CloverBootloader/MdePkg/Include/IndustryStandard/LowPowerIdleTable.h

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/** @file
ACPI Low Power Idle Table (LPIT) definitions
Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
@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