/**
SMI handler for AP.
@param CpuIndex AP processor Index.
@param ValidSmi Indicates that current SMI is a valid SMI or not.
@param SyncMode SMM MP sync mode.
**/
VOID
APHandler (
IN UINTN CpuIndex,
IN BOOLEAN ValidSmi,
IN SMM_CPU_SYNC_MODE SyncMode
)
{
UINT64 Timer;
UINTN BspIndex;
MTRR_SETTINGS Mtrrs;
//
// Timeout BSP
//
for (Timer = StartSyncTimer ();
!IsSyncTimerTimeout (Timer) &&
!mSmmMpSyncData->InsideSmm;
) {
CpuPause ();
}
if (!mSmmMpSyncData->InsideSmm) {
//
// BSP timeout in the first round
//
if (mSmmMpSyncData->BspIndex != -1) {
//
// BSP Index is known
//
BspIndex = mSmmMpSyncData->BspIndex;
ASSERT (CpuIndex != BspIndex);
//
// Send SMI IPI to bring BSP in
//
SendSmiIpi ((UINT32)gSmmCpuPrivate->ProcessorInfo[BspIndex].ProcessorId);
//
// Now clock BSP for the 2nd time
//
for (Timer = StartSyncTimer ();
!IsSyncTimerTimeout (Timer) &&
!mSmmMpSyncData->InsideSmm;
) {
CpuPause ();
}
if (!mSmmMpSyncData->InsideSmm) {
//
// Give up since BSP is unable to enter SMM
// and signal the completion of this AP
WaitForSemaphore (&mSmmMpSyncData->Counter);
return;
}
} else {
//
// Don't know BSP index. Give up without sending IPI to BSP.
//
WaitForSemaphore (&mSmmMpSyncData->Counter);
return;
}
}
//
// BSP is available
//
BspIndex = mSmmMpSyncData->BspIndex;
ASSERT (CpuIndex != BspIndex);
//
// Mark this processor's presence
//
mSmmMpSyncData->CpuData[CpuIndex].Present = TRUE;
if (SyncMode == SmmCpuSyncModeTradition || SmmCpuFeaturesNeedConfigureMtrrs()) {
//
// Notify BSP of arrival at this point
//
ReleaseSemaphore (&mSmmMpSyncData->CpuData[BspIndex].Run);
}
if (SmmCpuFeaturesNeedConfigureMtrrs()) {
//
// Wait for the signal from BSP to backup MTRRs
//
WaitForSemaphore (&mSmmMpSyncData->CpuData[CpuIndex].Run);
//
// Backup OS MTRRs
//
MtrrGetAllMtrrs(&Mtrrs);
//
// Signal BSP the completion of this AP
//
ReleaseSemaphore (&mSmmMpSyncData->CpuData[BspIndex].Run);
//
// Wait for BSP's signal to program MTRRs
//
WaitForSemaphore (&mSmmMpSyncData->CpuData[CpuIndex].Run);
//
// Replace OS MTRRs with SMI MTRRs
//
ReplaceOSMtrrs (CpuIndex);
//
// Signal BSP the completion of this AP
//
ReleaseSemaphore (&mSmmMpSyncData->CpuData[BspIndex].Run);
}
while (TRUE) {
//
// Wait for something to happen
//
WaitForSemaphore (&mSmmMpSyncData->CpuData[CpuIndex].Run);
//
// Check if BSP wants to exit SMM
//
if (!mSmmMpSyncData->InsideSmm) {
break;
}
//
// BUSY should be acquired by SmmStartupThisAp()
//
ASSERT (
!AcquireSpinLockOrFail (&mSmmMpSyncData->CpuData[CpuIndex].Busy)
);
//
// Invoke the scheduled procedure
//
(*mSmmMpSyncData->CpuData[CpuIndex].Procedure) (
(VOID*)mSmmMpSyncData->CpuData[CpuIndex].Parameter
);
//
// Release BUSY
//
ReleaseSpinLock (&mSmmMpSyncData->CpuData[CpuIndex].Busy);
}
if (SmmCpuFeaturesNeedConfigureMtrrs()) {
//
// Notify BSP the readiness of this AP to program MTRRs
//
ReleaseSemaphore (&mSmmMpSyncData->CpuData[BspIndex].Run);
//
