/** @file
This file declares EFI PCI Hot Plug Init Protocol.
This protocol provides the necessary functionality to initialize the Hot Plug
Controllers (HPCs) and the buses that they control. This protocol also provides
information regarding resource padding.
@par Note:
This protocol is required only on platforms that support one or more PCI Hot
Plug* slots or CardBus sockets.
The EFI_PCI_HOT_PLUG_INIT_PROTOCOL provides a mechanism for the PCI bus enumerator
to properly initialize the HPCs and CardBus sockets that require initialization.
The HPC initialization takes place before the PCI enumeration process is complete.
There cannot be more than one instance of this protocol in a system. This protocol
is installed on its own separate handle.
Because the system may include multiple HPCs, one instance of this protocol
should represent all of them. The protocol functions use the device path of
the HPC to identify the HPC. When the PCI bus enumerator finds a root HPC, it
will call EFI_PCI_HOT_PLUG_INIT_PROTOCOL.InitializeRootHpc(). If InitializeRootHpc()
is unable to initialize a root HPC, the PCI enumerator will ignore that root HPC
and continue the enumeration process. If the HPC is not initialized, the devices
that it controls may not be initialized, and no resource padding will be provided.
From the standpoint of the PCI bus enumerator, HPCs are divided into the following
two classes:
- Root HPC:
These HPCs must be initialized by calling InitializeRootHpc() during the
enumeration process. These HPCs will also require resource padding. The
platform code must have a priori knowledge of these devices and must know
how to initialize them. There may not be any way to access their PCI
configuration space before the PCI enumerator programs all the upstream
bridges and thus enables the path to these devices. The PCI bus enumerator
is responsible for determining the PCI bus address of the HPC before it
calls InitializeRootHpc().
- Nonroot HPC:
These HPCs will not need explicit initialization during enumeration process.
These HPCs will require resource padding. The platform code does not have
to have a priori knowledge of these devices.
Copyright (c) 2007 - 2009, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
@par Revision Reference:
This Protocol is defined in UEFI Platform Initialization Specification 1.2
Volume 5: Standards
**/
#ifndef _EFI_PCI_HOT_PLUG_INIT_H_
#define _EFI_PCI_HOT_PLUG_INIT_H_
///
/// Global ID for the EFI_PCI_HOT_PLUG_INIT_PROTOCOL
///
#define EFI_PCI_HOT_PLUG_INIT_PROTOCOL_GUID \
{ \
0xaa0e8bc1, 0xdabc, 0x46b0, {0xa8, 0x44, 0x37, 0xb8, 0x16, 0x9b, 0x2b, 0xea } \
}
///
/// Forward declaration for EFI_PCI_HOT_PLUG_INIT_PROTOCOL
///
typedef struct _EFI_PCI_HOT_PLUG_INIT_PROTOCOL EFI_PCI_HOT_PLUG_INIT_PROTOCOL;
///
/// Describes the current state of an HPC
///
typedef UINT16 EFI_HPC_STATE;
///
/// The HPC initialization function was called and the HPC completed
/// initialization, but it was not enabled for some reason. The HPC may be
/// disabled in hardware, or it may be disabled due to user preferences,
/// hardware failure, or other reasons. No resource padding is required.
///
#define EFI_HPC_STATE_INITIALIZED 0x01
///
/// The HPC initialization function was called, the HPC completed
/// initialization, and it was enabled. Resource padding is required.
///
#define EFI_HPC_STATE_ENABLED 0x02
///
/// Location definition for PCI Hot Plug Controller
///
typedef struct{
///
///
/// The device path to the root HPC. An HPC cannot control its parent buses.
/// The PCI bus driver requires this information so that it can pass the
/// correct HpcPciAddress to the InitializeRootHpc() and GetResourcePadding()
/// functions.
