1 /** @file 2 This file declares EFI PCI Hot Plug Init Protocol. 3 4 This protocol provides the necessary functionality to initialize the Hot Plug 5 Controllers (HPCs) and the buses that they control. This protocol also provides 6 information regarding resource padding. 7 8 @par Note: 9 This protocol is required only on platforms that support one or more PCI Hot 10 Plug* slots or CardBus sockets. 11 12 The EFI_PCI_HOT_PLUG_INIT_PROTOCOL provides a mechanism for the PCI bus enumerator 13 to properly initialize the HPCs and CardBus sockets that require initialization. 14 The HPC initialization takes place before the PCI enumeration process is complete. 15 There cannot be more than one instance of this protocol in a system. This protocol 16 is installed on its own separate handle. 17 18 Because the system may include multiple HPCs, one instance of this protocol 19 should represent all of them. The protocol functions use the device path of 20 the HPC to identify the HPC. When the PCI bus enumerator finds a root HPC, it 21 will call EFI_PCI_HOT_PLUG_INIT_PROTOCOL.InitializeRootHpc(). If InitializeRootHpc() 22 is unable to initialize a root HPC, the PCI enumerator will ignore that root HPC 23 and continue the enumeration process. If the HPC is not initialized, the devices 24 that it controls may not be initialized, and no resource padding will be provided. 25 26 From the standpoint of the PCI bus enumerator, HPCs are divided into the following 27 two classes: 28 29 - Root HPC: 30 These HPCs must be initialized by calling InitializeRootHpc() during the 31 enumeration process. These HPCs will also require resource padding. The 32 platform code must have a priori knowledge of these devices and must know 33 how to initialize them. There may not be any way to access their PCI 34 configuration space before the PCI enumerator programs all the upstream 35 bridges and thus enables the path to these devices. The PCI bus enumerator 36 is responsible for determining the PCI bus address of the HPC before it 37 calls InitializeRootHpc(). 38 - Nonroot HPC: 39 These HPCs will not need explicit initialization during enumeration process. 40 These HPCs will require resource padding. The platform code does not have 41 to have a priori knowledge of these devices. 42 43 Copyright (c) 2007 - 2018, Intel Corporation. All rights reserved.<BR> 44 SPDX-License-Identifier: BSD-2-Clause-Patent 45 46 @par Revision Reference: 47 This Protocol is defined in UEFI Platform Initialization Specification 1.2 48 Volume 5: Standards 49 50 **/ 51 52 #ifndef _EFI_PCI_HOT_PLUG_INIT_H_ 53 #define _EFI_PCI_HOT_PLUG_INIT_H_ 54 55 /// 56 /// Global ID for the EFI_PCI_HOT_PLUG_INIT_PROTOCOL 57 /// 58 #define EFI_PCI_HOT_PLUG_INIT_PROTOCOL_GUID \ 59 { \ 60 0xaa0e8bc1, 0xdabc, 0x46b0, {0xa8, 0x44, 0x37, 0xb8, 0x16, 0x9b, 0x2b, 0xea } \ 61 } 62 63 /// 64 /// Forward declaration for EFI_PCI_HOT_PLUG_INIT_PROTOCOL 65 /// 66 typedef struct _EFI_PCI_HOT_PLUG_INIT_PROTOCOL EFI_PCI_HOT_PLUG_INIT_PROTOCOL; 67 68 /// 69 /// Describes the current state of an HPC 70 /// 71 typedef UINT16 EFI_HPC_STATE; 72 73 /// 74 /// The HPC initialization function was called and the HPC completed 75 /// initialization, but it was not enabled for some reason. The HPC may be 76 /// disabled in hardware, or it may be disabled due to user preferences, 77 /// hardware failure, or other reasons. No resource padding is required. 78 /// 79 #define EFI_HPC_STATE_INITIALIZED 0x01 80 81 /// 82 /// The HPC initialization function was called, the HPC completed 83 /// initialization, and it was enabled. Resource padding is required. 84 /// 85 #define EFI_HPC_STATE_ENABLED 0x02 86 87 /// 88 /// Location definition for PCI Hot Plug Controller 89 /// 90 typedef struct{ 91 /// 92 /// 93 /// The device path to the root HPC. An HPC cannot control its parent buses. 