UefiCpuPkg/CpuDxe/CpuMp.c

   1 /** @file
   2   CPU DXE Module.
   3
   4   Copyright (c) 2008 - 2014, Intel Corporation. All rights reserved.<BR>
   5   This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #include "CpuDxe.h"
  16 #include "CpuMp.h"
  17
  18 UINTN gMaxLogicalProcessorNumber;
  19 UINTN gApStackSize;
  20
  21 VOID *mCommonStack = 0;
  22 VOID *mTopOfApCommonStack = 0;
  23 VOID *mApStackStart = 0;
  24
  25 volatile UINTN mNumberOfProcessors;
  26
  27 /**
  28   Application Processors do loop routine
  29   after switch to its own stack.
  30
  31   @param  Context1    A pointer to the context to pass into the function.
  32   @param  Context2    A pointer to the context to pass into the function.
  33
  34 **/
  35 VOID
  36 ProcessorToIdleState (
  37   IN      VOID                      *Context1,  OPTIONAL
  38   IN      VOID                      *Context2   OPTIONAL
  39   )
  40 {
  41   DEBUG ((DEBUG_INFO, "Ap apicid is %d\n", GetApicId ()));
  42
  43   AsmApDoneWithCommonStack ();
  44
  45   CpuSleep ();
  46   CpuDeadLoop ();
  47 }
  48
  49 /**
  50   Application Processor C code entry point.
  51
  52 **/
  53 VOID
  54 EFIAPI
  55 ApEntryPointInC (
  56   VOID
  57   )
  58 {
  59   mNumberOfProcessors++;
  60   mApStackStart = (UINT8*)mApStackStart + gApStackSize;
  61
  62   SwitchStack (
  63     (SWITCH_STACK_ENTRY_POINT)(UINTN)ProcessorToIdleState,
  64     NULL,
  65     NULL,
  66     mApStackStart);
  67 }
  68
  69
  70 /**
  71   Initialize Multi-processor support.
  72
  73 **/
  74 VOID
  75 InitializeMpSupport (
  76   VOID
  77   )
  78 {
  79   gMaxLogicalProcessorNumber = (UINTN) PcdGet32 (PcdCpuMaxLogicalProcessorNumber);
  80   if (gMaxLogicalProcessorNumber < 1) {
  81     DEBUG ((DEBUG_ERROR, "Setting PcdCpuMaxLogicalProcessorNumber should be more than zero.\n"));
  82     return;
  83   }
  84
  85   if (gMaxLogicalProcessorNumber == 1) {
  86     return;
  87   }
  88
  89   gApStackSize = (UINTN) PcdGet32 (PcdCpuApStackSize);
  90   ASSERT ((gApStackSize & (SIZE_4KB - 1)) == 0);
  91
  92   mApStackStart = AllocatePages (EFI_SIZE_TO_PAGES (gMaxLogicalProcessorNumber * gApStackSize));
  93   ASSERT (mApStackStart != NULL);
  94
  95   //
  96   // the first buffer of stack size used for common stack, when the amount of AP
  97   // more than 1, we should never free the common stack which maybe used for AP reset.
  98   //
  99   mCommonStack = mApStackStart;
 100   mTopOfApCommonStack = (UINT8*) mApStackStart + gApStackSize;
 101   mApStackStart = mTopOfApCommonStack;
 102
 103   mNumberOfProcessors = 1;
 104
 105   if (mNumberOfProcessors == 1) {
 106     FreePages (mCommonStack, EFI_SIZE_TO_PAGES (gMaxLogicalProcessorNumber * gApStackSize));
 107     return;
 108   }
 109
 110   if (mNumberOfProcessors < gMaxLogicalProcessorNumber) {
 111     FreePages (mApStackStart, EFI_SIZE_TO_PAGES ((gMaxLogicalProcessorNumber - mNumberOfProcessors) *
 112                                                  gApStackSize));
 113   }
 114 }