///
EFI_DEVICE_PATH_PROTOCOL *HpcDevicePath;
///
/// The device path to the Hot Plug Bus (HPB) that is controlled by the root
/// HPC. The PCI bus driver uses this information to check if a particular PCI
/// bus has hot-plug slots. The device path of a PCI bus is the same as the
/// device path of its parent. For Standard(PCI) Hot Plug Controllers (SHPCs)
/// and PCI Express*, HpbDevicePath is the same as HpcDevicePath.
///
EFI_DEVICE_PATH_PROTOCOL *HpbDevicePath;
} EFI_HPC_LOCATION;
///
/// Describes how resource padding should be applied
///
typedef enum {
///
/// Apply the padding at a PCI bus level. In other words, the resources
/// that are allocated to the bus containing hot-plug slots are padded by
/// the specified amount. If the hot-plug bus is behind a PCI-to-PCI
/// bridge, the PCI-to-PCI bridge apertures will indicate the padding
///
EfiPaddingPciBus,
///
/// Apply the padding at a PCI root bridge level. If a PCI root bridge
/// includes more than one hot-plug bus, the resource padding requests
/// for these buses are added together and the resources that are
/// allocated to the root bridge are padded by the specified amount. This
/// strategy may reduce the total amount of padding, but requires
/// reprogramming of PCI-to-PCI bridges in a hot-add event. If the hotplug
/// bus is behind a PCI-to-PCI bridge, the PCI-to-PCI bridge
/// apertures do not indicate the padding for that bus.
///
EfiPaddingPciRootBridge
} EFI_HPC_PADDING_ATTRIBUTES;
/**
Returns a list of root Hot Plug Controllers (HPCs) that require initialization
during the boot process.
This procedure returns a list of root HPCs. The PCI bus driver must initialize
these controllers during the boot process. The PCI bus driver may or may not be
able to detect these HPCs. If the platform includes a PCI-to-CardBus bridge, it
can be included in this list if it requires initialization. The HpcList must be
self consistent. An HPC cannot control any of its parent buses. Only one HPC can
control a PCI bus. Because this list includes only root HPCs, no HPC in the list
can be a child of another HPC. This policy must be enforced by the
EFI_PCI_HOT_PLUG_INIT_PROTOCOL. The PCI bus driver may not check for such
invalid conditions. The callee allocates the buffer HpcList
@param[in] This Pointer to the EFI_PCI_HOT_PLUG_INIT_PROTOCOL instance.
@param[out] HpcCount The number of root HPCs that were returned.
@param[out] HpcList The list of root HPCs. HpcCount defines the number of
elements in this list.
@retval EFI_SUCCESS HpcList was returned.
@retval EFI_OUT_OF_RESOURCES HpcList was not returned due to insufficient
resources.
@retval EFI_INVALID_PARAMETER HpcCount is NULL or HpcList is NULL.
**/
typedef
EFI_STATUS
(EFIAPI *EFI_GET_ROOT_HPC_LIST)(
IN EFI_PCI_HOT_PLUG_INIT_PROTOCOL *This,
OUT UINTN *HpcCount,
OUT EFI_HPC_LOCATION **HpcList
);
/**
Initializes one root Hot Plug Controller (HPC). This process may causes
initialization of its subordinate buses.
This function initializes the specified HPC. At the end of initialization,
the hot-plug slots or sockets (controlled by this HPC) are powered and are
connected to the bus. All the necessary registers in the HPC are set up. For
a Standard (PCI) Hot Plug Controller (SHPC), the registers that must be set
up are defined in the PCI Standard Hot Plug Controller and Subsystem
Specification.
@param[in] This Pointer to the EFI_PCI_HOT_PLUG_INIT_PROTOCOL instance.
@param[in] HpcDevicePath The device path to the HPC that is being initialized.
@param[in] HpcPciAddress The address of the HPC function on the PCI bus.
@param[in] Event The event that should be signaled when the HPC
initialization is complete. Set to NULL if the
caller wants to wait until the entire initialization
process is complete.
