UefiCpuPkg: Add NULL CPU Common Features Library instance
[mirror_edk2.git] / UefiCpuPkg / Library / CpuCommonFeaturesLib / LimitCpuIdMaxval.c
1 /** @file
2 LimitCpuidMaxval Feature.
3
4 Copyright (c) 2017, 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 **/
14
15 #include "CpuCommonFeatures.h"
16
17 /**
18 Detects if LimitCpuidMaxval feature supported on current processor.
19
20 @param[in] ProcessorNumber The index of the CPU executing this function.
21 @param[in] CpuInfo A pointer to the REGISTER_CPU_FEATURE_INFORMATION
22 structure for the CPU executing this function.
23 @param[in] ConfigData A pointer to the configuration buffer returned
24 by CPU_FEATURE_GET_CONFIG_DATA. NULL if
25 CPU_FEATURE_GET_CONFIG_DATA was not provided in
26 RegisterCpuFeature().
27
28 @retval TRUE LimitCpuidMaxval feature is supported.
29 @retval FALSE LimitCpuidMaxval feature is not supported.
30
31 @note This service could be called by BSP/APs.
32 **/
33 BOOLEAN
34 EFIAPI
35 LimitCpuidMaxvalSupport (
36 IN UINTN ProcessorNumber,
37 IN REGISTER_CPU_FEATURE_INFORMATION *CpuInfo,
38 IN VOID *ConfigData OPTIONAL
39 )
40 {
41 UINT32 Eax;
42
43 AsmCpuid (CPUID_SIGNATURE, &Eax, NULL, NULL, NULL);
44 return (Eax > 3);
45 }
46
47 /**
48 Initializes LimitCpuidMaxval feature to specific state.
49
50 @param[in] ProcessorNumber The index of the CPU executing this function.
51 @param[in] CpuInfo A pointer to the REGISTER_CPU_FEATURE_INFORMATION
52 structure for the CPU executing this function.
53 @param[in] ConfigData A pointer to the configuration buffer returned
54 by CPU_FEATURE_GET_CONFIG_DATA. NULL if
55 CPU_FEATURE_GET_CONFIG_DATA was not provided in
56 RegisterCpuFeature().
57 @param[in] State If TRUE, then the LimitCpuidMaxval feature must be enabled.
58 If FALSE, then the LimitCpuidMaxval feature must be disabled.
59
60 @retval RETURN_SUCCESS LimitCpuidMaxval feature is initialized.
61
62 @note This service could be called by BSP only.
63 **/
64 RETURN_STATUS
65 EFIAPI
66 LimitCpuidMaxvalInitialize (
67 IN UINTN ProcessorNumber,
68 IN REGISTER_CPU_FEATURE_INFORMATION *CpuInfo,
69 IN VOID *ConfigData, OPTIONAL
70 IN BOOLEAN State
71 )
72 {
73 CPU_REGISTER_TABLE_WRITE_FIELD (
74 ProcessorNumber,
75 Msr,
76 MSR_IA32_MISC_ENABLE,
77 MSR_IA32_MISC_ENABLE_REGISTER,
78 Bits.LimitCpuidMaxval,
79 (State) ? 1 : 0
80 );
81 return RETURN_SUCCESS;
82 }