system76-edk2/MdeModulePkg/Core/Dxe/Hand/Notify.c

/** @file
  Support functions for UEFI protocol notification infrastructure.

Copyright (c) 2006 - 2008, Intel Corporation. <BR>
All rights reserved. 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.

**/

#include "DxeMain.h"
#include "Handle.h"


/**
  Signal event for every protocol in protocol entry.

  @param  ProtEntry              Protocol entry

**/
VOID
CoreNotifyProtocolEntry (
  IN PROTOCOL_ENTRY   *ProtEntry
  )
{
  PROTOCOL_NOTIFY     *ProtNotify;
  LIST_ENTRY          *Link;

  ASSERT_LOCKED (&gProtocolDatabaseLock);

  for (Link=ProtEntry->Notify.ForwardLink; Link != &ProtEntry->Notify; Link=Link->ForwardLink) {
    ProtNotify = CR(Link, PROTOCOL_NOTIFY, Link, PROTOCOL_NOTIFY_SIGNATURE);
    CoreSignalEvent (ProtNotify->Event);
  }
}



/**
  Removes Protocol from the protocol list (but not the handle list).

  @param  Handle                 The handle to remove protocol on.
  @param  Protocol               GUID of the protocol to be moved
  @param  Interface              The interface of the protocol

  @return Protocol Entry

**/
PROTOCOL_INTERFACE *
CoreRemoveInterfaceFromProtocol (
  IN IHANDLE        *Handle,
  IN EFI_GUID       *Protocol,
  IN VOID           *Interface
  )
{
  PROTOCOL_INTERFACE  *Prot;
  PROTOCOL_NOTIFY     *ProtNotify;
  PROTOCOL_ENTRY      *ProtEntry;
  LIST_ENTRY          *Link;

  ASSERT_LOCKED (&gProtocolDatabaseLock);

  Prot = CoreFindProtocolInterface (Handle, Protocol, Interface);
  if (Prot != NULL) {

    ProtEntry = Prot->Protocol;

    //
    // If there's a protocol notify location pointing to this entry, back it up one
    //
    for(Link = ProtEntry->Notify.ForwardLink; Link != &ProtEntry->Notify; Link=Link->ForwardLink) {
      ProtNotify = CR(Link, PROTOCOL_NOTIFY, Link, PROTOCOL_NOTIFY_SIGNATURE);

      if (ProtNotify->Position == &Prot->ByProtocol) {
        ProtNotify->Position = Prot->ByProtocol.BackLink;
      }
    }

    //
    // Remove the protocol interface entry
    //
    RemoveEntryList (&Prot->ByProtocol);
  }

  return Prot;
}


/**
  Add a new protocol notification record for the request protocol.

  @param  Protocol               The requested protocol to add the notify
                                 registration
  @param  Event                  The event to signal
  @param  Registration           Returns the registration record

  @retval EFI_INVALID_PARAMETER  Invalid parameter
  @retval EFI_SUCCESS            Successfully returned the registration record
                                 that has been added

**/
EFI_STATUS
EFIAPI
CoreRegisterProtocolNotify (
  IN EFI_GUID       *Protocol,
  IN EFI_EVENT      Event,
  OUT  VOID         **Registration
  )
{
  PROTOCOL_ENTRY    *ProtEntry;
  PROTOCOL_NOTIFY   *ProtNotify;
  EFI_STATUS        Status;

  if ((Protocol == NULL) || (Event == NULL) || (Registration == NULL))  {
    return EFI_INVALID_PARAMETER;
  }

  CoreAcquireProtocolLock ();

  ProtNotify = NULL;

  //
  // Get the protocol entry to add the notification too
  //

  ProtEntry = CoreFindProtocolEntry (Protocol, TRUE);
  if (ProtEntry != NULL) {

    //
    // Allocate a new notification record
    //
    ProtNotify = AllocatePool (sizeof(PROTOCOL_NOTIFY));
    if (ProtNotify != NULL) {

