[PATCH v3] UefiCpuPkg/PiSmmCpuDxeSmm: Avoid allocate Token every time

["Dong, Eric" <eric.dong@intel.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2388

Token is new introduced by MM MP Protocol. Current logic allocate Token
every time when need to use it. The logic caused SMI latency raised to
very high. Update logic to allocate Token buffer at driver's entry point.
Later use the token from the allocated token buffer. Only when all the
buffer have been used, then need to allocate new buffer.

Signed-off-by: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
---
V3 changes:
  Introduce PCD to control the pre allocated toke buffer size.

v2 changes:
  Minor update based on comments.

 UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c        | 67 ++++++++++++++++++--
 UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h   | 15 +++++
 UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf |  1 +
 UefiCpuPkg/UefiCpuPkg.dec                    |  4 ++
 UefiCpuPkg/UefiCpuPkg.uni                    |  1 +
 5 files changed, 84 insertions(+), 4 deletions(-)

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
index 0685637c2b..b0caa4f3db 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
@@ -492,6 +492,24 @@ FreeTokens (
 {
   LIST_ENTRY            *Link;
   PROCEDURE_TOKEN       *ProcToken;
+  TOKEN_BUFFER          *TokenBuf;
+
+  //
+  // Not free the buffer, just clear the UsedTokenNum. In order to
+  // avoid triggering allocate action when we need to use the token,
+  // do not free the buffer.
+  //
+  gSmmCpuPrivate->UsedTokenNum = 0;
+
+  Link = GetFirstNode (&gSmmCpuPrivate->OldTokenBufList);
+  while (!IsNull (&gSmmCpuPrivate->OldTokenBufList, Link)) {
+    TokenBuf = TOKEN_BUFFER_FROM_LINK (Link);
+
+    Link = RemoveEntryList (&TokenBuf->Link);
+
+    FreePool (TokenBuf->Buffer);
+    FreePool (TokenBuf);
+  }
 
   while (!IsListEmpty (&gSmmCpuPrivate->TokenList)) {
     Link = GetFirstNode (&gSmmCpuPrivate->TokenList);
@@ -499,7 +517,6 @@ FreeTokens (
 
     RemoveEntryList (&ProcToken->Link);
 
-    FreePool ((VOID *)ProcToken->ProcedureToken);
     FreePool (ProcToken);
   }
 }
@@ -1115,13 +1132,37 @@ CreateToken (
   VOID
   )
 {
-  PROCEDURE_TOKEN    *ProcToken;
+  PROCEDURE_TOKEN     *ProcToken;
   SPIN_LOCK           *CpuToken;
   UINTN               SpinLockSize;
+  TOKEN_BUFFER        *TokenBuf;
+  UINT32              TokenCountPerChunk;
 
   SpinLockSize = GetSpinLockProperties ();
-  CpuToken = AllocatePool (SpinLockSize);
-  ASSERT (CpuToken != NULL);
+  TokenCountPerChunk = PcdGet32 (PcdTokenCountPerChunk);
+
+  if (gSmmCpuPrivate->UsedTokenNum == TokenCountPerChunk) {
+    DEBUG ((DEBUG_VERBOSE, "CpuSmm: No free token buffer, allocate new buffer!\n"));
+
+    //
+    // Record current token buffer for later free action usage.
+    // Current used token buffer not in this list.
+    //
+    TokenBuf = AllocatePool (sizeof (TOKEN_BUFFER));
+    ASSERT (TokenBuf != NULL);
+    TokenBuf->Signature = TOKEN_BUFFER_SIGNATURE;
+    TokenBuf->Buffer  = gSmmCpuPrivate->CurrentTokenBuf;
+
+    InsertTailList (&gSmmCpuPrivate->OldTokenBufList, &TokenBuf->Link);
+
+    gSmmCpuPrivate->CurrentTokenBuf = AllocatePool (SpinLockSize * TokenCountPerChunk);
+    ASSERT (gSmmCpuPrivate->CurrentTokenBuf != NULL);
+    gSmmCpuPrivate->UsedTokenNum = 0;
+  }
+
+  CpuToken = (SPIN_LOCK *)(gSmmCpuPrivate->CurrentTokenBuf + SpinLockSize * gSmmCpuPrivate->UsedTokenNum);
+  gSmmCpuPrivate->UsedTokenNum++;
+
   InitializeSpinLock (CpuToken);
   AcquireSpinLock (CpuToken);
 
