MdePkg: Add ACPI Low Power Idle Table (LPIT) definitions
ACPI Low Power Idle Table (LPIT) Revision 001, dated July 2014
http://www.uefi.org/sites/default/files/resources/ACPI_Low_Power_Idle_Table.pdf
Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Giri P Mudusuru <giri.p.mudusuru@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
diff --git a/MdePkg/Include/IndustryStandard/LowPowerIdleTable.h b/MdePkg/Include/IndustryStandard/LowPowerIdleTable.h
new file mode 100644
index 0000000..29ad42b
--- /dev/null
+++ b/MdePkg/Include/IndustryStandard/LowPowerIdleTable.h
@@ -0,0 +1,82 @@
+/** @file
+ ACPI Low Power Idle Table (LPIT) definitions
+
+ Copyright (c) 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
+ 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.
+
+ @par Revision Reference:
+ - ACPI Low Power Idle Table (LPIT) Revision 001, dated July 2014
+ http://www.uefi.org/sites/default/files/resources/ACPI_Low_Power_Idle_Table.pdf
+
+ @par Glossary:
+ - GAS - Generic Address Structure
+ - LPI - Low Power Idle
+**/
+#ifndef _LOW_POWER_IDLE_TABLE_H_
+#define _LOW_POWER_IDLE_TABLE_H_
+
+#include <IndustryStandard/Acpi.h>
+
+#pragma pack(1)
+
+///
+/// LPI Structure Types
+///
+#define ACPI_LPI_STRUCTURE_TYPE_NATIVE_CSTATE 0x00
+
+///
+/// Low Power Idle (LPI) State Flags
+///
+typedef union {
+ struct {
+ UINT32 Disabled : 1; ///< If set, LPI state is not used
+ /**
+ If set, Residency counter is not available for this LPI state and
+ Residency Counter Frequency is invalid
+ **/
+ UINT32 CounterUnavailable : 1;
+ UINT32 Reserved : 30; ///< Reserved for future use. Must be zero
+ } Bits;
+ UINT32 Data32;
+} ACPI_LPI_STATE_FLAGS;
+
+///
+/// Low Power Idle (LPI) structure with Native C-state instruction entry trigger descriptor
+///
+typedef struct {
+ UINT32 Type; ///< LPI State descriptor Type 0
+ UINT32 Length; ///< Length of LPI state Descriptor Structure
+ ///
+ /// Unique LPI state identifier: zero based, monotonically increasing identifier
+ ///
+ UINT16 UniqueId;
+ UINT8 Reserved[2]; ///< Must be Zero
+ ACPI_LPI_STATE_FLAGS Flags; ///< LPI state flags
+ /**
+ The LPI entry trigger, matching an existing _CST.Register object, represented as a
+ Generic Address Structure. All processors must request this state or deeper to trigger.
+ **/
+ EFI_ACPI_6_1_GENERIC_ADDRESS_STRUCTURE EntryTrigger;
+ UINT32 Residency; ///< Minimum residency or break-even in uSec
+ UINT32 Latency; ///< Worst case exit latency in uSec
+ /**
+ [optional] Residency counter, represented as a Generic Address Structure.
+ If not present, Flags[1] bit should be set.
+ **/
+ EFI_ACPI_6_1_GENERIC_ADDRESS_STRUCTURE ResidencyCounter;
+ /**
+ [optional] Residency counter frequency in cycles per second. Value 0 indicates that
+ counter runs at TSC frequency. Valid only if Residency Counter is present.
+ **/
+ UINT64 ResidencyCounterFrequency;
+} ACPI_LPI_NATIVE_CSTATE_DESCRIPTOR;
+
+#pragma pack()
+
+#endif
