X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=UefiCpuPkg%2FCpuDxe%2FCpuMp.c;fp=UefiCpuPkg%2FCpuDxe%2FCpuMp.c;h=f3ca813d2a1ce19c875dffcc8aa82c75b33df6d2;hb=0f7bccf584d93b2642c0a413a47fc821d1f5dbfd;hp=e385f585c7f15f455086a19aa0f29a2f82f72e5e;hpb=1da2012d938f141821740324e2dceee1b4cfa76d;p=mirror_edk2.git

diff --git a/UefiCpuPkg/CpuDxe/CpuMp.c b/UefiCpuPkg/CpuDxe/CpuMp.c
index e385f585c7..f3ca813d2a 100644
--- a/UefiCpuPkg/CpuDxe/CpuMp.c
+++ b/UefiCpuPkg/CpuDxe/CpuMp.c
@@ -596,23 +596,13 @@ CollectBistDataFromHob (
   }
 }
 
-/**
-  Get GDT register value.
-
-  This function is mainly for AP purpose because AP may have different GDT
-  table than BSP.
-
-  @param[in,out] Buffer  The pointer to private data buffer.
-
-**/
-VOID
-EFIAPI
-GetGdtr (
-  IN OUT VOID  *Buffer
-  )
-{
-  AsmReadGdtr ((IA32_DESCRIPTOR *)Buffer);
-}
+//
+// Structure for InitializeSeparateExceptionStacks
+//
+typedef struct {
+  VOID     *Buffer;
+  UINTN    *BufferSize;
+} EXCEPTION_STACK_SWITCH_CONTEXT;
 
 /**
   Initializes CPU exceptions handlers for the sake of stack switch requirement.
@@ -629,27 +619,17 @@ InitializeExceptionStackSwitchHandlers (
   IN OUT VOID  *Buffer
   )
 {
-  CPU_EXCEPTION_INIT_DATA  *EssData;
-  IA32_DESCRIPTOR          Idtr;
-  EFI_STATUS               Status;
+  EXCEPTION_STACK_SWITCH_CONTEXT  *SwitchStackData;
 
-  EssData = Buffer;
-  //
-  // We don't plan to replace IDT table with a new one, but we should not assume
-  // the AP's IDT is the same as BSP's IDT either.
-  //
-  AsmReadIdtr (&Idtr);
-  EssData->Ia32.IdtTable     = (VOID *)Idtr.Base;
-  EssData->Ia32.IdtTableSize = Idtr.Limit + 1;
-  Status                     = InitializeSeparateExceptionStacks (EssData);
-  ASSERT_EFI_ERROR (Status);
+  SwitchStackData = (EXCEPTION_STACK_SWITCH_CONTEXT *)Buffer;
+  InitializeSeparateExceptionStacks (SwitchStackData->Buffer, SwitchStackData->BufferSize);
 }
 
 /**
   Initializes MP exceptions handlers for the sake of stack switch requirement.
 
   This function will allocate required resources required to setup stack switch
-  and pass them through CPU_EXCEPTION_INIT_DATA to each logic processor.
+  and pass them through SwitchStackData to each logic processor.
 
 **/
 VOID
@@ -657,129 +637,53 @@ InitializeMpExceptionStackSwitchHandlers (
   VOID
   )
 {
-  UINTN                    Index;
-  UINTN                    Bsp;
-  UINTN                    ExceptionNumber;
-  UINTN                    OldGdtSize;
-  UINTN                    NewGdtSize;
-  UINTN                    NewStackSize;
-  IA32_DESCRIPTOR          Gdtr;
-  CPU_EXCEPTION_INIT_DATA  EssData;
-  UINT8                    *GdtBuffer;
-  UINT8                    *StackTop;
-
-  ExceptionNumber = FixedPcdGetSize (PcdCpuStackSwitchExceptionList);
-  NewStackSize    = FixedPcdGet32 (PcdCpuKnownGoodStackSize) * ExceptionNumber;
-
-  StackTop = AllocateRuntimeZeroPool (NewStackSize * mNumberOfProcessors);
-  ASSERT (StackTop != NULL);
-  StackTop += NewStackSize  * mNumberOfProcessors;
-
-  //
-  // The default exception handlers must have been initialized. Let's just skip
-  // it in this method.
-  //
-  EssData.Ia32.Revision            = CPU_EXCEPTION_INIT_DATA_REV;
-  EssData.Ia32.InitDefaultHandlers = FALSE;
-
-  EssData.Ia32.StackSwitchExceptions      = FixedPcdGetPtr (PcdCpuStackSwitchExceptionList);
-  EssData.Ia32.StackSwitchExceptionNumber = ExceptionNumber;
-  EssData.Ia32.KnownGoodStackSize         = FixedPcdGet32 (PcdCpuKnownGoodStackSize);
+  UINTN                           Index;
+  UINTN                           Bsp;
+  EXCEPTION_STACK_SWITCH_CONTEXT  SwitchStackData;
+  UINTN                           BufferSize;
 
