diff options
Diffstat (limited to 'UefiCpuPkg/PiSmmCpuDxeSmm')
| -rw-r--r-- | UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c index 57e788c01b..4bcd217917 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c @@ -40,14 +40,18 @@ WaitForSemaphore ( {
UINT32 Value;
- do {
+ for (;;) {
Value = *Sem;
- } while (Value == 0 ||
- InterlockedCompareExchange32 (
- (UINT32*)Sem,
- Value,
- Value - 1
- ) != Value);
+ if (Value != 0 &&
+ InterlockedCompareExchange32 (
+ (UINT32*)Sem,
+ Value,
+ Value - 1
+ ) == Value) {
+ break;
+ }
+ CpuPause ();
+ }
return Value - 1;
}
|