From b6f16ba332354607f73f5cb871ec0907d5923070 Mon Sep 17 00:00:00 2001
From: Michael Kinney <michael.d.kinney@intel.com>
Date: Tue, 17 Nov 2015 05:12:32 +0000
Subject: UefiCpuPkg: LocalApicLib: Add API to set SoftwareEnable bit

The LocalApicLib does not provide a function to manage the state of the
Local APIC SoftwareEnable bit in the Spurious Vector register.  There
are cases where this bit needs to be managed without side effects to.
other Local APIC registers.  One use case is in the DebugAgent in the
SourceLevelDebugPkg.

(Sync patch r18711 from main trunk.)

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Michael Kinney <michael.d.kinney@intel.com>
Reviewed-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/branches/UDK2015@18848 6f19259b-4bc3-4df7-8a09-765794883524
---
 UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c     | 38 +++++++++++++++++++---
 .../BaseXApicX2ApicLib/BaseXApicX2ApicLib.c        | 38 +++++++++++++++++++---
 2 files changed, 68 insertions(+), 8 deletions(-)

(limited to 'UefiCpuPkg/Library')

diff --git a/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c b/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c
index b73b1d3da9..7090cd4911 100644
--- a/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c
+++ b/UefiCpuPkg/Library/BaseXApicLib/BaseXApicLib.c
@@ -563,6 +563,39 @@ SendInitSipiSipiAllExcludingSelf (
   SendIpi (IcrLow.Uint32, 0);
 }
 
+/**
+  Initialize the state of the SoftwareEnable bit in the Local APIC
+  Spurious Interrupt Vector register.
+
+  @param  Enable  If TRUE, then set SoftwareEnable to 1
+                  If FALSE, then set SoftwareEnable to 0.
+
+**/
+VOID
+EFIAPI
+InitializeLocalApicSoftwareEnable (
+  IN BOOLEAN  Enable
+  )
+{
+  LOCAL_APIC_SVR  Svr;
+
+  //
+  // Set local APIC software-enabled bit.
+  //
+  Svr.Uint32 = ReadLocalApicReg (XAPIC_SPURIOUS_VECTOR_OFFSET);
+  if (Enable) {
+    if (Svr.Bits.SoftwareEnable == 0) {
+      Svr.Bits.SoftwareEnable = 1;
+      WriteLocalApicReg (XAPIC_SPURIOUS_VECTOR_OFFSET, Svr.Uint32);
+    }
+  } else {
+    if (Svr.Bits.SoftwareEnable == 1) {
+      Svr.Bits.SoftwareEnable = 0;
+      WriteLocalApicReg (XAPIC_SPURIOUS_VECTOR_OFFSET, Svr.Uint32);
+    }
+  }
+}
+
 /**
   Programming Virtual Wire Mode.
 
@@ -679,7 +712,6 @@ InitializeApicTimer (
   IN UINT8   Vector
   )
 {
-  LOCAL_APIC_SVR       Svr;
   LOCAL_APIC_DCR       Dcr;
   LOCAL_APIC_LVT_TIMER LvtTimer;
   UINT32               Divisor;
@@ -687,9 +719,7 @@ InitializeApicTimer (
   //
   // Ensure local APIC is in software-enabled state.
   //
-  Svr.Uint32 = ReadLocalApicReg (XAPIC_SPURIOUS_VECTOR_OFFSET);
-  Svr.Bits.SoftwareEnable = 1;
-  WriteLocalApicReg (XAPIC_SPURIOUS_VECTOR_OFFSET, Svr.Uint32);
+  InitializeLocalApicSoftwareEnable (TRUE);
 
   //
   // Program init-count register.
diff --git a/UefiCpuPkg/Library/BaseXApicX2ApicLib/BaseXApicX2ApicLib.c b/UefiCpuPkg/Library/BaseXApicX2ApicLib/BaseXApicX2ApicLib.c
index 9bbaca45dc..bc3d0a57e2 100644
--- a/UefiCpuPkg/Library/BaseXApicX2ApicLib/BaseXApicX2ApicLib.c
+++ b/UefiCpuPkg/Library/BaseXApicX2ApicLib/BaseXApicX2ApicLib.c
@@ -658,6 +658,39 @@ SendInitSipiSipiAllExcludingSelf (
   SendIpi (IcrLow.Uint32, 0);
 }
 
+/**
+  Initialize the state of the SoftwareEnable bit in the Local APIC
+  Spurious Interrupt Vector register.
+
+  @param  Enable  If TRUE, then set SoftwareEnable to 1
+                  If FALSE, then set SoftwareEnable to 0.
+
+**/
+VOID
+EFIAPI
+InitializeLocalApicSoftwareEnable (
+  IN BOOLEAN  Enable
+  )
+{
+  LOCAL_APIC_SVR  Svr;
+
+  //
+  // Set local APIC software-enabled bit.
+  //
+  Svr.Uint32 = ReadLocalApicReg (XAPIC_SPURIOUS_VECTOR_OFFSET);
+  if (Enable) {
+    if (Svr.Bits.SoftwareEnable == 0) {
+      Svr.Bits.SoftwareEnable = 1;
+      WriteLocalApicReg (XAPIC_SPURIOUS_VECTOR_OFFSET, Svr.Uint32);
+    }
+  } else {
+    if (Svr.Bits.SoftwareEnable == 1) {
+      Svr.Bits.SoftwareEnable = 0;
+      WriteLocalApicReg (XAPIC_SPURIOUS_VECTOR_OFFSET, Svr.Uint32);
+    }
+  }
+}
+
 /**
   Programming Virtual Wire Mode.
 
@@ -774,7 +807,6 @@ InitializeApicTimer (
   IN UINT8   Vector
   )
 {
-  LOCAL_APIC_SVR       Svr;
   LOCAL_APIC_DCR       Dcr;
   LOCAL_APIC_LVT_TIMER LvtTimer;
   UINT32               Divisor;
@@ -782,9 +814,7 @@ InitializeApicTimer (
   //
   // Ensure local APIC is in software-enabled state.
   //
-  Svr.Uint32 = ReadLocalApicReg (XAPIC_SPURIOUS_VECTOR_OFFSET);
-  Svr.Bits.SoftwareEnable = 1;
-  WriteLocalApicReg (XAPIC_SPURIOUS_VECTOR_OFFSET, Svr.Uint32);
+  InitializeLocalApicSoftwareEnable (TRUE);
 
   //
   // Program init-count register.
-- 
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