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UefiCpuPkg/MpInitLib: Add AsmRelocateApLoop() assembly code

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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 <michael.d.kinney@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Giri P Mudusuru <giri.p.mudusuru@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Giri P Mudusuru <giri.p.mudusuru@intel.com>
Reviewed-by: Michael Kinney <michael.d.kinney@intel.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Michael Kinney <michael.d.kinney@intel.com>
This commit is contained in:
Jeff Fan
2016-07-20 22:47:47 +08:00
parent 5c66d125ea
commit 7615702169
3 changed files with 99 additions and 0 deletions
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24
UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
View File

@@ -168,6 +168,30 @@ CProcedureInvoke:
jmp $ ; Never reach here
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);
;-------------------------------------------------------------------------------------