diff options
| author | Laszlo Ersek <lersek@redhat.com> | 2016-11-24 12:19:54 +0100 |
|---|---|---|
| committer | Laszlo Ersek <lersek@redhat.com> | 2016-11-29 10:05:52 +0100 |
| commit | 6e1987f19af720aa9991f3f9994370383f43222d (patch) | |
| tree | bfed7875173a3b092acc916590da4f16f51a5376 /UefiCpuPkg/Library | |
| parent | 2b2efe33eaceb3fd2b5c6859dcb5151970dc797b (diff) | |
| download | edk2-platforms-6e1987f19af720aa9991f3f9994370383f43222d.tar.xz | |
UefiCpuPkg/MpInitLib: wait no longer than necessary for initial AP startup
Sometimes a platform knows exactly how many CPUs it has at boot. It should
be able to
- set PcdCpuMaxLogicalProcessorNumber dynamically to this number,
- set PcdCpuApInitTimeOutInMicroSeconds to a very long time (for example
MAX_UINT32, approx. 71 minutes),
- and expect that MpInitLib wait exactly as long as necessary for all APs
to report in.
Other platforms should be able to continue setting a reasonably large
upper bound on supported CPUs, and waiting for a reasonable, fixed amount
of time for all APs to report in.
Add this functionality. The TimedWaitForApFinish() function will return
when all APs have reported in, or the timeout has expired -- whichever
happens first.
(Accessing these PCDs dynamically is safe. The PEI and DXE phase instances
of this library are restricted to PEIM and DXE_DRIVER client modules, thus
the PCD accesses cannot be linked into runtime code.)
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jeff Fan <jeff.fan@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Bugzilla: https://bugzilla.tianocore.org/show_bug.cgi?id=116
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
Diffstat (limited to 'UefiCpuPkg/Library')
| -rw-r--r-- | UefiCpuPkg/Library/MpInitLib/MpLib.c | 73 |
1 files changed, 72 insertions, 1 deletions
diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c index 15dbfa1e7d..ed22ce6778 100644 --- a/UefiCpuPkg/Library/MpInitLib/MpLib.c +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c @@ -684,6 +684,21 @@ FillExchangeInfoData ( }
/**
+ Helper function that waits until the finished AP count reaches the specified
+ limit, or the specified timeout elapses (whichever comes first).
+
+ @param[in] CpuMpData Pointer to CPU MP Data.
+ @param[in] FinishedApLimit The number of finished APs to wait for.
+ @param[in] TimeLimit The number of microseconds to wait for.
+**/
+VOID
+TimedWaitForApFinish (
+ IN CPU_MP_DATA *CpuMpData,
+ IN UINT32 FinishedApLimit,
+ IN UINT32 TimeLimit
+ );
+
+/**
This function will be called by BSP to wakeup AP.
@param[in] CpuMpData Pointer to CPU MP Data
@@ -748,7 +763,11 @@ WakeUpAP ( //
// Wait for all potential APs waken up in one specified period
//
- MicroSecondDelay (PcdGet32(PcdCpuApInitTimeOutInMicroSeconds));
+ TimedWaitForApFinish (
+ CpuMpData,
+ PcdGet32 (PcdCpuMaxLogicalProcessorNumber) - 1,
+ PcdGet32 (PcdCpuApInitTimeOutInMicroSeconds)
+ );
} else {
//
// Wait all APs waken up if this is not the 1st broadcast of SIPI
@@ -895,6 +914,58 @@ CheckTimeout ( }
/**
+ Helper function that waits until the finished AP count reaches the specified
+ limit, or the specified timeout elapses (whichever comes first).
+
+ @param[in] CpuMpData Pointer to CPU MP Data.
+ @param[in] FinishedApLimit The number of finished APs to wait for.
+ @param[in] TimeLimit The number of microseconds to wait for.
+**/
+VOID
+TimedWaitForApFinish (
+ IN CPU_MP_DATA *CpuMpData,
+ IN UINT32 FinishedApLimit,
+ IN UINT32 TimeLimit
+ )
+{
+ //
+ // CalculateTimeout() and CheckTimeout() consider a TimeLimit of 0
+ // "infinity", so check for (TimeLimit == 0) explicitly.
+ //
+ if (TimeLimit == 0) {
+ return;
+ }
+
+ CpuMpData->TotalTime = 0;
+ CpuMpData->ExpectedTime = CalculateTimeout (
+ TimeLimit,
+ &CpuMpData->CurrentTime
+ );
+ while (CpuMpData->FinishedCount < FinishedApLimit &&
+ !CheckTimeout (
+ &CpuMpData->CurrentTime,
+ &CpuMpData->TotalTime,
+ CpuMpData->ExpectedTime
+ )) {
+ CpuPause ();
+ }
+
+ if (CpuMpData->FinishedCount >= FinishedApLimit) {
+ DEBUG ((
+ DEBUG_VERBOSE,
+ "%a: reached FinishedApLimit=%u in %Lu microseconds\n",
+ __FUNCTION__,
+ FinishedApLimit,
+ DivU64x64Remainder (
+ MultU64x32 (CpuMpData->TotalTime, 1000000),
+ GetPerformanceCounterProperties (NULL, NULL),
+ NULL
+ )
+ ));
+ }
+}
+
+/**
Reset an AP to Idle state.
Any task being executed by the AP will be aborted and the AP
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