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| author | YuanhaoXie <yuanhao.xie@intel.com> | 2023-07-18 17:59:30 +0800 |
|---|---|---|
| committer | mergify[bot] <37929162+mergify[bot]@users.noreply.github.com> | 2023-08-14 14:40:41 +0000 |
| commit | eaffa1d7ff915d5af484e5e230a4dde41e4b9a00 (patch) | |
| tree | ad039788d5ab1f3dfb1e923ed7058cc4062845ac | |
| parent | 1d76560146b169f0f6c39a3de9ee1fdc4c41dd0b (diff) | |
| download | edk2-eaffa1d7ff915d5af484e5e230a4dde41e4b9a00.tar.gz | |
UefiCpuPkg:Wake up APs after power-up or RESET through SIPI.
The implementation of this new behavior aligns with the guidelines
outlined in the Intel SDM.
Following a power-up or RESET of an MP system, system hardware
dynamically selects one of the processors on the system bus as the BSP.
The remaining processors are designated as APs. The APs complete a
minimal self-configuration, then wait for a startup signal (a SIPI
message) from the BSP processor.
Additionally, the MP protocol is executed only after
a power-up or RESET. If the MP protocol has completed and a
BSP is chosen, subsequent INITs (either to a specific processor or
system wide) do not cause the MP protocol to be repeated. Instead, each
logical processor examines its BSP flag (in the IA32_APIC_BASE MSR) to
determine whether it should execute the BIOS boot-strap code (if it is
the BSP) or enter a wait-for-SIPI state (if it is an AP).
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Ray Ni <ray.ni@intel.com>
Signed-off-by: Yuanhao Xie <yuanhao.xie@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
| -rw-r--r-- | UefiCpuPkg/Library/MpInitLib/MpLib.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c index e7054adbcc..6f1456cfe1 100644 --- a/UefiCpuPkg/Library/MpInitLib/MpLib.c +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c @@ -1294,7 +1294,14 @@ WakeUpAP ( if (CpuMpData->SevSnpIsEnabled && (CpuMpData->InitFlag != ApInitConfig)) {
SevSnpCreateAP (CpuMpData, -1);
} else {
- SendInitSipiSipiAllExcludingSelf ((UINT32)ExchangeInfo->BufferStart);
+ if ((CpuMpData->InitFlag == ApInitConfig) && FixedPcdGetBool (PcdFirstTimeWakeUpAPsBySipi)) {
+ //
+ // SIPI can be used for the first time wake up after reset to reduce boot time.
+ //
+ SendStartupIpiAllExcludingSelf ((UINT32)ExchangeInfo->BufferStart);
+ } else {
+ SendInitSipiSipiAllExcludingSelf ((UINT32)ExchangeInfo->BufferStart);
+ }
}
}
|