* [PATCH v4] UefiCpuPkg/PiSmmCpu: Don't allocate Token for SmmStartupThisAp
@ 2021-03-10 10:12 Ni, Ray
2021-03-10 12:08 ` Laszlo Ersek
0 siblings, 1 reply; 2+ messages in thread
From: Ni, Ray @ 2021-03-10 10:12 UTC (permalink / raw)
To: devel; +Cc: Eric Dong, Laszlo Ersek, Rahul Kumar
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3199
When Token points to mSmmStartupThisApToken, this routine is called
from SmmStartupThisAp() in non-blocking mode due to
PcdCpuSmmBlockStartupThisAp == FALSE.
In this case, caller wants to startup AP procedure in non-blocking
mode and cannot get the completion status from the Token because there
is no way to return the Token to caller from SmmStartupThisAp().
Caller needs to use its specific way to query the completion status.
There is no need to allocate a token for such case so the 3 overheads
can be avoided:
1. Call AllocateTokenBuffer() when there is no free token.
2. Get a free token from the token buffer.
3. Call ReleaseToken() in APHandler().
Signed-off-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
---
UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c | 30 ++++++++++++++++++++-------
1 file changed, 23 insertions(+), 7 deletions(-)
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
index 6227b2428a..fd6583f9d1 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
@@ -1,7 +1,7 @@
/** @file
SMM MP service implementation
-Copyright (c) 2009 - 2020, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2009 - 2021, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -22,6 +22,7 @@ UINTN mSemaphoreSize;
SPIN_LOCK *mPFLock = NULL;
SMM_CPU_SYNC_MODE mCpuSmmSyncMode;
BOOLEAN mMachineCheckSupported = FALSE;
+MM_COMPLETION mSmmStartupThisApToken;
extern UINTN mSmmShadowStackSize;
@@ -1240,9 +1241,26 @@ InternalSmmStartupThisAp (
mSmmMpSyncData->CpuData[CpuIndex].Procedure = Procedure;
mSmmMpSyncData->CpuData[CpuIndex].Parameter = ProcArguments;
if (Token != NULL) {
- ProcToken= GetFreeToken (1);
- mSmmMpSyncData->CpuData[CpuIndex].Token = ProcToken;
- *Token = (MM_COMPLETION)ProcToken->SpinLock;
+ if (Token != &mSmmStartupThisApToken) {
+ //
+ // When Token points to mSmmStartupThisApToken, this routine is called
+ // from SmmStartupThisAp() in non-blocking mode (PcdCpuSmmBlockStartupThisAp == FALSE).
+ //
+ // In this case, caller wants to startup AP procedure in non-blocking
+ // mode and cannot get the completion status from the Token because there
+ // is no way to return the Token to caller from SmmStartupThisAp().
+ // Caller needs to use its implementation specific way to query the completion status.
+ //
+ // There is no need to allocate a token for such case so the 3 overheads
+ // can be avoided:
+ // 1. Call AllocateTokenBuffer() when there is no free token.
+ // 2. Get a free token from the token buffer.
+ // 3. Call ReleaseToken() in APHandler().
+ //
+ ProcToken = GetFreeToken (1);
+ mSmmMpSyncData->CpuData[CpuIndex].Token = ProcToken;
+ *Token = (MM_COMPLETION)ProcToken->SpinLock;
+ }
}
mSmmMpSyncData->CpuData[CpuIndex].Status = CpuStatus;
if (mSmmMpSyncData->CpuData[CpuIndex].Status != NULL) {
@@ -1474,8 +1492,6 @@ SmmStartupThisAp (
IN OUT VOID *ProcArguments OPTIONAL
)
{
- MM_COMPLETION Token;
-
gSmmCpuPrivate->ApWrapperFunc[CpuIndex].Procedure = Procedure;
gSmmCpuPrivate->ApWrapperFunc[CpuIndex].ProcedureArgument = ProcArguments;
@@ -1486,7 +1502,7 @@ SmmStartupThisAp (
ProcedureWrapper,
CpuIndex,
&gSmmCpuPrivate->ApWrapperFunc[CpuIndex],
- FeaturePcdGet (PcdCpuSmmBlockStartupThisAp) ? NULL : &Token,
+ FeaturePcdGet (PcdCpuSmmBlockStartupThisAp) ? NULL : &mSmmStartupThisApToken,
0,
NULL
);
--
2.27.0.windows.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v4] UefiCpuPkg/PiSmmCpu: Don't allocate Token for SmmStartupThisAp
2021-03-10 10:12 [PATCH v4] UefiCpuPkg/PiSmmCpu: Don't allocate Token for SmmStartupThisAp Ni, Ray
@ 2021-03-10 12:08 ` Laszlo Ersek
0 siblings, 0 replies; 2+ messages in thread
From: Laszlo Ersek @ 2021-03-10 12:08 UTC (permalink / raw)
To: Ray Ni, devel; +Cc: Eric Dong, Rahul Kumar
On 03/10/21 11:12, Ray Ni wrote:
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3199
>
> When Token points to mSmmStartupThisApToken, this routine is called
> from SmmStartupThisAp() in non-blocking mode due to
> PcdCpuSmmBlockStartupThisAp == FALSE.