-  //
-  // Initialize Gdtr to suppress incorrect compiler/analyzer warnings.
-  //
-  Gdtr.Base  = 0;
-  Gdtr.Limit = 0;
+  SwitchStackData.BufferSize = &BufferSize;
   MpInitLibWhoAmI (&Bsp);
+
   for (Index = 0; Index < mNumberOfProcessors; ++Index) {
-    //
-    // To support stack switch, we need to re-construct GDT but not IDT.
-    //
+    SwitchStackData.Buffer = NULL;
+    BufferSize             = 0;
+
     if (Index == Bsp) {
-      GetGdtr (&Gdtr);
+      InitializeExceptionStackSwitchHandlers (&SwitchStackData);
     } else {
       //
-      // AP might have different size of GDT from BSP.
+      // AP might need different buffer size from BSP.
       //
-      MpInitLibStartupThisAP (GetGdtr, Index, NULL, 0, (VOID *)&Gdtr, NULL);
+      MpInitLibStartupThisAP (InitializeExceptionStackSwitchHandlers, Index, NULL, 0, (VOID *)&SwitchStackData, NULL);
     }
 
-    //
-    // X64 needs only one TSS of current task working for all exceptions
-    // because of its IST feature. IA32 needs one TSS for each exception
-    // in addition to current task. Since AP is not supposed to allocate
-    // memory, we have to do it in BSP. To simplify the code, we allocate
-    // memory for IA32 case to cover both IA32 and X64 exception stack
-    // switch.
-    //
-    // Layout of memory to allocate for each processor:
-    //    --------------------------------
-    //    |            Alignment         |  (just in case)
-    //    --------------------------------
-    //    |                              |
-    //    |        Original GDT          |
-    //    |                              |
-    //    --------------------------------
-    //    |    Current task descriptor   |
-    //    --------------------------------
-    //    |                              |
-    //    |  Exception task descriptors  |  X ExceptionNumber
-    //    |                              |
-    //    --------------------------------
-    //    |  Current task-state segment  |
-    //    --------------------------------
-    //    |                              |
-    //    | Exception task-state segment |  X ExceptionNumber
-    //    |                              |
-    //    --------------------------------
-    //
-    OldGdtSize                        = Gdtr.Limit + 1;
-    EssData.Ia32.ExceptionTssDescSize = sizeof (IA32_TSS_DESCRIPTOR) *
-                                        (ExceptionNumber + 1);
-    EssData.Ia32.ExceptionTssSize = sizeof (IA32_TASK_STATE_SEGMENT) *
-                                    (ExceptionNumber + 1);
-    NewGdtSize = sizeof (IA32_TSS_DESCRIPTOR) +
-                 OldGdtSize +
-                 EssData.Ia32.ExceptionTssDescSize +
-                 EssData.Ia32.ExceptionTssSize;
-
-    GdtBuffer = AllocateRuntimeZeroPool (NewGdtSize);
-    ASSERT (GdtBuffer != NULL);
-
-    //
-    // Make sure GDT table alignment
-    //
-    EssData.Ia32.GdtTable     = ALIGN_POINTER (GdtBuffer, sizeof (IA32_TSS_DESCRIPTOR));
-    NewGdtSize               -= ((UINT8 *)EssData.Ia32.GdtTable - GdtBuffer);
-    EssData.Ia32.GdtTableSize = NewGdtSize;
-
-    EssData.Ia32.ExceptionTssDesc = ((UINT8 *)EssData.Ia32.GdtTable + OldGdtSize);
-    EssData.Ia32.ExceptionTss     = ((UINT8 *)EssData.Ia32.GdtTable + OldGdtSize +
-                                     EssData.Ia32.ExceptionTssDescSize);
+    if (BufferSize == 0) {
+      continue;
+    }
 
-    EssData.Ia32.KnownGoodStackTop = (UINTN)StackTop;
+    SwitchStackData.Buffer = AllocateRuntimeZeroPool (BufferSize);
+    ASSERT (SwitchStackData.Buffer != NULL);
     DEBUG ((
       DEBUG_INFO,
-      "Exception stack top[cpu%lu]: 0x%lX\n",
+      "Buffer[cpu%lu] for InitializeExceptionStackSwitchHandlers: 0x%lX with size 0x%x\n",
       (UINT64)(UINTN)Index,
-      (UINT64)(UINTN)StackTop
+      (UINT64)(UINTN)SwitchStackData.Buffer,
+      (UINT32)BufferSize
       ));
 
     if (Index == Bsp) {
-      InitializeExceptionStackSwitchHandlers (&EssData);
+      InitializeExceptionStackSwitchHandlers (&SwitchStackData);
     } else {
       MpInitLibStartupThisAP (
         InitializeExceptionStackSwitchHandlers,
         Index,
         NULL,
         0,
-        (VOID *)&EssData,
+        (VOID *)&SwitchStackData,
         NULL
         );
     }
-
-    StackTop -= NewStackSize;
   }
 }