@@ -1732,10 +1773,28 @@ InitializeDataForMmMp (
   VOID
   )
 {
+  UINTN              SpinLockSize;
+  UINT32             TokenCountPerChunk;
+
+  SpinLockSize = GetSpinLockProperties ();
+  TokenCountPerChunk = PcdGet32 (PcdTokenCountPerChunk);
+  ASSERT_EFI_ERROR (TokenCountPerChunk != 0);
+  if (TokenCountPerChunk == 0) {
+    DEBUG ((EFI_D_ERROR, "PcdTokenCountPerChunk should not be Zero!\n"));
+    CpuDeadLoop ();
+  }
+  DEBUG ((DEBUG_INFO, "CpuSmm: SpinLock Size = 0x%x, PreAllocateTokenNum = 0x%x\n", SpinLockSize, TokenCountPerChunk));
+
+  gSmmCpuPrivate->CurrentTokenBuf = AllocatePool (SpinLockSize * TokenCountPerChunk);
+  ASSERT (gSmmCpuPrivate->CurrentTokenBuf != NULL);
+
+  gSmmCpuPrivate->UsedTokenNum = 0;
+
   gSmmCpuPrivate->ApWrapperFunc = AllocatePool (sizeof (PROCEDURE_WRAPPER) * gSmmCpuPrivate->SmmCoreEntryContext.NumberOfCpus);
   ASSERT (gSmmCpuPrivate->ApWrapperFunc != NULL);
 
   InitializeListHead (&gSmmCpuPrivate->TokenList);
+  InitializeListHead (&gSmmCpuPrivate->OldTokenBufList);
 }
 
 /**
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h
index 7e7c73f27f..a5607590ce 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h
@@ -217,6 +217,17 @@ typedef struct {
 
 #define PROCEDURE_TOKEN_FROM_LINK(a)  CR (a, PROCEDURE_TOKEN, Link, PROCEDURE_TOKEN_SIGNATURE)
 
+#define TOKEN_BUFFER_SIGNATURE  SIGNATURE_32 ('T', 'K', 'B', 'S')
+
+typedef struct {
+  UINTN                   Signature;
+  LIST_ENTRY              Link;
+
+  UINT8                   *Buffer;
+} TOKEN_BUFFER;
+
+#define TOKEN_BUFFER_FROM_LINK(a)  CR (a, TOKEN_BUFFER, Link, TOKEN_BUFFER_SIGNATURE)
+
 //
 // Private structure for the SMM CPU module that is stored in DXE Runtime memory
 // Contains the SMM Configuration Protocols that is produced.
@@ -243,6 +254,10 @@ typedef struct {
   PROCEDURE_WRAPPER               *ApWrapperFunc;
   LIST_ENTRY                      TokenList;
 
+  LIST_ENTRY                      OldTokenBufList;
+
+  UINT8                           *CurrentTokenBuf;
+  UINTN                           UsedTokenNum;     // Only record tokens used in CurrentTokenBuf.
 } SMM_CPU_PRIVATE_DATA;
 
 extern SMM_CPU_PRIVATE_DATA  *gSmmCpuPrivate;
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf
index b12b2691f8..82d8c25db1 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf
@@ -139,6 +139,7 @@
   gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask    ## CONSUMES
   gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPropertyMask               ## CONSUMES
   gEfiMdePkgTokenSpaceGuid.PcdControlFlowEnforcementPropertyMask        ## CONSUMES
+  gUefiCpuPkgTokenSpaceGuid.PcdTokenCountPerChunk                       ## CONSUMES
 
 [Pcd.X64]
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmRestrictedMemoryAccess        ## CONSUMES
diff --git a/UefiCpuPkg/UefiCpuPkg.dec b/UefiCpuPkg/UefiCpuPkg.dec
index 12f4413ea5..349100371e 100644
--- a/UefiCpuPkg/UefiCpuPkg.dec
+++ b/UefiCpuPkg/UefiCpuPkg.dec
@@ -148,6 +148,10 @@
   # @Prompt Specify size of good stack of exception which need switching stack.
   gUefiCpuPkgTokenSpaceGuid.PcdCpuKnownGoodStackSize|2048|UINT32|0x30002001
 
+  ## Size of pre allocated token count per chunk.
+  # @Prompt Specify the size of pre allocated token count per chunk.
+  gUefiCpuPkgTokenSpaceGuid.PcdTokenCountPerChunk|64|UINT32|0x30002002
+
 [PcdsFixedAtBuild, PcdsPatchableInModule]
   ## This value is the CPU Local APIC base address, which aligns the address on a 4-KByte boundary.
   # @Prompt Configure base address of CPU Local APIC
diff --git a/UefiCpuPkg/UefiCpuPkg.uni b/UefiCpuPkg/UefiCpuPkg.uni
index bfd696f48c..fb0491350a 100644
--- a/UefiCpuPkg/UefiCpuPkg.uni
+++ b/UefiCpuPkg/UefiCpuPkg.uni
@@ -272,3 +272,4 @@
                                                                                             "24000000  -  6th and 7th generation Intel Core processors and Intel Xeon W Processor Family(24MHz).<BR>\n"
                                                                                             "19200000  -  Intel Atom processors based on Goldmont Microarchitecture with CPUID signature 06_5CH(19.2MHz).<BR>\n"
 
+#string STR_gUefiCpuPkgTokenSpaceGuid_PcdTokenCountPerChunk_PROMPT  #language en-US "Specify the size of pre allocated token count per chunk.\n"
\ No newline at end of file
-- 
2.23.0.windows.1