmsr ; Get current microcode signature
+ xor rax, rax
+ test edx, edx
+ jnz Exit2
+
; skip loading Microcode if the MicrocodeCodeSize is zero
; and report error if size is less than 2k
; first check UPD header revision
@@ -198,7 +214,7 @@ CheckMainHeader:
cmp ebx, dword [esi + MicrocodeHdr.MicrocodeHdrProcessor]
jne LoadMicrocodeDefault1
test edx, dword [esi + MicrocodeHdr.MicrocodeHdrFlags ]
- jnz LoadCheck ; Jif signature and platform ID match
+ jnz LoadMicrocode ; Jif signature and platform ID match
LoadMicrocodeDefault1:
; Check if extended header exists
@@ -231,7 +247,7 @@ CheckExtSig:
cmp dword [edi + ExtSig.ExtSigProcessor], ebx
jne LoadMicrocodeDefault2
test dword [edi + ExtSig.ExtSigFlags], edx
- jnz LoadCheck ; Jif signature and platform ID match
+ jnz LoadMicrocode ; Jif signature and platform ID match
LoadMicrocodeDefault2:
; Check if any more extended signatures exist
add edi, ExtSig.size
@@ -276,22 +292,7 @@ LoadMicrocodeDefault4:
; Is valid Microcode start point ?
cmp dword [esi + MicrocodeHdr.MicrocodeHdrVersion], 0ffffffffh
jz Done
-
-LoadCheck:
- ; Get the revision of the current microcode update loaded
- mov ecx, MSR_IA32_BIOS_SIGN_ID
- xor eax, eax ; Clear EAX
- xor edx, edx ; Clear EDX
- wrmsr ; Load 0 to MSR at 8Bh
-
- mov eax, 1
- cpuid
- mov ecx, MSR_IA32_BIOS_SIGN_ID
- rdmsr ; Get current microcode signature
-
- ; Verify this microcode update is not already loaded
- cmp dword [esi + MicrocodeHdr.MicrocodeHdrRevision], edx
- je Continue
+ jmp CheckMainHeader
LoadMicrocode:
; EAX contains the linear address of the start of the Update Data
@@ -306,10 +307,12 @@ LoadMicrocode:
mov eax, 1
cpuid
-Continue:
- jmp NextMicrocode
-
Done:
+ mov ecx, MSR_IA32_BIOS_SIGN_ID
+ xor eax, eax ; Clear EAX
+ xor edx, edx ; Clear EDX
+ wrmsr ; Load 0 to MSR at 8Bh
+
mov eax, 1
cpuid
mov ecx, MSR_IA32_BIOS_SIGN_ID
--
2.35.0.windows.1
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