The patch fixes the bug that the memory under 1MB is modified by
firmware in S3 boot.
Root cause is a racing condition in MpInitLib:
1. BSP: WakeUpByInitSipiSipi is set by NotifyOnS3SmmInitDonePpi()
2. BSP: WakeUpAP() wakes all APs to run certain procedure.
2.1. AllocateResetVector() uses <1MB memory for wake up vector.
2.1. FillExchangeInfoData() resets NumApsExecuting to 0.
2.2. WaitApWakeup() waits AP to clear WAKEUP_AP_SIGNAL.
3. AP: ApWakeupFunction() clears WAKEUP_AP_SIGNAL to inform BSP.
5. BSP: FreeResetVector() restores the <1MB memory
4. AP: ApWakeupFunction() calls the certain procedure.
4.1. NumApsExecuting is decreased.
#4.1 happens after the 1MB memory is restored so the result is
memory below 1MB is changed by #4.1
It happens only when the AP executes procedure a bit longer.
AP returns back to ApWakeupFunction() from procedure after
BSP restores the <1MB memory.
Since NumApsExecuting is only used when InitFlag == ApInitConfig
for counting the processor count.
The patch moves the NumApsExecuting decrease to the path when
InitFlag == ApInitConfig.
Signed-off-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Cc: Nandagopal Sathyanarayanan <nandagopal.sathyanarayanan@intel.com>
/** @file\r
CPU MP Initialize Library common functions.\r
\r
/** @file\r
CPU MP Initialize Library common functions.\r
\r
- Copyright (c) 2016 - 2018, Intel Corporation. All rights reserved.<BR>\r
+ Copyright (c) 2016 - 2019, Intel Corporation. All rights reserved.<BR>\r
SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
RestoreVolatileRegisters (&CpuMpData->CpuData[0].VolatileRegisters, FALSE);\r
InitializeApData (CpuMpData, ProcessorNumber, BistData, ApTopOfStack);\r
ApStartupSignalBuffer = CpuMpData->CpuData[ProcessorNumber].StartupApSignal;\r
RestoreVolatileRegisters (&CpuMpData->CpuData[0].VolatileRegisters, FALSE);\r
InitializeApData (CpuMpData, ProcessorNumber, BistData, ApTopOfStack);\r
ApStartupSignalBuffer = CpuMpData->CpuData[ProcessorNumber].StartupApSignal;\r
+\r
+ InterlockedDecrement ((UINT32 *) &CpuMpData->MpCpuExchangeInfo->NumApsExecuting);\r
} else {\r
//\r
// Execute AP function if AP is ready\r
} else {\r
//\r
// Execute AP function if AP is ready\r
// AP finished executing C code\r
//\r
InterlockedIncrement ((UINT32 *) &CpuMpData->FinishedCount);\r
// AP finished executing C code\r
//\r
InterlockedIncrement ((UINT32 *) &CpuMpData->FinishedCount);\r
- InterlockedDecrement ((UINT32 *) &CpuMpData->MpCpuExchangeInfo->NumApsExecuting);\r
\r
//\r
// Place AP is specified loop mode\r
\r
//\r
// Place AP is specified loop mode\r