@param[out] HpcState The state of the HPC hardware. The state is
EFI_HPC_STATE_INITIALIZED or EFI_HPC_STATE_ENABLED.
@retval EFI_SUCCESS If Event is NULL, the specific HPC was successfully
initialized. If Event is not NULL, Event will be
signaled at a later time when initialization is complete.
@retval EFI_UNSUPPORTED This instance of EFI_PCI_HOT_PLUG_INIT_PROTOCOL
does not support the specified HPC.
@retval EFI_OUT_OF_RESOURCES Initialization failed due to insufficient
resources.
@retval EFI_INVALID_PARAMETER HpcState is NULL.
**/
typedef
EFI_STATUS
(EFIAPI *EFI_INITIALIZE_ROOT_HPC)(
IN EFI_PCI_HOT_PLUG_INIT_PROTOCOL *This,
IN EFI_DEVICE_PATH_PROTOCOL *HpcDevicePath,
IN UINT64 HpcPciAddress,
IN EFI_EVENT Event, OPTIONAL
OUT EFI_HPC_STATE *HpcState
);
/**
Returns the resource padding that is required by the PCI bus that is controlled
by the specified Hot Plug Controller (HPC).
This function returns the resource padding that is required by the PCI bus that
is controlled by the specified HPC. This member function is called for all the
root HPCs and nonroot HPCs that are detected by the PCI bus enumerator. This
function will be called before PCI resource allocation is completed. This function
must be called after all the root HPCs, with the possible exception of a
PCI-to-CardBus bridge, have completed initialization.
@param[in] This Pointer to the EFI_PCI_HOT_PLUG_INIT_PROTOCOL instance.
@param[in] HpcDevicePath The device path to the HPC.
@param[in] HpcPciAddress The address of the HPC function on the PCI bus.
@param[in] HpcState The state of the HPC hardware.
@param[out] Padding The amount of resource padding that is required by the
PCI bus under the control of the specified HPC.
@param[out] Attributes Describes how padding is accounted for. The padding
is returned in the form of ACPI 2.0 resource descriptors.
@retval EFI_SUCCESS The resource padding was successfully returned.
@retval EFI_UNSUPPORTED This instance of the EFI_PCI_HOT_PLUG_INIT_PROTOCOL
does not support the specified HPC.
@retval EFI_NOT_READY This function was called before HPC initialization
is complete.
@retval EFI_INVALID_PARAMETER HpcState or Padding or Attributes is NULL.
@retval EFI_OUT_OF_RESOURCES ACPI 2.0 resource descriptors for Padding
cannot be allocated due to insufficient resources.
**/
typedef
EFI_STATUS
(EFIAPI *EFI_GET_HOT_PLUG_PADDING)(
IN EFI_PCI_HOT_PLUG_INIT_PROTOCOL *This,
IN EFI_DEVICE_PATH_PROTOCOL *HpcDevicePath,
IN UINT64 HpcPciAddress,
OUT EFI_HPC_STATE *HpcState,
OUT VOID **Padding,
OUT EFI_HPC_PADDING_ATTRIBUTES *Attributes
);
///
/// This protocol provides the necessary functionality to initialize the
/// Hot Plug Controllers (HPCs) and the buses that they control. This protocol
/// also provides information regarding resource padding.
///
struct _EFI_PCI_HOT_PLUG_INIT_PROTOCOL {
///
/// Returns a list of root HPCs and the buses that they control.
///
EFI_GET_ROOT_HPC_LIST GetRootHpcList;
///
/// Initializes the specified root HPC.
///
EFI_INITIALIZE_ROOT_HPC InitializeRootHpc;
///
/// Returns the resource padding that is required by the HPC.
///
EFI_GET_HOT_PLUG_PADDING GetResourcePadding;
};
extern EFI_GUID gEfiPciHotPlugInitProtocolGuid;
#endif