94 /// The PCI bus driver requires this information so that it can pass the 95 /// correct HpcPciAddress to the InitializeRootHpc() and GetResourcePadding() 96 /// functions. 97 /// 98 EFI_DEVICE_PATH_PROTOCOL *HpcDevicePath; 99 /// 100 /// The device path to the Hot Plug Bus (HPB) that is controlled by the root 101 /// HPC. The PCI bus driver uses this information to check if a particular PCI 102 /// bus has hot-plug slots. The device path of a PCI bus is the same as the 103 /// device path of its parent. For Standard(PCI) Hot Plug Controllers (SHPCs) 104 /// and PCI Express*, HpbDevicePath is the same as HpcDevicePath. 105 /// 106 EFI_DEVICE_PATH_PROTOCOL *HpbDevicePath; 107 } EFI_HPC_LOCATION; 108 109 /// 110 /// Describes how resource padding should be applied 111 /// 112 typedef enum { 113 /// 114 /// Apply the padding at a PCI bus level. In other words, the resources 115 /// that are allocated to the bus containing hot-plug slots are padded by 116 /// the specified amount. If the hot-plug bus is behind a PCI-to-PCI 117 /// bridge, the PCI-to-PCI bridge apertures will indicate the padding 118 /// 119 EfiPaddingPciBus, 120 /// 121 /// Apply the padding at a PCI root bridge level. If a PCI root bridge 122 /// includes more than one hot-plug bus, the resource padding requests 123 /// for these buses are added together and the resources that are 124 /// allocated to the root bridge are padded by the specified amount. This 125 /// strategy may reduce the total amount of padding, but requires 126 /// reprogramming of PCI-to-PCI bridges in a hot-add event. If the hotplug 127 /// bus is behind a PCI-to-PCI bridge, the PCI-to-PCI bridge 128 /// apertures do not indicate the padding for that bus. 129 /// 130 EfiPaddingPciRootBridge 131 } EFI_HPC_PADDING_ATTRIBUTES; 132 133 /** 134 Returns a list of root Hot Plug Controllers (HPCs) that require initialization 135 during the boot process. 136 137 This procedure returns a list of root HPCs. The PCI bus driver must initialize 138 these controllers during the boot process. The PCI bus driver may or may not be 139 able to detect these HPCs. If the platform includes a PCI-to-CardBus bridge, it 140 can be included in this list if it requires initialization. The HpcList must be 141 self consistent. An HPC cannot control any of its parent buses. Only one HPC can 142 control a PCI bus. Because this list includes only root HPCs, no HPC in the list 143 can be a child of another HPC. This policy must be enforced by the 144 EFI_PCI_HOT_PLUG_INIT_PROTOCOL. The PCI bus driver may not check for such 145 invalid conditions. The callee allocates the buffer HpcList 146 147 @param[in] This Pointer to the EFI_PCI_HOT_PLUG_INIT_PROTOCOL instance. 148 @param[out] HpcCount The number of root HPCs that were returned. 149 @param[out] HpcList The list of root HPCs. HpcCount defines the number of 150 elements in this list. 151 152 @retval EFI_SUCCESS HpcList was returned. 153 @retval EFI_OUT_OF_RESOURCES HpcList was not returned due to insufficient 154 resources. 155 @retval EFI_INVALID_PARAMETER HpcCount is NULL or HpcList is NULL. 156 157 **/ 158 typedef 159 EFI_STATUS 160 (EFIAPI *EFI_GET_ROOT_HPC_LIST)( 161 IN EFI_PCI_HOT_PLUG_INIT_PROTOCOL *This, 162 OUT UINTN *HpcCount, 163 OUT EFI_HPC_LOCATION **HpcList 164 ); 165 166 /** 167 Initializes one root Hot Plug Controller (HPC). This process may causes 168 initialization of its subordinate buses. 169 170 This function initializes the specified HPC. At the end of initialization, 171 the hot-plug slots or sockets (controlled by this HPC) are powered and are 172 connected to the bus. All the necessary registers in the HPC are set up. For 173 a Standard (PCI) Hot Plug Controller (SHPC), the registers that must be set 174 up are defined in the PCI Standard Hot Plug Controller and Subsystem 175 Specification. 176 177 @param[in] This Pointer to the EFI_PCI_HOT_PLUG_INIT_PROTOCOL instance. 