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source: vbox/trunk/src/VBox/Devices/EFI/FirmwareNew/MdePkg/Include/IndustryStandard/LowPowerIdleTable.h@ 77662

Last change on this file since 77662 was 77662, checked in by vboxsync, 6 years ago

EFI: First step in UDK2018 merge. Does not build yet.

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1/** @file
2 ACPI Low Power Idle Table (LPIT) definitions
3
4 Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
5 This program and the accompanying materials
6 are licensed and made available under the terms and conditions of the BSD License
7 which accompanies this distribution. The full text of the license may be found at
8 http://opensource.org/licenses/bsd-license.php
9
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
12
13 @par Revision Reference:
14 - ACPI Low Power Idle Table (LPIT) Revision 001, dated July 2014
15 http://www.uefi.org/sites/default/files/resources/ACPI_Low_Power_Idle_Table.pdf
16
17 @par Glossary:
18 - GAS - Generic Address Structure
19 - LPI - Low Power Idle
20**/
21#ifndef _LOW_POWER_IDLE_TABLE_H_
22#define _LOW_POWER_IDLE_TABLE_H_
23
24#include <IndustryStandard/Acpi.h>
25
26#pragma pack(1)
27
28///
29/// LPI Structure Types
30///
31#define ACPI_LPI_STRUCTURE_TYPE_NATIVE_CSTATE 0x00
32
33///
34/// Low Power Idle (LPI) State Flags
35///
36typedef union {
37 struct {
38 UINT32 Disabled : 1; ///< If set, LPI state is not used
39 /**
40 If set, Residency counter is not available for this LPI state and
41 Residency Counter Frequency is invalid
42 **/
43 UINT32 CounterUnavailable : 1;
44 UINT32 Reserved : 30; ///< Reserved for future use. Must be zero
45 } Bits;
46 UINT32 Data32;
47} ACPI_LPI_STATE_FLAGS;
48
49///
50/// Low Power Idle (LPI) structure with Native C-state instruction entry trigger descriptor
51///
52typedef struct {
53 UINT32 Type; ///< LPI State descriptor Type 0
54 UINT32 Length; ///< Length of LPI state Descriptor Structure
55 ///
56 /// Unique LPI state identifier: zero based, monotonically increasing identifier
57 ///
58 UINT16 UniqueId;
59 UINT8 Reserved[2]; ///< Must be Zero
60 ACPI_LPI_STATE_FLAGS Flags; ///< LPI state flags
61 /**
62 The LPI entry trigger, matching an existing _CST.Register object, represented as a
63 Generic Address Structure. All processors must request this state or deeper to trigger.
64 **/
65 EFI_ACPI_6_1_GENERIC_ADDRESS_STRUCTURE EntryTrigger;
66 UINT32 Residency; ///< Minimum residency or break-even in uSec
67 UINT32 Latency; ///< Worst case exit latency in uSec
68 /**
69 [optional] Residency counter, represented as a Generic Address Structure.
70 If not present, Flags[1] bit should be set.
71 **/
72 EFI_ACPI_6_1_GENERIC_ADDRESS_STRUCTURE ResidencyCounter;
73 /**
74 [optional] Residency counter frequency in cycles per second. Value 0 indicates that
75 counter runs at TSC frequency. Valid only if Residency Counter is present.
76 **/
77 UINT64 ResidencyCounterFrequency;
78} ACPI_LPI_NATIVE_CSTATE_DESCRIPTOR;
79
80#pragma pack()
81
82#endif
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