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| author | Jeff Fan <jeff.fan@intel.com> | 2016-11-25 12:58:36 +0800 |
|---|---|---|
| committer | Jeff Fan <jeff.fan@intel.com> | 2016-11-28 08:56:48 +0800 |
| commit | f56379f3610e51a01a18c00e4a0d5fded3af0657 (patch) | |
| tree | af1f0b74387eee3dd9ce94f3bb6e1e8f3e31ba1a /UefiCpuPkg | |
| parent | 9f91cb01c43e394f5368c6e9d16b58cbebf9ad9b (diff) | |
| download | edk2-f56379f3610e51a01a18c00e4a0d5fded3af0657.tar.gz edk2-f56379f3610e51a01a18c00e4a0d5fded3af0657.tar.bz2 edk2-f56379f3610e51a01a18c00e4a0d5fded3af0657.zip | |
UefiCpuPkg/DxeMpLib: Fix bug when getting target C-State from eax
AP will get target C-State from eax[7:4]. We do shift in ebx firstly before set
to eax. It will lead ebx is incorrect in the next time.
The fix is to set ebx to eax firstly and does shift in eax. Thus, ebx could keep
original value.
Reported-by: Laszlo Ersek <lersek@redhat.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Diffstat (limited to 'UefiCpuPkg')
| -rw-r--r-- | UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm index f8f471233e..34c07a6d51 100644 --- a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm +++ b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm @@ -266,8 +266,8 @@ MwaitLoop: 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]
+ shl eax, 4
mwait
jmp MwaitLoop
HltLoop:
|