      ProtNotify->Signature = PROTOCOL_NOTIFY_SIGNATURE;
      ProtNotify->Protocol = ProtEntry;
      ProtNotify->Event = Event;
      //
      // start at the begining
      //
      ProtNotify->Position = &ProtEntry->Protocols;

      InsertTailList (&ProtEntry->Notify, &ProtNotify->Link);
    }
  }

  CoreReleaseProtocolLock ();

  //
  // Done.  If we have a protocol notify entry, then return it.
  // Otherwise, we must have run out of resources trying to add one
  //

  Status = EFI_OUT_OF_RESOURCES;
  if (ProtNotify != NULL) {
    *Registration = ProtNotify;
    Status = EFI_SUCCESS;
  }

  return Status;
}


/**
  Reinstall a protocol interface on a device handle.  The OldInterface for Protocol is replaced by the NewInterface.

  @param  UserHandle             Handle on which the interface is to be
                                 reinstalled
  @param  Protocol               The numeric ID of the interface
  @param  OldInterface           A pointer to the old interface
  @param  NewInterface           A pointer to the new interface

  @retval EFI_SUCCESS            The protocol interface was installed
  @retval EFI_NOT_FOUND          The OldInterface on the handle was not found
  @retval EFI_INVALID_PARAMETER  One of the parameters has an invalid value

**/
EFI_STATUS
EFIAPI
CoreReinstallProtocolInterface (
  IN EFI_HANDLE     UserHandle,
  IN EFI_GUID       *Protocol,
  IN VOID           *OldInterface,
  IN VOID           *NewInterface
  )
{
  EFI_STATUS                Status;
  IHANDLE                   *Handle;
  PROTOCOL_INTERFACE        *Prot;
  PROTOCOL_ENTRY            *ProtEntry;

  Status = CoreValidateHandle (UserHandle);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  if (Protocol == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Handle = (IHANDLE *) UserHandle;

  //
  // Lock the protocol database
  //
  CoreAcquireProtocolLock ();

  //
  // Check that Protocol exists on UserHandle, and Interface matches the interface in the database
  //
  Prot = CoreFindProtocolInterface (UserHandle, Protocol, OldInterface);
  if (Prot == NULL) {
    Status = EFI_NOT_FOUND;
    goto Done;
  }

  //
  // Attempt to disconnect all drivers that are using the protocol interface that is about to be reinstalled
  //
  Status = CoreDisconnectControllersUsingProtocolInterface (
             UserHandle,
             Prot
             );
  if (EFI_ERROR (Status)) {
    //
    // One or more drivers refused to release, so return the error
    //
    goto Done;
  }

  //
  // Remove the protocol interface from the protocol
  //
  Prot = CoreRemoveInterfaceFromProtocol (Handle, Protocol, OldInterface);

  if (Prot == NULL) {
    Status = EFI_NOT_FOUND;
    goto Done;
  }

  ProtEntry = Prot->Protocol;

  //
  // Update the interface on the protocol
  //
  Prot->Interface = NewInterface;

  //
  // Add this protocol interface to the tail of the
  // protocol entry
  //
  InsertTailList (&ProtEntry->Protocols, &Prot->ByProtocol);

  //
  // Update the Key to show that the handle has been created/modified
  //
  gHandleDatabaseKey++;
  Handle->Key = gHandleDatabaseKey;

  //
  // Release the lock and connect all drivers to UserHandle
  //
  CoreReleaseProtocolLock ();
  //
  // Return code is ignored on purpose.
  //
  CoreConnectController (
    UserHandle,
    NULL,
    NULL,
    TRUE
    );
  CoreAcquireProtocolLock ();

  //
  // Notify the notification list for this protocol
  //
  CoreNotifyProtocolEntry (ProtEntry);

  Status = EFI_SUCCESS;

Done:
  CoreReleaseProtocolLock ();

  return Status;
}