PcAtChipsetPkg AcpiTimerLib: Clear bits [31:24] after reading by IoRead32()

Clear bits [31:24] after reading ACPI timer count by IoRead32(), and also add
comments "Note: The implementation uses the lower 24-bits of the ACPI timer
and is compatible with both 24-bit and 32-bit ACPI timers." in INF.

Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Michael Kinney <michael.d.kinney@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>

3 files changed, 15 insertions, 9 deletions

diff --git a/PcAtChipsetPkg/Library/AcpiTimerLib/AcpiTimerLib.c b/PcAtChipsetPkg/Library/AcpiTimerLib/AcpiTimerLib.c
index 020031e3f4..792781a33f 100644
--- a/PcAtChipsetPkg/Library/AcpiTimerLib/AcpiTimerLib.c
+++ b/PcAtChipsetPkg/Library/AcpiTimerLib/AcpiTimerLib.c
@@ -162,14 +162,14 @@ InternalAcpiDelay (
     //

     // The target timer count is calculated here

     //

-    Ticks = IoRead32 (Port) + Delay;

+    Ticks = IoBitFieldRead32 (Port, 0, 23) + Delay;

     Delay = BIT22;

     //

     // Wait until time out

     // Delay >= 2^23 could not be handled by this function

     // Timer wrap-arounds are handled correctly by this function

     //

-    while (((Ticks - IoRead32 (Port)) & BIT23) == 0) {

+    while (((Ticks - IoBitFieldRead32 (Port, 0, 23)) & BIT23) == 0) {

       CpuPause ();

     }

   } while (Times-- > 0);

@@ -371,7 +371,7 @@ InternalCalculateTscFrequency (
   // Use 363 * 9861 = 3579543 Hz which is within 2 Hz of ACPI_TIMER_FREQUENCY.

   // 363 counts is a calibration time of 101.4 uS.

   //

-  Ticks = IoRead32 (TimerAddr) + 363;

+  Ticks = IoBitFieldRead32 (TimerAddr, 0, 23) + 363;

 

   StartTSC = AsmReadTsc ();                                         // Get base value for the TSC

   //

@@ -380,7 +380,7 @@ InternalCalculateTscFrequency (
   // When the current ACPI timer value is greater than 'Ticks',

   // the while loop will exit.

   //

-  while (((Ticks - IoRead32 (TimerAddr)) & BIT23) == 0) {

+  while (((Ticks - IoBitFieldRead32 (TimerAddr, 0, 23)) & BIT23) == 0) {

     CpuPause();

   }

   EndTSC = AsmReadTsc ();                                           // TSC value 101.4 us later

diff --git a/PcAtChipsetPkg/Library/AcpiTimerLib/BaseAcpiTimerLib.inf b/PcAtChipsetPkg/Library/AcpiTimerLib/BaseAcpiTimerLib.inf
index 48caebff13..0113b26d36 100644
--- a/PcAtChipsetPkg/Library/AcpiTimerLib/BaseAcpiTimerLib.inf
+++ b/PcAtChipsetPkg/Library/AcpiTimerLib/BaseAcpiTimerLib.inf
@@ -2,9 +2,12 @@
 #  Base ACPI Timer Library

 #

 #  Provides basic timer support using the ACPI timer hardware.  The performance

-#  counter features are provided by the processors time stamp counter. 

+#  counter features are provided by the processors time stamp counter.

 #

-#  Copyright (c) 2013 - 2015, Intel Corporation. All rights reserved.<BR>

+#  Note: The implementation uses the lower 24-bits of the ACPI timer and

+#  is compatible with both 24-bit and 32-bit ACPI timers.

+#

+#  Copyright (c) 2013 - 2016, Intel Corporation. All rights reserved.<BR>

 #  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

diff --git a/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf b/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
index 3446c03eda..2c1cc7d33c 100644
--- a/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
+++ b/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.inf
@@ -2,9 +2,12 @@
 #  DXE ACPI Timer Library

 #

 #  Provides basic timer support using the ACPI timer hardware.  The performance

-#  counter features are provided by the processors time stamp counter. 

+#  counter features are provided by the processors time stamp counter.

 #

-#  Copyright (c) 2013 - 2015, Intel Corporation. All rights reserved.<BR>

+#  Note: The implementation uses the lower 24-bits of the ACPI timer and

+#  is compatible with both 24-bit and 32-bit ACPI timers.

+#

+#  Copyright (c) 2013 - 2016, Intel Corporation. All rights reserved.<BR>

 #  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

@@ -49,4 +52,4 @@
   gPcAtChipsetPkgTokenSpaceGuid.PcdAcpiIoPciBarRegisterOffset     ## CONSUMES

   gPcAtChipsetPkgTokenSpaceGuid.PcdAcpiIoPortBaseAddress          ## CONSUMES

   gPcAtChipsetPkgTokenSpaceGuid.PcdAcpiPm1TmrOffset               ## CONSUMES

-  gPcAtChipsetPkgTokenSpaceGuid.PcdAcpiIoPortBaseAddressMask      ## CONSUMES
\ No newline at end of file
+  gPcAtChipsetPkgTokenSpaceGuid.PcdAcpiIoPortBaseAddressMask      ## CONSUMES