From 878ddf1fc3540a715f63594ed22b6929e881afb4 Mon Sep 17 00:00:00 2001
From: bbahnsen <bbahnsen@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Fri, 21 Apr 2006 22:54:32 +0000
Subject: Initial import.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@3 6f19259b-4bc3-4df7-8a09-765794883524
---
 MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c | 168 +++++++++++++++++++++
 1 file changed, 168 insertions(+)
 create mode 100644 MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c

(limited to 'MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c')

diff --git a/MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c b/MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c
new file mode 100644
index 0000000000..6f78e4e4fd
--- /dev/null
+++ b/MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c
@@ -0,0 +1,168 @@
+/** @file
+  Timer Library functions built upon local APIC on IA32/x64.
+
+  @bug Should use PCD to retrieve all the constants including index of
+  the IA32_APIC_BASE MSR, the offsets of InitialCount, CorrentCount
+  and DivideConfiguration.
+
+  Copyright (c) 2006, Intel Corporation<BR>
+  All rights reserved. This program and the accompanying materials
+  are licensed and made available under the terms and conditions of the BSD License
+  which accompanies this distribution.  The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+  Module Name:  x86TimerLib.c
+
+**/
+
+static
+UINTN
+EFIAPI
+DelayWorker (
+  IN      UINT64                    NDelay
+  )
+{
+  UINTN                             Ticks;
+
+  Ticks = (UINTN)GetPerformanceCounter ();
+  Ticks -= (UINTN)DivU64x32 (
+                    MultU64x64 (
+                      GetPerformanceCounterProperties (NULL, NULL),
+                      NDelay
+                      ),
+                    1000000000u
+                    );
+  while (Ticks >= GetPerformanceCounter ());
+  return Ticks;
+}
+
+/**
+  Stalls the CPU for at least the given number of microseconds.
+
+  Stalls the CPU for the number of microseconds specified by MicroSeconds.
+
+  @param  MicroSeconds  The minimum number of microseconds to delay.
+
+  @return Return value depends on implementation.
+
+**/
+UINTN
+EFIAPI
+MicroSecondDelay (
+  IN      UINTN                     MicroSeconds
+  )
+{
+  return DelayWorker (MicroSeconds * 1000ull);
+}
+
+/**
+  Stalls the CPU for at least the given number of nanoseconds.
+
+  Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
+
+  @param  NanoSeconds The minimum number of nanoseconds to delay.
+
+  @return Return value depends on implementation.
+
+**/
+UINTN
+EFIAPI
+NanoSecondDelay (
+  IN      UINTN                     NanoSeconds
+  )
+{
+  return DelayWorker (NanoSeconds);
+}
+
+static
+UINTN
+EFIAPI
+GetApicBase (
+  VOID
+  )
+{
+  return (UINTN)AsmMsrBitFieldRead64 (27, 12, 35) << 12;
+}
+
+/**
+  Retrieves the current value of a 64-bit free running performance counter.
+
+  Retrieves the current value of a 64-bit free running performance counter. The
+  counter can either count up by 1 or count down by 1. If the physical
+  performance counter counts by a larger increment, then the counter values
+  must be translated. The properties of the counter can be retrieved from
+  GetPerformanceCounterProperties().
+
+  @return The current value of the free running performance counter.
+
+**/
+UINT64
+EFIAPI
+GetPerformanceCounter (
+  VOID
+  )
+{
+  return MmioRead32 (GetApicBase () + 0x390);
+}
+
+/**
+  Retrieves the 64-bit frequency in Hz and the range of performance counter
+  values.
+
+  If StartValue is not NULL, then the value that the performance counter starts
+  with immediately after is it rolls over is returned in StartValue. If
+  EndValue is not NULL, then the value that the performance counter end with
+  immediately before it rolls over is returned in EndValue. The 64-bit
+  frequency of the performance counter in Hz is always returned. If StartValue
+  is less than EndValue, then the performance counter counts up. If StartValue
+  is greater than EndValue, then the performance counter counts down. For
+  example, a 64-bit free running counter that counts up would have a StartValue
+  of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
+  that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
+
+  @param  StartValue  The value the performance counter starts with when it
+                      rolls over.
+  @param  EndValue    The value that the performance counter ends with before
+                      it rolls over.
+
+  @return The frequency in Hz.
+
+**/
+UINT64
+EFIAPI
+GetPerformanceCounterProperties (
+  IN      UINT64                    *StartValue,
+  IN      UINT64                    *EndValue
+  )
+{
+  static const UINT32               mFrequencies[] = {
+    100000000,
+    133000000,
+    200000000,
+    166000000
+  };
+  static const UINT8                mDivisor[] = {
+    0x02, 0x04, 0x08, 0x10,
+    0x02, 0x04, 0x08, 0x10,
+    0x20, 0x40, 0x80, 0x01,
+    0x20, 0x40, 0x80, 0x01
+  };
+
+  UINTN                             ApicBase;
+
+  ApicBase = GetApicBase ();
+
+  if (StartValue != NULL) {
+    *StartValue = MmioRead32 (ApicBase + 0x380);
+  }
+
+  if (EndValue != NULL) {
+    *EndValue = 0;
+  }
+
+  return mFrequencies[AsmMsrBitFieldRead32 (44, 16, 18)] /
+         mDivisor[MmioBitFieldRead32 (ApicBase + 0x3e0, 0, 3)];
+}
-- 
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