]> git.proxmox.com Git - mirror_edk2.git/blame - UefiCpuPkg/Library/CpuCommonFeaturesLib/LimitCpuIdMaxval.c
UefiCpuPkg/CpuCommonFeatures: Follow SDM for MAX CPUID feature detect
[mirror_edk2.git] / UefiCpuPkg / Library / CpuCommonFeaturesLib / LimitCpuIdMaxval.c
CommitLineData
80c4b236
JF
1/** @file\r
2 LimitCpuidMaxval Feature.\r
3\r
60cb4d1b 4 Copyright (c) 2017 - 2018, Intel Corporation. All rights reserved.<BR>\r
80c4b236
JF
5 This program and the accompanying materials\r
6 are licensed and made available under the terms and conditions of the BSD License\r
7 which accompanies this distribution. The full text of the license may be found at\r
8 http://opensource.org/licenses/bsd-license.php\r
9\r
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
12\r
13**/\r
14\r
15#include "CpuCommonFeatures.h"\r
16\r
17/**\r
18 Detects if LimitCpuidMaxval feature supported on current processor.\r
19\r
20 @param[in] ProcessorNumber The index of the CPU executing this function.\r
21 @param[in] CpuInfo A pointer to the REGISTER_CPU_FEATURE_INFORMATION\r
22 structure for the CPU executing this function.\r
23 @param[in] ConfigData A pointer to the configuration buffer returned\r
24 by CPU_FEATURE_GET_CONFIG_DATA. NULL if\r
25 CPU_FEATURE_GET_CONFIG_DATA was not provided in\r
26 RegisterCpuFeature().\r
27\r
28 @retval TRUE LimitCpuidMaxval feature is supported.\r
29 @retval FALSE LimitCpuidMaxval feature is not supported.\r
30\r
31 @note This service could be called by BSP/APs.\r
32**/\r
33BOOLEAN\r
34EFIAPI\r
35LimitCpuidMaxvalSupport (\r
36 IN UINTN ProcessorNumber,\r
37 IN REGISTER_CPU_FEATURE_INFORMATION *CpuInfo,\r
38 IN VOID *ConfigData OPTIONAL\r
39 )\r
40{\r
41 UINT32 Eax;\r
42\r
43 AsmCpuid (CPUID_SIGNATURE, &Eax, NULL, NULL, NULL);\r
60cb4d1b 44 return (Eax > 2);\r
80c4b236
JF
45}\r
46\r
47/**\r
48 Initializes LimitCpuidMaxval feature to specific state.\r
49\r
50 @param[in] ProcessorNumber The index of the CPU executing this function.\r
51 @param[in] CpuInfo A pointer to the REGISTER_CPU_FEATURE_INFORMATION\r
52 structure for the CPU executing this function.\r
53 @param[in] ConfigData A pointer to the configuration buffer returned\r
54 by CPU_FEATURE_GET_CONFIG_DATA. NULL if\r
55 CPU_FEATURE_GET_CONFIG_DATA was not provided in\r
56 RegisterCpuFeature().\r
57 @param[in] State If TRUE, then the LimitCpuidMaxval feature must be enabled.\r
58 If FALSE, then the LimitCpuidMaxval feature must be disabled.\r
59\r
60 @retval RETURN_SUCCESS LimitCpuidMaxval feature is initialized.\r
61\r
62 @note This service could be called by BSP only.\r
63**/\r
64RETURN_STATUS\r
65EFIAPI\r
66LimitCpuidMaxvalInitialize (\r
67 IN UINTN ProcessorNumber,\r
68 IN REGISTER_CPU_FEATURE_INFORMATION *CpuInfo,\r
69 IN VOID *ConfigData, OPTIONAL\r
70 IN BOOLEAN State\r
71 )\r
72{\r
73 CPU_REGISTER_TABLE_WRITE_FIELD (\r
74 ProcessorNumber,\r
75 Msr,\r
76 MSR_IA32_MISC_ENABLE,\r
77 MSR_IA32_MISC_ENABLE_REGISTER,\r
78 Bits.LimitCpuidMaxval,\r
79 (State) ? 1 : 0\r
80 );\r
81 return RETURN_SUCCESS;\r
82}\r