// Wait for the signal from BSP to program MTRRs
//
WaitForSemaphore (&mSmmMpSyncData->CpuData[CpuIndex].Run);
//
// Restore OS MTRRs
//
SmmCpuFeaturesReenableSmrr ();
MtrrSetAllMtrrs(&Mtrrs);
}
//
// Notify BSP the readiness of this AP to Reset states/semaphore for this processor
//
ReleaseSemaphore (&mSmmMpSyncData->CpuData[BspIndex].Run);
//
// Wait for the signal from BSP to Reset states/semaphore for this processor
//
WaitForSemaphore (&mSmmMpSyncData->CpuData[CpuIndex].Run);
//
// Reset states/semaphore for this processor
//
mSmmMpSyncData->CpuData[CpuIndex].Present = FALSE;
//
// Notify BSP the readiness of this AP to exit SMM
//
ReleaseSemaphore (&mSmmMpSyncData->CpuData[BspIndex].Run);
}
/**
Relocate SmmBases for each processor.
Execute on first boot and all S3 resumes
**/
VOID
EFIAPI
SmmRelocateBases (
VOID
)
{
UINT8 BakBuf[BACK_BUF_SIZE];
SMRAM_SAVE_STATE_MAP BakBuf2;
SMRAM_SAVE_STATE_MAP *CpuStatePtr;
UINT8 *U8Ptr;
UINT32 ApicId;
UINTN Index;
UINTN BspIndex;
//
// Make sure the reserved size is large enough for procedure SmmInitTemplate.
//
ASSERT (sizeof (BakBuf) >= gcSmmInitSize);
//
// Patch ASM code template with current CR0, CR3, and CR4 values
//
gSmmCr0 = (UINT32)AsmReadCr0 ();
gSmmCr3 = (UINT32)AsmReadCr3 ();
gSmmCr4 = (UINT32)AsmReadCr4 ();
//
// Patch GDTR for SMM base relocation
//
gcSmiInitGdtr.Base = gcSmiGdtr.Base;
gcSmiInitGdtr.Limit = gcSmiGdtr.Limit;
U8Ptr = (UINT8*)(UINTN)(SMM_DEFAULT_SMBASE + SMM_HANDLER_OFFSET);
CpuStatePtr = (SMRAM_SAVE_STATE_MAP *)(UINTN)(SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET);
//
// Backup original contents at address 0x38000
//
CopyMem (BakBuf, U8Ptr, sizeof (BakBuf));
CopyMem (&BakBuf2, CpuStatePtr, sizeof (BakBuf2));
//
// Load image for relocation
//
CopyMem (U8Ptr, gcSmmInitTemplate, gcSmmInitSize);
//
// Retrieve the local APIC ID of current processor
//
ApicId = GetApicId ();
//
// Relocate SM bases for all APs
// This is APs' 1st SMI - rebase will be done here, and APs' default SMI handler will be overridden by gcSmmInitTemplate
//
mIsBsp = FALSE;
BspIndex = (UINTN)-1;
for (Index = 0; Index < mNumberOfCpus; Index++) {
mRebased[Index] = FALSE;
if (ApicId != (UINT32)gSmmCpuPrivate->ProcessorInfo[Index].ProcessorId) {
SendSmiIpi ((UINT32)gSmmCpuPrivate->ProcessorInfo[Index].ProcessorId);
//
// Wait for this AP to finish its 1st SMI
//
while (!mRebased[Index]);
} else {
//
// BSP will be Relocated later
//
BspIndex = Index;
}
}
//
// Relocate BSP's SMM base
//
ASSERT (BspIndex != (UINTN)-1);
mIsBsp = TRUE;
SendSmiIpi (ApicId);
//
// Wait for the BSP to finish its 1st SMI
//
while (!mRebased[BspIndex]);
//
// Restore contents at address 0x38000
//
CopyMem (CpuStatePtr, &BakBuf2, sizeof (BakBuf2));
CopyMem (U8Ptr, BakBuf, sizeof (BakBuf));
}
/**
Given timeout constraint, wait for all APs to arrive, and insure when this function returns, no AP will execute normal mode code before
entering SMM, except SMI disabled APs.
