From 6a26a597a38d36c670a5c1ce0bf54c8a413a1868 Mon Sep 17 00:00:00 2001
From: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
Date: Thu, 13 Nov 2014 18:25:48 +0000
Subject: UefiCpuPkg/CpuDxe: introduce two PCD value

introduce PCD value: PcdCpuMaxLogicalProcessorNumber and PcdCpuApStackSize,
used for initialize APs stacks.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16350 6f19259b-4bc3-4df7-8a09-765794883524
---
 UefiCpuPkg/CpuDxe/CpuMp.c | 42 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

(limited to 'UefiCpuPkg/CpuDxe/CpuMp.c')

diff --git a/UefiCpuPkg/CpuDxe/CpuMp.c b/UefiCpuPkg/CpuDxe/CpuMp.c
index ea403e8e12..bfd0d8d853 100644
--- a/UefiCpuPkg/CpuDxe/CpuMp.c
+++ b/UefiCpuPkg/CpuDxe/CpuMp.c
@@ -15,9 +15,14 @@
 #include "CpuDxe.h"
 #include "CpuMp.h"
 
+UINTN gMaxLogicalProcessorNumber;
+UINTN gApStackSize;
+
 VOID *mCommonStack = 0;
 VOID *mTopOfApCommonStack = 0;
+VOID *mApStackStart = 0;
 
+volatile UINTN mNumberOfProcessors;
 
 /**
   Application Processor C code entry point.
@@ -29,6 +34,7 @@ ApEntryPointInC (
   VOID
   )
 {
+  mNumberOfProcessors++;
 }
 
 
@@ -41,5 +47,39 @@ InitializeMpSupport (
   VOID
   )
 {
-}
+  gMaxLogicalProcessorNumber = (UINTN) PcdGet32 (PcdCpuMaxLogicalProcessorNumber);
+  if (gMaxLogicalProcessorNumber < 1) {
+    DEBUG ((DEBUG_ERROR, "Setting PcdCpuMaxLogicalProcessorNumber should be more than zero.\n"));
+    return;
+  }
+
+  if (gMaxLogicalProcessorNumber == 1) {
+    return;
+  }
+
+  gApStackSize = (UINTN) PcdGet32 (PcdCpuApStackSize);
+  ASSERT ((gApStackSize & (SIZE_4KB - 1)) == 0);
+
+  mApStackStart = AllocatePages (EFI_SIZE_TO_PAGES (gMaxLogicalProcessorNumber * gApStackSize));
+  ASSERT (mApStackStart != NULL);
 
+  //
+  // the first buffer of stack size used for common stack, when the amount of AP
+  // more than 1, we should never free the common stack which maybe used for AP reset.
+  //
+  mCommonStack = mApStackStart;
+  mTopOfApCommonStack = (UINT8*) mApStackStart + gApStackSize;
+  mApStackStart = mTopOfApCommonStack;
+
+  mNumberOfProcessors = 1;
+
+  if (mNumberOfProcessors == 1) {
+    FreePages (mCommonStack, EFI_SIZE_TO_PAGES (gMaxLogicalProcessorNumber * gApStackSize));
+    return;
+  }
+
+  if (mNumberOfProcessors < gMaxLogicalProcessorNumber) {
+    FreePages (mApStackStart, EFI_SIZE_TO_PAGES ((gMaxLogicalProcessorNumber - mNumberOfProcessors) *
+                                                 gApStackSize));
+  }
+}
-- 
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