178 @param[in] HpcDevicePath The device path to the HPC that is being initialized. 179 @param[in] HpcPciAddress The address of the HPC function on the PCI bus. 180 @param[in] Event The event that should be signaled when the HPC 181 initialization is complete. Set to NULL if the 182 caller wants to wait until the entire initialization 183 process is complete. 184 @param[out] HpcState The state of the HPC hardware. The state is 185 EFI_HPC_STATE_INITIALIZED or EFI_HPC_STATE_ENABLED. 186 187 @retval EFI_SUCCESS If Event is NULL, the specific HPC was successfully 188 initialized. If Event is not NULL, Event will be 189 signaled at a later time when initialization is complete. 190 @retval EFI_UNSUPPORTED This instance of EFI_PCI_HOT_PLUG_INIT_PROTOCOL 191 does not support the specified HPC. 192 @retval EFI_OUT_OF_RESOURCES Initialization failed due to insufficient 193 resources. 194 @retval EFI_INVALID_PARAMETER HpcState is NULL. 195 196 **/ 197 typedef 198 EFI_STATUS 199 (EFIAPI *EFI_INITIALIZE_ROOT_HPC)( 200 IN EFI_PCI_HOT_PLUG_INIT_PROTOCOL *This, 201 IN EFI_DEVICE_PATH_PROTOCOL *HpcDevicePath, 202 IN UINT64 HpcPciAddress, 203 IN EFI_EVENT Event, OPTIONAL 204 OUT EFI_HPC_STATE *HpcState 205 ); 206 207 /** 208 Returns the resource padding that is required by the PCI bus that is controlled 209 by the specified Hot Plug Controller (HPC). 210 211 This function returns the resource padding that is required by the PCI bus that 212 is controlled by the specified HPC. This member function is called for all the 213 root HPCs and nonroot HPCs that are detected by the PCI bus enumerator. This 214 function will be called before PCI resource allocation is completed. This function 215 must be called after all the root HPCs, with the possible exception of a 216 PCI-to-CardBus bridge, have completed initialization. 217 218 @param[in] This Pointer to the EFI_PCI_HOT_PLUG_INIT_PROTOCOL instance. 219 @param[in] HpcDevicePath The device path to the HPC. 220 @param[in] HpcPciAddress The address of the HPC function on the PCI bus. 221 @param[in] HpcState The state of the HPC hardware. 222 @param[out] Padding The amount of resource padding that is required by the 223 PCI bus under the control of the specified HPC. 224 @param[out] Attributes Describes how padding is accounted for. The padding 225 is returned in the form of ACPI 2.0 resource descriptors. 226 227 @retval EFI_SUCCESS The resource padding was successfully returned. 228 @retval EFI_UNSUPPORTED This instance of the EFI_PCI_HOT_PLUG_INIT_PROTOCOL 229 does not support the specified HPC. 230 @retval EFI_NOT_READY This function was called before HPC initialization 231 is complete. 232 @retval EFI_INVALID_PARAMETER HpcState or Padding or Attributes is NULL. 233 @retval EFI_OUT_OF_RESOURCES ACPI 2.0 resource descriptors for Padding 234 cannot be allocated due to insufficient resources. 235 236 **/ 237 typedef 238 EFI_STATUS 239 (EFIAPI *EFI_GET_HOT_PLUG_PADDING)( 240 IN EFI_PCI_HOT_PLUG_INIT_PROTOCOL *This, 241 IN EFI_DEVICE_PATH_PROTOCOL *HpcDevicePath, 242 IN UINT64 HpcPciAddress, 243 OUT EFI_HPC_STATE *HpcState, 244 OUT VOID **Padding, 245 OUT EFI_HPC_PADDING_ATTRIBUTES *Attributes 246 ); 247 248 /// 249 /// This protocol provides the necessary functionality to initialize the 250 /// Hot Plug Controllers (HPCs) and the buses that they control. This protocol 251 /// also provides information regarding resource padding. 252 /// 253 struct _EFI_PCI_HOT_PLUG_INIT_PROTOCOL { 254 /// 255 /// Returns a list of root HPCs and the buses that they control. 256 /// 257 EFI_GET_ROOT_HPC_LIST GetRootHpcList; 258 259 /// 260 /// Initializes the specified root HPC. 261 /// 262 EFI_INITIALIZE_ROOT_HPC InitializeRootHpc; 263 264 /// 265 /// Returns the resource padding that is required by the HPC. 266 /// 267 EFI_GET_HOT_PLUG_PADDING GetResourcePadding; 268 }; 269 270 extern EFI_GUID gEfiPciHotPlugInitProtocolGuid; 271 272 #endif 273