audk/UefiCpuPkg/CpuMpPei
Jeff Fan 4da1ebf3b3 UefiCpuPkg/CpuMpPei: Fix potential AP mwait wakeup issue
If ApLoopMode is set to ApInMwaitLoop, AP will be placed into C-State by mwait
instruction. BSP will wakeup AP by write start-up signal in monitor address.
However, AP maybe waken by SMI/NMI/MCE and other condition. On this case, AP
will check if BSP wants to wakeup itself really. If not, AP will continue to
execute mwait to C-State.

One potential issue: BSP may not recognize AP was wakeup from C-State by other
event and BSP still writes start-up signal to wakeup AP. But AP does not aware
it and still execute mwait instruction to C-State. So, AP cannot be wakeup on
this case.

This fix is let AP to clear start-up signal when it really is wakeup to execute
AP function. And BSP will write start-up signal till AP clears it.

Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>
2016-04-11 14:15:45 +08:00
..
Ia32 UefiCpuPkg/CpuMpPei: Remove un-used AsmCliHltLoop() 2015-12-18 03:26:40 +00:00
X64 UefiCpuPkg/CpuMpPei: Remove un-used AsmCliHltLoop() 2015-12-18 03:26:40 +00:00
CpuBist.c UefiCpuPkg/CpuMpPei: Fix CPU Healthy issue in PeiGetProcessorInfo () 2015-09-01 08:56:14 +00:00
CpuMpPei.c UefiCpuPkg/CpuMpPei: Fix potential AP mwait wakeup issue 2016-04-11 14:15:45 +08:00
CpuMpPei.h UefiCpuPkg/CpuMpPei: Remove un-used AsmCliHltLoop() 2015-12-18 03:26:40 +00:00
CpuMpPei.inf UefiCpuPkg/CpuMpPei: Wake up APs by proper method 2015-12-18 03:26:03 +00:00
CpuMpPei.uni UefiCpuPkg: Convert all .uni files to utf-8 2015-12-15 04:59:14 +00:00
CpuMpPeiExtra.uni UefiCpuPkg: Convert all .uni files to utf-8 2015-12-15 04:59:14 +00:00
Microcode.c UefiCpuPkg/CpuMpPei: Load microcode if found newer revision 2016-03-03 09:10:15 +08:00
Microcode.h UefiCpuPkg/CpuMpPei: Update files format to DOS 2015-08-06 06:57:47 +00:00
PeiMpServices.c UefiCpuPkg/CpuMpPei: Wake up APs by proper method 2015-12-18 03:26:03 +00:00
PeiMpServices.h UefiCpuPkg/CpuMpPei: Update files format to DOS 2015-08-06 06:57:47 +00:00