**/
VOID
SmmWaitForApArrival (
VOID
)
{
UINT64 Timer;
UINTN Index;
ASSERT (mSmmMpSyncData->Counter <= mNumberOfCpus);
//
// Platform implementor should choose a timeout value appropriately:
// - The timeout value should balance the SMM time constrains and the likelihood that delayed CPUs are excluded in the SMM run. Note
// the SMI Handlers must ALWAYS take into account the cases that not all APs are available in an SMI run.
// - The timeout value must, in the case of 2nd timeout, be at least long enough to give time for all APs to receive the SMI IPI
// and either enter SMM or buffer the SMI, to insure there is no CPU running normal mode code when SMI handling starts. This will
// be TRUE even if a blocked CPU is brought out of the blocked state by a normal mode CPU (before the normal mode CPU received the
// SMI IPI), because with a buffered SMI, and CPU will enter SMM immediately after it is brought out of the blocked state.
// - The timeout value must be longer than longest possible IO operation in the system
//
//
// Sync with APs 1st timeout
//
for (Timer = StartSyncTimer ();
!IsSyncTimerTimeout (Timer) &&
!AllCpusInSmmWithExceptions (ARRIVAL_EXCEPTION_BLOCKED | ARRIVAL_EXCEPTION_SMI_DISABLED );
) {
CpuPause ();
}
//
// Not all APs have arrived, so we need 2nd round of timeout. IPIs should be sent to ALL none present APs,
// because:
// a) Delayed AP may have just come out of the delayed state. Blocked AP may have just been brought out of blocked state by some AP running
// normal mode code. These APs need to be guaranteed to have an SMI pending to insure that once they are out of delayed / blocked state, they
// enter SMI immediately without executing instructions in normal mode. Note traditional flow requires there are no APs doing normal mode
// work while SMI handling is on-going.
// b) As a consequence of SMI IPI sending, (spurious) SMI may occur after this SMM run.
// c) ** NOTE **: Use SMI disabling feature VERY CAREFULLY (if at all) for traditional flow, because a processor in SMI-disabled state
// will execute normal mode code, which breaks the traditional SMI handlers' assumption that no APs are doing normal
// mode work while SMI handling is on-going.
// d) We don't add code to check SMI disabling status to skip sending IPI to SMI disabled APs, because:
// - In traditional flow, SMI disabling is discouraged.
// - In relaxed flow, CheckApArrival() will check SMI disabling status before calling this function.
// In both cases, adding SMI-disabling checking code increases overhead.
//
if (mSmmMpSyncData->Counter < mNumberOfCpus) {
//
// Send SMI IPIs to bring outside processors in
//
for (Index = mMaxNumberOfCpus; Index-- > 0;) {
if (!mSmmMpSyncData->CpuData[Index].Present && gSmmCpuPrivate->ProcessorInfo[Index].ProcessorId != INVALID_APIC_ID) {
SendSmiIpi ((UINT32)gSmmCpuPrivate->ProcessorInfo[Index].ProcessorId);
}
}
//
// Sync with APs 2nd timeout.
//
for (Timer = StartSyncTimer ();
!IsSyncTimerTimeout (Timer) &&
!AllCpusInSmmWithExceptions (ARRIVAL_EXCEPTION_BLOCKED | ARRIVAL_EXCEPTION_SMI_DISABLED );
) {
CpuPause ();
}
}
return;
}
