AsmRelocateApLoop() is used to place APs into MWAIT-loop if MonitorMwait feature is supported before hand-off to OS, or place APs into HLT-loop if MonitorMwait feature is not supported.
If the current mode is long mode, we will switch APs to protected mode before placing APs in MWAIT-loop or HLT-loop. Thus, once APs wakeup from loop, APs needn't the page table that may be crashed by OS. v3: 1. Rename AsmRellocateApLoop to AsmRelocateApLoop. 2. Fix typo Proteced to Protected. 3. Fix typo segement to segment 4. Use word MONITOR instead of mwait-monitor. Cc: Michael Kinney <[email protected]> Cc: Feng Tian <[email protected]> Cc: Giri P Mudusuru <[email protected]> Cc: Laszlo Ersek <[email protected]> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Jeff Fan <[email protected]> Reviewed-by: Giri P Mudusuru <[email protected]> --- UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm | 24 ++++++++++++ UefiCpuPkg/Library/MpInitLib/MpLib.h | 21 ++++++++++ UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm | 54 ++++++++++++++++++++++++++ 3 files changed, 99 insertions(+) diff --git a/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm b/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm index 8bacb42..49f5503 100644 --- a/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm +++ b/UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm @@ -169,6 +169,30 @@ CProcedureInvoke: RendezvousFunnelProcEnd: ;------------------------------------------------------------------------------------- +; AsmRelocateApLoop (MwaitSupport, ApTargetCState, PmCodeSegment); +;------------------------------------------------------------------------------------- +global ASM_PFX(AsmRelocateApLoop) +ASM_PFX(AsmRelocateApLoop): +AsmRelocateApLoopStart: + cmp byte [esp + 4], 1 + jnz HltLoop +MwaitLoop: + mov eax, esp + xor ecx, ecx + xor edx, edx + monitor + mov eax, [esp + 8] ; Mwait Cx, Target C-State per eax[7:4] + shl eax, 4 + mwait + jmp MwaitLoop +HltLoop: + cli + hlt + jmp HltLoop + ret +AsmRelocateApLoopEnd: + +;------------------------------------------------------------------------------------- ; AsmGetAddressMap (&AddressMap); ;------------------------------------------------------------------------------------- global ASM_PFX(AsmGetAddressMap) diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.h b/UefiCpuPkg/Library/MpInitLib/MpLib.h index 28a3cd4..39ec5de 100644 --- a/UefiCpuPkg/Library/MpInitLib/MpLib.h +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.h @@ -60,5 +60,26 @@ typedef struct { } MP_CPU_EXCHANGE_INFO; #pragma pack() +/** + Assembly code to place AP into safe loop mode. + + Place AP into targeted C-State if MONITOR is supported, otherwise + place AP into hlt state. + Place AP in protected mode if the current is long mode. Due to AP maybe + wakeup by some hardware event. It could avoid accessing page table that + may not available during booting to OS. + + @param[in] MwaitSupport TRUE indicates MONITOR is supported. + FALSE indicates MONITOR is not supported. + @param[in] ApTargetCState Target C-State value. + @param[in] PmCodeSegment Protected mode code segment value. +**/ +typedef +VOID +(EFIAPI * ASM_RELOCATE_AP_LOOP) ( + IN BOOLEAN MwaitSupport, + IN UINTN ApTargetCState, + IN UINTN PmCodeSegment + ); #endif diff --git a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm index 3c55ffa..d5d7efe 100644 --- a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm +++ b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm @@ -177,6 +177,60 @@ CProcedureInvoke: RendezvousFunnelProcEnd: ;------------------------------------------------------------------------------------- +; AsmRelocateApLoop (MwaitSupport, ApTargetCState, PmCodeSegment); +;------------------------------------------------------------------------------------- +global ASM_PFX(AsmRelocateApLoop) +ASM_PFX(AsmRelocateApLoop): +AsmRelocateApLoopStart: + push rcx + push rdx + + lea rsi, [PmEntry] ; rsi <- The start address of transition code + + push r8 + push rsi + DB 0x48 + retf +BITS 32 +PmEntry: + mov eax, cr0 + btr eax, 31 ; Clear CR0.PG + mov cr0, eax ; Disable paging and caches + + mov ebx, edx ; Save EntryPoint to rbx, for rdmsr will overwrite rdx + mov ecx, 0xc0000080 + rdmsr + and ah, ~ 1 ; Clear LME + wrmsr + mov eax, cr4 + and al, ~ (1 << 5) ; Clear PAE + mov cr4, eax + + pop edx + add esp, 4 + pop ecx, + add esp, 4 + cmp cl, 1 ; Check mwait-monitor support + jnz HltLoop + mov ebx, edx ; Save C-State to ebx +MwaitLoop: + mov eax, esp ; Set Monitor Address + xor ecx, ecx ; ecx = 0 + xor edx, edx ; edx = 0 + monitor + shl ebx, 4 + mov eax, ebx ; Mwait Cx, Target C-State per eax[7:4] + mwait + jmp MwaitLoop +HltLoop: + cli + hlt + jmp HltLoop + ret +BITS 64 +AsmRelocateApLoopEnd: + +;------------------------------------------------------------------------------------- ; AsmGetAddressMap (&AddressMap); ;------------------------------------------------------------------------------------- global ASM_PFX(AsmGetAddressMap) -- 2.7.4.windows.1 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