>
> In this case, caller wants to startup AP procedure in non-blocking
> mode and cannot get the completion status from the Token because there
> is no way to return the Token to caller from SmmStartupThisAp().
> Caller needs to use its specific way to query the completion status.
>
> There is no need to allocate a token for such case so the 3 overheads
> can be avoided:
> 1. Call AllocateTokenBuffer() when there is no free token.
> 2. Get a free token from the token buffer.
> 3. Call ReleaseToken() in APHandler().
>
> Signed-off-by: Ray Ni <ray.ni@intel.com>
> Reviewed-by: Eric Dong <eric.dong@intel.com>
> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
> Cc: Rahul Kumar <rahul1.kumar@intel.com>
> ---
> UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c | 30 ++++++++++++++++++++-------
> 1 file changed, 23 insertions(+), 7 deletions(-)
Thanks for the update, Ray!
Laszlo
>
> diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
> index 6227b2428a..fd6583f9d1 100644
> --- a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
> +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
> @@ -1,7 +1,7 @@
> /** @file
> SMM MP service implementation
>
> -Copyright (c) 2009 - 2020, Intel Corporation. All rights reserved.<BR>
> +Copyright (c) 2009 - 2021, Intel Corporation. All rights reserved.<BR>
> Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
>
> SPDX-License-Identifier: BSD-2-Clause-Patent
> @@ -22,6 +22,7 @@ UINTN mSemaphoreSize;
> SPIN_LOCK *mPFLock = NULL;
> SMM_CPU_SYNC_MODE mCpuSmmSyncMode;
> BOOLEAN mMachineCheckSupported = FALSE;
> +MM_COMPLETION mSmmStartupThisApToken;
>
> extern UINTN mSmmShadowStackSize;
>
> @@ -1240,9 +1241,26 @@ InternalSmmStartupThisAp (
> mSmmMpSyncData->CpuData[CpuIndex].Procedure = Procedure;
> mSmmMpSyncData->CpuData[CpuIndex].Parameter = ProcArguments;
> if (Token != NULL) {
> - ProcToken= GetFreeToken (1);
> - mSmmMpSyncData->CpuData[CpuIndex].Token = ProcToken;
> - *Token = (MM_COMPLETION)ProcToken->SpinLock;
> + if (Token != &mSmmStartupThisApToken) {
> + //
> + // When Token points to mSmmStartupThisApToken, this routine is called
> + // from SmmStartupThisAp() in non-blocking mode (PcdCpuSmmBlockStartupThisAp == FALSE).
> + //
> + // In this case, caller wants to startup AP procedure in non-blocking
> + // mode and cannot get the completion status from the Token because there
> + // is no way to return the Token to caller from SmmStartupThisAp().
> + // Caller needs to use its implementation specific way to query the completion status.
> + //
> + // There is no need to allocate a token for such case so the 3 overheads
> + // can be avoided:
> + // 1. Call AllocateTokenBuffer() when there is no free token.
> + // 2. Get a free token from the token buffer.
> + // 3. Call ReleaseToken() in APHandler().
> + //
> + ProcToken = GetFreeToken (1);
> + mSmmMpSyncData->CpuData[CpuIndex].Token = ProcToken;
> + *Token = (MM_COMPLETION)ProcToken->SpinLock;
> + }
> }
> mSmmMpSyncData->CpuData[CpuIndex].Status = CpuStatus;
> if (mSmmMpSyncData->CpuData[CpuIndex].Status != NULL) {
> @@ -1474,8 +1492,6 @@ SmmStartupThisAp (
> IN OUT VOID *ProcArguments OPTIONAL
> )
> {
> - MM_COMPLETION Token;
> -
> gSmmCpuPrivate->ApWrapperFunc[CpuIndex].Procedure = Procedure;
> gSmmCpuPrivate->ApWrapperFunc[CpuIndex].ProcedureArgument = ProcArguments;
>
> @@ -1486,7 +1502,7 @@ SmmStartupThisAp (
> ProcedureWrapper,
> CpuIndex,
> &gSmmCpuPrivate->ApWrapperFunc[CpuIndex],
> - FeaturePcdGet (PcdCpuSmmBlockStartupThisAp) ? NULL : &Token,
> + FeaturePcdGet (PcdCpuSmmBlockStartupThisAp) ? NULL : &mSmmStartupThisApToken,
> 0,
> NULL
> );
>
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