MdePkg/Include/Protocol/PciHotPlugInit.h

   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